The effect of visual deprivation on pattern recognition in the rat

In 2 experiments the performances of light-reared (LR) and dark-reared (DR) 90-day-old rats were compared on a variety of transfer tests following acquisition of 3 pattern discriminations. Significant differences due to rearing condition were found in performance on a discrimination involving horizontal separations between pairs of vertical contours. No such differences due to rearing were observed during either acquisition or transfer testing of a discrimination involving pairs of mirror image oblique contours. Significant differences due to rearing were observed in acquisition of a discrimination between a checkerboard pattern and a similar pattern containing an irregularity and in performance on a subsequent series of transfer tests. The results suggest that the spatial integration necessary to discriminate basic as well as complex relational properties between linear elements involves mechanisms which require experience for their development and maintenance.