If You Want to Remember a Landscape Be Sure to Include a Human....

Fascinating observations by Jimenez et al.  on our inherent human drive to understand our vastly social world...(and in the same issue of PNAS note this study on the importance of the social presence of either human or virtual instructors in multimedia instructional videos.)

Significance

Writer Kurt Vonnegut once said “if you describe a landscape or a seascape, or a cityscape, always be sure to include a human figure somewhere in the scene. Why? Because readers are human beings, mostly interested in other human beings.” Consistent with Vonnegut’s intuition, we found that the human brain prioritizes learning scenes including people, more so than scenes without people. Specifically, as soon as participants rested after viewing scenes with and without people, the dorsomedial prefrontal cortex of the brain’s default network immediately repeated the scenes with people during rest to promote social memory. The results add insight into the human bias to process the social landscape.

Abstract

Sociality is a defining feature of the human experience: We rely on others to ensure survival and cooperate in complex social networks to thrive. Are there brain mechanisms that help ensure we quickly learn about our social world to optimally navigate it? We tested whether portions of the brain’s default network engage “by default” to quickly prioritize social learning during the memory consolidation process. To test this possibility, participants underwent functional MRI (fMRI) while viewing scenes from the documentary film, Samsara. This film shows footage of real people and places from around the world. We normed the footage to select scenes that differed along the dimension of sociality, while matched on valence, arousal, interestingness, and familiarity. During fMRI, participants watched the “social” and “nonsocial” scenes, completed a rest scan, and a surprise recognition memory test. Participants showed superior social (vs. nonsocial) memory performance, and the social memory advantage was associated with neural pattern reinstatement during rest in the dorsomedial prefrontal cortex (DMPFC), a key node of the default network. Moreover, it was during early rest that DMPFC social pattern reinstatement was greatest and predicted subsequent social memory performance most strongly, consistent with the “prioritization” account. Results simultaneously update 1) theories of memory consolidation, which have not addressed how social information may be prioritized in the learning process, and 2) understanding of default network function, which remains to be fully characterized. More broadly, the results underscore the inherent human drive to understand our vastly social world.