Infant Behavior and Development, 27, 315-322.
Asymmetry for the perception of expansion/contraction in infancy.
*Shirai N. ** Kanazawa S. & * Yamaguchi M.K.

* Department of psychology, Chuo University, Tokyo, JAPAN
** Department of psychology, Shukutoku University, Chiba, JAPAN

Abstract
We examined the developmental process of the sensitivity to expansion and contraction with two separate experiments. In the present study, 121 2- to 8-month-old-infants were participated. In the expansion search condition, 58 infants were exposed to a display consisted of an expansion (target) and 11 contractions (distractors). In the contraction search condition, the other 63 infants were exposed to a display consisted of a contraction (target) and 11 expansions (distractors). The results showed that in the expansion search condition the infants except for 2-month-olds show significant preference for the target. The sensitivity (or insensitivity) to expansion (or contraction) over 3 months of age observed in the present study is similar to the asymmetry for the perception of expansion/contraction [T. Takeuchi, Visual search of expansion and contraction, Vision Res. 37 (1997) 2083-2090]. The relation between the development of the asymmetric perception of expansion/contraction and that of the cortical pathway was discussed.

Keywords: Expansion/contraction; Asymmetry; Infants; The dorsal pathway

- Click on the links down below to see the demonstrations of the stimuli from our paper entitled 'Asymmetry for the perception of expansion/contraction in infancy'.

The Expansion Search Condition

The Contraction Search Condition