Relationship between Response Time and the Alpha Attenuation of Congruence Judgments in Two-model Imagery

In a mental rotation study, if the degree of the rotation angle of a visual stimulus becomes large, the response time for congruence judgment increases. Simultaneously, the cranial nerve becomes active. However, the relevance of the reaction response time to the same mental rotation angle degree conditions (e.g., the angle difference is 180o), and cranial nerve activity is unclear. Therefore, this study examined the relationship between the reaction time for congruence judgment in the degree of the rotation angle of the same visual stimulus, and the cranial nerve activity that resulted in alpha attenuation of the index. Twelve university students (seven male and five female; mean age = 20.3 years, standard deviation SD = 0.9) judged as quickly as possible whether two poses corresponded to each other or not. The angular difference between the two poses was 0o or 180o. The EEG signals were recorded from Fp1, Fp2, F3, F4, C3, C4, P3, and P4 electrodes according to the international 10-20 electrode system, and the frequency bands of α (8–13 Hz) was analyzed. The results showed the response time at 0o was faster than that at 180o, and the response time was correlated with the amplitude of P4 while judging at 180o. These results indicated that the 180o visual stimulus needs to be mentally rotated; the cranial nerve activity of the right parietal region increases when the response time is quick and the cranial nerve activity of the right parietal region become comparatively small.