Abstract
When two people are engaged in a conversation and feel they understand each other's perspectives, they often describe their experience as "on the same wavelength." During these interactions, people tend to automatically mirror one another's gestures and facial expressions. It has recently been shown that this overt behavioral mimicry is correlated with increased interpersonal neural synchrony, especially in alpha-band (~10Hz) oscillations. Building on this line of work, we investigated a causal link between interpersonal alpha-band synchronization and visually guided behavioral coordination. Using electrocorticography we verified that amplitude-modulated sounds generate widespread cortical alpha-band oscillations (well beyond the auditory cortex) phase-locked to the amplitude modulation. We therefore used amplitude-modulated sounds to generate interpersonally synchronized or desynchronized alpha-band oscillations. A pair of individuals sat face-to-face and tried to finger-tap as synchronously as possible by visually observing each other's tapping behavior. On each trial, the interacting individuals were either synchronized in their alpha-band oscillations (e.g. heard identical auditory alpha rhythm) or desynchronized in their alpha oscillations (e.g. heard slightly different auditory alpha rhythms, generating alpha-band oscillations that are continuously phase-shifting between the two individuals). We show that the pair's visual-motor coordination was enhanced (i.e., they tapped in greater synchrony) when their alpha oscillations were synchronized. We verified that this effect is not explained by direct entrainment of tapping to the rate or phase of amplitude-modulated sounds. We further showed that hearing the same alpha-band amplitude-modulated sound does not increase the temporal correlation between individuals' responses to the same computer-generated rhythm. Taken together, these results suggest that interpersonal alpha-band neural synchronization facilitates visual processes that guide interpersonal visual-motor coordination. Thus, when people are truly "on the same wavelength," they have improved visual coordination as a result.
Meeting abstract presented at VSS 2014