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  • 1.
    Awad, Amar
    et al.
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Levi, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rehabiliteringsmedicin.
    Lindgren, Lenita
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Hultling, Claes
    Department of Neurobiology, Care Sciences and Society (Neurorehabilitation), Karolinska Institute, Stockholm, Sweden.
    Westling, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Preserved somatosensory conduction in a patient with complete cervical spinal cord injury2015Ingår i: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 47, nr 5, s. 426-431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: Neurophysiological investigation has shown that patients with clinically complete spinal cord injury can have residual motor sparing ("motor discomplete"). In the current study somatosensory conduction was assessed in a patient with clinically complete spinal cord injury and a novel ethodology for assessing such preservation is described, in this case indicating "sensory discomplete" spinal cord injury. Methods: Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) was used to examine the somatosensory system in a healthy subject and in a subject with a clinically complete cervical spinal cord injury, by applying tactile stimulation above and below the level of spinal cord injury, with and without visual feedback. Results: In the participant with spinal cord injury, somatosensory stimulation below the neurological level of the lesion gave rise to BOLD signal changes in the corresponding areas of the somatosensory cortex. Visual feedback of the stimulation strongly modulated the somatosensory BOLD signal, implying that cortico-cortical rather than spino-cortical connections can drive activity in the somatosensory cortex. Critically, BOLD signal change was also evident when the visual feedback of the stimulation was removed, thus demonstrating sensory discomplete spinal cord injury. Conclusion: Given the existence of sensory discomplete spinal cord injury, preserved but hitherto undetected somatosensory conduction might contribute to the unexplained variability related to, for example, the propensity to develop decubitus ulcers and neuropathic pain among patients with clinically complete spinal cord injury.

  • 2.
    Berginström, Nils
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Nordström, Peter
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Ekman, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Karolinska Inst, Dept Neurobiol Care Sci & Soc, Stockholm, Sweden.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Andersson, Micael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nordström, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Fatigue after traumatic brain injury is linked to altered striato-thalamic-cortical functioning2017Ingår i: Brain Injury: Accepted Abstracts from the International Brain Injury Association’s 12th World Congress on Brain Injury, 2017, Vol. 31, s. 755-755Konferensbidrag (Refereegranskat)
    Abstract [en]

    Mental fatigue is a common symptom in the chronic phase of traumatic brain injury. Despite its high prevalence, no treatmentis available for this disabling symptom, and the mechanisms underlying fatigue are poorly understood. Some studies have suggested that fatigue in traumatic brain injury and other neurological disorders might reflect dysfunction within striato-thalamic-cortical loops. In the present study, we investigated whether functional magnetic resonance imaging(fMRI) can be used to detect chronic fatigue after traumatic brain injury (TBI), with emphasis on the striato-thalamic cortical-loops. We included patients who had suffered traumatic brain injury (n = 57, age range 20–64 years) and experienced mental fatigue > 1 year post injury (mean = 8.79 years, SD = 7.35), and age- and sex-matched healthycontrols (n = 27, age range 25–65 years). All participants completed self-assessment scales of fatigue and other symptoms, underwent an extensive neuropsychological test battery and performed a fatiguing 27-minute attention task (the modified Symbol Digit Modalities Test) during fMRI. Accuracy did not differ between groups, but reaction times were slower in the traumatic brain injury group (p < 0.001). Patients showed a greater increase in fatigue than controls from before to after task completion (p < 0.001). Patients showed less fMRI blood oxygen level–dependent activity in several a priori hypothesized regions (family-wise error corrected,p < 0.05), including the bilateral caudate, thalamus and anterior insula. Using the left caudate as a region of interest and testing for sensitivity and specificity, we identified 91% of patients and 81% of controls. As expected, controls showed decreased activation over time in regions of interest—the bilateral caudate and anterior thalamus (p < 0.002, uncorrected)—whereas patients showed no corresponding activity decrease. These results suggest that chronic fatigue after TBI is linked to altered striato-thalamic-cortical functioning. The high precision of fMRI for the detection of fatigue is of great clinical interest, given the lack of objective measures for the diagnosis of fatigue.

  • 3.
    Berginström, Nils
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Nordström, Peter
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Ekman, Urban
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Karolinska Inst, Dept Neurobiol Care Sci & Soc, Stockholm, Sweden.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Andersson, Micael
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Nordström, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin. Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Using Functional Magnetic Resonance Imaging to Detect Chronic Fatigue in Patients With Previous Traumatic Brain Injury: changes linked to altered Striato-Thalamic-Cortical Functioning2018Ingår i: The journal of head trauma rehabilitation, ISSN 0885-9701, E-ISSN 1550-509X, Vol. 33, nr 4, s. 266-274Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: To investigate whether functional magnetic resonance imaging (fMRI) can be used to detect fatigue after traumatic brain injury (TBI).

    Setting: Neurorehabilitation clinic.

    Participants: Patients with TBI (n = 57) and self-experienced fatigue more than 1 year postinjury, and age- and gender-matched healthy controls (n = 27).

    Main Measures: Self-assessment scales of fatigue, a neuropsychological test battery, and fMRI scanning during performance of a fatiguing 27-minute attention task.

    Results: During testing within the fMRI scanner, patients showed a higher increase in self-reported fatigue than controls from before to after completing the task (P < .001).The patients also showed lower activity in several regions, including bilateral caudate, thalamus, and anterior insula (all P < .05). Furthermore, the patients failed to display decreased activation over time in regions of interest: the bilateral caudate and anterior thalamus (all P < .01). Left caudate activity correctly identified 91% of patients and 81% of controls, resulting in a positive predictive value of 91%.

    Conclusion: The results suggest that chronic fatigue after TBI is associated with altered striato-thalamic-cortical functioning. It would be of interest to study whether fMRI can be used to support the diagnosis of chronic fatigue in future studies.

