Objective: 

The aim of this study was to determine the hemispheric differences of primer visual processing and P300 responses by using Visual Oddball Paradigm.

Methods: 

Ten healthy volunteers (5 male, 5 female) participated the study. Brain electrical activity (EEG) recorded by using WinEEG program (MITSAR) from 19 different locations. Volunteers are instructed to press a button every time when they see the blue square at the bottom of edge (target stimulus) and not to press button when they see the blue square at the top of the edge (standart stimulus). In average 330 stimuli were presented with percent 20 target stimulus (I.U. Ethics Commision File No: 2009/2648-43). Repeated measured ANOVA (SSPSS-PC 16.0) test is used for the statistical analysis.

Results: 

There was no significant difference on the amplitudes [F(1,9) = 2.918, p = 0.122] and latency [F(1,9)=0.289, p=0.604] of P300 responses between left and right hemisphere. On the other hand, the amplitudes of N100 component for left hemisphere were higher than in right hemisphere [F(1,9)=5.249, p<0.05] but there was no difference in latency of N100 component [F(1,9)=2.716, p=0.134]. Amplitudes of N100 component is especially higher at the centro-posterior region [F(7,63)=2.554, p<0.05].

Conclusions: 

The present study is important to show that the hemispheric properties of primer visual processing and also cognitive responses. This work was supported by scientific research projects coordination unit of Istanbul University. Project number 4965.