<p>Few aspects of human cognition are more personal than the choices we make. Our decisions &mdash; from the mundane to the impossibly complex &mdash; continually shape the courses of our lives. In recent years, researchers have applied the tools of neuroscience to understand the mechanisms that underlie decision making, as part of the new discipline of decision neuroscience. A primary goal of this emerging field has been to identify the processes that underlie specific decision variables, including the value of rewards, the uncertainty associated with particular outcomes, and the consequences of social interactions. Here, across three independent studies, I focus on the neural circuitry supporting social valuation &mdash; which shapes our social interactions and interpersonal choices. In the first study (Chapter 2), I demonstrate that social valuation relies on the posterior ventromedial prefrontal cortex (pVMPFC). Extending these findings, I next show that idiosyncratic responses within pVMPFC predict individual differences in complex social decision scenarios (Chapter 3). In addition, I also demonstrate that decisions involving other people (e.g., donations to a charitable organization) produce increased activation in brain regions associated with social cognition, particularly the temporal-parietal junction (TPJ). Finally, in my last study (Chapter 4), I employ functional connectivity analyses and show that social cognition regions &mdash; including the TPJ &mdash; exhibit increased connectivity with pVMPFC during social valuation, an effect that depends upon individual differences in preferences for social stimuli. Collectively, these results demonstrate that the computation of social value relies on distributed neural circuitry, including both value regions and social cognition regions. Future research on social valuation and interpersonal choice must build upon this emerging theme by linking neural circuits and behavior.</p> / Dissertation

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The clinical presentation of social phobia suggests that alterations in theory of mind (TOM) may play a systematic role in the development and maintenance of the disorder. In the current study we leverage a quantitative neuroeconmic approach to probe for neural and behavior markers of cognitive TOM, as well as rejection estimation, with a particular focus on social phobia. Participants comprised a non-clinical sample that was divided into low (N = 10) and high (N = 7) social anxiety groups based on self-report. Participants completed a one-sided uncertainty ultimatum game designed to probe individual differences in cognitive TOM, as well as rejection estimation. Contrary to predictions, there were no behavioral differences between high and low social anxiety groups in terms of rejection estimation. Although no between-group differences emerged in the traditional TOM network, significant differences were observed in subregions of the striatum during formulation of offers, likely corresponding to estimation of reward expectations. As hypothesized, and consistent with past research, imaging results support the existence of a network regions implicated in TOM, including the medial prefrontal cortex (MPFC) and the temporal parietal junction (TPJ). In addition to these regions, additional areas, including the caudate and insula, were also active during mentalizing components of the task. Collectively, results suggest a novel role for expected-value computations in the development and maintenance of social phobia. / Master of Science

Deal or no deal? Hold ‘em or fold ‘em? Buy, hold or sell? When faced with uncertainty, a wise decision-maker evaluates each option and chooses the one they deem most valuable. Scientists studying decision making processes have spent much theoretical and experimental effort formalizing a framework that captures how decision makers can maximize the amount of subjective value they accrue from such decisions. This thesis tested two hypotheses. The first was that subjective value guides our simplest and most common of motor actions similar to how it guides more deliberative economic decisions. The second was that subjective value is allocated across pre-motor regions of the brain to make our actions more efficient. To accomplish these goals, I adapted a paradigm used by behavioural economists for use in neurophysiological experiments in non-human primates. In our task, monkeys repeatedly make quick, orienting eye movements, known as saccades, to targets, which they learned through experience, had different values. In support of the hypothesis that subjective value influences simple motor actions, the speed with which monkeys responded, known as saccadic reaction time (SRT), and their saccadic choices to valued targets were highly correlated and therefore both acted as a behavioural measures of subjective value. Two complimentary results support the hypothesis that subjective value influences activity in the intermediate layers of the superior colliculus (SCi) – a well-studied brain region important to the planning and execution of saccades - to produce efficient actions. First, when saccades were elicited with microstimulation, we found that the timing and spatial allocation of pre-saccadic activity in the SC was shaped by subjective value. Second, the baseline preparatory activity and transient visual activity of SCi neurons prior to saccade generation was also influenced by subjective value. Our results can be incorporated into existing models of SC functioning that use dynamic neural field theory. I suggest that saccades of higher subjective value will result in higher activation of their associated neural field such that they will be more likely and more quickly selected. In summary, this thesis demonstrates that subjective value influences neural mechanisms, not only for deliberative decision making, but also for the efficient selection of simple motor actions. / Thesis (Ph.D, Neuroscience Studies) -- Queen's University, 2013-06-25 17:18:25.393

Humans exhibit a number of suboptimal behaviours in the wake of a loss. For example, gamblers often ‘chase' their losses in an attempt to break even. Similarly, investors tend to hold on to losing stocks too long in the hope that the declining share price might make a recovery. However, the neural mechanisms that instantiate such behaviour are poorly understood. I begin the introductory chapter with a basic historical overview of fundamental economic concepts, interleaving intersecting ideas from psychology and neuroscience. This leads to a more in-depth exploration of the notion that loss-related behavioural biases might provide insight into the neural mechanisms that underlie risky choice. From this, I argue that rats represent a viable animal model of risky decision- making for neuroeconomic research. The original research presented in Chapters 2 – 5 pave the way toward advancing our current understanding of loss-related biases in behaviour with rat models of risky decision-making. By employing insight from psychology and economics, I developed two models of rat behaviour that can be used to study the neural substrates of loss valuation. I presented the experimental paradigms in Chapters 2 and 5, while demonstrating novel loss-related correlations between the midbrain dopamine system and observed loss behaviour in Chapters 3 and 4. The results presented in Chapter 5 demonstrate that rats are capable of producing behavioural patterns akin to loss aversion and the disposition effect. This work has also highlighted a number of areas for future research. In Chapter 6, I explore potential theoretical implications of the results discussed in previous chapters. In summary, this thesis uses experimental risky decision-making tasks in rats to advance our current knowledge of the ways in which concepts such as loss aversion critically influence our internal representation of value.

