Four-day-old human neonates look longer at non-biological motions of a single point-of-light.

David Méary,Edouard Gentaz,Elenitsa Kitromilides,Christian Graff,Karine Mazens,Bernhard Baune

doi:10.1371/journal.pone.0000186

Abstract

BackgroundBiological motions, that is, the movements of humans and other vertebrates, are characterized by dynamic regularities that reflect the structure and the control schemes of the musculo-skeletal system. Early studies on the development of the visual perception of biological motion showed that infants after three months of age distinguished between biological and non-biological locomotion.Methodology/Principal FindingsUsing single point-light motions that varied with respect to the “two-third-power law” of motion generation and perception, we observed that four-day-old human neonates looked longer at non-biological motions than at biological motions when these were simultaneously presented in a standard preferential looking paradigm.Conclusion/SignificanceThis result can be interpreted within the “violation of expectation” framework and can indicate that neonates' motion perception — like adults'—is attuned to biological kinematics.

Highlights

The movements of humans and other vertebrates, form a class of salient visual stimuli [1,2,3]
The type of motion and the sequence were treated as within-subjects factors and the path shape was treated as a between-subjects factor
The type of motion and the sequence influenced the mean looking time (type of motion: F (1,49) = 4.97, p = .03; sequence: F (1,49) = 5.55, p = .022) but the effect of the path shape was not significant (F (1,49) = 0.23, p = .63). To resume these results: the neonates spent more time looking at the non-biological motions and they spent less time looking at the motions during the second sequence

Summary

Introduction

The movements of humans and other vertebrates, (i.e., biological motions) form a class of salient visual stimuli [1,2,3]. This was first observed by Johansson with his famous ‘‘point-light’’ paradigm [1]. He attached small lights to the joints of actors and filmed them executing different activities. Using single point-light motions that varied with respect to the ‘‘two-third-power law’’ of motion generation and perception, we observed that four-day-old human neonates looked longer at non-biological motions than at biological motions when these were simultaneously presented in a standard preferential looking paradigm. This result can be interpreted within the ‘‘violation of expectation’’ framework and can indicate that neonates’ motion perception — like adults’—is attuned to biological kinematics

Methods

Results

Conclusion