  • 4.
    Berginström, Nils
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik. Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Nordström, Peter
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Ekman, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Nordström, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Pharmaco-fMRI in Patients With Traumatic Brain Injury: A Randomized Controlled Trial With the Monoaminergic Stabilizer (-)-OSU6162.2018Ingår i: The journal of head trauma rehabilitation, ISSN 0885-9701, E-ISSN 1550-509XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To examine the effects of monoaminergic stabilizer (-)-OSU6162 on brain activity, as measured by blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI), in patients in the chronic phase of traumatic brain injury suffering from fatigue.

    SETTING: Neurorehabilitation clinic.

    PARTICIPANTS: Patients with traumatic brain injury received either placebo (n = 24) or active treatment (n = 28). Healthy controls (n = 27) went through fMRI examination at one point and were used in sensitivity analysis on normalization of BOLD response.

    DESIGN: Randomized, double-blinded, placebo-controlled design.

    MAIN MEASURES: Effects on BOLD signal changes from before to after treatment during performance of a fatiguing attention task.

    RESULTS: The fMRI results revealed treatment effects within the right occipitotemporal cortex and the right orbitofrontal cortex. In these regions, the BOLD response was normalized relative to healthy controls at the postintervention fMRI session. No effects were seen in regions in which we previously observed activity differences between patients and healthy controls while performing this fMRI task, such as the striatum.

    CONCLUSION: (-)-OSU6162 treatment had influences on functional brain activity, although the normalized regional BOLD response was observed in regions that were not a priori hypothesized to be sensitive to this particular treatment, and was not accompanied by any effects on in-scanner test performance or on fatigue.

  • 5.
    Bergström, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Maintenance of non-consciously presented information engages the prefrontal cortex2014Ingår i: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 8, s. 938-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Conscious processing is generally seen as required for flexible and willful actions, as well as for tasks that require durable information maintenance. Here we present research that questions the assumption that only consciously perceived information is durable (>500 ms). Using the attentional blink (AB) phenomenon, we rendered otherwise relatively clearly perceived letters non conscious. In a first experiment we systematically manipulated the delay between stimulus presentation and response, for the purpose of estimating the durability of non-conscious perceptual representations. For items reported not seen, we found that behavioral performance was better than chance across intervals up to 15 s. In a second experiment we used fMRI to investigate the neural correlates underlying the maintenance of non conscious perceptual representations. Critically, the relatively long delay period demonstrated in experiment 1 enabled isolation of the signal change specifically related to the maintenance period, separate from stimulus presentation and response. We found sustained BOLD signal change in the right mid-lateral prefrontal cortex, orbitofrontal cortex, and crus II of the cerebellum during maintenance of non consciously perceived information. These findings are consistent with the controversial claim that working-memory mechanisms are involved in the short-term maintenance of non-conscious perceptual representations.

  • 6.
    Bergström, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Faculty of Psychology and Educational Sciences, University of Coimbra, Portugal.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Neural evidence for non-conscious working memory2018Ingår i: Cerebral Cortex, ISSN 1047-3211, E-ISSN 1460-2199, Vol. 28, nr 9, s. 3217-3228Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies have found that non-consciously perceived information can be retained for several seconds, a feat that has been attributed to non-conscious working memory processes. However, these studies have mainly relied on subjective measures of visual experience, and the neural processes responsible for non-conscious short-term retention remains unclear. Here we used continuous flash suppression to render stimuli non-conscious in a delayed match-to-sample task together with fMRI to investigate the neural correlates of non-conscious short-term (5-15 s) retention. The participants' behavioral performance was at chance level when they reported no visual experience of the sample stimulus. Critically, multivariate pattern analyses of BOLD signal during the delay phase could classify presence versus absence of sample stimuli based on signal patterns in frontal cortex, and its spatial position based on signal patterns in occipital cortex. In addition, univariate analyses revealed increased BOLD signal change in prefrontal regions during memory recognition. Thus, our findings demonstrate short-term maintenance of information presented non-consciously, defined by chance performance behaviorally. This non-consciously retained information seems to rely on persistent neural activity in frontal and occipital cortex, and may engage further cognitive control processes during memory recognition.

  • 7.
    Bergström, Fredrik
    et al.
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    The conjunction of non-consciously perceived object identity and spatial position can be retained during a visual short-term memory task2015Ingår i: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 6, artikel-id 1470Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although non-consciously perceived information has previously been assumed to be short-lived (<500 ms), recent findings show that non-consciously perceived information can be maintained for at least 15s Such findings can be explained as working memory without a conscious experience of the information to be retained. However, whether or not working memory can operate on non-consciously perceived information remains controversial, and little is known about the nature of such non-conscious visual short-term memory (VSTM). Here we used continuous flash suppression to render stimuli non-conscious, to investigate the properties of non-consciously perceived representations in delayed match-to-sample (DMS) tasks. In Experiment I we used variable delays (5 or 15s) and found that performance was significantly better than chance and was unaffected by delay duration, thereby replicating previous findings. In Experiment II the DMS task required participants to combine information of spatial position and object identity on a trial-by-trial basis to successfully solve the task. We found that the conjunction of spatial position and object identity was retained, thereby verifying that non-conscious, trial-specific information can be maintained for prospective use. We conclude that our results are consistent with a working memory interpretation, but that more research is needed to verify this interpretation.

