Selfies as Duplex Non-verbal Communication: Human—Media Interaction, Human—Human Interaction, Case Study, and Research Manifesto

The amygdala plays key roles in emotion and social cognition, but how this translates to face-to-face interactions involving real people remains unknown. Here we found that a patient with complete amygdala lesions lacks any sense of personal space. Furthermore, healthy individuals showed amygdala activation to close personal proximity. The amygdala may be required to trigger the strong emotional reactions normally following personal space violations, thus regulating interpersonal distance in humans.

Every day, millions of users interact in real-time via avatars in online environments, such as massively-multiplayer online role-playing games (MMORPGs). These online environments could potentially be unique research platforms for the social sciences and clinical therapy, but it is crucial to first establish that social behavior and norms in virtual environments are comparable to those in the physical world. In an observational study of Second Life, a virtual community, we collected data from avatars in order to explore whether social norms of gender, interpersonal distance (IPD), and eye gaze transfer into virtual environments even though the modality of movement is entirely different (i.e., via keyboard and mouse as opposed to eyes and legs). Our results showed that established findings of IPD and eye gaze transfer into virtual environments: (1) male-male dyads have larger IPDs than female-female dyads, (2) male-male dyads maintain less eye contact than female-female dyads, and (3) decreases in IPD are compensated with gaze avoidance as predicted by the Equilibrium Theory. We discuss implications for users of online games as well as for social scientists who seek to conduct research in virtual environments.

Functional cortical circuits for central executive functions have been shown to emerge by theta (~6 Hz) phase-coupling of distant cortical areas. It has been repeatedly shown that frontoparietal theta coupling at ~0° relative phase is associated with recognition, encoding, short-term retention, and planning; however, a causal link has not been demonstrated so far. Here we used transcranial alternating current stimulation simultaneously applied at 6 Hz over left prefrontal and parietal cortices with a relative 0° ("synchronized" condition) or 180° ("desynchronized" condition) phase difference or a placebo stimulation condition, whereas healthy subjects performed a delayed letter discrimination task. We show that exogenously induced frontoparietal theta synchronization significantly improves visual memory-matching reaction times as compared to placebo stimulation. In contrast, exogenously induced frontoparietal theta desynchronization deteriorates performance. The present findings provide for the first time evidence of causality of theta phase-coupling of distant cortical areas for cognitive performance in healthy humans. Moreover, the results demonstrate the suitability of transcranial alternating current stimulation to artificially induce coupling or decoupling of behaviorally relevant brain rhythms between segregated cortical regions. Copyright © 2012 Elsevier Ltd. All rights reserved.