TY  - JOUR
AU  - Froböse, M.I.
AU  - Swart, J.C.
AU  - Cook, J.L.
AU  - Geurts, D.E.M.
AU  - Ouden, H.E.M. den
AU  - Cools, R.
PY  - 2018
UR  - https://hdl.handle.net/2066/198509
AB  - The catecholamines have long been associated with cognitive control and value-based decision-making. More recently, we proposed that the catecholamines might modulate value-based decision-making about whether or not to engage in cognitive control. We test this hypothesis by assessing effects of a catecholamine challenge in a large sample of young, healthy adults (n = 100) on the avoidance of a cognitively demanding control process: task switching. Prolonging catecholamine transmission by blocking reuptake with methylphenidate altered the avoidance, but not the execution of cognitive control. Crucially, these effects could be isolated by taking into account individual differences in trait impulsivity, so that participants with higher trait impulsivity became more avoidant of cognitive control, despite faster task performance. One implication of these findings is that performance-enhancing effects of methylphenidate may be accompanied by an undermining effect on the willingness to exert cognitive control. Taken together, these findings integrate hitherto segregated literatures on catecholamines' roles in value-based learning/choice and cognitive control.
TI  - Catecholaminergic modulation of the avoidance of cognitive control
EP  - 1781
SN  - 0096-3445
IS  - iss. 12
SP  - 1763
JF  - Journal of Experimental Psychology - General
VL  - vol. 147
PS  - 19 p.
DO  - https://doi.org/10.1037/xge0000523
ER  - 
TY  - JOUR
AU  - Schaaf, M.E. van der
AU  - Lange, F.P. de
AU  - Schmits, I.C.
AU  - Geurts, D.E.M.
AU  - Roelofs, K.
AU  - Meer, J.W.M. van der
AU  - Toni, I.
AU  - Knoop, H.
PY  - 2017
UR  - https://hdl.handle.net/2066/163005
AB  - Background: Chronic fatigue syndrome (CFS) is characterized by severe fatigue persisting for ≥6 months and leading to considerable impairment in daily functioning. Neuroimaging studies of patients with CFS have revealed alterations in prefrontal brain morphology. However, it remains to be determined whether these alterations are specific for fatigue or whether they relate to other common CFS symptoms (e.g., chronic pain, lower psychomotor speed, and reduced physical activity). Methods: We used magnetic resonance imaging to quantify gray matter volume (GMV) and the N-acetylaspartate and N-acetylaspartylglutamate/creatine ratio (NAA/Cr) in a group of 89 women with CFS. Building on previous reports, we tested whether GMV and NAA/Cr in the dorsolateral prefrontal cortex are associated with fatigue severity, pain, psychomotor speed, and physical activity, while controlling for depressive symptoms. We also considered GMV and NAA/Cr differences between patients with CFS and 26 sex-, age-, and education-matched healthy controls. Results: The presence of pain symptoms was the main predictor of both GMV and NAA/Cr in the left dorsolateral prefrontal cortex of patients with CFS. More pain was associated with reduced GMVs and NAA/Cr, over and above the effects of fatigue, depressive symptoms, physical activity, and psychomotor speed. In contrast to previous reports and despite a large representative sample, global GMV did not differ between the CFS and healthy control groups. Conclusions: CFS, as diagnosed by Centers for Disease Control and Prevention criteria, is not a clinical entity reliably associated with reduced GMV. Individual variation in the presence of pain, rather than fatigue, is associated with neuronal alterations in the dorsolateral prefrontal cortex of patients with CFS.
TI  - Prefrontal structure varies as a function of pain symptoms in chronic fatigue syndrome
EP  - 365
SN  - 0006-3223
IS  - iss. 4
SP  - 358
JF  - Biological Psychiatry
VL  - vol. 81
PS  - 8 p.
DO  - https://doi.org/10.1016/j.biopsych.2016.07.016
ER  - 
TY  - JOUR
AU  - Geurts, D.E.M.
AU  - Borries, A.K.L. von
AU  - Volman, I.A.C.
AU  - Bulten, B.H.
AU  - Cools, R.
AU  - Verkes, R.J.
PY  - 2016
UR  - https://hdl.handle.net/2066/159075
AB  - Criminal behaviour poses a big challenge for society. A thorough understanding of neurobiological mechanisms underlying criminality could optimize its prevention and management. Recently, it has been proposed that neural mechanisms underpinning reward expectation might be pivotal to understanding criminal behavior. However this proposal has not been tested in a criminal sample. To fill this gap, we assessed reward expectation in incarcerated, psychopathic criminals. We compared this group to two groups of non-criminal individuals: one with high levels and another with low levels of impulsive/antisocial traits. Functional magnetic resonance imaging (fMRI) was used to quantify neural responses to reward expectancy. Psychophysiological interaction analyses were performed to examine differences in functional connectivity patterns of reward-related regions. The data suggest that overt criminality is characterized, not by abnormal reward expectation per se, but rather by enhanced communication between reward-related striatal regions and frontal brain regions. We establish that incarcerated psychopathic criminals can be dissociated from noncriminal individuals with comparable impulsive/antisocial personality tendencies based on the degree to which reward-related brain regions interact with brain regions that control behavior. The present results help us understand why some people act according to their impulsive/antisocial personality while others are able to behave adaptively despite reward-related urges.