  • 8.
    Ekman, Urban
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Forsgren, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Domellöf, Magdalena
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Elgh, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Psykiatri.
    Lundquist, Anders
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Samhällsvetenskapliga fakulteten, Handelshögskolan vid Umeå universitet, Statistik.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Longitudinal changes in task-evoked brain responses in Parkinson's disease patients with and without mild cognitive impairment2014Ingår i: Frontiers in Neuroscience, ISSN 1662-4548, E-ISSN 1662-453X, Vol. 8, artikel-id 207Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cognitive deficits are common in Parkinson's disease. Previous cross-sectional research has demonstrated a link between cognitive impairments and fronto-striatal dopaminergic dysmodulation. However, longitudinal studies that link disease progression with altered task-evoked brain activity are lacking. Therefore, our objective was to longitudinally evaluate working-memory related brain activity changes in Parkinson's disease patients with and without mild cognitive impairment (MCI). Patients were recruited within a longitudinal cohort study of incident patients with idiopathic parkinsonism. We longitudinally (at baseline examination and at 12-months follow-up) compared 28 patients with Parkinson's disease without MCI with 11 patients with Parkinson's disease and MCI. Functional MRI blood oxygen level dependent signal was measured during a verbal two-back working-memory task. Patients with MCI under-recruited bilateral medial prefrontal cortex at both time-points (main effect of group: p < 0.001, uncorrected). Critically, a significant group-by-time interaction effect (p < 0.001, uncorrected) was found in the right fusiform gyrus, indicating that working-memory related activity decreased for patients with Parkinson's disease and MCI between baseline and follow-up, while patients without MCI were stable across time-points. The functional connectivity between right fusiform gyrus and bilateral caudate nucleus was stronger for patients without MCI relative to patients with MCI. Our findings support the view that deficits in working-memory updating are related to persistent fronto-striatal under-recruitments in patients with early phase Parkinson's disease and MCI. The longitudinal evolution of MCI in Parkinson's disease translates into additional task-evoked posterior cortical changes.

  • 9.
    Ekman, Urban
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Forsgren, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Jakobson Mo, Susanna
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Riklund, Katrine
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Functional brain activity and presynaptic dopamine uptake in patients with Parkinson's disease and mild cognitive impairment: a cross-sectional study2012Ingår i: Lancet Neurology, ISSN 1474-4422, E-ISSN 1474-4465, Vol. 11, nr 8, s. 679-687Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Many patients with Parkinson's disease have mild cognitive impairment (MCI). Deficits in executive functions and working memory suggest dysfunctional frontostriatal brain circuitry. We aimed to assess brain responses during a working memory task in a cohort of newly diagnosed drug-naive patients with Parkinson's disease with and without MCI.

    Methods: Participants were recruited within a prospective cohort study of incident patients with idiopathic parkinsonism, including Parkinson's disease. Between Jan 1, 2004, and April 30, 2009, all physicians in the Umea catchment area were requested to refer all individuals with suspected parkinsonism to the Department of Neurology at lima University. Included patients fulfilled the UK Parkinson's Disease Society Brain Bank clinical diagnostic criteria for Parkinson's disease. Control individuals were matched on the basis of age and sex with the first 50 patients included in the study. Participants who scored 1.5 SDs or more below the population mean on at least two cognitive measures were diagnosed with MCI. The primary outcome measures were functional MRI blood-oxygen-level-dependent signal and SPECT presynaptic uptake. Functional MRI was done during a verbal two-back working memory task. Presynaptic dopamine SPECT was done to assess presynaptic striatal dopaminergic system integrity. Event-related transient analyses of functional MRI data were done for the whole brain and for frontostriatal regions of interest, and semi-quantitative SPECT analyses were done for striatal regions of interest.

    Findings: Compared with controls (n=24), patients with Parkinson's disease (n=77) had under-recruitment in an extensive brain network including bilateral striatal and frontal regions (p<0.001). Within the Parkinson's disease group, patients with Parkinson's disease and MCI (n=30) had additional under-recruitment in the right dorsal caudate nucleus (p=0.005) and the bilateral anterior cingulate cortex (p<0.001) compared with patients with Parkinson's disease without MCI (n=26). In patients with Parkinson's disease and MCI, SPECT uptake in the right caudate was lower than in patients with Parkinson's disease without MCI (p=0.008) and correlated with striatal functional MRI blood-oxygen-level-dependent signal (r=0.32, p=0.031).

    Interpretation: These altered brain responses in patients with Parkinson's disease and MCI suggest that cognitive impairment is linked to frontostriatal dysfunction.

  • 10.
    Ekman, Urban
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
    Fordell, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Lenfeldt, Niklas
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap.
    Wåhlin, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap.
    Increase of frontal neuronal activity in chronic neglect after training in virtual reality2018Ingår i: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 138, nr 4, s. 284-292Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives: A third of patients with stroke acquire spatial neglect associated with poor rehabilitation outcome. New effective rehabilitation interventions are needed. Scanning training combined with multisensory stimulation to enhance the rehabilitation effect is suggested. In accordance, we have designed a virtual-reality based scanning training that combines visual, audio and sensori-motor stimulation called RehAtt((R)). Effects were shown in behavioural tests and activity of daily living. Here, we use fMRI to evaluate the change in brain activity during Posners Cuing Task (attention task) after RehAtt((R)) intervention, in patients with chronic neglect.

    Methods: Twelve patients (mean age=72.7years, SD=6.1) with chronic neglect (persistent symptoms >6months) performed the interventions 3 times/wk during 5weeks, in total 15hours. Training effects on brain activity were evaluated using fMRI task-evoked responses during the Posners cuing task before and after the intervention.

    Results: Patients improved their performance in the Posner fMRI task. In addition, patients increased their task-evoked brain activity after the VR interventions in an extended network including pre-frontal and temporal cortex during attentional cueing, but showed no training effects during target presentations.

    Conclusions: The current pilot study demonstrates that a novel multisensory VR intervention has the potential to benefit patients with chronic neglect in respect of behaviour and brain changes. Specifically, the fMRI results show that strategic processes (top-down control during attentional cuing) were enhanced by the intervention. The findings increase knowledge of the plasticity processes underlying positive rehabilitation effects from RehAtt((R)) in chronic neglect.

  • 11.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Activity in part of the neural correlates of consciousness reflects integration2017Ingår i: Consciousness and Cognition, ISSN 1053-8100, E-ISSN 1090-2376, Vol. 55, s. 26-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Integration is commonly viewed as a key process for generating conscious experiences. Accordingly, there should be increased activity within the neural correlates of consciousness when demands on integration increase. We used fMRI and "informational masking" to isolate the neural correlates of consciousness and measured how the associated brain activity changed as a function of required integration. Integration was manipulated by comparing the experience of hearing simple reoccurring tones to hearing harmonic tone triplets. The neural correlates of auditory consciousness included superior temporal gyrus, lateral and medial frontal regions, cerebellum, and also parietal cortex. Critically, only activity in left parietal cortex increased significantly as a function of increasing demands on integration. We conclude that integration can explain part of the neural activity associated with the generation conscious experiences, but that much of associated brain activity apparently reflects other processes.

