1. Functional neuroanatomy of the human near/far response of the visual system to blur cues: Fixation to point targets at different viewing distances
- Author
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José V. Pardo, Joel T. Lee, Scott R. Sponheim, Patricia Costello, Hans O. Richter, and Ying Han
- Subjects
Temporal cortex ,Monocular ,genetic structures ,business.industry ,Eye movement ,eye diseases ,Cerebral blood flow ,Cerebellar cortex ,Functional neuroanatomy ,Fixation (visual) ,Biological neural network ,Computer vision ,Artificial intelligence ,Psychology ,business ,Neuroscience - Abstract
The neural circuits associated with the human monocular near/far response (NFR) were studied in thirteen normal volunteers by changes in relative regional cerebral blood flow (rCBF) measured with H2 15O infusion and positron emission tomography (PET). Behavioral tasks were selected to differentially recruit relevant circuits in three states of activity: resting, fixating, and near/far accommodating. Neural networks selectively activated for eliciting the NFR to blur cues during constant visual fixation occupy posterior structures which include occipital visual regions, temporal cortex, cerebellar hemispheres and vermis. Of note, no significant activation occurred in prefrontal regions. The NFR recruited many regions already active during constant visual fixation, and it engaged circuits partly dissociable from those mediating other types of eye movements as well as those participating in visual fixation.
- Published
- 2000