umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Nyberg, Lars
Alternative names
Publications (10 of 270) Show all publications
Wåhlin, A. & Nyberg, L. (2019). At the Heart of Cognitive Functioning in Aging. Trends in cognitive sciences, 23(9), 717-720
Open this publication in new window or tab >>At the Heart of Cognitive Functioning in Aging
2019 (English)In: Trends in cognitive sciences, ISSN 1364-6613, E-ISSN 1879-307X, Vol. 23, no 9, p. 717-720Article in journal, Editorial material (Other academic) Published
Abstract [en]

Several neural and non-neural factors contribute to individual differences in cognitive performance. Here we outline a sequence of vascular events where excessive transfer of arterial-pressure pulsatility damages hippocampal capillaries. We argue that the vascular alterations decrease the ability to sustain neural activity and thereby contribute to episodic-memory impairment in aging.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
episodic memory, brain maintenance, vascular, blood–brain barrier, arteries, neurovascular coupling, hippocampus
National Category
Neurosciences Psychology Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:umu:diva-162831 (URN)10.1016/j.tics.2019.06.004 (DOI)000480652500003 ()31303538 (PubMedID)
Available from: 2019-09-16 Created: 2019-09-16 Last updated: 2019-09-16Bibliographically approved
Stillesjö, S., Nyberg, L. & Karlsson Wirebring, L. (2019). Building Memory Representations for Exemplar-Based Judgment: A Role for Ventral Precuneus. Frontiers in Human Neuroscience, 13, Article ID 228.
Open this publication in new window or tab >>Building Memory Representations for Exemplar-Based Judgment: A Role for Ventral Precuneus
2019 (English)In: Frontiers in Human Neuroscience, ISSN 1662-5161, E-ISSN 1662-5161, Vol. 13, article id 228Article in journal (Refereed) Published
Abstract [en]

The brain networks underlying human multiple-cue judgment, the judgment of a continuous criterion based on multiple cues, have been examined in a few recent studies, and the ventral precuneus has been found to be a key region. Specifically, activation differences in ventral precuneus (as measured with functional magnetic resonance imaging, fMRI) has been linked to an exemplar-based judgment process, where judgments are based on memory for previous similar cases. Ventral precuneus is implicated in various episodic memory processes, notably such that increased activity during learning in this region as well as in the ventromedial prefrontal cortex (vmPFC) and the medial temporal lobes (MTL) have been linked to retrieval success. The present study used fMRI during a multiple-cue judgment task to gain novel neurocognitive evidence informative for the link between learning-related activity changes in ventral precuneus and exemplar-based judgment. Participants (N = 27) spontaneously learned to make judgments during fMRI, in a multiple-cue judgment task specifically designed to induce exemplar-based processing. Contrasting brain activity during late learning to early learning revealed higher activity in ventral precuneus, the bilateral MTL, and the vmPFC. Activity in the ventral precuneus and the vmPFC was found to parametrically increase between each judgment event, and activity levels in the ventral precuneus predicted performance after learning. These results are interpreted such that the ventral precuneus supports the aspects of exemplar-based processes that are related to episodic memory, tentatively by building, storing, and being implicated in retrieving memory representations for judgment.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
multiple-cue judgment, exemplar-based model, cognitive modeling, fMRI, judgment and decision making, precuneus
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-159176 (URN)10.3389/fnhum.2019.00228 (DOI)000475956500001 ()31379536 (PubMedID)2-s2.0-85069499904 (Scopus ID)
Note

Originally included in thesis in manuscript form.