  • 12.
    Eriksson, Johan
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Neuroimaging Consciousness: What happens in the brain when we become aware of what we percieve?2004Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Although consciousness has been studied since the beginning of the history of psychology, how the brain implements consciousness is seen as one of the last great mysteries. This thesis investigates neural correlates of consciousness by measuring brain activity while specific contents of consciousness are defined and maintained. Study 1 showed that distinct but similar brain regions are activated for the initial creation of a percept and for sustaining that percept over time. Specifically, frontal and parietal regions were activated during both temporal aspects of consciousness. Study 2 investigated the generality of this activation pattern for consciousness in different sensory modalities, and showed that frontal regions were commonly activated for visual and auditory awareness whereas posterior activity was modality specific. However, frontal andparietal regions were jointly activated for both modalities during sustained perception. These results indicate that frontal regions interact with posterior, sensory-specific regions to instantiate a conscious percept. The percept is then maintained by a more general network including frontal and parietal regions.

  • 13.
    Eriksson, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Bergström, Fredrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Unconscious working memory engages the prefrontal cortex2013Ingår i: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 25, nr Suppl., s. S74-S74Artikel i tidskrift (Övrigt vetenskapligt)
  • 14.
    Eriksson, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Kalpouzos, Grégoria
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Rewiring the brain with repeated retrieval: A parametric fMRI study of the testing effect2011Ingår i: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 505, nr 1, s. 36-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The "testing effect" refers to the beneficial effects on memory performance from being tested, a phenomenon of potentially substantial implications in educational settings. While the effect itself is firmly established in previous research, little is known of related brain changes. Here we used fMRI and a parametric design to show that repeated successful retrieval during a memory acquisition phase leads to higher brain activity in the anterior cingulate cortex (ACC) at a subsequent test phase. The extent of ACC activity increase correlated across individuals with memory performance 5 months later. In relation to recent research that associates the ACC with memory consolidation processes, the present results suggest that the testing effect may operate at the systems level by enhancing consolidation of memory representations.

  • 15.
    Eriksson, Johan
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Larsson, Anne
    Nyberg, Lars
    Item-specific training reduces prefrontal cortical involvement in perceptual awarenessManuskript (Övrigt vetenskapligt)
  • 16.
    Eriksson, Johan
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Larsson, Anne
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Riklund Åhlström, Katrine
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Similar frontal and distinct posterior cortical regions mediate visual and auditory perceptual awareness2007Ingår i: Cerebral Cortex, ISSN 1047-3211, E-ISSN 1460-2199, Vol. 17, nr 4, s. 760-765Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Activity in ventral visual cortex is a consistent neural correlate of visual consciousness. However, activity in this area seems insufficient to produce awareness without additional involvement of frontoparietal regions. To test the generality of the frontoparietal response, neural correlates of auditory awareness were investigated in a paradigm that previously has revealed frontoparietal activity during conscious visual perception. A within-experiment comparison showed that frontal regions were related to both visual and auditory awareness, whereas parietal activity was correlated with visual awareness and superior temporal activity with auditory awareness. These results indicate that frontal regions interact with specific posterior regions to produce awareness in different sensory modalities.

  • 17.
    Eriksson, Johan
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Larsson, Anne
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Riklund Åhlström, Katrine
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Visual consciousness: dissociating the neural correlates of perceptual transitions from sustained perception with fMRI2004Ingår i: Consciousness and Cognition, ISSN 1053-8100, E-ISSN 1090-2376, Vol. 13, nr 1, s. 61-72Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To investigate the possible dichotomy between the neurophysiological bases of perceptual transitions versus sustaining a particular percept over time, an fMRI study was conducted with subjects viewing fragmented pictures. Unlike most other perceptually unstable stimuli, fragmented pictures give rise to only one perceptual transition and a continuous period of sustained perception. Earlier research is inconclusive on the subject of which anatomical regions should be attributed to what temporal aspect of perception, and the aim of the present study was to shed more light on the subject. In this study occipitotemporal and fronto-parietal regions were found to be activated for both aspects. However, regions in the medial-temporal lobe were activated specifically for transitions, whereas medial and dorsolateral prefrontal regions were activated specifically for sustained perception. These results provide further support for the theory that the initial creation of perceptual awareness and upholding perceptual awareness over time are separate processes involving different brain regions.

  • 18.
    Eriksson, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Details of the construction of perception: a closer look at illusory contours2009Ingår i: Frontiers in neuroscience, ISSN 1662-453X, Vol. 3, nr 2, s. 159-160Artikel i tidskrift (Refereegranskat)
  • 19.
    Eriksson, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Stiernstedt, Mikael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Öhlund, Maria
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Changing Zaire to Congo: The fate of no-longer relevant mnemonic information.2014Ingår i: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 101, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In an ever-changing world there is constant pressure on revising long-term memory, such when people or countries change name. What happens to the old, pre-existing information? One possibility is that old associations gradually are weakened and eventually lost. Alternatively, old and no longer relevant information may still be an integral part of memory traces. To test the hypothesis that old mnemonic information still becomes activated when people correctly retrieve new, currently relevant information, brain activity was measured with fMRI while participants performed a cued-retrieval task. Paired associates (symbol-sound and symbol-face pairs) were first learned during two days. Half of the associations were then updated during the next two days, followed by fMRI scanning on day 5 and also 18months later. As expected, retrieval reactivated sensory cortex related to the most recently learned association (visual cortex for symbol-face pairs, auditory cortex for symbol-sound pairs). Critically, retrieval also reactivated sensory cortex related to the no-longer relevant associate. Eighteen months later, only non-updated symbol-face associations were intact. Intriguingly, a subset of the updated associations was now treated as though the original association had taken over, in that memory performance was significantly worse than chance and that activity in sensory cortex for the original but not the updated associate correlated (negatively) with performance. Moreover, the degree of "residual" reactivation during day 5 inversely predicted memory performance 18months later. Thus, updating of long-term memory involves adding new information to already existing networks, in which old information can stay resilient for a long time.

