NeuroGOAL Lab PhD Graduate Student
University of Minnesota - Twin Cities
Psychology Department
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She/her/hers
LATEST PROJECTS
Project | 01
Project 01 | Stress influences on the explore-exploit tradeoff in reward-guided decision making
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Stress has been implicated in changes in decision making, but the implementation of such changes via computational processes of reinforcement learning remains unclear. Stress causes a widespread refocusing of cognitive resources, and alters catecholamine function, including dopamine, to affect reward valuation. We examined the effects of acute saline injection stress as part of a behavioral pharmacology experiment on decision making in mice in a restless bandit task. This translational task involves repeatedly selecting between two illuminated squares on a touchscreen operant chamber, which are rewarded probabilistically. This bandit task is “restless” because the reward probability of each choice changes randomly and independently across trials. To maximize reward, animals have to balance between exploiting a current high-value option and exploring potential better alternatives. We hypothesized that acute stress would increase reward sensitivity, leading mice to exploit more choices following rewarded trials (win-stay). Thirty-two 129/b6j F1 mice (16 male and 16 female) were tested on restless bandit schedules with and without saline injection prior to testing in a within-subjects design. Our preliminary results indicate that acute injection stress negatively impacted the performance over chance for both male and female mice across sessions, with cumulative impacts of each injection. We found that animals showed reduced locomotor behavior in the chamber after saline injection. As hypothesized, acute injection stress appears to increase win-stay behavior, which may prevent animals from exploring to maximize changing reward values.
Project | 02
Project 02 | Dopamine, religiosity, and utilitarian moral judgment
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Dopamine is a neurotransmitter involved in reward processing and decision-making, including moral judgments. Utilitarian moral judgments occur when a specific action is based on the outcome rather than its consistency with moral norms. Our goal was to examine the relationship between biological and cultural factors that predict utilitarian moral judgment. More specifically, we predicted that (1) individuals with higher levels of dopamine will make more utilitarian decisions, (2) individuals who express greater religiosity will make less utilitarian judgments, and (3) individuals with low levels of dopamine and a high religiosity score will make the least utilitarian judgments. We measured dopamine using spontaneous eye blink rate, an indirect measure associated with striatal dopaminergic transmission. A total of 96 participants completed a utilitarian moral judgment task where they made appropriateness judgments regarding nonmoral, impersonal, personal-low conflict, and personal-high conflict moral dilemmas (Koenigs et al., 2007). Then, participants completed a questionnaire related to religiosity (Huber & Huber, 2012). We found a negative relationship between religiosity and the proportion of yes judgments participants made in the high-conflict personal dilemmas, which was consistent with our second hypothesis. None of our other hypotheses were supported. Understanding biological and cultural factors that relate to utilitarian moral judgment may also help in developing AI and autonomous vehicles that more closely mimic human behavior.
Mueller, D. & Halfmann, K. (2021). Dopamine, religiosity, and utilitarian moral judgment. Social Neuroscience, 16(6), 627-638.
Project | 03
Project 03 | Music exposure and its effects on an individual's perceived mood
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Many stimuli have the ability to affect mood. Sandra Garrido’s (2014) research involving music exposure defines mood as a mild affective state that lingers after exposure, while emotion is a more intense and brief response which occurs post-exposure. In our research involving the effects of music exposure on mood, we expect to find that (1a) classical music will elicit a pleasant mood, (1b) metal music will elicit an unpleasant mood, (1c) dance/electronic music will elicit a pleasant mood; and (2) there will be an interaction between genre preference and mood. The participant demographics match that of a rural Midwestern four-year public university. We measured the mood of participants with the Brief Mood Introspection Scale (BMIS; Mayer & Gaschke, 1988) after exposure to the following songs: Master of Puppets by Metallica, Happy Now by Zedd, and The Marriage of Figaro by Mozart. The results approached significance in indicating that participants’ mood was more pleasant for dance/electronic and classical music, rather than metal. The effect that musical exposure has on mood has many applications. Retail stores may be able to use these or similar results to convey certain moods in their stores and attract customers.
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Mueller, D., Dye, A., & Eshelman, A. (In Preparation). Music exposure and its effects on an individual's perceived mood.
Project | 04
Project 04 | The Relationship Between Impulsive Choice and Student Debt Attitudes
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This study examines whether delay of gratification and/or risky choice predict student attitudes toward debt. Examples of delay of gratification are patience, self control, or temporal discounting. Risky choice refers to risk tolerance or choice under uncertainty. I specifically helped by completing a literature review on and writing about debt attitude.
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Halfmann, K., Kornely, D., Kerkel, B., Mueller, D., & Davis, C. (In Preparation). The relationship between impulsive choice and student debt attitudes.