Prefrontal Cortex Activation during Writing and Hand-Shape Changing Dual-Task Performance: A Near-Infrared Spectroscopy Study

Abstract

Aim: To clarify the characteristics of desktop dual tasks that cause dorsolateral prefrontal cortex (DLPFC) activation. Methods: Subjects (29 young adults and 22 middle-aged adults) performed three different combinations of dual tasks composed of a pencil and paper task (copying numbers or calculation) and a hand-shape changing task (in response to visual hints or self judgment). We measured brain activation using near-infrared spectroscopy. Results: Right DLPFC activation was significantly higher for the simplest dual task than the complex dual task with the younger group, whereas there was no significant difference between tasks with the middle-aged group. Task performance was higher in the younger group than the middle-aged group, whereas there was no difference in brain activation between the two age groups. Conclusion: A dual task including two of each task performed automatically could be used for training frontal lobe functions, and the difficulty level should be adjusted depending on age.