  • 20.
    Eriksson, Johan
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Vogel, Edward K.
    Lansner, Anders
    Bergström, Fredrik
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Neurocognitive Architecture of Working Memory2015Ingår i: Neuron, ISSN 0896-6273, E-ISSN 1097-4199, Vol. 88, nr 1, s. 33-46Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    A crucial role for working memory in temporary information processing and guidance of complex behavior has been recognized for many decades. There is emerging consensus that working-memory maintenance results from the interactions among long-term memory representations and basic processes, including attention, that are instantiated as reentrant loops between frontal and posterior cortical areas, as well as sub-cortical structures. The nature of such interactions can account for capacity limitations, lifespan changes, and restricted transfer after working-memory training. Recent data and models indicate that working memory may also be based on synaptic plasticity and that working memory can operate on non-consciously perceived information.

  • 21.
    Holm, Linus
    et al.
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Eriksson, Johan
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Andersson, Linus
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Looking as if you know: Systematic object inspection precedes object recognition2008Ingår i: Journal of Vision, ISSN 1534-7362, E-ISSN 1534-7362, Vol. 8(4), nr 14, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sometimes we seem to look at the very object we are searching for, without consciously seeing it. How do we select object relevant information before we become aware of the object? We addressed this question in two recognition experiments involving pictures of fragmented objects. In Experiment 1, participants preferred to look at the target object rather than a control region 25 fixations prior to explicit recognition. Furthermore, participants inspected the target as if they had identified it around 9 fixations prior to explicit recognition. In Experiment 2, we investigated the influence of semantic knowledge in guiding object inspection prior to explicit recognition. Consistently, more specific knowledge about target identity made participants scan the fragmented stimulus more efficiently. For instance, non-target regions were rejected faster when participants knew the target object's name. Both experiments showed that participants were looking at the objects as if they knew them before they became aware of their identity.

  • 22.
    Kalpouzos, Gregoria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Memory Self-Efficacy Beliefs Modulate Brain Activity when Encoding Real-World Future Intentions2013Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 9, s. e73850-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: While the use of different cognitive strategies when encoding episodic memory information has been extensively investigated, modulation of brain activity by memory self-efficacy beliefs has not been studied yet.

    Methodology/Principal Findings: Sixteen young adults completed the prospective and retrospective metamemory questionnaire, providing individual subjective judgments of everyday memory function. The day after, using functional magnetic resonance imaging, the participants had to memorize real-world intentions (e. g., return a book to the library), which were performed later on in a virtual environment. Participants also performed offline cognitive tasks evaluating executive functions, working memory, and attention. During encoding, activity was found in medial temporal lobe, left prefrontal cortex, medial parietal regions, occipital areas, and regions involved in (pre) motor processes. Based on results from the questionnaire, the group was split into low and high memory self-efficacy believers. Comparison of encoding-related brain activity between the 2 groups revealed that the low memory self-efficacy believers activated more the hippocampus bilaterally, right posterior parahippocampal cortex, precuneus, and left lateral temporal cortex. By contrast, more activity was found in dorsal anterior cingulate gyrus for the high-memory believers. In addition, the low-memory believers performed more poorly at feature binding and (at trend) manipulating visuospatial information in working memory.

    Conclusion/Significance: Overall, these findings indicate that memory self-efficacy beliefs modulate brain activity during intentional encoding. Low memory self-efficacy believers activated more brain areas involved in visuospatial operations such as the hippocampus. Possibly, this increase reflects attempts to compensate for poor performance of certain neurocognitive processes, such as feature binding. By contrast, high-memory believers seemed to rely more on executive-like processes involved in cognitive control.

  • 23.
    Kalpouzos, Grégoria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Sjölie, Daniel
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Molin, Jonas
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Neurocognitive systems related to real-world prospective memory2010Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 5, nr 10, s. e13304-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Taken together, these findings show how brain systems complementary interact during real-world PM, and support a more complete model of PM that can be applied to naturalistic PM tasks and that we named PROspective MEmory DYnamic (PROMEDY) model because of its dynamics on both multi-phase iteration and the interactions of distinct neurocognitive networks.

  • 24.
    Karlsson, Linnea
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Wiklund-Hornqvist, Carola
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Jonsson, Bert
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Retrieval practice is characterized by reduced fronto-striatal activity2013Ingår i: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 25, nr Suppl., s. S82-S83Artikel i tidskrift (Övrigt vetenskapligt)
  • 25.
    Karlsson Wirebring, Linnea
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Wiklund-Hörnqvist, Carola
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Andersson, Micael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Jonsson, Bert
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI). Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Lesser neural pattern similarity across repeated tests is associated with better long-term memory retention2015Ingår i: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 35, nr 26, s. 9595-9602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability—the altering or adding of underlying memory representa- tions. Human participants studied 60 Swahili–Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgot- ten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. 

  • 26. Martensson, Johan
    et al.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Bodammer, Nils Christian
    Lindgren, Magnus
    Johansson, Mikael
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Lovden, Martin
    Growth of language-related brain areas after foreign language learning2012Ingår i: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 63, nr 1, s. 240-244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of adult foreign-language acquisition on human brain organization is poorly understood. We studied cortical thickness and hippocampal volumes of conscript interpreters before and after three months of intense language studies. Results revealed increases in hippocampus volume and in cortical thickness of the left middle frontal gyrus, inferior frontal gyrus, and superior temporal gyrus for interpreters relative to controls. The right hippocampus and the left superior temporal gyrus were structurally more malleable in interpreters acquiring higher proficiency in the foreign language. Interpreters struggling relatively more to master the language displayed larger gray matter increases in the middle frontal gyrus. These findings confirm structural changes in brain regions known to serve language functions during foreign-language acquisition. (C) 2012 Elsevier Inc. All rights reserved.

