RÉSUMÉ
Objective To study the response characteristics of left and right brain to signals from left(LVF) and right(RVF) visual fields during cognitive activity. Method ERPs at 9 locations to LVF and RVF signals were compared in 23 normal subjects in 3 task conditions:looking forward only (VC); making switch response to target signals(T) only(SR); making switch response to T differentially(DR). Result (1)Significant difference in ERPs was found between that induced by LVF and RVF signals on left brain especially at frontal location(F5), which appeared as slow negative deflection induced by T and NT from RVF in SR and DR;(2) Condition-dependent unsymmetrical features between left and right brain were found: the slow potential at F5 was significantly more negative in T and contralateral spatial relation(i.e., left brain for RVF) but more positive in NT and ipsilateral relation than that at F6.Conclusion Signals with psychological meaning in RVF might cause more psychological load as suggested by the results obtained in this study.