Available from: 2019-05-21 Created: 2019-05-21 Last updated: 2019-08-08Bibliographically approved
Karalija, N., Papenberg, G., Wåhlin, A., Johansson, J., Andersson, M., Axelsson, J., . . . Nyberg, L. (2019). C957T-mediated Variation in Ligand Affinity Affects the Association between C-11-raclopride Binding Potential and Cognition. Journal of cognitive neuroscience, 31(2), 314-325
Open this publication in new window or tab >>C957T-mediated Variation in Ligand Affinity Affects the Association between C-11-raclopride Binding Potential and Cognition
Show others...
2019 (English)In: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 31, no 2, p. 314-325Article in journal (Refereed) Published
Abstract [en]

The dopamine (DA) system plays an important role in cognition. Accordingly, normal variation in DA genes has been found to predict individual differences in cognitive performance. However, little is known of the impact of genetic differences on the link between empirical indicators of the DA system and cognition in humans. The present work used PET with C-11-raclopride to assess DA D2-receptor binding potential (BP) and links to episodic memory, working memory, and perceptual speed in 179 healthy adults aged 64-68 years. Previously, the T-allele of a DA D2-receptor single-nucleotide polymorphism, C957T, was associated with increased apparent affinity of C-11-raclopride, giving rise to higher BP values despite similar receptor density values between allelic groups. Consequently, we hypothesized that C-11-raclopride BP measures inflated by affinity rather than D2-receptor density in T-allele carriers would not be predictive of DA integrity and therefore prevent finding an association between C-11-raclopride BP and cognitive performance. In accordance with previous findings, we show that C-11-raclopride BP was increased in T-homozygotes. Importantly, C-11-raclopride BP was only associated with cognitive performance in groups with low or average ligand affinity (C-allele carriers of C957T, n = 124), but not in the high-affinity group (T-homozygotes, n = 55). The strongest C-11-raclopride BP-cognition associations and the highest level of performance were found in C-homozygotes. These findings show that genetic differences modulate the link between BP and cognition and thus have important implications for the interpretation of DA assessments with PET and C-11-raclopride in multiple disciplines ranging from cognitive neuroscience to psychiatry and neurology.

Place, publisher, year, edition, pages
MIT Press, 2019
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-155630 (URN)10.1162/jocn_a_01354 (DOI)000454429400011 ()30407135 (PubMedID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg FoundationRagnar Söderbergs stiftelseTorsten Söderbergs stiftelseThe Swedish Brain FoundationVästerbotten County Council
Available from: 2019-01-28 Created: 2019-01-28 Last updated: 2019-01-28Bibliographically approved
Salami, A., Garrett, D. D., Wåhlin, A., Rieckmann, A., Papenberg, G., Karalija, N., . . . Nyberg, L. (2019). Dopamine D2/3 Binding Potential Modulates Neural Signatures of Working Memory in a Load-Dependent Fashion.. Journal of Neuroscience, 39(3), 537-547
Open this publication in new window or tab >>Dopamine D2/3 Binding Potential Modulates Neural Signatures of Working Memory in a Load-Dependent Fashion.
Show others...
2019 (English)In: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 39, no 3, p. 537-547Article in journal (Refereed) Published
Abstract [en]

Dopamine (DA) modulates corticostriatal connections. Studies in which imaging of the DA system is integrated with functional imaging during cognitive performance have yielded mixed findings. Some work has shown a link between striatal DA (measured by PET) and fMRI activations, whereas others have failed to observe such a relationship. One possible reason for these discrepant findings is differences in task demands, such that a more demanding task with greater prefrontal activations may yield a stronger association with DA. Moreover, a potential DA–BOLD association may be modulated by task performance. We studied 155 (104 normal-performing and 51 low-performing) healthy older adults (43% females) who underwent fMRI scanning while performing a working memory (WM) n-back task along with DA D2/3 PET assessment using [11C]raclopride. Using multivariate partial-least-squares analysis, we observed a significant pattern revealing positive associations of striatal as well as extrastriatal DA D2/3 receptors to BOLD response in the thalamo–striatal–cortical circuit, which supports WM functioning. Critically, the DA–BOLD association in normal-performing, but not low-performing, individuals was expressed in a load-dependent fashion, with stronger associations during 3-back than 1-/2-back conditions. Moreover, normal-performing adults expressing upregulated BOLD in response to increasing task demands showed a stronger DA–BOLD association during 3-back, whereas low-performing individuals expressed a stronger association during 2-back conditions. This pattern suggests a nonlinear DA–BOLD performance association, with the strongest link at the maximum capacity level. Together, our results suggest that DA may have a stronger impact on functional brain responses during more demanding cognitive tasks.