  • 27.
    Naghavi, Hamid Reza
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Larsson, Anne
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Cortical regions underlying successful encoding of semantically congruent and incongruent associations between common auditory and visual objects.2011Ingår i: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 505, nr 2, s. 191-195Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies implicate regions in the frontal, temporal and occipital cortices of the brain in audio-visual (AV) integration of familiar objects. It remains unclear, however, which brain regions contribute to the creation of object-related AV memories, and whether activation of these regions is affected by crossmodal congruency. Here we used event-related functional MRI in a subsequent memory paradigm to investigate the neural substrates of successful encoding of semantically congruent and incongruent AV memories. Creation of both types of memories activated a region in the left inferior frontal gyrus (IFG). In addition, successful encoding of semantically related and unrelated AV pairs was correlated with increased activity in regions within the right lateral occipital cortex and bilateral lateral temporal cortex, respectively. These results may highlight a common role of IFG in retrieval of semantic information during encoding and suggest that the occipital and temporal cortices differentially process perceptual versus conceptual associations of AV memories.

  • 28.
    Naghavi, Hamid Reza
    et al.
    Tehran University of Medical Sciences, Institute for Cognitive Science Studies, Tehran, Iran.
    Eriksson, Johan
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Larsson, Anne
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    The claustrum/insula region integrates conceptually related sounds and pictures2007Ingår i: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 422, nr 1, s. 77-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The brain is able to create coherent percepts from multisensory input. This phenomenon, known as multisensory integration (MSI), is a ubiquitous feature of everyday life and has been found to be essential for a reliable interaction with the environment. Recent functional neuroimaging studies suggest that several different networks are engaged in various forms of MSI depending on the nature of information being integrated. However, little is known about the neural basis of a fundamental form of MSI in natural conditions; integration of common auditory and visual objects which are conceptually related, such as when we look at a cat and hear a meowing sound. Here we used event-related fMRI to compare the brain response to conceptually related and unrelated pairs of audio-visual stimuli denoting common objects. Our protocol was designed to preclude contamination of the results by cognitive processes additional to those needed for MSI. The results indicate that higher-order temporal and occipital areas respond to coincident sounds and pictures regardless of their semantic relationship; whereas, the right claustrum/insula region is differentially activated in association with multisensory integration of conceptually related common objects. This observation has important implications for understanding how multimodal information about common objects is represented in the brain.

  • 29.
    Nyberg, Lars
    et al.
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Working Memory: Maintenance, Updating, and the Realization of Intentions2016Ingår i: Cold Spring Harbor Perspectives in Biology, ISSN 1943-0264, E-ISSN 1943-0264, Vol. 8, nr 2, artikel-id a021816Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    "Working memory" refers to avast set of mnemonic processes and associated brain networks, relates to basic intellectual abilities, and underlies many real-world functions. Working-memory maintenance involves frontoparietal regions and distributed representational areas, and can be based on persistent activity in reentrant loops, synchronous oscillations, or changes in synaptic strength. Manipulation of content of working memory depends on the dorsofrontal cortex, and updating is realized by a frontostriatal '"gating" function. Goals and intentions are represented as cognitive and motivational contexts in the rostrofrontal cortex. Different working-memory networks are linked via associative reinforcement-learning mechanisms into a self-organizing system. Normal capacity variation, as well as working-memory deficits, can largely be accounted for by the effectiveness and integrity of the basal ganglia and dopaminergic neurotransmission.

  • 30.
    Nyberg, Lars
    et al.
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi. Umeå universitet, Medicinsk fakultet, Strålningsvetenskaper, Diagnostisk radiologi.
    Eriksson, Johan
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Larsson, Anne
    Umeå universitet, Medicinsk fakultet, Strålningsvetenskaper, Radiofysik.
    Marklund, Petter
    Umeå universitet, Samhällsvetenskaplig fakultet, Psykologi.
    Learning by doing versus learning by thinking: An fMRI study of motor and mental training2006Ingår i: Neuropsychologia, Vol. 44, s. 711-717Artikel i tidskrift (Refereegranskat)
  • 31.
    Nyberg, Lars
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Larsson, Anne
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Sundström, Torbjörn
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Riklund Åhlström, Katrine
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Comparing 1,5T and 3T BOLD fMRI imaging of finger tapping with familiar and novel sequences.2007Ingår i: Neuroscience Imaging, ISSN 1556-4010, Vol. 2, nr 1, s. 53-64Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It has been suggested that fMRI at 3T yields stronger and more extensive BOLD activations than fMRI at 1.5T, and that imaging at higher field strengths can reveal unique activations. In the present study we compared, within-subjects, activation patterns during a finger-tapping task at 1.5 and 3T. The data were analyzed with a random-effects model in SPM2. At a strict statistical level (p<0.05, FWE correction for multiple comparisons), ipsilateral cerebellar activation was revealed at 1.5T. At 3T, activation in sensory-motor regions in the contra-lateral cerebrum was identified in addition to the activation in cerebellum. At a less stringent statistical threshold, imaging at 1.5T and 3T revealed overlapping cortical regions with more extensive clusters at 3T. A similar pattern was seen in a comparison of familiar and novel sequences. However, subcortical activations of thalamus and parts of the basal ganglia were uniquely identified at 3T. Analyses at the individual level substantiated the group results by showing that the higher sensitivity of the 3T resulted in images with higher between-individual consistency in activation patterns.

