Since ancient times, many masters have warned against using words when performing skills because it can cause a momentary delay. Also, there have been many reports that words are related to perceptions from the perspective of cognitive science, and it is equally clear that conscious word processing affects movement judgments. On the other hand, the effect of word usage during motion of skills on the reaction has not been fully clarified. The purpose of this study is to empirically verify the effects of color discrimination of perceptual objects by cognitive speech acts on the reaction time based on a perceptual reaction test and subjects’ kinesthetic impressions. As a method, under the setting where the control task (CT) was defined as a saying “yes (hai)” regardless of whether a red or blue circle was displayed on the screen, whereas the target task (TT) was defined as a saying “red (aka)” when a red circle was displayed and “blue (ao)” when a blue circle was displayed, 30 subjects were instructed to click the space key as quickly as possible only when a red circle was displayed to verify the differences of reaction time. In addition, as an exploratory approach, the brain activity of the prefrontal cortex was measured using a portable brain activity measurement device. As a result, to verify the equivalence of the accuracy rates for both tasks using a two one-sided tests was within the range of the pre-set equivalence threshold (Δ = ±5%), indicating that the difficulty levels of both tasks were equivalent. Next, the result of an analysis of the reaction times using a paired t-test showed a significant difference (at the 1% level) between CT and TT (t(29) = 5.71, p < .001). And regarding the number of people who answered the question about the kinesthetic impression of the speed of clicking the space key were analyzed using the chi-square goodness-of-fit test, the results showed that the distribution of the responses was statistically equal (χ²(2) = 1.40, p = .497). In addition, exploratory analysis of brain activity showed that the right prefrontal cortex was significantly more active in CT than in TT (t(29) = 2.22, p = .035). The discussion suggested that TT compared to CT involved a judgment for color discrimination of perceptual objects and had slower reaction times due to the additional cognitive processes. The results that the subjective kinesthetic impressions and the objective movement do not always match were also demonstrated, suggesting that the difference in speech act which the subjects are not aware of during movement may affect performance of skill. The brain activity of the prefrontal cortex examined was suggested that the rhythm of speech in CT was related to the activation of the right prefrontal cortex, which is responsible for controlling information for decision-making.