Dual-Task Performance with Center-Surround Auditory-Only Displays

摘要

Investigations of possibly parallel dual cognitive decision behavior usually are designed so that the stimulus sensory channels for the dual tasks are independent. Experiments with dual audio-visual stimuli had interference delays of only 5-10ms and less than 1% errors by the best performers. This study used a dual decision paradigm but with auditory-only stimuli organized in a 'centersurround' presentation. 'Surround' stimuli were shaped white noise pulses presented over a headset in dichotic mode so as to be localizable in the space outside the listener's head. 'Center' stimuli were spoken words presented in diotic mode localized inside the head. Responses to the externalized sounds were made by button presses while memorized verbal responses were required for the internalized words. The best performers with this auditory-only organization had mean interference times of about 20ms with nearly 10% error rate. For these conditions, the center-surround arrangement did not support 'virtually perfect' dual decision-making as well as the auditory-visual presentation. Further testing is planned with a simplified verbal task.