Keywords
PET, aging, dopamine, fMRI, working memory
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-155492 (URN)10.1523/JNEUROSCI.1493-18.2018 (DOI)000455849400013 ()30478031 (PubMedID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg FoundationTorsten Söderbergs stiftelseRagnar Söderbergs stiftelseThe Swedish Brain FoundationVästerbotten County Council
Available from: 2019-01-18 Created: 2019-01-18 Last updated: 2019-02-08Bibliographically approved
de Boer, L., Axelsson, J., Chowdhury, R., Riklund, K., Dolan, R. J., Nyberg, L., . . . Guitart-Masip, M. (2019). Dorsal striatal dopamine D1 receptor availability predicts an instrumental bias in action learning. Proceedings of the National Academy of Sciences of the United States of America, 116(1), 261-270
Open this publication in new window or tab >>Dorsal striatal dopamine D1 receptor availability predicts an instrumental bias in action learning
Show others...
2019 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, no 1, p. 261-270Article in journal (Refereed) Published
Abstract [en]

Learning to act to obtain reward and inhibit to avoid punishment is easier compared with learning the opposite contingencies. This coupling of action and valence is often thought of as a Pavlovian bias, although recent research has shown it may also emerge through instrumental mechanisms. We measured this learning bias with a rewarded go/no-go task in 60 adults of different ages. Using computational modeling, we characterized the bias as being instrumental. To assess the role of endogenous dopamine (DA) in the expression of this bias, we quantified DA D1 receptor availability using positron emission tomography (PET) with the radioligand [11C]SCH23390. Using principal-component analysis on the binding potentials in a number of cortical and striatal regions of interest, we demonstrated that cortical, dorsal striatal, and ventral striatal areas provide independent sources of variance in DA D1 receptor availability. Interindividual variation in the dorsal striatal component was related to the strength of the instrumental bias during learning. These data suggest at least three anatomical sources of variance in DA D1 receptor availability separable using PET in humans, and we provide evidence that human dorsal striatal DA D1 receptors are involved in the modulation of instrumental learning biases.

Place, publisher, year, edition, pages
National Academy of Sciences, 2019
Keywords
decision making, dopamine, Pavlovian bias, instrumental learning, positron emission tomography
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-155637 (URN)10.1073/pnas.1816704116 (DOI)000454707700042 ()30563856 (PubMedID)
Funder
Swedish Research Council, VR521-2013-2589
Available from: 2019-01-25 Created: 2019-01-25 Last updated: 2019-01-25Bibliographically approved
Zetterberg, H., Winblad, B., Bernick, C., Yaffe, K., Majdan, M., Johansson, G., . . . Blennow, K. (2019). Head trauma in sports - clinical characteristics, epidemiology and biomarkers. Journal of Internal Medicine, 285(6), 624-634
Open this publication in new window or tab >>Head trauma in sports - clinical characteristics, epidemiology and biomarkers
Show others...
2019 (English)In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 285, no 6, p. 624-634Article, review/survey (Refereed) Published
Abstract [en]

