Impaired Flicker Detection in Visual Fields Subserved by Non-Damaged Hemispheres
| Autor: | R. K. Majumder, Peter J. Chandler, Oscar A. Parsons |
|---|---|
| Rok vydání: | 1967 |
| Předmět: |
Communication
medicine.medical_specialty genetic structures business.industry Cognitive Neuroscience media_common.quotation_subject Flicker Experimental and Cognitive Psychology Audiology eye diseases Lateralization of brain function Arousal Visual field Neuropsychology and Physiological Psychology medicine.anatomical_structure Frontal lobe Cortex (anatomy) Perception medicine Psychology business N2pc media_common |
| Zdroj: | Cortex. 3:307-316 |
| ISSN: | 0010-9452 |
| DOI: | 10.1016/s0010-9452(67)80019-4 |
| Popis: | Summary Visual temporal acuity (flicker detection) throughout the visual field has been found to be a more sensitive indicant of brain dysfunction than standard visual field examinations. This finding may be largely due to non-specific and indirect effects of brain injury upon temporal resolving processes. If there were evidence for impaired flicker thresholds in visual fields subserved by uninjured cortex, the hypothesis of non-specific effects would be supported. The flicker detection thresholds for left and right visual fields at the 30° circle were compared for 50 non-brain-damaged S s, 18 left hemisphere damaged and 16 right hemisphere damaged S s. The brain-injured S s, who had temporal, parietal and frontal lobe damage, were selected on the basis of having clear-cut evidence for unilateral damage only, according to the best available neurological ratings. They manifested no visual field abnormalities by standard perimetry in the fields subsumed by the “unimpaired” hemisphere. The brain-damaged S , regardless of location of lesion, had a significant impairment in the perimetrically “spared” field. The impairment was about half that found in the field subserved by the injured cortex. Discussion of the possible effect of interrupted cross-hemispheric cortical and cortical-lower brain center reverberating circuits, emphasized the complexity of “central” factors in flicker perception. The sensitivity of measures of visual temporal acuity appears to be due to their reflecting the generalized dimension of arousal level as well as specific and focal deficits in visual functions. |
| Databáze: | OpenAIRE |
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