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Awad, A., Blomstedt, P., Westling, G. & Eriksson, J. (2020). Deep brain stimulation in the caudal zona incerta modulates the sensorimotor cerebello-cerebral circuit in essential tremor. NeuroImage, 209, Article ID 116511.
Open this publication in new window or tab >>Deep brain stimulation in the caudal zona incerta modulates the sensorimotor cerebello-cerebral circuit in essential tremor
2020 (English)In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 209, article id 116511Article in journal (Refereed) Published
Abstract [en]

Essential tremor is effectively treated with deep brain stimulation (DBS), but the neural mechanisms underlying the treatment effect are poorly understood. Essential tremor is driven by a dysfunctional cerebello-thalamo-cerebral circuit resulting in pathological tremor oscillations. DBS is hypothesised to interfere with these oscillations at the stimulated target level, but it is unknown whether the stimulation modulates the activity of the cerebello-thalamo-cerebral circuit during different task states (with and without tremor) in awake essential tremor patients. To address this issue, we used functional MRI in 16 essential tremor patients chronically implanted with DBS in the caudal zona incerta. During scanning, the patients performed unilateral tremor-inducing postural holding and pointing tasks as well as rest, with contralateral stimulation turned On and Off.

We show that DBS exerts both task-dependent as well as task-independent modulation of the sensorimotor cerebello-cerebral regions (p ​≤ ​0.05, FWE cluster-corrected for multiple comparisons). Task-dependent modulation (DBS ​× ​task interaction) resulted in two patterns of stimulation effects. Firstly, activity decreases (blood oxygen level-dependent signal) during tremor-inducing postural holding in the primary sensorimotor cortex and cerebellar lobule VIII, and activity increases in the supplementary motor area and cerebellar lobule V during rest (p ​≤ ​0.05, post hoc two-tailed t-test). These effects represent differences at the effector level and may reflect DBS-induced tremor reduction since the primary sensorimotor cortex, cerebellum and supplementary motor area exhibit less motor task-activity as compared to the resting condition during On stimulation. Secondly, task-independent modulation (main effect of DBS) was observed as activity increase in the lateral premotor cortex during all motor tasks, and also during rest (p ​≤ ​0.05, post hoc two-tailed t-test). This task-independent effect may mediate the therapeutic effects of DBS through the facilitation of the premotor control over the sensorimotor circuit, making it less susceptible to tremor entrainment.

Our findings support the notion that DBS in essential tremor is modulating the sensorimotor cerebello-cerebral circuit, distant to the stimulated target, and illustrate the complexity of stimulation mechanisms by demonstrating task-dependent as well as task-independent actions in cerebello-cerebral regions.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Essential tremor, Deep brain stimulation, Caudal zona incerta, Functional MRI, Cerebello-cerebral circuit
National Category
Neurology Physiology Neurosciences
Research subject
Neurosurgery; Neurology; Physiology
Identifiers
urn:nbn:se:umu:diva-167200 (URN)10.1016/j.neuroimage.2019.116511 (DOI)
Funder
Västerbotten County Council
Available from: 2020-01-11 Created: 2020-01-11 Last updated: 2020-04-15Bibliographically approved
Eriksson, J., Fontan, A. & Pedale, T. (2020). Make the Unconscious Explicit to Boost the Science of Consciousness. Frontiers in Psychology, 11, Article ID 260.
Open this publication in new window or tab >>Make the Unconscious Explicit to Boost the Science of Consciousness
2020 (English)In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 11, article id 260Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Frontiers Media S.A., 2020
Keywords
consciousness, unconscious, false negative, neural correlates of consciousness, high-level cognition
National Category
Psychology (excluding Applied Psychology)
Identifiers
urn:nbn:se:umu:diva-169045 (URN)10.3389/fpsyg.2020.00260 (DOI)000519066200001 ()32140132 (PubMedID)
Available from: 2020-03-19 Created: 2020-03-19 Last updated: 2020-03-19Bibliographically approved
Andersson, L., Eriksson, J., Stillesjö, S., Juslin, P., Nyberg, L. & Karlsson Wirebring, L. (2020). Neurocognitive processes underlying heuristic and normative probability judgments. Cognition, 196, 1-7, Article ID 104153.
Open this publication in new window or tab >>Neurocognitive processes underlying heuristic and normative probability judgments
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2020 (English)In: Cognition, ISSN 0010-0277, E-ISSN 1873-7838, Vol. 196, p. 1-7, article id 104153Article in journal (Refereed) Published
Abstract [en]

