STIMULUS SPECIFICITY OF P300

P300 recordings are a valuable and noninvasive neurophysiological rese arch tool to gain further insight into higher cerebral function. Due t o methodological and technological restrictions the clinical applicabi lity of these investigations for neuropediatric purposes was limited. To enhance the usefulness of this phenomenon for clinical practice in neuropediatrics a convenient, painless and short-lasting procedure was imperative. For this purpose we developed a visual priming technique to average P300 components in children. To estimate the sensitivity of this procedure two classes of modality-different stimuli were used to prime visual P300 recordings. Forty children were examined, while P30 0 averagings for target and related nontarget events were recorded dur ing spatial and verbal stimulation. Topographical brain electrical act ivities of match/mismatch events were compared by complex statistical MANOVA methods for each period to compute modality-specific components within the surface recorded P300 waveforms. Latency statistics were c orrelated. Our data indicate significant differences between various t opographical P300 distributions, showing a close relationship between the experimental priming period and the activity of distinct cortical regions involved in spatial-imagination and language processing.