Source:http://linkedlifedata.com/resource/pubmed/id/15548215
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
10
|
| pubmed:dateCreated |
2004-11-19
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| pubmed:abstractText |
The purpose of this study was to identify the networks involved in the regulation of visual accommodation/vergence by contrasting the cortical functions subservient to eye-lens accommodation with those evoked by foveal fixation. Neural activity was assessed in normal volunteers by changes in rCBF measured with PET. Thirteen right-handed subjects participated in three monocular tasks: (i) resting with eyes closed; (ii) sustained foveal fixation upon a LED at 1.2 m (0.83 D); and (iii) accommodating alternately on a near (24 cm, 4.16 D) vs. a far (3.0 m, 0.33 D) LED alternately illuminated in sequential 2 s epochs. The contrast between the conditions of near/far accommodation and of constant foveal fixation revealed activation in cerebellar hemispheres and vermis; middle and inferior temporal cortex (BA 20, 21, 37); striate cortex and associative visual areas (BA 17/18). Comparison of the condition of constant fixation with the condition of resting with closed eyes indicated activation of cerebellar hemispheres and vermis; visual cortices (BA 17/18); a right hemisphere dominant network encompassing prefrontal (BA 6, 9, 47), superior parietal (BA 7), and superior temporal (BA 40) cortices; and bilateral thalamus. The contrast between the conditions of near/far accommodation with closed-eye rest reflected an incremental summation of the activations found in the previous comparisons (i.e. activations associated with constant fixation). Neural circuits activated selectively during the near/far response to blur cues over those during constant visual fixation, occupy posterior structures that include occipital visual regions, cerebellar hemispheres and vermis, and temporal cortex.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:status |
MEDLINE
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| pubmed:month |
Nov
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| pubmed:issn |
0953-816X
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
20
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
2722-32
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:15548215-Accommodation, Ocular,
pubmed-meshheading:15548215-Adaptation, Ocular,
pubmed-meshheading:15548215-Adolescent,
pubmed-meshheading:15548215-Adult,
pubmed-meshheading:15548215-Brain,
pubmed-meshheading:15548215-Brain Mapping,
pubmed-meshheading:15548215-Cues,
pubmed-meshheading:15548215-Eye Movements,
pubmed-meshheading:15548215-Functional Laterality,
pubmed-meshheading:15548215-Humans,
pubmed-meshheading:15548215-Male,
pubmed-meshheading:15548215-Middle Aged,
pubmed-meshheading:15548215-Photic Stimulation,
pubmed-meshheading:15548215-Psychomotor Performance,
pubmed-meshheading:15548215-Regional Blood Flow,
pubmed-meshheading:15548215-Tomography, Emission-Computed,
pubmed-meshheading:15548215-Vision, Ocular,
pubmed-meshheading:15548215-Visual Perception
|
| pubmed:year |
2004
|
| pubmed:articleTitle |
Functional neuroanatomy of the human near/far response to blur cues: eye-lens accommodation/vergence to point targets varying in depth.
|
| pubmed:affiliation |
Department of Ophthalmology, Karolinska Institute, Huddinge, Sweden. hrr@hig.se
|
| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
|