Relationship Between the Reaction Time and EEG Parameters During Judgments on the Correspondence of Delayed or Simultaneously Presented Images of Two Models

This study examined how judging whether the poses of two figures are the same in tasks with delayed and simultaneous image presentation affects the participants’ reaction times and electroencephalograms (EEGs). Eighteen university students performed a delayed task, in which an image of a doll was first presented for 3 sec followed by a second image of the doll, and a simultaneous task, in which images of two dolls were presented on the left and right sides of the monitor at the same time. The dolls were shown from the front and rear angles. The participants were instructed to judge whether the images were the same as accurately and quickly as possible, and the reaction times were recorded. EEG signals were recorded from Fp1, Fp2, F3, F4, C3, C4, P3, and P4. The reaction times in the delayed task were found to be shorter then those in the simultaneous task, and that these times for the 0° condition were shorter than for the 180° condition. The amplitudes of EEG responses at Fp1 and Fp2 were larger than those at other electrodes, and the responses in the right hemisphere during the 180° condition and the delayed task within the α1 frequency band were smaller than the responses at other electrodes. These results indicate that cerebral activity in the frontal region of the right hemisphere is associated with the judgment of correspondence or non-correspondence in spatial compatibility tasks.