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Turning attention towards or away from a painful heat stimulus is known to modify both the subjective intensity of pain and the cortical evoked potentials to noxious stimuli. Using PET, we investigated in 12 volunteers whether pain-related regional cerebral blood flow (rCBF) changes were also modulated by attention. High (mean 46.6 degrees C) or low (mean(More)
METHODS Auditory evoked potentials (AEPs) to the subject's own name and to seven other first names were recorded in ten normal adults during wakefulness, in both passive listening and active detection conditions, and during sleep stage II (SII) and paradoxical sleep (PS). All stimuli were disyllabic, equiprobable and presented in random order. RESULTS(More)
The somatosensory evoked potential negative components in the 100-150-ms range were studied under conditions where attention was directed either toward or away from the probe stimulus. An N120 component, not sensitive to spatial attention, appeared in all conditions, including the no-task condition. Its distribution was consistent with an origin in the(More)
Cortical areas responsive to somatosensory inputs were assessed by recording somatosensory evoked magnetic fields (SEF) to electrical stimulation of the left median nerve at wrist, using a 122-SQUID neuromagnetometer in various conditions of stimulus rate, attentional demand and detection task. Source modelling combined with magnetic resonance imaging (MRI)(More)
Thalamic and cortical activities are assumed to be time-locked throughout all vigilance states. Using simultaneous intracortical and intrathalamic recordings, we demonstrate here that the thalamic deactivation occurring at sleep onset most often precedes that of the cortex by several minutes, whereas reactivation of both structures during awakening is(More)
The aim of our study was to assess abnormalities in 5-hydroxytryptamine-1A (5-HT1A) receptor density in patients suffering from refractory temporal lobe epilepsy (TLE). Experimental data in animals show that 5-HT1A receptors are predominantly located in limbic areas, and that serotonin, via these receptors, mediates an antiepileptic and anticonvulsant(More)
Auditory evoked potentials (AEPs) to frequent (90%) and deviant (10%) tones were recorded during both wakefulness and all-night sleep in eight drug-free volunteers. During presleep waking (10:00-11:00 p.m.), deviant stimuli elicited, in all subjects, a prominent "P300" wave of parieto-central topography, culminating at 344 ms (average), which was absent in(More)
We used PET to study regional cerebral blood flow (rCBF) changes in nine patients with unilateral central pain after a lateral medullary infarct (Wallenberg's syndrome). All patients presented, on the abnormal side, a combination of hypaesthesia to noxious and thermal stimuli and allodynia to rubbing of the skin with a cold object (i.e. abnormal pain to(More)
The functional anatomy of perceptual and semantic processings for odors was studied using positron emission tomography (PET). The first experiment was a pretest in which 71 normal subjects were asked to rate 185 odorants in terms of intensity, familiarity, hedonicity, and comestibility and to name the odorants. This pretest was necessary to select the most(More)
In this study we used a repeated measures design and univariate analysis of variance to study the respective effects of ISI, spatial attention and stimulus detection on the strengths of the sources previously identified by modelling SEFs during the 200 ms following mentally counted left median nerve stimuli delivered at long and random ISIs (Part I). We(More)