Changes in Event-Related Potentials Related to Pattern Recognition of Teeth in Dental Students

Abstract

　This study investigated brain cognition using P300 for fundamental examination of information-processing modes generated in tooth, script, and hand discrimination by dental students. Subjects were 19 second-year dental students. The task was to differentiate a tooth, script character, or hand in each of a rotated series of line drawings. Images were presented at random using the oddball paradigm with a target-to-non-target ratio of 2: 8,with the subject instructed to press a button only on observation of the target stimulus. Correct answer rate, reaction time, P300 amplitude, and P300 latency were analyzed using electroencephalography (EEG). Results of EEG were divided into waveform components,feature extraction of the waveform was performed, and the relevance of presented orientation was examined.
　Reaction time was longest for the 180° orientation with all tasks. No differences in P300 latency were seen by presented orientation for any task, but P300 amplitude was smallest at 180° for all tasks. Script characters and hands at 0° were easily discriminated, but tooth did not show any orientation difference.
　These findings suggest that discrimination in script and hand tasks was performed by top-down processing and bottom-up processing efficiently, and that discrimination in tooth task was intentionally performed in a bottom-up manner.