  • 32.
    Nyberg, Lars
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Salami, Alireza
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Andersson, Mikael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Kalpouzos, Grégoria
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Kauppi, Karolina
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Lind, Johanna
    Center for Study of Human Cognition, Department of Psychology, University of Oslo, Norway.
    Pudas, Sara
    Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Persson, Jonas
    Department of Psychology and Stockholm Brain Institute, Stockholm University, 106 91 Stockholm, Sweden .
    Nilsson, Lars-Göran
    Department of Psychology and Stockholm Brain Institute, Stockholm University, 106 91 Stockholm, Sweden .
    Longitudinal evidence for diminished frontal cortex function in aging2010Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 107, nr 52, s. 22682-22686Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cross-sectional estimates of age-related changes in brain structure and function were compared with 6-y longitudinal estimates. The results indicated increased sensitivity of the longitudinal approach as well as qualitative differences. Critically, the cross-sectional analyses were suggestive of age-related frontal overrecruitment, whereas the longitudinal analyses revealed frontal underrecruitment with advancing age. The cross-sectional observation of overrecruitment reflected a select elderly sample. However, when followed over time, this sample showed reduced frontal recruitment. These findings dispute inferences of true age changes on the basis of age differences, hence challenging some contemporary models of neurocognitive aging, and demonstrate age-related decline in frontal brain volume as well as functional response.

  • 33.
    Salami, Alireza
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Kompus, Kristiina
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Habib, Reza
    Southern Illinois University , Carbondale.
    Kauppi, Karolina
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Characterizing the neural correlates of modality-specific and modality-independent accessibility and availability signals in memory using partial-least squares2010Ingår i: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 52, nr 2, s. 686-698Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous studies have shown that information that currently cannot be retrieved but will be retrieved on a subsequent, more supported task (i.e. is available but not accessible) has a distinct neural signature compared with non-available information. For verbal paired-associates, an availability signal has been revealed in left middle temporal cortex, an area potentially involved in the storage of such information, raising the possibility that availability signals are expressed in modality-specific storage sites. In the present study subjects encoded pictures and sounds representing concrete objects. One day later, during fMRI scanning, a verbal cued-recall task was administrated followed by a post-scan recognition task. Items remembered on both tasks were classified as accessible; items not remembered on the first but on the second task were classified as available; and items not remembered on any of the tasks were classified as not available. Multivariate partial-least-squares analyses revealed a modality-independent accessibility network with dominant contributions of left inferior parietal cortex, left inferior frontal cortex, and left hippocampus. Additionally, a modality-specific availability network was identified which included increased activity in visual regions for available pictorial information and in auditory regions for available sound information. These findings show that availability in memory, at least in part, is characterized by systematic changes in brain activity in sensory regions whereas memory access reflects differential activity in a modality-independent, conceptual network, thus indicating qualitative differences between availability and accessibility in memory.

  • 34.
    Salami, Alireza
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nilsson, Lars-Göran
    Stockholm University.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Age-related white matter microstructural differences partly mediate age-related decline in processing speed but not cognition2012Ingår i: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1822, nr 3, s. 408-415Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aging is associated with declining cognitive performance as well as structural changes in brain gray and white matter (WM). The WM deterioration contributes to a disconnection among distributed brain networks and may thus mediate age-related cognitive decline. The present diffusion tensor imaging (DTI) study investigated age-related differences in WM microstructure and their relation to cognition (episodic memory, visuospatial processing, fluency, and speed) in a large group of healthy subjects (n=287) covering 6 decades of the human life span. Age related decreases in fractional anisotropy (FA) and increases in mean diffusivity (MD) were observed across the entire WM skeleton as well as in specific WM tracts, supporting the WM degeneration hypothesis. The anterior section of the corpus callosum was more susceptible to aging compared to the posterior section, lending support to the anterior-posterior gradient of WM integrity in the corpus callosum. Finally, and of critical interest, WM integrity differences were found to mediate age-related reductions in processing speed but no significant mediation was found for episodic memory, visuospatial ability, or fluency. These findings suggest that compromised WM integrity is not a major contributing factor to declining cognitive performance in normal aging. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.

  • 35.
    Salami, Alireza
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Opposing effects of aging on large-scale brain systems for memory encoding and cognitive control2012Ingår i: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 32, nr 31, s. 10749-10757Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Episodic memory declines with advancing age. Neuroimaging studies have associated such decline to age-related changes in general cognitive-control networks as well as to changes in process-specific encoding or retrieval networks. To assess the specific influence of aging on encoding and retrieval processes and associated brain systems, it is vital to dissociate encoding and retrieval from each other and from shared cognitive-control processes. We used multivariate partial-least-squares to analyze functional magnetic resonance imaging data from a large population-based sample (n = 292, 25-80 years). The participants performed a face-name paired-associates task and an active baseline task. The analysis revealed two significant network patterns. The first reflected a process-general encoding-retrieval network that included frontoparietal cortices and posterior hippocampus. The second pattern dissociated encoding and retrieval networks. The anterior hippocampus was differentially engaged during encoding. Brain scores, representing whole-brain integrated measures of how strongly an individual recruited a brain network, were correlated with cognitive performance and chronological age. The scores from the general cognitive-control network correlated negatively with episodic memory performance and positively with age. The encoding brain scores, which strongly reflected hippocampal functioning, correlated positively with episodic memory performance and negatively with age. Univariate analyses confirmed that bilateral hippocampus showed the most pronounced activity reduction in older age, and brain structure analyses found that the activity reduction partly related to hippocampus atrophy. Collectively, these findings suggest that age-related structural brain changes underlie age-related reductions in the efficient recruitment of a process-specific encoding network, which cascades into upregulated recruitment of a general cognitive-control network.

