Blocking D2/D3 dopamine receptors in male participants increases volatility of beliefs when learning to trust others.

The ability to learn about other people is crucial for human social functioning. Dopamine has been proposed to regulate the precision of beliefs, but direct behavioural evidence of this is lacking. In this study, we investigate how a high dose of the D2/D3 dopamine receptor antagonist sulpiride impacts learning about other people's prosocial attitudes in a repeated Trust game.

The Human Basolateral Amygdala Is Indispensable for Social Experiential Learning.

Trust and betrayal are central to our social world, and adaptive responses to generous and selfish behavior are crucial to our economic and social well-being [1]. We learn about others' trustworthiness through trial and error during repeated interactions [2]. By reinforcing and suppressing behavior during positive and negative interactions with conspecifics, rodent research has established a crucial role for the basolateral amygdala (BLA) in social experiential learning [3, 4].

Testosterone and androgen receptor gene polymorphism are associated with confidence and competitiveness in men.

A contribution to a special issue on Hormones and Human Competition. Studies in non-human animals and humans have demonstrated the important role of testosterone in competitive interactions. Here, we investigated whether endogenous testosterone levels predict the decision to compete, in a design excluding spite as a motive underlying competitiveness.

Role of dopamine D2 receptors in human reinforcement learning.

Influential neurocomputational models emphasize dopamine (DA) as an electrophysiological and neurochemical correlate of reinforcement learning. However, evidence of a specific causal role of DA receptors in learning has been less forthcoming, especially in humans. Here we combine, in a between-subjects design, administration of a high dose of the selective DA D2/3-receptor antagonist sulpiride with genetic analysis of the DA D2 receptor in a behavioral study of reinforcement learning in a sample of 78 healthy male volunteers.

Combining behavioral endocrinology and experimental economics: testosterone and social decision making.

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in rodents have shown a direct link between testosterone and aggressive behavior(1) and folk wisdom adapts these findings to humans, suggesting that testosterone induces antisocial, egoistic or even aggressive behavior(2). However, many researchers doubt a direct testosterone-aggression link in humans, arguing instead that testosterone is primarily involved in status-related behavior(3,4).

Unexplained gonad alterations in whitefish (Coregonus spp.) from Lake Thun, Switzerland: levels of persistent organic pollutants in different morphs.

Since 2000, a surprisingly high number of macroscopical gonad alterations has been reported in whitefish (Coregonus spp.) from Lake Thun, Switzerland. This unique phenomenon is still unexplained and has received much public attention.