Biological Psychology

Abstract

An experiment was carried out on 345 participants in a within- subject design, to determine the quantity of balancing interference between the left and right hand while carrying out dual task performances, for both verbal and silent conditions. Participants placed a wooden dowel on the index finger of both the left and right hand until the rod either fell to the floor or came into contact with the body. Balancing times were recorded in seconds and performance was measured on the amount of interference between verbal and silent conditions. Results indicated a significant difference between both hands with the greatest interference for the right hand under verbal conditions. Previous studies have indicated that this higher balancing interference in the right hand may have been caused by the left hemispheric specialisation in speech.

Effects of Dual Task Performance in a Manual Verbal Task Combination

There is a growing amount of research that reports loss of efficiency in normal people when performing two or more tasks simultaneously (Kinsourne & Cook 1971). Hemispheric sharing of function notion implies performing a dual task concurrently will require the sharing of functional resources within the left hemisphere, which would produce a higher level of interference (McGowan & Duka, 2000). This experiment is designed to examine an issue in hemispheric specialisation using a dual task procedure. It is hypothesised that balancing interference will be greater in the verbal condition of sounding out every other letter of the alphabet whilst maintaining control of the rod, compared to the silent condition of balancing the dowel rod. It is also hypothesised that interference will be higher for the right hand in comparison to the left hand.

Hemispheric specialisation has many documented studies to date that gained interest from the modern split brain studies investigated by M.S.Gazaniga and colleagues (Gazzangia, 2002). The split brain...