| Abstract: | For each of 2 sex-balanced groups of 3.5-mo-old infants (N = 24), illumination of a black and white slide with either a 2 * 2 or a 24 * 24 checkerboard pattern was made directly proportional to the momentary rate of nonnutritive sucks greater than a predetermined criterion. A noncontingent baseline period of responding was followed by several minutes of conjugate sucking. Sucking performance was assessed by (a) the number of minutes to reach the decrement criterion (satiation time), (b) the rate of criterion sucking, and (c) the proportion of sucks which exceeded the amplitude criterion. Results indicate that check density did not differentially affect the sucking performance on any of the measures; sex of the S was significantly related to performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
