Stimulus specificity of P300

: P300 recordings are valuable and noninvasive neurophysiological research tool to gain further insight into higher cerebral function. Due to methodological and technological restrictions the clinical applicability 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 P300 averagings for target and related nontarget events were recorded during spatial and verbal stimulation. Topographical brain electrical activities 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 correlated. Our data indicate significant differences between various topographical 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.