Abstract
Cooperative behavior, the ability of individuals to coordinate their actions toward shared goals, is fundamental to survival and social success across species. However, the mechanisms supporting cooperation and disruptions leading to social deficits in neurodevelopmental disorders such as autism spectrum disorder remain poorly understood. To address these questions, we developed a novel cooperation task in which rat pairs had to visit matching reward wells on paired spatial mazes under deterministic and probabilistic reward contingencies, utilizing dyads of littermate wild-type (WT) and
knockout (
) rats, a model of Fragile X syndrome. Both WT and
male rat pairs exhibited dynamic turn-taking with mixed leader-follower behavior for cooperation; however, WT pairs achieved significantly greater cooperation success than
pairs. WT and
pairs both successfully utilized a simple follower-tracking-leader strategy, resulting in slower asynchronous transitions between reward wells, with
pairs more reliant on this reactive strategy. WT rat pairs also exhibited a more efficient and flexible predictive cooperation strategy, requiring anticipation and coordination of optimal transition patterns with peers, resulting in faster synchronous transitions.
rats were unable to utilize this more efficient social reciprocity strategy of higher complexity, leading to deficits in adapting to the probabilistic reward condition and in cooperative behavior. These findings reveal distinct strategies of varying complexity for cooperation, demonstrate the existence of a complex predictive social reciprocity strategy in WT rats and it's disruption in a rat autism model, providing a foundation for investigating mechanisms underlying social interactions with relevance to neurodevelopmental disorders.
Successful cooperation requires monitoring others' actions and flexibly adjusting self-behavior, yet
cooperation and associated deficits in neurodevelopmental disorders such as autism remain unclear. Using a novel spatial cooperation task in rats, we identify hierarchical strategies that support cooperative behavior - a simpler follower-tracking-leader reactive strategy, and a more complex reciprocity-based predictive strategy that enabled synchronized coordination of actions with peers. While both WT and
rats exhibited the slower reactive strategy, only WT rats flexibly adopted more complex predictive strategies for efficient cooperation.
rats thus showed selective disruption in social reciprocity due to impaired ability to predict and synchronize with partner actions. These findings provide a novel framework for dissecting the behavioral and neural mechanisms underlying social cooperation.