Support
This summer I was granted the opportunity to complete a fellowship under the guidance of Dr. Adam Fox where we examined the effects of variable delays on impulsive choice in rats, using a delay discounting task. Delay discounting tasks involve repeated choices between a smaller sooner reward and a larger later reward. Consistent choice of the smaller, sooner alternative is an impulsive choice and associated with maladaptive behaviors that negatively affect health and psychological wellbeing. The opposite, consistent choice of a larger later reward, may be thought of as self-control. In most experimental manipulations, the delay to outcomes is fixed, however this does not capture real world variability we experience in delays to outcomes. For example, positive health outcomes do not occur in a fixed amount of days, email responses do not occur in fixed amounts of time. Variable interval delays deliver rewards in average delays rather than fixed delays. In this study, the variable interval reinforcement schedule was applied to both alternatives of the delay discounting task to reflect real life dynamic conditions. This is a manipulation that, to our knowledge, has never been done before and will strengthen our understanding of delay discounting.
This study involved the use of Long Evans rats. Rats completed a discounting task in an operant chamber daily for approximately 8 weeks. We manipulated the variability of the range of intervals that could be experienced across conditions. Preliminary results suggest that the more variable the delays, the less impulsive the animals chose—counter perhaps to intuition, but consistent with some limited adjacent work.
This summer I learned to collect data and proper animal care. I was also responsible for teaching these skills to new lab members to ensure accurate and precise techniques were being used for data collection and proper animal handling.
I appreciate Adam Fox for supporting me through this project and challenging me in the best ways this summer. This fellowship gave me to opportunity to strengthen skills that will be applied this following year, allowing me to lead with confidence through my Senior Year Experience project.