Judging two events in combination (A&B) as more probable than one of the events (A) is known as a conjunction fallacy. According to dual-process explanations of human judgment and decision making, the fallacy is due to the application of a heuristic, associative cognitive process. Avoiding the fallacy has been suggested to require the recruitment of a separate process that can apply normative rules. We investigated these assumptions using functional magnetic resonance imaging (fMRI) during conjunction tasks. Judgments, whether correct or not, engaged a network of brain regions identical to that engaged during similarity judgments. Avoidance of the conjunction fallacy additionally, and uniquely, involved a fronto-parietal network previously linked to supervisory, analytic control processes. The results lend credibility to the idea that incorrect probability judgments are the result of a representativeness heuristic that requires additional neurocognitive resources to avoid.

Place, publisher, year, edition, pages
ELSEVIER, 2020
Keywords
Decision making, Dual-system, Dual-process, fMRI, Representativeness
National Category
Philosophy
Identifiers
urn:nbn:se:umu:diva-169341 (URN)10.1016/j.cognition.2019.104153 (DOI)000518704700021 ()31838247 (PubMedID)
Available from: 2020-04-15 Created: 2020-04-15 Last updated: 2020-04-15Bibliographically approved
Eriksson, J., Lindgren, B.-M. & Lindahl, E. (2020). Newly trained operating room nurses' experiences of nursing care in the operating room. Scandinavian Journal of Caring Sciences
Open this publication in new window or tab >>Newly trained operating room nurses' experiences of nursing care in the operating room
2020 (English)In: Scandinavian Journal of Caring Sciences, ISSN 0283-9318, E-ISSN 1471-6712Article in journal (Refereed) Epub ahead of print
Abstract [en]

There is limited research on nurses' experiences of nursing care in the operating room. The operating room nurses' responsibility is to ensure good nursing care before, during and after surgery. In an increasingly technological health care environment, there is always a risk of turning the focus away from nursing care towards technology and medicine. Integration of past experiences into the role as an operating room nurse becomes a challenge for those who recently worked as general nurses. The present study aimed to explore newly trained operating room nurses' experiences of nursing care in an operating room. Semi-structured interviews were performed with ten operating room nurses with a maximum three years' work experience from an operating room. The interviews were subjected to qualitative content analysis. The findings revealed three themes describing operating room nurses' searching for their new role. They experienced a gap between theory and practice, felt alone and insignificant and had to find their own place. The operating room nurses' experienced threats to safe nursing when they lacked time for the patients as well as for their own recovery, and they lacked feedback in order to improve care. They ensured security for patients by establishing one-to-one contact, protecting patients' well-being and working in teams for the patients' best interest, participants also focused on the task at hand instead of the patient as a person. New ways of organising work in operating units, and well-functioning teams can be a key to a successful integration of experiences from ward nurse to an operating room nurse, and provide support so that they feel more visible, at ease and safe in their new profession.

Place, publisher, year, edition, pages
John Wiley & Sons, 2020
Keywords
lived experience, surgical nursing, theatre nursing, theory-practice gap, workforce issues
National Category
Nursing
Identifiers
urn:nbn:se:umu:diva-167742 (URN)10.1111/scs.12817 (DOI)000507136300001 ()31943310 (PubMedID)
Available from: 2020-02-03 Created: 2020-02-03 Last updated: 2020-02-04Bibliographically approved
Awad, A., Levi, R., Waller, M., Westling, G., Lindgren, L. & Eriksson, J. (2020). Preserved somatosensory conduction in complete spinal cord injury: Discomplete SCI. Clinical Neurophysiology, 131(5), 1059-1067
Open this publication in new window or tab >>Preserved somatosensory conduction in complete spinal cord injury: Discomplete SCI
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2020 (English)In: Clinical Neurophysiology, ISSN 1388-2457, E-ISSN 1872-8952, Vol. 131, no 5, p. 1059-1067Article in journal (Refereed) Published
Abstract [en]

Objective: Spinal cord injury (SCI) disrupts the communication between brain and body parts innervated from below-injury spinal segments, but rarely results in complete anatomical transection of the spinal cord. The aim of this study was to investigate residual somatosensory conduction in clinically complete SCI, to corroborate the concept of sensory discomplete SCI.

