Biology subjects

Soutschek, A.

Publications and source records attributed to Soutschek, A..

6 recordsLinked to original sources

bioRxiv2025

Ventromedial prefrontal cortex shields value computations from bodily arousal in decision making

Emotional reactions to norm violations influence how people trade-off selfish interests against social norms, but it remains unknown which brain regions causally contribute to integrating physiological arousal associated with norm violations into the decision process. Here, we provide evidence that the ventromedial prefrontal cortex (vmPFC) causally contributes to decoupling value computations in normative choice from physiological arousal. Excitatory brain stimulation over the vmPFC reduced aversion to disadvantageous inequality in an Ultimatum game and increased post-decision confidence after acceptance of unfair monetary splits. Physiological arousal as measured via heart rate changes was increased in response to splits perceived as unfair. Enhancing vmPFC excitability reduced the sensitivity to unfairness not by directly inhibiting physiological arousal but by blocking its influence on the decision process. This suggests that vmPFC causally moderates how physiological responses to norm violations affect trade-offs between self-interests and norm considerations, highlighting its key role for integrating emotional and cognitive processes in decision making. Significance statementEmotions like anger about the violation of social norms are associated with physiological arousal, and the interoceptive awareness of this arousal is thought to influence decision making. Here, we identify the neural mechanism that causally mediates the influence of physiological arousal on the decision process. Increasing the excitability of the ventromedial prefrontal cortex strengthened selfish interests over fairness considerations in social interactions via decoupling the decision process from unfairness-evoked arousal. This provides a neuroscientific explanation for how physiological arousal influences social decisions and suggests that the role of the ventromedial prefrontal cortex for the interaction between emotion and cognition in decision making is based on interoception rather than emotion regulation.

neuroscience↗

bioRxiv2025

Changing the Motivation for Mental Work with Temporal Interference Stimulation

Successful goal-directed behavior often requires the exertion of effortful control processes. The striatum is thought to play a key role in determining whether a goal is worth the required cognitive effort, but whether and how the striatum causally influences effort-based decisions in humans remains unclear. Here, we address this gap by employing transcranial temporal interference stimulation (tTIS), a novel non-invasive brain stimulation technique capable of targeting deeper brain regions. We applied striatum-targeted tTIS to healthy participants performing an effort-based decision task during functional MRI scanning. Supporting the idea that the striatum encodes both the benefits and costs of actions, we found that, on the behavioral level, striatum-targeted tTIS increased the sensitivity to both reward magnitudes and effort costs. At the neural level, this was mirrored by stronger representations of effort demands in the striatum under stimulation as well as by enhanced functional coupling between the striatum and the anterior cingulate cortex, a region at the intersection of motivation and cognition. Together, our findings provide insights into the causal contributions of the striatum to trading-off rewards against effort costs, informing neural accounts of motivated cognition and suggesting novel neural interventions for the treatment of amotivation.

neuroscience↗

bioRxiv2024

Frontoparietal theta synchronization causally links working memory with impulsive decision making

Delaying gratification in value-based decision making is canonically related to activation in the dorsolateral prefrontal cortex (dlPFC), but past research neglected that the dlPFC is part of a larger frontoparietal network. It is therefore unknown whether the dlPFC causally implements delay of gratification in concert with posterior parts of the frontoparietal network rather than in isolation. Here, we addressed this gap by testing the effects of frontoparietal theta synchronization and desynchronization on impulsive decision making using transcranial alternating current stimulation (tACS). Healthy participants performed an intertemporal choice task and a 3-back working memory task while left frontal and parietal cortices were stimulated with a 5 Hz theta frequency at in-phase (synchronization), anti-phase (desynchronization), or sham tACS. We found frontoparietal theta coupling to improve working memory performance, while in the decision task desynchronization was associated with more impulsive choices and stronger hyperbolic discounting of future rewards. Overall, our findings overcome the past focus of the dlPFC in isolation and show that patient decision making causally relies on synchronous activation in a frontoparietal network related to working memory.

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bioRxiv2022

A Process Model Account of the Role of Dopamine in Intertemporal Choice

Theoretical accounts disagree on the role of dopamine in intertemporal choice and assume that dopamine either promotes delay of gratification by increasing the preference for larger rewards or that dopamine reduces patience by enhancing the sensitivity to waiting costs. Here, we reconcile these conflicting accounts by providing empirical support for a novel process model according to which dopamine contributes to two dissociable components of the decision process, evidence accumulation and starting bias. We re-analyzed a previously published data set where intertemporal decisions were made either under the D2 antagonist amisulpride or under placebo by fitting a hierarchical drift diffusion model that distinguishes between dopaminergic effects on the speed of evidence accumulation and the starting point of the accumulation process. Blocking dopaminergic neurotransmission not only strengthened the sensitivity to whether a reward is perceived as worth the delay costs during evidence accumulation (drift rate) but also attenuated the impact of waiting costs on the starting point of the evidence accumulation process (bias). Taken together, our findings support a novel, process-based account of the role of dopamine for cost-benefit decision making, highlight the potential benefits of process-informed analyses and advance our understanding of dopaminergic contributions to decision making.

neuroscience↗

bioRxiv2021

Learning from ingroup experiences changes intergroup impressions

Living in multicultural societies, humans form impressions towards individuals of their own social groups (ingroup members) and of different social groups (outgroup members). Some psychological theories predict that intergroup impressions are mainly shaped by experiences with outgroup individuals ("outgroup focused theories"), while other theories predict that ingroup experiences play a dominant role ("ingroup focused theories"). Here we test predictions from these two psychological theories by estimating how intergroup impressions are dynamically shaped when people learn from both ingroup and outgroup experiences. Participants expected to receive painful shocks but were saved from pain by different ingroup or outgroup members in 75% of all trials. We measured neural responses using functional magnetic resonance imaging (fMRI), and participants rated their social closeness as well as impressions towards the ingroup and the outgroup. Behavioral results showed an initial ingroup bias in impression ratings which was significantly reduced over the course of learning. Computational learning models revealed that these changes in intergroup impressions were predicted by the weight given to ingroup prediction errors. The weight of the ingroup prediction error and its effect on intergroup impression change was stronger the more individuals identified with their ingroup. On the neural level, the left inferior parietal lobule (IPL) encoded more negative prediction errors for the ingroup compared to the outgroup. Moreover, stronger weight for ingroup prediction errors was related to increased neural coupling between the left IPL and the anterior insula (AI). This coupling further predicted learning-related changes in intergroup impressions. Together, our work provides computational and neural evidence for "ingroup focused theories", highlighting the importance of ingroup experiences in shaping social impressions in intergroup settings.

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bioRxiv2021

Opioid antagonism reduces wanting by strengthening frontostriatal connectivity

Goal-directed behavior depends on both motivational ("wanting") and hedonic ("liking") dimensions of rewards. Previous animal and human research linked wanting and liking to anatomically and neurochemically distinct brain mechanisms, but it remains unknown as to how the different brain regions and neurotransmitter systems interact in processing distinct reward dimensions. Here, we assessed how pharmacological manipulations of opioid and dopamine receptor activation modulate the neural processing of wanting and liking in humans in a randomized, placebo-controlled, double-blind clinical trial. Blocking opioid receptor activation with naltrexone selectively reduced wanting of rewards, which on a neural level was reflected by stronger coupling between dorsolateral prefrontal cortex and the striatum under naltrexone compared with placebo. Our findings thus provide insights into how opioid receptors mediate frontostriatal gating of specifically motivational, not hedonic, aspects of rewards.

neuroscience↗