Curious Monkeys have Increased Gray Matter Density in the Precuneus

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Curiosity is a cornerstone of cognition that has the potential to lead to innovations and increase the behavioral repertoire of individuals. A defining characteristic of curiosity is inquisitiveness directed toward novel objects. Species differences in innovative behavior and inquisitiveness have been linked to social complexity and neocortical size . [18]. In this study, we observed behavioral actions among nine socially reared and socially housed capuchin monkeys in response to an unfamiliar object, a paradigm widely employed as a means to assess curiosity. . K-means hierarchical clustering analysis of the behavioral responses revealed three monkeys engaged in significantly more exploratory behavior of the novel object than other monkeys. Using voxel-based-morphometry analysis of MRIs obtained from these same subjects, we demonstrated that the more curious monkeys had significantly greater gray matter density in the precuneus, a cortical region involved in highly integrated processes including memory and self-awareness. These results linking variation in precuneus gray matter volume to exploratory behavior suggest that monitoring states of self-awareness may play a role in cognitive processes mediating individual curiosity.




Elsevier Ireland Ltd.

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Neuroscience Letters