Sex differences in reward- and punishment-guided actions

Abstract

Differences in the prevalence and presentation of psychiatric illnesses in men and women suggest that neurobiological sex differences confer vulnerability or resilience in these disorders. Rodent behavioral models are critical for understanding the mechanisms of these differences. Reward processing and punishment avoidance are fundamental dimensions of the symptoms of psychiatric disorders. Here we explored sex differences along these dimensions using multiple and distinct behavioral paradigms. We found no sex difference in reward-guided associative learning but a faster punishment-avoidance learning in females. After learning, females were more sensitive than males to probabilistic punishment but less sensitive when punishment could be avoided with certainty. No sex differences were found in reward-guided cognitive flexibility. Thus, sex differences in goal-directed behaviors emerged selectively when there was an aversive context. These differences were critically sensitive to whether the punishment was certain or unpredictable. Our findings with these new paradigms provide conceptual and practical tools for investigating brain mechanisms that account for sex differences in susceptibility to anxiety and impulsivity. They may also provide insight for understanding the evolution of sex-specific optimal behavioral strategies in dynamic environments.

Men Show Higher Neural Sensitivity to Wins – Large or Small – than Women in the Monetary Incentive Delay Task

“…In another EEG study of an incentive delay task, boys as compared to girls showed reduced stimulus-preceding negativity when anticipating punishment and greater feedback P3 to monetary than social reward (33). These findings are consistent with a literature of higher female sensitivity to loss, punishment or other negative feedback (27,34,35).…”

“…A study of multiple rodent behavioral paradigms reported no sex difference in reward-guided associative learning. However, females showed faster punishment-avoidance learning and, after learning, were more sensitive than males to probabilistic punishment but less sensitive when punishment could be avoided with certainty (27).…”

“…Biological, including hormonal, and socio-cultural factors may all account for sex differences in reward sensitivity and reward-directed behavior (26,27). Indeed, the literature has suggested a rather complex picture of sex differences in reward-related behavior and the neural processes underlying such differences.…”

Biological Sex and Sex Hormone Impacts on Deficits in Episodic-Like Memory in a Rat Model of Early, Pre-motor Stages of Parkinson's Disease

“…These variables require that study design and data interpretation be informed by known sex differences in key behaviors, and by the broad range of metabolic and motivational states that gonadal hormones modulate in sex-specific ways. These include prominent sex differences in and sex hormone impacts on, sensitivity to positive and negative reinforcement (80)(81)(82)(83)(84)(85)(86)(87)(88). Thus, while there are several options for laboratory testing of ELM in rodents (89)(90)(91)(92)(93), the WWWhen task was selected for its leveraging of rats' innate preference for novelty and spontaneous investigations of novel objects encountered in the environment (63,92).…”

A novel multidimensional reinforcement task in mice elucidates sex-specific behavioral strategies

“…In practical contexts, rewards are generally weighed with potential negative consequences (7), requiring consideration of the value of a reward and of associated aversive outcomes. Sex-based differences in reward seeking and avoidance -developed over evolutionary history -offer an ideal model to explore bias and strategy in a behavioral task while providing insight into the neurobiological basis of information encoding (8)(9)(10)(11)(12). Previous work has shown that the schedule under which a stimulus is presented is more of a behavioral determinant than the stimulus itself (13,14); while these principles laid the ground-work for behavioral neuroscience, many of these fundamental findings are no longer considered when developing and designing behavioral models in animals.…”