Dual Task Performance: The Effects of Task Emphasis and Ear of Input

This experiment explored the lateralization of the processing of spatial and verbal information during dual-tasks. This study also investigated the relationship between right ear advantage and spatial ability, degree of handedness, and degree of familial handedness. Thirty-two male subjects performed a spatial rotation task and a dichotic listening task. During half of the dual tasks, subjects concentrated on both tasks equally. During the other half of the dual trials, 16 subjects emphasized the spatial processing task and 16 subjects emphasized the dichotic listening task. The results of this experiment do not support either the independent-hemispheric resources or the task-hemispheric integrity theorization of the lateralization of information processing. The degree of handedness, and the degree of familial handedness were predictor variables for right ear advantage. These two variables may explain some of the inconsistencies found in previous lateralization research.