Linked Life Data

1933233

Source:http://linkedlifedata.com/resource/pubmed/id/1933233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1991-12-26
pubmed:abstractText
The ability to maintain central-gaze fixation was studied in 35 patients with unilateral frontal lobe lesions. The stability of central-gaze fixation was tested in 2 oculomotor tasks requiring the suppression of reflexive saccades triggered by the sudden appearance of novel, peripheral visual stimuli. In the first task ('Instructed'), maintenance of gaze fixation was based on verbal instruction, whereas, in the second task ('Non-instructed'), it was based upon a foveating mechanism maintained by sensory stimulation during the performance of a categorization task. Patients with frontal lobe lesions were classified into 3 groups: a ventrolateral (n = 18), a dorsolateral (n = 10) and a medial (n = 7) group. The control group consisted of 20 healthy subjects. In the Non-instructed task, no group differences were found in the rate of reflexive saccades. Thus, lesions of the frontal lobe did not affect reactivity to extraneous stimuli per se. The only exception to this rule was the group of patients with ventrolateral lesions in the left frontal lobe, in which a higher number of reflexive saccades directed to the contralateral hemifield was observed. In the Instructed task, 2 different patterns of deficit in suppression of reflexive saccades were found. First, a bidirectional deficit was noted in the ventrolateral group, which might be attributed to an impairment in either maintaining a selected program of behaviour 'on-line' or suppressing inappropriate alternatives interfering with that program. Second, a unidirectional deficit in voluntary suppression of reflexive saccades triggered from within the contralateral hemifield was observed in the medial group. It is suggested that this type of deficit may reflect malfunctioning of the supplementary motor area--anterior cingulate system involved in the suppression of externally triggered interfering programs. Finally, no significant impairment was found in the dorsolateral group.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-8950
pubmed:author
pubmed:issnType
Print
pubmed:volume
114 ( Pt 5)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2051-67
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Medial vs lateral frontal lobe lesions and differential impairment of central-gaze fixation maintenance in man.
pubmed:affiliation
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't