Date of Award


Document Type


Degree Name

Bachelor of Science



First Advisor

Kelly Lambert


The anticipation of positive events and optimism have been shown to improve health and emotional states in rats and humans. The current study is interested in the impact of positive anticipation on optimistic cognitive bias and emotional resilience, as well as neural markers of resilience. Male (n = 12) and female (n = 12) rats were assigned to either unpredictable positive expectancy response (UPER) training or the control (CON) group (n = 6 per group). Optimism was assessed using an ambiguous cue test (ACT) in which the rats were trained to associate a specific visual pattern with a high-value (Froot Loop) or low-value (Cheerio) reward and then completed an ambiguous cue trial. If the rats chose the high-value reward, the response was interpreted as optimistic. A novel car exploration test and a cat ball problem-solving test were also conducted to assess exploratory behavior and persistence. In the optimism assessment, the results indicated a sex by treatment interaction. The UPER training was more effective for the males such that the UPER males displayed more optimistic choices than the CON males, whereas no training effects were observed in the females [χ2 (1, 12) = 6.000, p = .014]. In the car exploration task, the CON males exhibited significantly longer latencies to consume the Foot Loop than the CON females [F(1, 19) = 4.547, p = .046]. There were no significant results in the cat ball test; however, the UPER males interacted with the ball longer and more frequently than the CON males. In the neural marker assessment, no effects of training or sex were observed in mineralocorticoid receptor (MR) expression in the hippocampus. Thus, the results of the current study suggest that positive anticipation training can increase optimism and exploratory behavior in rats, but the effect is dependent on sex. Consequently, these results highlight the impact of positive anticipation on optimism and deserve further investigation to determine the potential value of positive anticipation training as an intervention for a variety of physical and mental health conditions.

Available for download on Monday, June 22, 2026