Emerging research suggests that individuals experience vicarious social pain (i.e., ostracism). It has been proposed that observing ostracism increases activity in the insula and in the prefrontal... Show moreEmerging research suggests that individuals experience vicarious social pain (i.e., ostracism). It has been proposed that observing ostracism increases activity in the insula and in the prefrontal cortex (PFC), two key brain regions activated by directly experiencing ostracism. Here, we assessed the causal role of the insula and PFC in modulating neural activity in these areas by applying transcutaneous Vagus Nerve Stimulation (tVNS), a new non-invasive and safe method to stimulate the vagus nerve that has been shown to activate the insula and PFC. A single-blind, sham-controlled, within-subjects design was used to assess the effect of on-line (i.e., stimulation overlapping with the critical task) tVNS in healthy young volunteers (n = 24) on the prosocial Cyberball game, a virtual ball-tossing game designed to measure prosocial compensation of ostracism. Active tVNS did not increase prosocial helping behavior toward an ostracized person, as compared to sham (placebo) stimulation. Corroborated by Bayesian inference, we conclude that tVNS does not modulate reactions to vicarious ostracism, as indexed by performance in a Cyberball game. Show less
Colzato, L.S.; Rover, M. de; Wildenberg, W.P.M. van den; Nieuwenhuis, S. 2013
BACKGROUND The brain-derived neurotrophic factor (BDNF) is a key protein in maintaining neuronal integrity. The BDNF gene is thought to play an important role in the pathophysiology of mood and... Show moreBACKGROUND The brain-derived neurotrophic factor (BDNF) is a key protein in maintaining neuronal integrity. The BDNF gene is thought to play an important role in the pathophysiology of mood and anxiety disorders. The aim of this study was to investigate, for the first time in a single study, the association between BDNF Val(66)Met polymorphism, anxiety, alcohol consumption, and cortisol stress response. METHOD 98 healthy university students (54 females and 44 males), genotyped for the Val(66)Met polymorphism, participated in a physical-stress procedure (cold pressure test, CPT) after having been informed that they would undergo a painful experience. Indices of anxiety and of stress were collected from repeated measurement of salivary cortisol, blood pressure, and heart rate. RESULTS BDNF Met carriers, were more anxious during the CPT (p<0.001), drank more alcohol per week, (p<0.05), and showed significantly higher anticipatory cortisol response (p<0.05), but not in response to the CPT, than Val/Val homozygotes. The association of BDNF Val(66)Met polymorphism with HPA axis reactivity to stress was not modulated by gender. These results suggest that Met carriers are particularly sensitive in anticipating stressful events, which extends previous findings on the moderating role of the BDNF Val(66)Met polymorphism in the face of stressful life events. Show less
Colzato, L.S.; Does, A.J.W. van der; Kouwenhoven, C.; Elzinga, B.M.; Hommel, B. 2011
The present fMRI study tested the assumption that a single pairing of a stimulus and a logically unrelated response is sufficient for binding the corresponding stimulus and response codes into an... Show moreThe present fMRI study tested the assumption that a single pairing of a stimulus and a logically unrelated response is sufficient for binding the corresponding stimulus and response codes into an event representation (event file) that is automatically retrieved upon processing of at least one of its components. In particular, we investigated whether repeating a face or a house stimulus and/or a left or a right manual response induces the automatic retrieval of the response or stimulus that it previously accompanied. ROI analyses of fusiform face area, parahippocampal place area, and right and left motor cortex revealed that repeating one component of a previously encountered stimulus-response episode leads to the suppression of cortical areas processing the other components, suggesting that these components were indeed automatically retrieved and conflicted with ongoing processing. The particular pattern obtained is consistent with predictions from diffusion models of decision making, which suggest a crucial role of local competition in response selection. Show less
Colzato, L.S.; Wildenberg, W.P.M. van den; Does, A.J.W. van der; Hommel, B. 2010
Various psychiatric disorders are characterized by elevated levels of impulsivity. Although extensive evidence supports a specific role of striatal, but not frontal dopamine (DA) in human... Show moreVarious psychiatric disorders are characterized by elevated levels of impulsivity. Although extensive evidence supports a specific role of striatal, but not frontal dopamine (DA) in human impulsivity, recent studies on genetic variability have raised some doubts on such a role. Importantly, impulsivity consists of two dissociable components that previous studies have failed to separate: functional and dysfunctional impulsivity. We compared participants with a genetic predisposition to have relatively high striatal DA levels (DAT1 9-repeat carriers, DRD2 C957T T/T homozygotes, and DRD4 7-repeat carriers) with participants with other genetic predispositions. We predicted that the first group would show high scores of dysfunctional, but not functional, self-reported impulsivity and greater difficulty in inhibiting a behavioral response to a stop-signal, a behavioral measure of impulsivity. In a sample of 130 healthy adults, we studied the relation between DAT1, DRD4, and C957T polymorphism at the DRD2 gene (polymorphisms related to striatal DA) and catechol-Omethyltransferase (COMT) Val158Met (a polymorphism related to frontal DA) on self-reported dysfunctional and functional impulsivity, assessed by the Dickman impulsivity inventory (DII), and the efficiency of inhibitory control, assessed by the stop-signal paradigm. DRD2 C957T T/T homozygotes and DRD4 7-repeat carriers indeed had significantly higher scores on self-reported dysfunctional, but not functional, impulsivity. TIT homozygotes were also less efficient in inhibiting prepotent responses. Our findings support the claim that dopaminergic variation affects dysfunctional impulsivity. This is in line with the notion that the over-supply of striatal DA might weaken inhibitory pathways, thereby enhancing the activation of, and the competition between responses. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved. Show less