Methods: We used fMRI with a somatosensory protocol in which blinded and randomized tactile and nociceptive stimulation was applied on both legs (below-injury level) and one arm (above-injury level) in eleven participants with chronic complete SCI. The experimental design accounts for possible confounding mechanical (e.g. vibration) and cortico-cortical top-down mechanisms (e.g. attention/expectation).

Results: Somatosensory stimulation on below-level insensate body regions activated the somatotopically corresponding part of the contralateral primary somatosensory cortex in six out of eleven participants.

Conclusions: Our results represent afferent-driven cortical activation through preserved somatosensory connections to the brain in a subgroup of participants with clinically complete SCI, i.e. sensory discomplete SCI.

Significance: Identifying patients with residual somatosensory connections might open the door for new rehabilitative and restorative strategies as well as inform research on SCI-related conditions such as neuropathic pain and spasticity.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Spinal cord injury, Functional MRI, Somatosensory, Discomplete, Non-conscious
National Category
Neurology Neurosciences Physiology
Research subject
Neurology; Neurosurgery; Rehabilitation Medicine; Physiology
Identifiers
urn:nbn:se:umu:diva-169138 (URN)10.1016/j.clinph.2020.01.017 (DOI)
Available from: 2020-03-22 Created: 2020-03-22 Last updated: 2020-04-14Bibliographically approved
Berginström, N., Nordström, P., Ekman, U., Eriksson, J., Nyberg, L. & Nordström, A. (2019). Pharmaco-fMRI in Patients With Traumatic Brain Injury: A Randomized Controlled Trial With the Monoaminergic Stabilizer (-)-OSU6162. The journal of head trauma rehabilitation, 34(3), 189-198
Open this publication in new window or tab >>Pharmaco-fMRI in Patients With Traumatic Brain Injury: A Randomized Controlled Trial With the Monoaminergic Stabilizer (-)-OSU6162
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2019 (English)In: The journal of head trauma rehabilitation, ISSN 0885-9701, E-ISSN 1550-509X, Vol. 34, no 3, p. 189-198Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Wolters Kluwer, 2019
Keywords
dopaminergic agents, functional magnetic resonance imaging, randomized controlled trial, traumatic brain injury
National Category
Neurology Neurosciences
Identifiers
urn:nbn:se:umu:diva-152090 (URN)10.1097/HTR.0000000000000440 (DOI)000474249100015 ()30234850 (PubMedID)
Funder
Ragnar Söderbergs stiftelseTorsten Söderbergs stiftelseKnut and Alice Wallenberg FoundationVästerbotten County Council
Available from: 2018-09-26 Created: 2018-09-26 Last updated: 2019-08-06Bibliographically approved
Sjöberg, R. L., Stålnacke, M., Andersson, M. & Eriksson, J. (2019). The supplementary motor area syndrome and cognitive control. Neuropsychologia, 129, 141-145
Open this publication in new window or tab >>The supplementary motor area syndrome and cognitive control
2019 (English)In: Neuropsychologia, ISSN 0028-3932, E-ISSN 1873-3514, Vol. 129, p. 141-145Article in journal (Refereed) Published
Abstract [en]

