Asymmetric interference between concurrent tasks: an evaluation of competing explanatory models

Area of Science:

• Cognitive Neuroscience
• Neuropsychology
• Human Performance

Background:

• Kinsbourne's functional cerebral distance model posits asymmetric interference between cognitive and manual tasks reflects hemispheric specialization.
• Alternative models include statistical bias, manual dominance, and a two-factor model combining distance and dominance.
• Previous research has not definitively resolved the underlying mechanisms of task interference.

Purpose of the Study:

• To evaluate competing models explaining asymmetric interference between concurrent cognitive and manual tasks.
• To determine if functional cerebral distance, manual dominance, or a combination explains interference patterns.
• To investigate the role of cognitive load and manual task difficulty in modulating interference.

Main Methods:

• Four experiments were conducted with right- and left-handed university students.
• Manual dominance was reversed by assigning the dominant hand to the more difficult manual task.
• Cognitive load of the nonmanual task was systematically varied within each experiment.

Main Results:

• The results did not support Kinsbourne's functional cerebral distance model or the alternative models.
• Observed asymmetries in performance were primarily attributed to tradeoffs between manual and nonmanual task execution.
• No significant evidence for hemispheric specialization or manual dominance as the sole explanatory factor was found.

Conclusions:

• Current models of cognitive-manual task interference require revision.
• Future research must measure performance on both tasks and ensure sensitivity to inter-task interference for accurate interpretation.
• Tradeoffs in performance capacity between concurrent tasks are a crucial factor in observed interference patterns.