Spatiotemporal symmetry and multifractal structure of head movements during dyadic conversation

J Exp Psychol Hum Percept Perform. 2009 Aug;35(4):1072-91. doi: 10.1037/a0015017.

Abstract

This study examined the influence of sex, social dominance, and context on motion-tracked head movements during dyadic conversations. Windowed cross-correlation analyses found high peak correlation between conversants' head movements over short ( approximately 2-s) intervals and a high degree of nonstationarity. Nonstationarity in head movements was found to be positively related to the number of men in a conversation. Surrogate data analysis offsetting the conversants' time series by a large lag was unable to reject the null hypothesis that the observed high peak correlations were unrelated to short-term coordination between conversants. One way that high peak correlations could be observed when 2 time series are offset by a large time lag is for each time series to exhibit self-similarity over a range of scales. Multifractal analysis found small-scale fluctuations to be persistent, tau(q) < 0.5, and large-scale fluctuations to be antipersistent, tau(q) > 0.5. These results are consistent with a view that symmetry is formed between conversants over short intervals and that this symmetry is broken at longer, irregular intervals.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Female
  • Fractals*
  • Head*
  • Humans
  • Interpersonal Relations
  • Male
  • Midwestern United States
  • Models, Theoretical
  • Movement / physiology*
  • Nonverbal Communication*
  • Sex Factors
  • Social Dominance*