Biology subjects

van Timmeren, T.

Publications and source records attributed to van Timmeren, T..

3 recordsLinked to original sources

bioRxiv2022

Can the brain strategically go on automatic pilot? An fMRI study investigating the effect of if-then planning on behavioral flexibility

People often have good intentions but fail to adhere to them. Implementation intentions, a form of strategic planning, can help people to close this intention-behavior gap. Their effectiveness has been proposed to depend on the mental formation of a stimulus-response association between a trigger and target behavior, thereby creating an instant habit. If implementation intentions do indeed lead to reliance on habitual control, then this may come at the cost of reduced behavioral flexibility. Furthermore, we would expect a shift from recruitment of corticostriatal brain regions implicated in goal-directed control towards habit regions. To test these ideas, we performed a functional MRI study in which participants received instrumental training supported by either implementation or goal intentions, followed by an outcome-revaluation to test reliance on habitual versus goal-directed control. We found that implementation intentions led to increased efficiency during training, as reflected in higher accuracy, faster reaction times, and decreased engagement of the anterior caudate. However, implementation intentions did not reduce behavioral flexibility when goals changed during the test phase, nor did it affect the underlying corticostriatal pathways. Additionally, this study showed that slips of action towards devalued outcomes are associated with reduced activity in brain regions implicated in goal-directed control. In conclusion, our behavioral and neuroimaging findings suggest that strategic if-then planning does not lead to a shift from goal-directed towards habitual control.

neuroscience↗

bioRxiv2022

Striatal ups or downs? Neural correlates of monetary reward anticipation, cue reactivity and their interaction in alcohol use disorder and gambling disorder

Striatal dysfunction is a key characteristic of addictive disorders, but neuroimaging studies have reported conflicting findings. An integrative model of addiction points to the presence or absence of addiction-related cues as an explanation for striatal hypo-or hyperactivations, respectively, but has never been directly tested. Here, we developed a novel paradigm to investigate striatal activation during monetary reward anticipation in the presence versus absence of addiction-related pictures using functional MRI. Across two studies, we compared 46 alcohol use disorder (AUD) patients with 30 matched healthy controls; and 24 gambling disorder (GD) patients with 22 matched healthy controls. During monetary reward anticipation, hypoactivation of the reward system was seen in AUD individuals compared to HCs. Additionally, a behavioral interaction was seen where gambling cues made participants, across groups, respond faster for bigger, but slower for smaller rewards. However, no striatal differences were seen between the participants with AUD or GD and their matched controls. In sum, these findings suggest that striatal dysfunction is a key but heterogeneous mechanism within both AUD and GD and indicates an important but complex role for addiction-related cues in explaining striatal dysfunction in addiction.

neuroscience↗

bioRxiv2018

Altered orbitofrontal sulcogyral patterns in gambling disorder: a multicenter study

Gambling disorder is a serious psychiatric condition characterized by decision-making and reward processing impairments that are associated with dysfunctional brain activity in the orbitofrontal cortex (OFC). However, it remains unclear whether OFC functional abnormalities in gambling disorder are accompanied by structural abnormalities. We addressed this question by examining the organization of sulci and gyri in the OFC. This organization is in place very early and stable across life, such that OFC sulcogyral patterns (classified into Type I, II and III) can be regarded as potential pre-morbid markers of pathological conditions. We gathered structural brain data from nine existing studies, reaching a total of 165 individuals with gambling disorder and 159 healthy controls. Our results, supported by both frequentist and Bayesian statistics, show that the distribution of OFC sulcogyral patterns is skewed in individuals with gambling disorder, with an increased prevalence of Type II pattern compared with healthy controls. Examination of gambling severity did not reveal any significant relationship between OFC sulcogyral patterns and disease severity. Altogether, our results provide evidence for a skewed distribution of OFC sulcogyral patterns in gambling disorder, and suggest that pattern Type II might represent a pre-morbid structural brain marker of the disease. It will be important to investigate more closely the functional implications of these structural abnormalities in future work.

neuroscience↗