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Eight right-handed adult humans underwent functional magnetic resonance imaging (fMRI) of their brain while a vibratory stimulus was applied to an individual digit tip (digit 1, 2, or 5) on the right hand. Multislice echoplanar imaging techniques were utilized during digit stimulation to investigate the organization of the human primary somatosensory (SI)(More)
Cortical activity due to a thermal painful stimulus applied to the right hand was studied in the middle third of the contralateral brain and compared to activations for vibrotactile and motor tasks using the same body part, in nine normal subjects. Cortical activity was demonstrated utilizing multislice echo-planar functional magnetic resonance imaging(More)
Assessing the size of objects rapidly and accurately clearly has survival value. A central multisensory module for subjective magnitude assessment is therefore highly likely, suggested by psychophysical studies, and proposed on theoretical grounds. Given that pain perception is fundamentally an assessment of stimulus intensity, it must necessarily engage(More)
To assess cortical activity during pain perception, regional cerebral blood flow (rCBF) studies were done in humans using single photon emission computed tomography (SPECT) with the radiotracer Tc99m-HMPAO and magnetic resonance imaging localization. Normalized SPECT data were analyzed by region of interest and change distribution. Contralateral(More)
Postherpetic neuralgia (PHN) is a debilitating chronic pain condition, yet there is a lack of knowledge regarding underlying brain activity. Here we identify brain regions involved in spontaneous pain of PHN (n=11) and determine its modulation with Lidoderm therapy (patches of 5% lidocaine applied to the PHN affected body part). Continuous ratings of(More)
The termination sites of the dorsolateral (DSTT) and ventral (VSTT) spinothalamic pathways were determined by using anterograde transport of horseradish peroxidase from the lumbar spinal cord in primates. One animal had no spinal cord lesion, while of two other animals, one received a midthoracic dorsolateral funiculus lesion, and the other received a(More)
Many lines of evidence implicate the somatosensory areas near the lateral sulcus (Sylvian fissure) in the cortical representation of pain. Anatomical tracing studies in the monkey show nociceptive projection pathways to the vicinity of the secondary somatosensory cortex in the parietal operculum, and to anterior parts of insular cortex deep inside the(More)
The properties of a new anterograde tracer, biotin-dextran (BD), are reported. Iontophoretic or pressure injections of BD in the spinal cord of rats and monkeys revealed terminal-like BD label in many regions of the brain. The BD label was visualized by an avidin-biotin reaction combined with diaminobenzidine, with and without nickel enhancement. This(More)
The incidence and response properties of nociresponsive neurons, their locations relative to spinothalamic terminals, and their relations to cytoarchitectonic borders were studied in the lateral thalamus of the squirrel monkey. Nociceptive neurons were found in ventral posterior inferior nucleus (VPI), in the lateral and medial nuclei (VPL and VPM) of the(More)
The gate control theory of pain (Melzack and Wall, 1965) suggests that tactile stimuli can decrease the perception of pain. We have found the reverse effect: Heat at levels that induce pain can substantially suppress tactile sensitivity, independently of shifts in attention or arousal. Ten human observers were stimulated by a tonic, pain-producing heat(More)