Direct serotonin release in humans shapes aversive learning and inhibition.

The role of serotonin in human behaviour is informed by approaches which allow in vivo modification of synaptic serotonin. However, characterising the effects of increased serotonin signalling in human models of behaviour is challenging given the limitations of available experimental probes, notably selective serotonin reuptake inhibitors. Here we use a now-accessible approach to directly increase synaptic serotonin in humans (a selective serotonin releasing agent) and examine its influence on domains of behaviour historically considered core functions of serotonin. Computational techniques, including reinforcement learning and drift diffusion modelling, explain participant behaviour at baseline and after week-long intervention. Reinforcement learning models reveal that increasing synaptic serotonin reduces sensitivity for outcomes in aversive contexts. Furthermore, increasing synaptic serotonin enhances behavioural inhibition, and shifts bias towards impulse control during exposure to aversive emotional probes. These effects are seen in the context of overall improvements in memory for neutral verbal information. Our findings highlight the direct effects of increasing synaptic serotonin on human behaviour, underlining its role in guiding decision-making within aversive and more neutral contexts, and offering implications for longstanding theories of central serotonin function.

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research.

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.

Can extreme experiences enhance creativity? The case of the underwater nightclub.

Creativity is a valuable commodity. Research has revealed some identifying characteristics of creative people and some of the emotional states that can bring out the most creativity in all of us. It has also been shown that the long-term experience of different cultures and lifestyles that is the result of travel and immigration can also enhance creativity. However, the role of one-off, extreme, or unusual experiences on creativity has not been directly observed before. In part, that may be because, by their very nature, such experiences are very difficult to bring into the laboratory. Here, we brought the tools and empirical methods of the laboratory into the wild, measuring the psychological effects of a unique multisensory experience: an underwater nightclub. We showed - with fully randomized and experimentally controlled conditions - that such an experience boosted measures of divergent thinking in participants. This demonstrates that one element of creativity can be directly enhanced by unusual situations, and that experimental tools of psychology can be used to investigate a range of consumer experiences.