Résumé
@#ObjectiveTo investigate if there were potential components similar to auditory mismatch negativity (MMN) in the visual modality.MethodsEvent-related potentials (ERP) of 15 healthy adults were tested. Subjects were demanded to complete shape-matching task and double-matching task under 4 kinds visual stimuli including no-difference (Nd), contour-difference (Cd), shape-difference (Sd) and double-difference (Dd).ResultsWithin P1-N1 latent period (100～140 ms), three kinds of deviant stimuli (Cd, Sd, Dd) elicited a positivity, mismatch positivity (MMP). MMP amplitude elicited by Dd was a sum elicited by Cd and Sd (single-difference).ConclusionIn the visual modality, MMP elicited by warp stimulus may be an element similar to auditory MMN and reflect auto-processing of brain to visual stimulus.
Résumé
@#ObjectiveTo explore the neural basis of visual completion for the occluded faces.Methods2 types of visual stimuli were presented randomly: pictures of complete faces,pictures of incomplete faces(the occluded part was the left-top quadrant).Subjects were instructed to perform a gender discrimination task while event-related potentials(ERPs) were recorded.ResultsCompared with complete faces,incomplete faces enhanced the amplitude of N1 on the occipito-temporal scalp bilaterally,with the right hemisphere advantage.The peak latency of N2 elicited by incomplete faces was delayed compared with that of complete faces.ConclusionThe enhancement of N1 is related to visual completion processing that requires additional time.
Résumé
@#ObjectiveTo explore the neural basis of visual completion for the occluded faces.Methods2 types of visual stimuli were presented randomly: pictures of complete faces,pictures of incomplete faces(the occluded part was the left-top quadrant).Subjects were instructed to perform a gender discrimination task while event-related potentials(ERPs) were recorded.ResultsCompared with complete faces,incomplete faces enhanced the amplitude of N1 on the occipito-temporal scalp bilaterally,with the right hemisphere advantage.The peak latency of N2 elicited by incomplete faces was delayed compared with that of complete faces.ConclusionThe enhancement of N1 is related to visual completion processing that requires additional time.