Showing papers in "Electroencephalography and Clinical Neurophysiology in 1996"

TL;DR: It is argued that the N2pc component that is assumed to indicate attentional filtering processes during visual search tasks may reflect the attentional selection of task-relevant stimuli and that this component is also elicited when targets are presented together with just one non-target item.

TL;DR: Post-movement beta (around 20 Hz) synchronization was investigated in 2 experiments with self-paced finger extension and flexion and externally paced wrist movement and is interpreted as a correlate of "idling" motor cortex neurons.

TL;DR: It is concluded that the N2 reflects either the detection or the inhibition of an inappropriate tendency to respond, as well as the lateralized readiness potential, in go and nogo trials.

TL;DR: Re-examination of single channel EEG data obtained from normal human subjects suggests that the previous indication of low-dimensional structure was an artifact of autocorrelation in the oversampled signal, and discriminatory analysis indicates that the correlation dimension is a poor discriminator for distinguishing between EEGs recorded at rest and during periods of cognitive activity.

TL;DR: It can be concluded that nonlinear measures yield additional information, which improves the able to discriminate sleep stages and which may in general improve the ability to distinguish different psychophysiological states.

TL;DR: A psycholinguistic processing model of picture naming is related to the dynamics of cortical activation during picture naming, showing a clear progression over these time windows from early occipital activation, via parietal and temporal to frontal activation.

TL;DR: Specific age effects on different ERP components were confirmed andMultichannel analysis demonstrated that ERP latencies and amplitudes depended on electrode location, while N1 amplitude distribution was unaffected by age.

TL;DR: Simulation experiments showed that the information content of scalp-recorded potentials was clearly better when the RL estimator computed the SL of the potential on an MR-constructed scalp surface model.

TL;DR: The findings suggest that the second somatosensory area contralateral to the stimulation is the first involved in the building of pain-related responses, followed by ipsilateral second somatic area and limbic areas receiving noxious inputs from the periphery.

TL;DR: It is speculated that the high-frequency oscillations represent a localized activity of the GABAergic inhibitory interneurons of layer 4, which have been shown in animal experiments to respond monosynaptically to thalamo-cortical input with a high- frequencies burst of short duration spikes.

TL;DR: High resolution evoked potentials, sampled from 115 channels and spatially sharpened with the finite element deblurring method, were recorded from 8 subjects during working memory and control tasks and indicate that WM is a function of a distributed system with both task-specific and task-independent components.

TL;DR: During spinal surgery, motor evoked potentials were recorded from distal upper and lower limb muscles following multipulse transcranial electrical stimulation of the cortex using propofol +/- nitrous oxide, which is believed to be an advance over previously reported non-invasive techniques for peroperative MEP monitoring.

TL;DR: A simple approach to calculating time courses of coherence for data recorded during an event-related paradigm was demonstrated and it was demonstrated that ERCoh can provide information regarding the dynamic interaction of spatially separated brain regions.

TL;DR: Based on known effects of the ISI on intracellular evoked potentials, the following tentative model is presented for the generation mechanism of the SMI response: N20m represents early excitatory postsynaptic potentials (EPSPs), P35m early inhibitory post synapses (IPSPs), N45m secondary EPSPs and P60m late IPSPs in pyramidal neurones of area 3b.

TL;DR: Ten female patients with fibromyalgia syndrome investigated with laser evoked potentials after hand stimulations and compared with 10 female pain-free and age-matched control patients exhibited significantly lower heat pain thresholds than controls and had higher amplitudes of LEP components N170 and P390 in response to intensities of 20 W.

TL;DR: The findings suggest that the surface diameters of domains of spatially correlated activity underlying perceptual categorization in human gamma band ECoG are limited to less than 2 cm and that the intermittent synchronization observed across separations of 1 cm and 1.4 cm is not solely due to volume conduction.

TL;DR: A strong relationship was observed between the presence of REDs on scalp EEG and the occurrence of CEDs on ECoG recordings, which indicates that focal cortical dysplastic lesions are likely to be present when rhythmic epileptiform discharges are found.

TL;DR: The results suggest that the ERD phenomenon is closely associated with higher cortical processes such as memory functions rather than with auditory stimulus processing per se and provides a potentially valuable tool for studying cortical activity during cognitive processing in the auditory stimulus modality.

TL;DR: The results confirm the hypothesis that after a jump in the brain dynamics complexity during puberty a linear increase with age is observed, and the "wisdom of old age' may find its neurophysiological basis in greater complexity of brain dynamics compared to young ages.

TL;DR: This study with a large number of subjects was able to statistically distinguish two adjacent cortical sources, located on opposite walls of the central sulcus, and within a few millimeters of each other.

TL;DR: An algorithm for automated seizure detection using the self-organizing map (SOM) neural network (NN), with unsupervised training, was used to detect seizures in 24 long-term EEG recordings, showing a promising direction in the combination of rule-based detection criteria employing contextual parameters and un supervised training of NNs to recognize time-frequency patterns.

TL;DR: The relation between scalp-recorded movement-related activity, intracranially recorded potentials, and findings from functional imaging studies of voluntary movement, appears more transparent than suggested by previous dipole source analyses of premovement potentials.

TL;DR: The early temporo-parietal asymmetry of the EEEG most probably reflects an interface between sensory and movement-related processes.

TL;DR: It is indicated that non-linear dynamics analysis is suitable for measuring complexity of brain activity during maturation and provides age-dependent normal values as a basis for further study.

TL;DR: It is suggested that BP receives contribution from the early bilateral activation of the crown of the precentral gyrus, whereas RF reflects later activity of the fissural motor cortex in healthy adults.

TL;DR: Results indicate that distinct patterns of high-frequency cortical responses correspond to the different cognitive processes invoked by words and pseudowords, and it is hypothesized that differential high- frequencies signal the activation or activation failure of distributed Hebbian cell assemblies representing words and other elements of cognitive processing.

TL;DR: It is concluded that both the correlation dimension and the mutual dimension are very sensitive to EEG changes during simple visual information processing and during mental arithmetic.

TL;DR: Methods of localizing functional regions of the mesial wall are described, based on 47 patients studied intraoperatively or following chronic implantation of subdural electrodes, which revealed a rough somatotopic organization within the SMA and little evidence of the "pre-SMA" region described in monkeys.

TL;DR: The LEP of targets, frequent non-targets and during distraction was dominated by a single large positivity, which was task-dependent and increased the more attention the subject payed to the laser stimuli.

TL;DR: It is suggested that N100mA may index the activity of two distinct processes in auditory sensory memory, whose time constant is such that sensation persists for 200-300 msec after stimulus offset, and so serves as a short memory store.