Hemispheric lateralization in aging: interest of the verbal-manual concurrency paradigm.

Introduction: The aim of this study was to evaluate whether the classic asymmetry seen in hemispheric functioning is modified in older adults by using a verbal-manual concurrency task.

Method: Thirty-five right-handed participants divided into two groups according to age (15 older participants, mean age: 68 ? 8 years, without cognitive decline and 20 younger participants, mean age: 23 ? 2 years) had to perform a 30-second uni-manual tapping task, in both a single task (tapping alone) and dual task (tapping and performing a letter fluency task together) condition.

Results: In younger participants, the letter fluency task disrupted the right hand more than the left hand whereas, in older participants, the letter fluency task disrupted both hands equally.