Movement Coordination during Conversation

<div><p>Behavioral coordination and synchrony contribute to a common biological mechanism that maintains communication, cooperation and bonding within many social species, such as primates and birds. Similarly, human language and social systems may also be attuned to coordination to facilitate communication and the formation of relationships. Gross similarities in movement patterns and convergence in the acoustic properties of speech have already been demonstrated between interacting individuals. In the present studies, we investigated how coordinated movements contribute to observers’ perception of affiliation (friends vs. strangers) between two conversing individuals. We used novel computational methods to quantify motor coordination and demonstrated that individuals familiar with each other coordinated their movements more frequently. Observers used coordination to judge affiliation between conversing pairs but only when the perceptual stimuli were restricted to head and face regions. These results suggest that observed movement coordination in humans might contribute to perceptual decisions based on availability of information to perceivers.</p></div

Example stimuli used in Experiment 2.

<p>A) Head-Only condition B) Head+Body condition C) Body-Only.</p

Mean affiliation score for full-body videos.

<p>Stimuli were calibrated to more clearly discriminate between high and low correlation levels. A greater score indicates a preference towards a judgment of ‘Friends’ and a lower score indicates preference towards a ‘strangers’ rating. Results replicate the results in the Head+Body condition in Experiment 2 where participants accurately discriminated between friends and strangers. Error Bars = Standard Error.</p

Mean correlation value for friends and strangers compared to a null distribution.

<p>Individuals in conversation, in general, shows significantly higher correlations than randomly paired motion, especially in the earlier lags closes to synchronous. Friends show significantly higher correlations than strangers at all lags.</p

Three-dimensional average correlation difference distributions for A) friends-strangers, B) random-pair subtractions and C) real-pair random subtractions.

<p>Redder colors indicate higher correlation differences along the x-axis with height indicating frequency of events. Lag counts (in frames) indicate 16 temporal points between 0 and 0.5 s where average correlation was computed. Greater positive peaks indicate more correlated events for friends in comparison to strangers.</p

Movement Coordination during Conversation - Figure 5

<p>A) Mean affiliation score collapsed across correlation levels as a function of true affiliation for the three conditions. A greater score indicates a preference towards a judgment of ‘Friends’ and a lower score indicates preference towards a ‘strangers’ rating. When both head and body information was presented, participants could discriminate between friends and strangers accurately. B) Mean affiliation score collapsed across affiliation category as a function of correlation level for the three conditions. When only head information was presented, participants assumed a ‘friends’ affiliation for high correlation and a ‘strangers’ affiliation for low correlation, even if this may have been erroneous. Error Bars = Standard Error.</p

Correlation map Analysis.

<p>This method was used to compute time-varying coordination between interlocutors. This method computes the correlation between a pair of signals as a function of both time and delay between the signals resulting in a 2D correlations map (Barbosa et al, 2012). Here, the top panel indicates the motion of the two individuals in red and black. The second panel shows instantaneous correlation with no time lag introduced (lag 0). The third panel shows that some coordination can only be captured by introducing a lag between the conversing individuals’ motion. The red color indicating higher correlation demonstrates how conversations change and evolve in the amount of coordination present.</p