Effect of patterned surfaces on infants crawling to mother.

Summary.-12 infants were placed on each of 6 stimuli which varied in complexiry. Ss tended to delay their approach to mother when placed on complexly patterned stimuli, and they remrned significantly less often to the complex stimuli after approaching mother. The results were interpreted in terms of perceptual exploratory behaviors interfering with crawling. Smith, Zwerg, and Smith (1963) reported that young infants use locomotor behaviors to control their perceptual environment, and Corter, Rheingold, and Eckerman (1972) found that infants delay following their mothers when a coy (3-dimensional complexity) is present. Assuming that patterned surfaces (2-dimensional complexity) on which infants crawl evoke perceptual exploration which interferes with locomotor behavior, it was expected that the delay in crawling to mother would be an increasing function of the complexity of the patterns. The frequency of leaving and returning to the patterned surfaces was expected to be an increasing function of their complexity, since Cortec, et al. (1972) speculate that infants crawl to complex stimulation. Method.-Twelve 8-mo.-old Caucasian infants (6 of each sex) served as Ss. The surface patterns (cloth sheets, 2.0 X 2.6 m., painted in black acrylic paint) were (listed in order of increasing complexity) : (a) Plain Control: a white sheet; (b) Two-stripe: 2 black parallel stripes (.3 m. wide, .6 m. apart, and centered and transversing the length of the sheet); (c) Border: a .3-m.-wide border located on the edge of the sheet; (d) Bordercenter: a border plus a rectangle (.3 X .7 m.) in the center of the sheet; (e) Double-twostripe: 2 pairs of parallel stripes, with each pair perpendicu!ar to the other; and (f) Complex: a center, border, and a checkerboard pattern between the center and border. The mother and S were escorted to an empty, unfamiliar room. The mother was instructed to (a) place S on his hands and knees in the center of a pattern on the floor (his head was directly over a small "x" marked in the center of a smooth protective plastic covering, through which a pattern could not be felt), (b) step back from S and stand 1 m. from a corner of the stimulus, within S's view. E stood 2 m. from the mother, started a stop watch, and signaled a trained observer (behind a one-way mirror) to begin recording the behaviors of S. Each S was placed on each of the 6 stimuli for 1 min. and the stimuli were presented in a semi-random order. After each stimulus period, the mother was asked to pick up S while one stimulus was replaced with another (the interval was 2 rnin.). Results.-Behavior records were scored for (a) latency from the beginning of a stimulus period to leaving a stimulus and (b) frequency of leaving a stimulus, e.g., after S initially left a stimulus, he might rerurn, then Leave again-this would be counted as 2 responses. The median latency for leaving and frequency of leaving are presented in Table 1. The Friedman non-parametric analysis of variance applied to (a) the latency data showed no significant effect of complexiry of the surface stimuli (p > .lo), but (b) the frequency data showed a significant effect of complexity (X2 = 11.1, fl < .05). Subsequent comparisons of the 5 patterns with the Plain Control stimulus (Wilcoxon test for