Publication Type: Individual Poster
Abstract: Background and Aims: Visual habituation and dishabituation responses are assumed to reflect information processing abilities in infancy. Following the comparator model based on Sokolov (1963), two factors - speed of processing and discriminatory memory - contribute to individual differences in infant cognition and to the continuity in cognitive functioning from infancy to later ages. Thus, individual differences in habituation performance are assumed to reflect differences in speed of processing (i.e. encoding the habituation stimulus and forming a mental representation), whereas differences in dishabituation responses indicate discriminatory memory abilities (i.e. detecting the mismatch between mental representation and test stimulus). While the comparator model has been empirically supported by visual recognition studies presenting one stimulus for habituation, its validity is less clear with respect to categorization studies in which different habituation stimuli of the same kind are presented. The aim of the present study was to compare habituation responses across these two tasks, testing the same infants.
Methods: Two visual habituation tasks involving abstract geometric stimuli were developed: In a single-stimulus task, infants were habituated to one black-and-white star-shaped pattern presented repeatedly before a new stimulus of the same kind was presented at test. In a categorization task, infants were habituated to different exemplars from a category of similar shaped and colored objects (e.g. angular red-and-orange) and tested with an object from a category differing in color and shape (e.g. round blue-and-green). In a modified infant-control design, N = 41 five-months-olds and N = 36 seven-months-olds were tested with both types of task (order of tasks counterbalanced).
Key Results: Infants showed great variance in total looking times as well as in strength of habituation and dishabituation responses. Total looking times were significantly correlated between both tasks (5 months: r=.42, p<.01; 7 months: r=.60, p<.01). About two thirds of all infants (66.2%) showed a consistent habituation response (yes, no) in both tasks. For the single-stimulus-task, strength of habituation and dishabituation were positively related (5 months: r=.24, p=.07; 7 months: r=.43, p<.01). Corresponding relations were not found for the categorization task, however.
Conclusions: The positive relations between looking behavior in both tasks indicate some intra-individual consistency in information processing over different types of visual fixation tasks. Relations between habituation and dishabituation responses were found only for the visual recognition but not for the categorization task, suggesting that the processing of categorical stimuli might differ from the processing of a single repeated stimulus. Implications of these findings with respect to comparator theory will be discussed.