Brain evoked potentials of 3‐D auditory stimuli

Abstract

For evaluation of spatial cognitive function, we studied the brain evoked potentials (EP) of 3-D auditory stimuli in regard to the change of latencies in normal subjects aged 1-21 years and compared them with patients who have mental retardation (MR). A total of 144 normal subjects and 67 patients with MR were tested. The EP were elicited by 1000 Hz fixed and enlarged tones with Doppler effect randomly presented. No specific task was imposed in relation to the auditory stimuli. Electroencephalograms were recorded at the Fpz, Fz, Cz, Pz and Oz scalp locations (10-20 system), referenced to linked earlobes. The 64 responses of EP were averaged. The EP were measured from the difference in waveform by subtracting the EP of the fixed tone stimuli from that of the enlarged tone stimuli. The waveforms of EP consisted of the components P0, N1, P1, N2 and P2. These components (P0, N1, P1, N2 and P2) in the EP gradually shortened with increasing age in children. About 30% of patients with MR showed more prolonged latencies than normal subjects. These results suggest that these components indicated auditory kinetic evoked potentials. This developmental change could be related to maturational phenomena regarding spatial cognitive function. The EP of 3-D auditory stimuli may be used in children to evaluate the development of spatial cognitive function.