ABSTRACT AND FAMILIAR VISUAL TARGETS ELICIT SIMILAR P3 POTENTIALS

Objective: The event-related potentials (ERPs) are voltage changes recorded from the human scalp that are time-locked to sensory, motor or cognitive processes. The P3 potential is the most studied ERP component in cognitive electrophysiology. The P3 potential occurring in response to targets has a parietal topography in the oddball paradigm. The P3 potential is assumed to reflect selective attention and memory updating processes. In this study, we aimed to investigate the effects of abstract and familiar visual targets on the ERP responses. Material and methods: Fourteen healthy volunteers (ages between 19 and 23 years) participated in the study. ERPs were recorded with 30 electrodes (according to international 10/20 system) using a visual oddball paradigm. Blue square served as standards whereas equal-sized colorful pictures served as targets in the oddball paradigm. Target stimuli were divided into two groups: familiar objects and abstract pictures. The target ratio was 20%. Visual stimuli were presented on a computer monitor in a random series, 90 cm in front of the subject once every 2 s with 750 ms duration. Results: The amplitudes and latencies of ERP responses were measured and analyzed by repeated measures analyses of variance (ANOVA) for both target groups. Statistical analyses indicated that amplitudes and latencies of N1, N2, and P3 potentials were not significantly different between two target groups (p>0.05). Conclusion: Our results indicate that abstract and familiar visual targets elicit similar P3 potentials.