Linked Life Data

7537197

Source:http://linkedlifedata.com/resource/pubmed/id/7537197

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-5-26
pubmed:abstractText
Evoked potentials (EPs) were recorded from 991 frontal and peri-rolandic sites (106 electrodes) in 36 patients during an auditory discrimination task with target and non-target (distractor) rare stimuli. Variants of this task explored the effects of attention, dishabituation and stimulus characteristics (including modality). Rare stimuli evoked a widespread triphasic waveform with negative, positive and negative peaks at about 210, 280 and 390 msec, respectively. This waveform was identified with the scalp EP complex termed the N2a/P3a/slow wave and associated with orienting. It was evoked by rare target and distractor auditory and visual stimuli, as well as by rare stimulus repetitions or omissions. Across most frontal trajectories, N2a/P3a/SW amplitudes changed only slowly with distance. However, large (120 microV) P3as with steep voltage gradients were observed laterally, especially near the inferior frontal sulcus, and clear inversions of the P3a were noted in the orbito-frontal and the anterior cingulate cortices. The frontal P3a was earlier to distractor than to target stimuli, but only in some sites and with a latency difference much smaller than that observed at the scalp. Frontal P3a latencies were significantly shorter than those recorded simultaneously at the scalp and often were also shorter than P3a latency in the parietal or temporal lobes. In summary, this study demonstrates an early P3a-like activity that polarity inverts over short distances in the medial frontal lobe, and that it has a significantly shorter latency than similar potentials recorded in the temporal and parietal cortices.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0013-4694
pubmed:author
pubmed:issnType
Print
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
251-64
pubmed:dateRevised
2008-9-9
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Intracerebral potentials to rare target and distractor auditory and visual stimuli. III. Frontal cortex.
pubmed:affiliation
INSERM U97, Centre Paul Broca, Paris, France.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't