Publication Date


Document Type


First Advisor

Corwin, James V.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Psychology


Cerebrovascular disease--Treatment; Neglect (Neurology)--Treatment


Common effects of bilateral posterior parietal cortex (PPC) stroke include devastating allocentric spatial deficits. Unilateral PPC stroke produces not only deficits in allocentric spatial processing, but also a complex array of debilitating neurologic deficits known as hemispatial neglect. Spontaneous recovery and therapeutic treatments typically result in only incomplete recovery of spatial function. A rat model of the allocentric spatial processing deficits and of hemispatial neglect has been developed that demonstrates dramatic behavioral, anatomic, and pharmacologic similarities to the human condition. Studies suggest that an environmental manipulation, 48 hours of light deprivation (LD), produces dramatic, long-term recovery from neglect induced by unilateral PPC lesions. However, at this point, there have been no investigations regarding recovery of function from the allocentric spatial deficits following PPC destruction. Therefore, the present study was designed to empirically assess the effects of light deprivation from neglect and the allocentric spatial processing deficits following both bilateral and unilateral PPC damage. Overall, the results from the current study provide only minimal support for the role of PPC in neglect and allocentric spatial processing. In general, statistical analyses indicated that neither bilateral nor unilateral lesions of the PPC produced the severe deficits in neglect or in the allocentric spatial processing tasks that have been documented in the literature. Because the current study was unable to produce deficits following PPC damage, it also failed in its ability to assess the effects of LD on these deficits. In general, LD did not appear to affect performances in the allocentric spatial tasks. However, it should be noted that in the small subset of animals that did demonstrate severe neglect, LD was effective in producing significant recovery. Further research is needed to better analyze the possible effects of LD on neglect and allocentric spatial deficits following PPC deficits. Modifications from the current experiment in inclusion criteria and/or testing procedures may provide valuable information regarding the role of PPC and the therapeutic effectiveness of LD.


Includes bibliographical references (pages [208]-223).


xii, 223 pages (some color pages)




Northern Illinois University

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