Honors Theses
Date of Award
2004
Document Type
Undergraduate Thesis
Department
Chemistry and Biochemistry
First Advisor
Karen Sabol
Relational Format
Dissertation/Thesis
Abstract
Animal models of attention have been used by researchers to better understand the neurophysiological basis of attention, as well as attentional disorders such as Alzheimer’s Disease and ADHD. Acetylcholine has been found to play a significant role in the ability of subjects to maintain focused attention in studies evaluating both human and animal performance. Percent omissions committed, performance accuracy, and reaction time are variables that have been interpreted by researchers as measures of attention. An alternate method for evaluating attention has been proposed that is based on dividing overall reaction time into initiation time and movement time. The initiation time distribution is then subdivided into mode and skew. The primary purpose for this project was to evaluate initiation time distribution skew as a measure of attention distinct from the behavioral elements represented within the mode. Rats were evaluated using a twochoice reaction time task in the presence and absence of a flashing light above the center nose-poke hole. The effects of the visual distracter upon the mode and skew of the distribution were examined in the salient condition (chamber light off) and the non salient condition (chamber light illuminated). The visual distracter proved to be an effective challenge of attention, producing changes in both the initiation time mode and the initiation time skew. The significant effect of the distracter on both variables 111 prevented their dissociation, although the increase in skew appeared to be greater than the observed increase in mode. The results suggest that either 1) the mode and skew of reaction time distributions represent non-dissociable elements of behavior, or 2) the mode and skew represent distinct elements of behavior that were simultaneously affected by the visual distracter. A secondary purpose of this project was to study the effects of acetylcholine blockade on the initiation time distribution. The acetylcholine (muscarinic) antagonist scopolamine (0.03 mg/kg, 0.06 mg/kg, and 0.10 mg/kg) was administered prior to reaction time test sessions. This phase of the project is still in progress and will be reported elsewhere.
Recommended Citation
Damico, Karen Melissa, "The Effects of a Distractor on Reaction Time Tasks in Rats: Mode vs. Distribution Skew" (2004). Honors Theses. 1976.
https://egrove.olemiss.edu/hon_thesis/1976
Accessibility Status
Searchable text