College of Behavioral & Social Sciences
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The collections in this community comprise faculty research works, as well as graduate theses and dissertations..
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Item Information Uncertainty Influences Learning Strategy from Sequentially Delayed Rewards(2023) Maulhardt, Sean Richard; Charpentier, Caroline; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The problem of temporal credit assignment has long been posed as a nontrivial obstacle to identifying signal from data. However, human solutions in complex environments, involving repeated and intervening decisions, as well as uncertainty in reward timing, remain elusive. To this end, our task manipulated uncertainty via the amount of information given in their feedback stage. Using computational modeling, two learning strategies were developed that differentiated participants’ updates of sequentially delayed rewards: eligibility trace whereby previously selected actions are updated as a function of the temporal sequence - and tabular update - whereby additional feedback information is used to only update systematically-related rather than randomly related past actions. In both models, values were discounted over time with an exponential decay. We hypothesized that higher uncertainty would be associated with (i) a switch from tabular to eligibility strategy and (ii) higher rates of discounting. Participants’ data (N = 142) confirmed our first hypothesis, additionally revealing an effect of the starting condition. However, our discounting hypothesis had only weak evidence of an effect and remains an open question for future studies. We explore potential explanations for these effects and possibilities of future directions, models, and designs.Item Motivation and Effort in Individuals with Social Anhedonia(2012) McCarthy, Julie; Blanchard, Jack J; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The current study sought to better understand differences in motivation and effort in individuals with social anhedonia. Social anhedonia is a core negative symptom and one of the strongest predictors for the development of schizophrenia-spectrum disorders. Because current research examining motivation and effort deficits has focused on self-report questionnaires and behavioral tasks, little is known about possible underlying mechanisms of social anhedonia. Thus, the current study examined effortful decision making (monetary reward task) and physiological measures of effort mobilization (cardiovascular reactivity) and investigated whether findings were specific to social anhedonia or were shared with positive symptoms of schizophrenia spectrum disorders (e.g., perceptual aberrations and magical ideation, together referred to as `PerMag') and healthy controls. Results indicated that elevated social anhedonia was related to more effortful decision making in the context of uncertain probability of reward, but there were no group differences with respect to physiological measures of effort.