Task-Hemispheric Integrity Effect: Level of Task Difficulty and Mental Workload in a Dual Task

The task-hemispheric integrity effect states that when a spatial and verbal task must be time-shared, superior performance would be obtained when the same hemisphere that processes information also controls the hand used to respond. The effect of increasing the level of task difficulty on an unstable tracking task on the concurrent performance of a dichotic listening task was investigated. The results indicated that performance on the unstable tracking task significantly deteriorated as task difficulty level increased in both single- and dual-task conditions. However, performance on both the unstable tracking task and the dichotic listening task was not influenced by hand used to respond, nor did the change in unstable tracking difficulty affect dichotic listening performance. Future research should consider using spatial tasks that require greater cognitive demand in processing and responding.