Effects of Discrimination of Perceptual Objects by Cognitive Speech Acts on the Reaction Time of Body Motion Focusing on a Perceptual Reaction Test and Brain Activity in Prefrontal Cortex

Abstract

There have been many reports that words are related to perceptions associated with body motion from the perspective of cognitive science, and it is equally clear that conscious word processing affects body motion of skills. On the other hand, the effect of word usage during motion on the perception associated with physical motion of skills has not been fully clarified. The purpose of this research is to empirically verify the effects of discrimination of perceptual objects by cognitive speech acts on the reaction time of body motion based on a perceptual reaction test and brain activity in the prefrontal cortex measured using near-infrared light. As a specific method, under the setting where the control task (CT) was defined as a subject 's saying "yes (hai)" regardless of whether a red or blue circle was displayed, whereas the target task (TT) was defined as a subject 'saying "red (aka)" when a red circle was displayed and "blue (ao)" when a blue circle was displayed, 30 able-bodied subjects were instructed to press down the space key only when a red circle was displayed to verify the differences in their reaction time between the two tasks. In addition, using the Near-Infrared Spectroscopy (NIS) system to measure brain activity, the brain activities of the subjects were compared between the two tasks based on changes in cerebral blood flow in their prefrontal cortex. Results showed that the reaction times of all subjects were significantly slower (t (1735) = 6.57, p< .05) in TT than in CT (at 5% level), that 16 out of 30 subjects had statistically slower reaction times in TT compared to CT, a hypothesis was supported. And the right brain activity in CT tended to be more activated than that in TT. The discussion suggested that TT compared to CT involved an additional judgment to discriminate perceptual objects by cognitive speech and therefore had slower reaction times due to the additional burden on the subjects' cognitive resources.