| Abstract: | 20 93–119 day old infants were presented with utterances varying in content or temporal structure that were contingent on fixation on a visual target. Treatment A consisted of utterances of equal duration and continually varying content. Treatment B consisted of utterances of slightly variable duration (temporal runs) and continually varying content. Treatment C included utterances organized in temporal runs and was composed of partial content variations (content runs). For Group AB, each A trial alternated with a B trial 4 times. For Group AC, each A trial alternated with a C trial 4 times. Half of the Ss in each group received Treatment A as their 1st trial; half of the Ss in Group AB received Treatment B; and half of the Ss in Group AC received Treatment C as their 1st trial. Group AB Ss showed a longer total fixation time than those of Group AC, with a more homogeneous distribution of number of fixations across treatments. Mean length of fixations was longer for Treatment A than B in Group AB, whereas Group AC showed a longer mean length of fixation for Treatment C relative to Treatment A. Those with Treatment B or C as their 1st trial looked more frequently at the target, and their decrease in looking time over trials showed a linear trend, whereas Ss with Treatment A at first displayed irregular decreases. These differences between groups and presentation orders suggest that 3-mo-old infants are sensitive to differences in linguistic material. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
