3 students and Dr.John Lefebvre

Senior Theses: 2004-2005

The Effect of Self-Awareness on Children's Peer Impression Formation
Kim Collins, Caitlin Johnston, Stephanie Ripberger, and Dotty Strobel
Faculty advisor: C. B. McAninch, Ph.D. 

Peer rejection has many harmful effects on children, and current intervention methods fail to adequately prevent negative consequences.  This study examines the effect of self-awareness and expectancy on peer perceptions of a target child in order to suggest future interventions.  Participants were assigned randomly to one of four experimental conditions:  self-aware/outgoing expectancy, self-aware/shy expectancy, not self-aware/outgoing expectancy, or not self-aware/shy expectancy.  Participants rated a target child both before and after watching him or her on videotape, and performed a free recall task following the videotape.  Results suggest that although prior expectancies are modified by the videotape, participants remain prone to recall expectancy-congruent information.  These results indicate that future interventions might involve methods of increasing self-awareness to eradicate peer rejection.

Pain and Catastrophizing:  The effects of a video manipulationStefanie Carrigan, Josh Simmons, Laura Robinson, and Aja’ Russell
Faculty Advisor: John C. Lefebvre, Ph.D.

Robinson and Wise (2004) recently found that prior experience of a painful experience made participants more accurate in estimating pain in others.  One factor that was not manipulated in the in the study was the degree of pain behaviors and catastrophizing that was demonstrated by the other in the video.  The focus of the current study was to assess whether a video manipulation had an effect on ratings of pain, catastrophizing, positive affect, and negative affect for both the participant and ratings of the same variables in others.  The study included 80 subjects randomly assigned to one of four conditions: catastrophizing video then cold-pressor task, non-catastrophizing video then cold-pressor task, cold-pressor-task then catastrophizing video, and cold-pressor task then non-catastrophizing video.  The results showed a significant effect in video condition for observed pain, catastrophizing, and negative affectivity ratings in the video confederate.  These results suggest that those who watched the catastrophizing video, regardless of sequence, rated higher levels of pain, catastrophizing, and negative affect in the confederate.  Thus, prior experience was not as significant as the pain behaviors and cognitions displayed by the confederate in the video.  These results are discussed in terms of the effect of observed catastrophizing on the ratings of pain behaviors in others and the effect of catastrophizing on the self rating of the experience of experimental pain.

The Role of Discriminative Stimuli in Response Sequences
Kim Collins, Erin Higgenbotham, Caroline Labban, and Meghan Lijewski
Faculty Advisor: Alliston K. Reid, Ph.D.

Ten rats were trained and tested on four-level response sequences for accuracy in responding to individual response components. Subjects were exposed to alternating light and tone sessions with alternating stimulus and no-stimulus trials within sessions. Data from two subjects were analyzed due to time constraints and insufficient data from the other subjects. Results demonstrate no significant improvement in accuracy given the tone stimulus. Given the light stimulus subjects responded more accurately in the absence of the stimulus, as though the light acted as some sort of distracter. The results obtained are not conclusive and should be viewed in light of the limitations of the experiment. This proved to be a successful pilot study with information on methodological improvements for future research.

The Role of the Chorda Tympani Nerve in the Gustatory Detection of Free Fatty Acids.
Leah Harris, Lauren Murchison, Sara Shields, Jennifer Wallace
Faculty Advisor: Dave Pittman, Ph.D.

Both the World Health Organization and the International Obesity Task Force have classified the prevalence of obesity as a global epidemic. The primary causes of obesity are sedentary lifestyles and high-fat diets. Such diets are preferred due to their high palatability. Fats are broken down into free fatty acids, such as linoleic and oleic acids. In order to determine the neural pathway responsible for transducing these free fatty acids, the chorda tympani nerve was examined. In this study, a conditioned taste aversion to linoleic and oleic acid was measured following chorda tympani nerve avulsion as demonstrated in a taste-salient assay by means of the Davis Rig.
Animals formed conditioned taste aversion to linoleic acid at concentrations exceeding 44 uM. After cutting the chorda tympani nerve, rats no longer avoided linoleic acid. No taste aversion to oleic acid was detected; therefore, a stimulus generalization between linoleic and oleic acids did not exist. A second experiment was conducted with intact chorda tympani nerve animals, which demonstrated an active avoidance to NaCl.
This study shows that rats are able to detect fat. Furthermore, the chorda tympani nerve is responsible for relaying taste information to the brain. It is understood that this animal model is applicable to humans. Therefore, in the future, this taste research could be useful in formulating dietary foods that are more palatable without high fat content. 

Stimulus Value in Higher-Order Autoshaping
Rachel Ashton, Lindsay Barnard, and Lizzie Davis
Faculty Advisor: Alliston K. Reid, Ph.D.

The present study was a follow up to Reid's (2003) experiment concerning why the initial response was more resistant to change than the terminal. By eliminating the operant contingencies from Reid's (2003) study, a higher-order autoshaping procedure was used to determine the difference in stimulus value between the initial and terminal stimuli. Also, a 30-sec inter-trial interval (ITI) was implemented as a disruptor for the resistance-to-change (RTC) manipulation. A second RTC manipulation used was prefeeding. This study found that by removing the operant contingencies and keeping the Pavlovian contingencies constant (from the previous study), the terminal response was the most resistant to change. Also, a 30-sec ITI was an adequate method in determining resistance to change.