Effect of selective attention on somatosensory evoked potentials in healthy people

The effect of selective attention on various waves of the somatosensory evoked potentials was studied in healthy people in the area of specific projection (sensorimotor) and the area of non-specific projection (occipital). Significant changes of the amplitude of waves with latency exceeding 55 msec were observed when attention was concentrated on the received stimulus (I and II group of subjects). In group I the process of attention concentration was associated with a phenomenon connected with the new yet unknown experimental situation (prevalence of amplitude increase), while in group II habituation was observed (prevailing amplitude fall). Waves M125 and N200 in the sensorimotor area and N200 and N235-255 in the occipital area seemed to be associated in a peculiar way with the process of attention concentration.