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Parietal neurophysiology during sustained attentional performance: assessment of cholinergic contribution to parietal processing

Broussard, John Isaac
http://rave.ohiolink.edu/etdc/view?acc_num=osu1190122494

Abstract Details

2007, Doctor of Philosophy, Ohio State University, Psychology.
There were three major aims of this dissertation, all of which pertained to neurophysiological correlates of sustained attention task performance in rats. The first aim was to examine whether the evoked neurophysiological responses of local field potential activity of the parietal cortex during the detection of signals and the rejection of nonsignals produces behavioral correlates similar to that of single unit activity. The second aim was to test whether removal of local cholinergic input to the PPC via infusion of a specific cholinotoxin reduces the signal-related increases in firing rate of PPC neurons. The third aim was to test whether unilateral cholinergic deafferentation of the medial prefrontal cortex of rats specifically reduced the responses of PPC in the presence of a visual distractor. In the first study, it was determined that visual signal recruited an event-related potential (ERP) similar to the P300, an ERP component found in human PPC during the detection of infrequent and unpredictable stimuli. Amplitude of the ERP varied as a function of signal duration. Analysis of the spectral content of the evoked response indicated increases in alpha power as a function of correct detection. In the second study it was determined that restricted loss of cholinergic input near the recording site significantly reduced the relative number of signal-related neurons in the PPC. This manipulation also increased the relative number of neurons responsive to the visual distractor, and increased the baseline firing rate of neurons initially activated by the signal. In the third study cholinergic deafferentation of mPFC did not reduce the number of neurons responsive to the visual signal, but analysis of the trial blocks indicated a specific impairment of these neurons to encode the signal in the presence of the distractor. Further, bilateral cholinergic deafferentation produced a side bias to the hit lever during distractor sessions. The results of these experiments suggest that cholinergic input to the PPC is necessary for the filtering of distractors and the optimization of signal-related activity, whereas cholinergic input to the mPFC of rats is specifically required to produce the behavioral flexibility to maintain task performance under attentional challenges.
Bennet Givens (Advisor)
154 p.
Psychology, Psychobiology
posterior parietal cortex; medial prefrontal cortex; attention; single unit activity; local field potentials

Recommended Citations

Citations

  • Broussard, J. I. (2007). Parietal neurophysiology during sustained attentional performance: assessment of cholinergic contribution to parietal processing [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1190122494

    APA Style (7th edition)

  • Broussard, John. Parietal neurophysiology during sustained attentional performance: assessment of cholinergic contribution to parietal processing. 2007. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1190122494.

    MLA Style (8th edition)

  • Broussard, John. "Parietal neurophysiology during sustained attentional performance: assessment of cholinergic contribution to parietal processing." Doctoral dissertation, Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1190122494

    Chicago Manual of Style (17th edition)

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© 2007, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.