Ongoing Projects:

Effects of Win-Paired Stimulus Delivery on Loss Trials On Risky Choice in Rats: Connor Lambert​

Gambling by way of electronic gambling machine is very common. Electronic gambling machines are things like slot machines, video lottery, and video poker. There is evidence that electronic gambling machines are relatively more addictive than other forms of gambling, and may accelerate the development of pathological gambling disorder. One theorized reason for this is the many audio and visual stimuli presented while using electronic gambling machines. These stimuli, or "cues", are paired with winning outcomes and may take on conditioned reinforcing properties. Then, when these cues are presented on losses, they may disguise the aversive properties of the loss, otherwise known as a loss-disguised as win. Probability-discounting procedures can be used to examine risky choice. The presentation of stimuli within a probability discounting procedure can be systematically arranged so as to mimic the stimulus presentations used in electronic gambling machines. The present study aims to clarify the relationship between win-paired stimuli and risky choice by systematically presenting a win-paired stimulus on a proportion of trials where no reinforcement is delivered.

Recently Completed Projects:
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Effects of Light/Dark Cycle Shifts on Delay DIscounting: Katya Nolder​

Modern society has become increasingly reliant on around-the-clock provision of many services including protective, medical, and transportation amenities. As a result, the prevalence of shift work is increasing to support these conditions. Shift workers have an increased risk of developing multiple negative health outcomes such as type 2 diabetes, heart disease, stroke, gastrointestinal disorders, reproductive issues, and cancer. There is increasing evidence that shift workers are more likely to engage in unhealthy lifestyle choices compared to non-shift workers. These lifestyle choices may mediate the relation between shift work and negative health outcomes. Many employees follow rotating shift-work schedules. These work schedules typically alternate from one shift to another on a weekly or monthly basis and employees take turns working each shift over time. Certain elements of rotating shift-work conditions can be mimicked in animal models by shifting the light/dark cycle in the animals’ living quarters, which negatively affects multiple physiological variables, but effects of these manipulations on decision making are less clear. The present study will clarify the relation between light/dark cycle disruptions and maladaptive decision making, measured via a delay-discounting procedure.

Effects of Combined Ethanol and Nicotine Administration on Impulsive Choice in Male and Female Sprague-Dawley Rats: Rebecca Chalmé​

Alcohol and nicotine are among the most commonly used drugs, as a result of their legality, affordability, and ease of access.  Although they are often used together, relatively little research has been published investigating behavioral outcomes of their combined administration.  Additionally, female subjects remain underrepresented in the literature, despite evidence of sex differences in alcohol and nicotine’s individual effects on neurotransmission and behavior.  Rebecca’s dissertation is designed to assess delay discounting at baseline and following acute ethanol, nicotine, and combined administration in both male and female rats.

Effects of Ethanol and Nicotine Co-Administration on Risky Choice in Rats: Erin Wylie

Individuals often engage in the comorbid use of alcohol and nicotine, leading to further-escalated health consequences than the use of either drug in isolation. Given these poor health outcomes from combined administration of alcohol and nicotine, some of which may be due to increased risky choice, more basic research is needed to better characterize drug/dose interactions on risky choice. Probability-discounting procedures allow for the assessment of risky choice across studies that may facilitate the understanding of factors underlying increases in risky choice seen following the consumption of these drugs in humans. Probability-discounting procedures involve a series of discrete choices between a smaller, certain reward and a larger, increasingly uncertain reward. The administration of drugs can alter probability discounting, resulting in more or less maladaptive outcomes for an individual. The present study involves the acute administration of ethanol alone and in combination with nicotine. Experiment 1 will involve the administration of several doses of ethanol alone, and Experiment 2 will involve the combined administration of several doses of ethanol together with several doses of nicotine. Effects of these drugs on risky choice, as measured through a probability-discounting procedure, will be evaluated. Through an assessment of how ethanol, and ethanol and nicotine in combination, alter choice, there may be increased understanding of how common drugs of abuse affect these choices.