Browsing by Subject "Regret"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Neuroeconomics of social decisions
    (2008-12) Grygolec, Jaroslaw
    This dissertation is about how social comparisons leading to envy and pride impact decisions. We, humans, may feel envious and proud for different reasons. One view is that comparing our performance with others' can give us a useful signal about our productivity and skill, and then envy and pride just help us to learn from such experience. The other plausible view is that envy and pride may reflect changes in social status, where dominance in social group is the ultimate objective. In Chapter 1 we report the results of fMRI experiment in which subjects faced simple decision problem in both private and social environments without strategic interactions. The analysis of behavioral and neural data provides evidence for subjects performing social comparisons exhibiting envy and pride while evaluating outcomes of decisions. This effect is even stronger if decision-makers bear relatively more responsibility for the resulting difference in outcomes. In Chapters 2 and 3 we explore social comparisons in strategic situations focusing on 3-person ultimatum game, first in purely behavioral and then in fMRI experiments. In the former we find evidence for responders exhibiting envy and pride. In Chapter 3 we focused on neural basis of rejections of low but positive amounts of money by responders. We show that the involvement of negative emotions in rejections of such low but positive offers is not due to their unfairness, but rather reflects negative reputational signal that the actual acceptance can send to others about the responder. Finally, we implicated nucleus accumbens in the decision process behind responders' decision on low but positive offers. This is an area, shown elsewhere to track subjective value of rewards, and that exhibited envy and pride effects documented in chapter 1. From the methodological standpoint Chapters 1 and 3 show how an economist can test an economic model on both behavioral and neural data. Such tests of economic theory are more credible in our view despite the necessity of making additional assumptions related to the use of neural data.
  • Thumbnail Image
    Item
    Regretful choices: neural representations of choice in the orbitofrontal cortex
    (2014-10) Steiner, Adam Patrick
    In order to successfully acquire reward under many different circumstances, a decision maker must learn to expect a particular outcome in a specific situation. The ability to predict an expected outcome simplifies the decision process and enables a decision maker to accurately choose between multiple options without having to experience each option independently. The orbitofrontal cortex represents specific outcomes and aids in the selection of actions to acquire specific outcomes without experiencing the direct action-outcome sequence. Without the orbitofrontal cortex, humans, non-human primates, and rats all exhibit an inability to modify their actions to changing reward conditions. In addition, an intact orbitofrontal cortex is required to correctly identify cues paired with and predictive of reward. Without the orbitofrontal cortex the ability to distinguish between differing expectations collapses. The ability to create counterfactuals, a representation of the alternative would-have-been received outcome, is thought to aid in the process of simulating the expected outcomes of a situation. The representation of counterfactuals has been found in the orbitofrontal cortex in humans and non-human primates. While there is some evidence that rats can represent the counterfactual, the only direct neural evidence is presented in this thesis. Without the representation of a counterfactual, it is impossible to experience regret. If the orbitofrontal cortex is homologous across species and if rats can represent the counterfactual, can rats represent the counterfactual during regret inducing situations? Chapters 1 and 2 of this thesis examine the homology of the orbitofrontal cortex comparing the structure of OFC in humans, rats and non-human primates. These chapters also summarize the current hypotheses regarding Orbitofrontal cortex function. Orbitofrontal cortex has been shown to be largely homologous among humans, non-human primates and rats. The third chapter of this thesis introduces the concept of regret and counterfactuals and explains the etymology, psychology and economics that describe how regret and counterfactuals can be studied.Chapter 4 of this thesis shows that rats are capable of representing the counterfactual. One key aspect of orbitofrontal function is in the representation of counterfactuals and regret. Counterfactuals are defined as the alternative, would-have-been option. Rats performing on a multiple T maze, stopped at a decision point and looked both directions before continuing to reward. During this pause, orbitofrontal neurons represented reward after ventral striatal neurons represented reward. The reward representation was general. Once rats arrived at the reward sites, orbitofrontal neurons reliably represented the reward and continued to do so for every reward encounter. However, when rats arrived at reward locations that were not active, orbitofrontal neurons represented the other reward site, representing the counterfactual. Chapters 5 and 6 of this thesis expand on the necessity of counterfactuals to decision making and shows that rats are capable of experiencing regret on an economic foraging task. Rats showed distinct economic preferences on a circular foraging task. Rats waited longer for flavors of reward that they preferred and spent less time waiting for rewards they did not prefer. Neural responses reliably differentiated between reward flavors and the zones associated with the reward flavors. When a rat left a preferred reward early, without receiving reward, then encountered a non-preferred reward with a longer wait, the rat's behavior matched the economic definition of regret. Regret occurs when a decision maker selects between two options and the option finally received is less valuable than what the alternative option would have produced. Importantly this can be differentiated from disappointment, where an option received is less than expected even though it was not the fault of the decision maker. Counterfactuals are necessary for the experience of regret. Humans without an orbitofrontal cortex do not experience regret. However, regret has traditionally been known as a human experience. Economic definitions of regret make it possible to measure regret in rodents. During these regret instances neural ensembles in the orbitofrontal cortex represented the missed, previous action. These representations agree with psychological accounts of regret that state decision makers regret the action that led to outcome more than outcome. In the final chapter, chapter 7, the role of orbitofrontal cortex is re-examined in the context of regret and counterfactuals. Specifically, the previously introduced hypotheses from Chapter 2 are reviewed under the framework introduced by counterfactuals and regret.
  • Thumbnail Image
    Item
    Towards a Translational Model of Decision-Making: Findings from the Web-Surf Task
    (2017-08) Abram, Samantha
    Interventions targeting cognitive disorders often hinge on assumptions that humans and nonhuman animals recruit equivalent cognitive mechanisms during decision- making. Identifying parallel decision systems across species could help bridge gaps between clinical and non-clinical research, and in turn, improve intervention efficacy. The goal of this dissertation is to assess for similar behavioral and neural markers of decision-making across humans and rodents using a sequential foraging paradigm (“The Web-Surf Task”) that was adapted from a rodent spatial neuroeconomic task (“Restaurant Row”). The included studies highlight a functional translational approach that aims to access similar functional constructs via parallel tasks and methodological approaches. The results provide evidence of cross-species behavioral equivalents, such as the ability to detect revealed preferences. Findings from a neuroimaging study suggest that different neural systems track past and forward representations, indicative of human prospection during deliberation (i.e., episodic future thinking). Moreover, neural activation related to difficult decisions is similar to many of the structures that underlie rodent deliberation. Lastly, a risk-variant of the task suggests that regret-instances provide a bridge between our liking and pursuit of rewards. This final study also finds that impulsive individuals may fail to learn from regret. Collectively, this dissertation demonstrates the utility of this novel task for elucidating human deliberative mechanisms and identifying cross-species decision system compatibilities.