The Supplementary Motor Area (SMA)-syndrome is a transient disturbance of the ability to initiate voluntary motor and speech actions that will often occur immediately after neurosurgical resections in the dorsal superior frontal gyrus but will typically have disappeared after 3 months. The purpose of the present study was to investigate the extent to which this syndrome is associated with alterations in cognitive control. Five patients who were to different extents affected by the SMA-syndrome after surgery for WHO grade II gliomas in the left hemisphere, were tested with the color word interference (Stroop) test; the Bergen dichotic listening test and for letter and category verbal fluency before surgery, 1–2 days after surgery and approximately 3 months after surgery. Results suggest that the motor symptoms known as the SMA syndrome co-occur with pronounced deficits in cognitive control.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Cognitive control, Executive function, SMA-syndrome, Supplementary motor area, Stroop test, Dichotic listening
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-164009 (URN)10.1016/j.neuropsychologia.2019.03.013 (DOI)000493911900014 ()30930302 (PubMedID)
Funder
Västerbotten County Council
Available from: 2019-10-12 Created: 2019-10-12 Last updated: 2019-12-03Bibliographically approved
Karlsson Wirebring, L., Stillesjö, S., Eriksson, J., Juslin, P. & Nyberg, L. (2018). A Similarity-Based Process for Human Judgment in the Parietal Cortex. Frontiers in Human Neuroscience, 12, Article ID 481.
Open this publication in new window or tab >>A Similarity-Based Process for Human Judgment in the Parietal Cortex
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2018 (English)In: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 12, article id 481Article in journal (Refereed) Published
Abstract [en]

One important distinction in psychology is between inferences based on associative memory and inferences based on analysis and rules. Much previous empirical work conceive of associative and analytical processes as two exclusive ways of addressing a judgment task, where only one process is selected and engaged at a time, in an either-or fashion. However, related work indicate that the processes are better understood as being in interplay and simultaneously engaged. Based on computational modeling and brain imaging of spontaneously adopted judgment strategies together with analyses of brain activity elicited in tasks where participants were explicitly instructed to perform similarity-based associative judgments or rule-based judgments (n = 74), we identified brain regions related to the two types of processes. We observed considerable overlap in activity patterns. The precuneus was activated for both types of judgments, and its activity predicted how well a similarity-based model fit the judgments. Activity in the superior frontal gyrus predicted the fit of a rule-based judgment model. The results suggest the precuneus as a key node for similarity-based judgments, engaged both when overt responses are guided by similarity-based and rule-based processes. These results are interpreted such that similarity-based processes are engaged in parallel to rule-based-processes, a finding with direct implications for cognitive theories of judgment.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2018
Keywords
judgment and decision-making, fMRI, exemplar model, multiple-cue judgment, cognitive model
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-154869 (URN)10.3389/fnhum.2018.00481 (DOI)000453235900001 ()2-s2.0-85058995922 (Scopus ID)
Available from: 2019-01-04 Created: 2019-01-04 Last updated: 2019-05-21Bibliographically approved
Ekman, U., Fordell, H., Eriksson, J., Lenfeldt, N., Wåhlin, A., Eklund, A. & Malm, J. (2018). Increase of frontal neuronal activity in chronic neglect after training in virtual reality. Acta Neurologica Scandinavica, 138(4), 284-292
Open this publication in new window or tab >>Increase of frontal neuronal activity in chronic neglect after training in virtual reality
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2018 (English)In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 138, no 4, p. 284-292Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
cognitive rehabilitation, functional magnetic resonance imaging, neuronal plasticity, spatial neglect, virtual reality
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-152199 (URN)10.1111/ane.12955 (DOI)000443931400003 ()29770439 (PubMedID)
Available from: 2018-10-31 Created: 2018-10-31 Last updated: 2019-11-25Bibliographically approved
Bergström, F. & Eriksson, J. (2018). Neural evidence for non-conscious working memory. Cerebral Cortex, 28(9), 3217-3228
Open this publication in new window or tab >>Neural evidence for non-conscious working memory
2018 (English)In: Cerebral Cortex, ISSN 1047-3211, E-ISSN 1460-2199, Vol. 28, no 9, p. 3217-3228Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Oxford University Press, 2018
Keywords
consciousness, continuous flash suppression, fMRI, unconscious, subjective measure, working memory
National Category
Neurosciences Psychology
Identifiers
urn:nbn:se:umu:diva-124806 (URN)10.1093/cercor/bhx193 (DOI)000443545600012 ()28981609 (PubMedID)
Funder
Swedish Research CouncilEU, FP7, Seventh Framework Programme, 604102
Note

Originally included in thesis in manuscript form with title "Neural evidence for non-conscious short-term memory".

Available from: 2016-08-25 Created: 2016-08-25 Last updated: 2018-10-25Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-4653-2067

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