Traumatic brain injury (TBI) is clinically divided into a spectrum of severities, with mild TBI being the least severe form and a frequent occurrence in contact sports, such as ice hockey, American football, rugby, horse riding and boxing. Mild TBI is caused by blunt nonpenetrating head trauma that causes movement of the brain and stretching and tearing of axons, with diffuse axonal injury being a central pathogenic mechanism. Mild TBI is in principle synonymous with concussion; both have similar criteria in which the most important elements are acute alteration or loss of consciousness and/or post-traumatic amnesia following head trauma and no apparent brain changes on standard neuroimaging. Symptoms in mild TBI are highly variable and there are no validated imaging or fluid biomarkers to determine whether or not a patient with a normal computerized tomography scan of the brain has neuronal damage. Mild TBI typically resolves within a few weeks but 10-15% of concussion patients develop postconcussive syndrome. Repetitive mild TBI, which is frequent in contact sports, is a risk factor for a complicated recovery process. This overview paper discusses the relationships between repetitive head impacts in contact sports, mild TBI and chronic neurological symptoms. What are these conditions, how common are they, how are they linked and can they be objectified using imaging or fluid-based biomarkers? It gives an update on the current state of research on these questions with a specific focus on clinical characteristics, epidemiology and biomarkers.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2019
Keywords
biomarkers, clinical characteristics, epidemiology, head trauma, traumatic brain injury
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-161600 (URN)10.1111/joim.12863 (DOI)000473089500004 ()30481401 (PubMedID)
Funder
Stiftelsen Gamla Tjänarinnor
Available from: 2019-07-18 Created: 2019-07-18 Last updated: 2019-07-18Bibliographically approved
Lövheim, H., Norman, T., Weidung, B., Olsson, J., Josefsson, M., Adolfsson, R., . . . Elgh, F. (2019). Herpes Simplex Virus, APOE ɛ4, and Cognitive Decline in Old Age: Results from the Betula Cohort Study. Journal of Alzheimer's Disease, 67(1), 211-220
Open this publication in new window or tab >>Herpes Simplex Virus, APOE ɛ4, and Cognitive Decline in Old Age: Results from the Betula Cohort Study
Show others...
2019 (English)In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 67, no 1, p. 211-220Article in journal (Refereed) Published
Abstract [en]

Background: Herpes simplex virus (HSV) has been suggested to play a role in Alzheimer’s disease (AD) development.

Objective: The aim of the present study was to investigate the early AD-related symptom episodic memory decline in relation to HSV and carriage of allele 4 of the apolipoprotein E gene (APOE ɛ4) in a large population-based cohort with a long follow-up time.

Methods: The study included 3,413 persons, with longitudinal data available for 1,293 persons with a mean follow-up time of 11.6 years. The associations between HSV carriage, APOE ɛ4 carriage, and episodic memory was investigated at baseline, as well as in longitudinal analyses where individuals with and without HSV antibodies (HSV1/2 non-specific) were matched and episodic memory decline compared.

Results: Cross-sectional analyses revealed an age-dependent association of HSV carriage with lower episodic memory function, particularly among APOE ɛ4 carriers (p = 0.008). Longitudinal analyses showed an increased risk of episodic memory decline in HSV carriers (≥65 years: p < 0.001, all ages: non-significant), and a significant interaction between HSV and APOE ɛ4 for episodic memory decline (p < 0.001).

Conclusion: In this large population-based cohort study, both cross-sectional and longitudinal results support an association between HSV carriage and declining episodic memory function, especially among APOE ɛ4 carriers. The results strengthen the hypothesis that HSV is associated with AD development.

Place, publisher, year, edition, pages
IOS Press, 2019
Keywords
Alzheimer’s disease, APOE ɛ4, apolipoprotein E4, cognitive impairment, cohort study, dementia, epidemiological study, episodic memory, herpes simplex virus
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-162728 (URN)10.3233/JAD-171162 (DOI)000457778000017 ()30636735 (PubMedID)
Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-09-10Bibliographically approved
Jonasson, L. S., Nyberg, L., Axelsson, J., Kramer, A. F., Riklund, K. & Boraxbekk, C.-J. (2019). Higher striatal D2-receptor availability in aerobically fit older adults but non-selective intervention effects after aerobic versus resistance training. NeuroImage, 202, Article ID 116044.
Open this publication in new window or tab >>Higher striatal D2-receptor availability in aerobically fit older adults but non-selective intervention effects after aerobic versus resistance training
Show others...
2019 (English)In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 202, article id 116044Article in journal (Refereed) Published
Abstract [en]