TI  - Neural connectivity during reward expectation dissociates psychopathic criminals from noncriminal individuals with high impulsive/antisocial psychopathic traits
EP  - 1334
SN  - 1749-5016
IS  - iss. 8
SP  - 1326
JF  - Social Cognitive and Affective Neuroscience
VL  - vol. 11
PS  - 9 p.
DO  - https://doi.org/10.1093/scan/nsw040
L1  - https://repository.ubn.ru.nl/bitstream/handle/2066/159075/159075.pdf?sequence=1
ER  - 
TY  - JOUR
AU  - Schaaf, M.E. van der
AU  - Schmits, I.C.
AU  - Roerink, M.E.
AU  - Geurts, D.E.M.
AU  - Toni, I.
AU  - Roelofs, K.
AU  - Lange, F.P. de
AU  - Nater, U.M.
AU  - Meer, J.W.M. van der
AU  - Knoop, H.
PY  - 2015
UR  - https://hdl.handle.net/2066/153223
AB  - BACKGROUND: Chronic fatigue syndrome (CFS) is characterized by profound and disabling fatigue with no known somatic explanation. Cognitive behavioral therapy (CBT) has proven to be a successful intervention leading to a reduction in fatigue and disability. Based on previous neuroimaging findings, it has been suggested that central neural mechanisms may underlie CFS symptoms and play a role in the change brought on by CBT. In this randomized controlled trial we aim to further investigate the neural mechanisms that underlie fatigue in CFS and their change by CBT. METHODS/DESIGN: We will conduct a randomized controlled trial in which we collect anatomical and functional magnetic resonance imaging (MRI) measures from female CFS patients before and after CBT (N = 60) or waiting list (N = 30) and compare these with measures from age and education matched healthy controls (N = 30). By including a large treatment group we will also be able to compare patients that benefit from CBT with those that do not. In addition, to further investigate the role of endocrine and immune biomarkers in CFS, we will determine cortisol and cytokine concentrations in blood, hair and/or saliva. DISCUSSION: This project creates an unique opportunity to enhance our understanding of CFS symptoms and its change by CBT in terms of neuroanatomical, neurofunctional, endocrinological and immunological mechanisms and can help to further improve future treatments strategies. TRIAL REGISTRATION: Dutch Trial Register #15852. Registered 9 December 2013 ( http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4311 ).
TI  - Investigating neural mechanisms of change of cognitive behavioural therapy for chronic fatigue syndrome: a randomized controlled trial (Study protocol)
SN  - 1471-244X
JF  - BMC Psychiatry
VL  - vol. 15
PS  - 13 p.
DO  - https://doi.org/10.1186/s12888-015-0515-9
L1  - https://repository.ubn.ru.nl/bitstream/handle/2066/153223/153223.pdf?sequence=1
ER  - 
TY  - JOUR
AU  - Ouden, H.E.M. den
AU  - Swart, J.C.
AU  - Schmidt, K.
AU  - Fekkes, D.
AU  - Geurts, D.E.M.
AU  - Cools, R.
PY  - 2015
UR  - https://hdl.handle.net/2066/153477
AB  - RATIONALE: The neurotransmitter serotonin has long been implicated in the motivational control of behaviour. Recent theories propose that the role of serotonin can be understood in terms of an interaction between a motivational and a behavioural activation axis. Experimental support for these ideas, however, has been mixed. OBJECTIVES: In the current study, we aimed to investigate the role of serotonin (5HT) in behavioural vigour as a function of incentive motivation. METHODS: We employed dietary acute tryptophan depletion (ATD) to lower the 5HT precursor tryptophan during the performance of a speeded visual discrimination task. Feedback valence and feedback probability were manipulated independently and cued prior to target onset. On feedback trials, fast correct responses led to either reward or avoidance of punishment, while slow or incorrect responses led to reward omission or punishment. RESULTS: We show that behavioural responding is inhibited under high incentive motivation (i.e. high-feedback probability) at baseline 5HT levels and that lowering these leads to behavioural disinhibition, while leaving accuracy unaffected. Surprisingly, there were no differential effects of motivational valence, with 5HT depletion releasing behavioural inhibition under both appetitive and aversive motivation. CONCLUSIONS: Our findings extend current theories on the role of 5HT in behavioural inhibition by showing that reductions in serotonin lead to increased behavioural vigour only if there is a motivational drive to inhibit behaviour at baseline.
TI  - Acute serotonin depletion releases motivated inhibition of response vigour
EP  - 1312
SN  - 0033-3158
IS  - iss. 7
SP  - 1303
JF  - Psychopharmacology
VL  - vol. 232
PS  - 10 p.
DO  - https://doi.org/10.1007/s00213-014-3762-4
ER  - 
TY  - JOUR
AU  - Ouden, H.E.M. den
AU  - Daw, N.D.
AU  - Schmidt, K.
AU  - Geurts, D.E.M.
AU  - Cools, R.
PY  - 2011
UR  - https://hdl.handle.net/2066/219158
TI  - Serotonin's role in behaviour: Aversion and/or inhibition?
SN  - 0006-3223
IS  - iss. 9 - Suppl.
SP  - 49S
JF  - Biological Psychiatry
VL  - vol. 69
PS  - 1 p.
DO  - https://doi.org/10.1016/j.biopsych.2011.03.030
ER  -