Development of intrasensory and intersensory integration in seven and nine year olds: role of spatial-temporal organization and memory requirements

Intersensory integration refers to an organism's ability to coordinate sensory information coming in from different modalities, permitting more flexible, adaptive behavior in a complex environment. It has been suggested that this capacity has a developmental component in man, and is functionally related to the emergence of increasingly complex, adaptive behaviors in the growing child. Using what has come to be called the cross-modal (C-M) pattern matching task, many studies demonstrated that auditory-visual (A-V) integrative ability is a sensitive indicator of human dysfunction in a wide variety of "at risk" populations (e.g., reading disabled, brain injured). The A-V integrative ability also showed age-related improvement. However, other studies questioned these results on both conceptual and methodological grounds. The present research emerged as an attempt to follow up on the more salient issues raised in these criticisms. The C-M task was examined in the context of the child's age, gender and specific task requirements such as memory and form of processing information (i.e., temporal vs. spatial organization of input).

Forty subjects, balanced for age and gender, were given four multiple-choice pattern-matching tasks (VS-VS, VT-VS, AT-VS, VTSch-VS) and a memory task (VADS). The data were analyzed using an Age (2) X Gender (2) X Task (4) analysis of variance with repeated measures on the Task variable, Tukey's post hoc mean comparisons and multiple regression analysis.

The results indicated that 9-year-olds performed more accurately than did 7-year-olds only on the AT-VS task, and males showed inferior performance compared to females only on the VT-VS task. The greatest percentage of variance in accuracy was accounted for by the shift from a spatial to a temporal standard in a within-modal (W-M) task (VS-VS vs. VT-VS) The shift from a W-M to C-M task also accounted for a substantial percentage of variance in accuracy, but only for 9-year-olds in the analysis by age and males in the analysis by gender (VT-VS vs. AT-VS). The AT-VS task was easier than the VT-VS task in these comparisons. Performance on the chunking task was not different from VS-VS performance, but was superior to VT-VS and AT-VS performance. A moderate relationship exists between memory (VADS) and AT-VS for the total sample, 9-year-olds and females.

Conceptual modifications are needed for intersensory integration to remain a useful theoretical construct in developmental psychology. It is concluded that behaviors requiring participation of more than one sense modality do require some additional explanatory mechanism beyond the developmental level within each separate modality. However, that additional mechanism cannot be a simplistic unitary process, but rather a complex constellation of mechanisms that vary according to age, gender and specific task requirements made on the organism. Improvements in auditory-visual integration do occur from ages 7 to 9, which cannot be explained solely on the basis of development in visual perception. There are no gender differences in performance accuracy on the auditory-visual task. There is, however, a suggestion of qualitative gender differences whereby females go about solving this task with a greater reliance on memory skills. The form of organization of stimulus input is an integral, inseparable part of the act of perceiving through any given modality. The fact that auditory information is temporally organized and visual information is spatial does not detract from the concept of auditory-visual integration. It is part of the complexity which must be incorporated into any meaningful notion of any kind of sensory integration (inter- or intra-).