There is much evidence that dopamine is vital for cognitive functioning in aging. Here we tested the hypothesis that aerobic exercise and fitness influence dopaminergic neurotransmission in the striatum, and in turn performance on offline working-memory updating tasks. Dopaminergic neurotransmission was measured by positron emission tomography (PET) and the non-displacable binding potential (BPND) of [11C]raclopride, i.e. dopamine (DA) D2-receptor (D2R) availability. Fifty-four sedentary older adults underwent a six-months exercise intervention, performing either aerobic exercise or stretching, toning, and resistance active control training. At baseline, higher aerobic fitness levels (VO2peak) were associated with higher BPND in the striatum, providing evidence of a link between an objective measure of aerobic fitness and D2R in older adults. BPND decreased substantially over the intervention in both groups but the intervention effects were non-selective with respect to exercise group. The decrease was several times larger than any previously estimated annual decline in D2R, potentially due to increased endogenous DA. Working-memory was unrelated to D2R both at baseline and following the intervention. To conclude, we provide partial evidence for a link between physical exercise and DA. Utilizing a PET protocol able to disentangle both D2R and DA levels could shed further light on whether, and how, aerobic exercise impacts the dopaminergic system in older adults.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Aerobic exercise, Fitness, Dopamine, D2, Working memory, Raclopride
National Category
Neurosciences
Identifiers
urn:nbn:se:umu:diva-162742 (URN)10.1016/j.neuroimage.2019.116044 (DOI)31352122 (PubMedID)2-s2.0-85069908673 (Scopus ID)
Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-08-30Bibliographically approved
Vidal-Pineiro, D., Sneve, M. H., Nyberg, L., Mowinckel, A. M., Sederevicius, D., Walhovd, K. B. & Fjell, A. M. (2019). Maintained Frontal Activity Underlies High Memory Function Over 8 Years in Aging. Cerebral Cortex, 29(7), 3111-3123
Open this publication in new window or tab >>Maintained Frontal Activity Underlies High Memory Function Over 8 Years in Aging
Show others...
2019 (English)In: Cerebral Cortex, ISSN 1047-3211, E-ISSN 1460-2199, Vol. 29, no 7, p. 3111-3123Article in journal (Refereed) Published
Abstract [en]

Aging is characterized by substantial average decline in memory performance. Yet contradictory explanations have been given for how the brains of high-performing older adults work: either by engagement of compensatory processes such as recruitment of additional networks or by maintaining young adults' patterns of activity. Distinguishing these components requires large experimental samples and longitudinal follow-up. Here, we investigate which features are key to high memory in aging, directly testing these hypotheses by studying a large sample of adult participants (n > 300) with fMRI during an episodic memory experiment where item-context relationships were implicitly encoded. The analyses revealed that low levels of activity in frontal networks-known to be involved in memory encoding-were associated with low memory performance in the older adults only. Importantly, older participants with low memory performance and low frontal activity exhibited a strong longitudinal memory decline in an independent verbal episodic memory task spanning 8 years back (n = 52). These participants were also characterized by lower hippocampal volumes and steeper rates of cortical atrophy. Altogether, maintenance of frontal brain function during encoding seems to be a primary characteristic of preservation of memory function in aging, likely reflecting intact ability to integrate information.

Place, publisher, year, edition, pages
OXFORD UNIV PRESS INC, 2019
Keywords
aging, brain maintenance, encoding, episodic memory, fMRI
National Category
Psychology (excluding Applied Psychology)
Identifiers
urn:nbn:se:umu:diva-162009 (URN)10.1093/cercor/bhy177 (DOI)000477708300026 ()30137326 (PubMedID)
Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-08-13Bibliographically 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
Show others...
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
Organisations

Search in DiVA

Show all publications