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Pharmacological Isolation of Cognitive Components Influencing the Pupillary Light Reflex
Joint Authors
Steinhauer, Stuart R.
Condray, Ruth
Pless, Misha L.
Source
Issue
Vol. 2015, Issue 2015 (31 Dec. 2015), pp.1-7, 7 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2015-05-24
Country of Publication
Egypt
No. of Pages
7
Main Subjects
Abstract EN
Cognitive operations can be detected by reduction of the pupillary light response.
Neurophysiological pathways mediating this reduction have not been distinguished.
We utilized selective blockade of pupillary sphincter or dilator muscles to isolate parasympathetic or sympathetic activity during cognition, without modifying central processes.
Pupil diameter was measured during the light reaction in 29 normal adults under three processing levels: No Task, during an easy task (Add 1), or a difficult task (Subtract 7).
At three separate sessions, the pupil was treated with placebo, tropicamide (blocking the muscarinic sphincter receptor), or dapiprazole (blocking the adrenergic dilator receptor).
With placebo, pupil diameter increased with increasing task difficulty.
The light reaction was reduced only in the Subtract 7 condition.
Dapiprazole (which decreased overall diameter) showed similar task-related changes in diameter and light reflex as for placebo.
Following tropicamide (which increased overall diameter), there was a further increase in diameter only in the difficult task.
Findings suggest two separate inhibitory components at the parasympathetic oculomotor center.
Changes in baseline diameter are likely related to reticular activation.
Inhibition of the light reaction in the difficult task is likely associated with cortical afferents.
Sustained sympathetic activity also was present during the difficult task.
American Psychological Association (APA)
Steinhauer, Stuart R.& Condray, Ruth& Pless, Misha L.. 2015. Pharmacological Isolation of Cognitive Components Influencing the Pupillary Light Reflex. Journal of Ophthalmology،Vol. 2015, no. 2015, pp.1-7.
https://search.emarefa.net/detail/BIM-1069662
Modern Language Association (MLA)
Steinhauer, Stuart R.…[et al.]. Pharmacological Isolation of Cognitive Components Influencing the Pupillary Light Reflex. Journal of Ophthalmology No. 2015 (2015), pp.1-7.
https://search.emarefa.net/detail/BIM-1069662
American Medical Association (AMA)
Steinhauer, Stuart R.& Condray, Ruth& Pless, Misha L.. Pharmacological Isolation of Cognitive Components Influencing the Pupillary Light Reflex. Journal of Ophthalmology. 2015. Vol. 2015, no. 2015, pp.1-7.
https://search.emarefa.net/detail/BIM-1069662
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1069662