Microelectrode recordings in adult mammals have clearly demonstrated that somatosensory cortical maps reorganize following peripheral nerve injuries and functional modifications; however, such reorganization has never been directly demonstrated in humans. Using magnetoencephalography, we have been able to demonstrate the somatotopic organization of the hand area in normal humans with high spati...

An electrophysiological system for monitoring the spinal cord during operations for scoliosis is described. During the development of the technique the recording of cortical somatosensory evoked potentials from the scalp and spinal somatosensory evoked potentials from the laminae or spines was superseded by the positioning of recording electrodes in the epidural space cephalad to the area to be...

Three inferior prefrontal regions in the monkey receive afferents from somatosensory cortices: the orbitofrontal cortex (OFC), the ventral area of the principal sulcus, and the anterior frontal operculum. To determine whether these areas show responses to tactile stimuli in humans, we examined data from an ongoing series of PET studies of somatosensory processing. Unlike previous work showing v...

Although numerous anatomical and electrophysiological findings in animal studies have supported a hierarchical scheme of somatosensory processing, precise activation timings of each cortical area are not known. Therefore we examined the temporal relationship of activities among multiple cortical areas using magnetoencephalography in humans. We found activations in Brodmann's areas 3b, 4, 1, 5 a...

How are local motion signals integrated to form a global motion percept? We investigate the neural mechanisms of tactile motion integration by presenting tactile gratings and plaids to the fingertips of monkeys, using the tactile analogue of a visual monitor and recording the responses evoked in somatosensory cortical neurons. The perceived directions of the gratings and plaids are measured in ...

AIM In individuals with cerebral palsy (CP), cerebral insults during early development may induce profound reorganization of the motor representation. This study determined the extent of alterations in cortical somatosensory functions in adolescents with hemiplegic CP with subcortical brain lesions. METHOD We recorded somatosensory evoked magnetic fields in response to hand area stimulation f...

Recent anatomical, physiological, and neuroimaging findings indicate multisensory convergence at early, putatively unisensory stages of cortical processing. The objective of this study was to confirm somatosensory-auditory interaction in A1 and to define both its physiological mechanisms and its consequences for auditory information processing. Laminar current source density and multiunit activ...

Simultaneous early processing of sensory input in human primary (SI) and secondary (SII) somatosensory cortices. The anatomic connectivity of the somatosensory system supports the simultaneous participation of widely separated cortical areas in the early processing of sensory input. We recorded evoked neuromagnetic responses noninvasively from human primary (SI) and secondary (SII) somatosensor...