  • 36.
    Sjölie, Daniel
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Bodin, Kenneth
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Elgh, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Geriatrik.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Janlert, Lars-Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Effects of interactivity and 3D-motion on mental rotation brain activity in an immersive virtual environment2010Ingår i: Proceedings of the 28th international conference on Human factors in computing systems, Association for Computing Machinery (ACM), 2010, s. 869-878Konferensbidrag (Refereegranskat)
    Abstract [en]

    The combination of virtual reality (VR) and brain measurements is a promising development of HCI, but the maturation of this paradigm requires more knowledge about how brain activity is influenced by parameters of VR applications. To this end we investigate the influence of two prominent VR parameters, 3d-motion and interactivity, while brain activity is measured for a mental rotation task, using functional MRI (fMRI). A mental rotation network of brain areas is identified, matching previous results. The addition of interactivity increases the activation in core areas of this network, with more profound effects in frontal and preparatory motor areas. The increases from 3d-motion are restricted to primarily visual areas. We relate these effects to emerging theories of cognition and potential applications for brain-computer interfaces (BCIs). Our results demonstrate one way to provoke increased activity in task-relevant areas, making it easier to detect and use for adaptation and development of HCI.

  • 37.
    Sjölie, Daniel
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Bodin, Kenneth
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Janlert, Lars-Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Using brain imaging to assess interaction in immersive VR2009Ingår i: Challenges in the evaluation of usability and user experience in reality based interaction / [ed] Georgios Christou, Effie Lai-Chong Law, William Green, & Kasper Hornbæk, Boston, MA, USA: ACM , 2009, s. 23-27Konferensbidrag (Refereegranskat)
    Abstract [en]

    We have developed a system where the combination of functional brain imaging (fMRI) and Virtual Reality (VR) can be used to study and evaluate user experience based on brain activation and models of cognitive neuroscience. The ability to study the brain during natural interaction with an (ecologically valid) environment has great potential for several areas of research and development, including evaluation of Reality-Based Interaction (RBI). The RBI concept of tradeoffs is of particular interest since we want to further explore the relation between how the brain works with an accepted reality and what happens when this reality is disrupted. We present the system with an overview of conducted studies to illustrate capabilities and feasibility. In particular, feasibility is supported by the fact that the brain activations seen in these studies match expectations based on existing literature. Further discussion elaborates on the relation to RBI and evaluation; and finally some possible future work is presented.

  • 38.
    Sjölie, Daniel
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Kalpouzos, Grégoria
    Aging Research Center (ARC), Karolinska Institute and Stockholm University, Stockholm, Sweden.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB). Umeå universitet, Medicinska fakulteten, Umeå centrum för funktionell hjärnavbildning (UFBI).
    Capturing neural correlates of disrupted presence ina naturalistic virtual environment2013Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The concept of presence is commonly related to whether or not a user feels, acts, and reacts as if he/she were in a real familiar environment when using a virtual reality (VR) application. Understanding the neural correlates of presence may provide a foundation for objective measurements of presence and important constraints for theoretical explanations of presence. Discussions about the neural basis for presence are relatively common, but brain imaging has rarely been applied to investigating this issue. Previous studies have focused on detecting average differences between conditions that correlate with differences in reported presence. In this study we focused on breaks in presence and associated periods of disrupted presence as an important complement to previous work. Specifically, we measured brain activity with functional magnetic resonance imaging (fMRI) during execution of an everyday task in a naturalistic virtual environment (VE). Time periods of disrupted presence were identified by subject reports indicating something strange in the current environment, interpreted as a violation of expectations related to the sense of presence. Disrupted presence was associated with increased activity in the frontopolar cortex (FPC), lateral occipito-temporal cortex (LOTC), the temporal poles (TP), and the posterior superior temporal cortex (pSTC). We relate these areas to integration of key aspects of a presence experience, relating the (changing) situation to management of task and goals (FPC), interpretation of visual input (LOTC), emotional evaluation of the context (TP) and possible interactions (pSTC). Modulation of the activity level in these brain areas is consistent with an interpretation of disrupted presence as a re-evaluation of key aspects of a subjective mental reality, updating the synchronization with the virtual environment as previous predictions fail. Such a subjective mental reality may also be related to a self-centered type of mentalization, providing a link to accounts of presence building on the self.

  • 39.
    Stigsdotter Neely, Anna
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Sehlstedt, I
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Ekman, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi. Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Sandberg, Petra
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Qwillbard, Tony
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi. Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Working Memory Updating Training in Older Adults: Is Level of Performance After Training Related to Transfer?2013Ingår i: Journal of Psychophysiology, ISSN 0269-8803, E-ISSN 2151-2124, Vol. 27, nr Supplement 1, s. 69-70Artikel i tidskrift (Övrigt vetenskapligt)
  • 40.
    Wiklund-Hörnkvist, Carola
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Karlsson, Linnea
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Jonsson, Bert
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    The neural mechanisms underlying test-enhanced learning: An event-related functional magnetic resonance imaging study2012Ingår i: Earli-SIG 22: Neuroscience and Education" 24th-26th May 2012, Institute of Education, London, 2012, s. 9-9Konferensbidrag (Refereegranskat)
    Abstract [en]

    Considerable research in cognitive psychology has demonstrated that testing improves the performance on later retention tests, a phenomenon called the testing-effect. However, the neural mechanisms of test-enhanced learning are not well understood. The current study examined changes in functional brain networks in relation to repeated retrieval (i.e. test-enhanced learning).

    Participants (n=20) first studied 60 Swahili-Swedish word-pairs. Subsequently, they underwent functional magnetic resonance imaging while being tested on each study item three times.

    Successful repeated retrieval was characterized by decreased activity in prefrontal and premotor regions and in the right caudate, compared to items not successfully retrieved at consecutive tests. Successful repeated retrieval was also characterized by increased activity in right middle temporal cortex (BA 37 & 21).

    Tentatively, these results imply that the benefits of test-enhanced learning in part is due to decreased need for executive processing along with strengthening of semantic representations.

    The current results generate novel information on the effectiveness of testing as a learning method and thus contribute to bridge the current gap between cognitive neuroscience and educational research.

  • 41.
    Wiklund-Hörnqvist, Carola
    et al.
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Karlsson, Linnea
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Eriksson, Johan
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Andersson, Micael
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Jonsson, Bert
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Nyberg, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Activity in left temporal-parietal regions characterizes long-term retention after repeated testing2013Ingår i: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 25, nr Suppl., s. S114-S114Artikel i tidskrift (Övrigt vetenskapligt