Forensic Study on Objective Evaluation of Visual Acuity of Ametropia with the Event-related Potential P3

Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiological evidence for the objective evaluation of VA.Methods We recruited 32 participants with myopia-related ametropia.They reported no other ocular diseases and had an uncorrected VA of 4.0 in both eyes.We used the block letter“E”at different visual angles and orientations as the graphic stimuli.The oddball paradigm,consisting of 4 modules,was used for ERP analysis.The standard stimuli of each module were identical,with a visual angle of 1°15′.The visual angles of the target stimuli were 1°15′,55′,24′,and 15′.The VA test was performed on each eye separately for all participants,and all characteristics of the P3 component were analyzed.Results There was no significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 55′group,or between the target stimulation angle 24′group and the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 24′group as well as the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 55′group and the 24′group as well as the 15′group.No significant differences were observed in the P3 amplitude between modules.Conclusion In the oddball paradigm,P3 elicitation indicated a cognitive response to the target stimuli.These data showed that the characteristics of P3 can be used as an objective evaluation of VA.

Behavioral inhibition in female college students with schizotypal traits: An event-related potential study

This study investigated behavioral inhibition in female college students with psychometrically defined schizotypal traits using a Go/NoGo task and event-related potentials (ERPs). The schizotypal-trait (n = 15) and normal control (n = 15) groups were selected based on scores of the Schizotypal Personality Questionnaire (SPQ). The Go/NoGo task consisted of Go (requires response) and NoGo (requires no response) conditions. In terms of response time and accuracy rate for the Go/NoGo task, the two groups did not differ significantly. In terms of ERPs, the control group showed greater N2 amplitudes in response to NoGo (NoGo-N2) than to Go stimuli (Go-N2), whereas the schizotypal-trait group showed no significant difference in NoGo-N2 and Go-N2 amplitudes. In addition, the schizotypal-trait group showed reduced NoGo-N2 amplitudes at the frontal site compared to controls, and an association between SPQ scores and NoGo-N2 amplitudes measured at the frontal site. The two groups did not differ in P3 amplitudes. Since the N2 reflects the detection of response conflict and behavioral inhibition, the present results indicate that nonclinical individuals with schizotypal traits have difficulties in detecting response conflict and behavioral inhibition.