Present work describes two ways of application of psychological findings to economic theory of advertisement. Psychological findings may help with evaluation of different economic approaches of the study of advertisement. Evidence from psychology of persuasion is applied to the question, whether advertisement is used as a source of information. The work then inquires into the possibility, that advertisement can enhance utility. Summarized studies indicate, that it may indeed be so. During the inquiry, neuroeconomics is applied and it's basic methods are presented. The concluding part describes ramifications of chosen approach.

La théorie économique standard postule que les préférences individuelles sont stables. Cependant, de nombreux résultats en psychologie et en économie expérimentale montrent que le comportement humain contrevient régulièrement à ce principe fondamental. Certains facteurs connus pour influencer la valeur, comme le contexte affectif, ne sont pas pris en compte en économie. Leurs effets sont encore considérés comme des phénomènes contingents– des anomalies en marge de la rationalité, qui en tant que telles n’informent pas la théorie. Aujourd’hui que l’imagerie cérébrale permet de formuler et tester de nouvelles hypothèses, nous interrogeons le caractère contingent de l’influence du contexte sur les préférences, avec en tête l’idée que ces « biais » découleraient de propriétés inhérentes à la structure physique qui génère le comportement, à savoir le cerveau. Parce qu’ils reflètent les conditions a priori de tout jugement de valeur, ils ne sont pas contingents mais nécessaires, ce qui explique leur prévalence. Notre première étude fait la preuve de cette hypothèse dans le cas des biais de contexte : nous montrons que l’inertie de l’activité cérébrale combinée à l’automaticité de l’évaluation permet d'expliquer les effets du contexte sur la valeur chez le singe et l’être humain. Notre deuxième étude montre que la confiance est codée dans la même région cérébrale que la valeur, suggérant que la peut être comprise comme un jugement de valeur de second ordre. Enfin, notre troisième étude montre un biais d’attribution comportemental menant à des interférences entre valeur et confiance, ce qui était prédit par la combinaison des résultats de la première et de la deuxième étude. / Standard economic theory postulates that individual preferences are stable. However, numerous psychology and experimental economics findings show this fundamental principle is often violated in actual human behavior. Some factors known to influence value, such as affective context, are not taken into account. Their effects are still considered contingent phenomena – anomalies observed on the margins of rationality – and as such do not inform economic theories. As modern neuroimaging techniques enable us to formulate and test new hypotheses, we propose to examine the contingent nature of this instability, in the light of the idea that these "biases" are in fact directly related to the inherent properties of the physical structure that generates behavior, namely the brain. Because they reflect the a priori conditions of any value judgment, they are not contingent but necessary, which explains their prevalence in observed behavior. Our first study proves this hypothesis in the case of context‐induced valuation biases: we show that the inertia of cerebral activity combined with the automaticity of evaluation can explain the effects of context on valuation in macaque monkeys and humans. Our second study shows that confidence is encoded in the same brain region as value in humans, suggesting that confidence judgments can be understood as second‐order value judgments. Our third study behaviorally demonstrates an attribution bias leading to interferences between value and confidence judgments, as predicted by combining the results of the first and the second study in humans.

xv, 173 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Economists typically assume that individuals behave in accordance with rational choice theory. In practice, however, individual behavior can deviate from the predictions of models founded upon basic economic theory. The extent to which these deviations are important to individual decision-making in environmental economics, and thus to the development of sound environmental policies, is not fully understood. The objective in this dissertation research is to investigate potential deviations from rational choice behavior in some environmental economics contexts and to identify their relevance to environmental policy. Chapter I uses a stated-preference survey for the valuation of environmental health-risk reductions in which respondents rate the subjective difficulty of each key choice they are asked to consider. Existing literature identifies many potential categories of biases in the empirically estimated valuation of non-market goods in stated-preference research. One potential source of bias stems from the "objective complexity" of the choice scenario. I find that existing objective measures of choice set complexity do not fully explain subjective choice difficulty ratings in this valuation survey. Instead, subjective difficulty appears to result from the interplay among objective complexity, preferences, and cognitive resource constraints. In Chapter II, I consider the possible consequences of choice difficulty from the standpoint of neuroeconomics. Within the scope of neuroeconomics, one can identify some neurobiological correlates of economic decision-making activity. I study the apparent effects of choice difficulty on the neurobiological encoding of individuals' value assessments. Information from this study provides a neurological basis for deviations from simple economic theory based on conventional models of rational choice. Chapter III examines risk perceptions that may influence individuals' decisions to migrate within the U.S. to reduce potential health and economic risks related to climate change. My analysis treats historical patterns of migration among counties as a function of varying spatial and temporal patterns in tornado activity, along with other spatially and temporally delineated variables intended to capture the evolution of subjective perceptions of these tornado risks. Results suggest that the perception of risk from extreme weather events can have a small but statistically discernible effect on migration behavior across sociodemographic groups for both out-migrants and in-migrants. / Committee in charge: Trudy Cameron, Chairperson, Economics; William Harbaugh, Member, Economics; Jason Lindo, Member, Economics; Ulrich Mayr, Outside Member, Psychology

Decisions often require weighing the costs and benefits of available prospects. Value-based decision making depends on the coordination of multiple cognitive faculties, making it potentially susceptible to at least two forms of variability. First, there is heterogeneity in brain organization across individuals in areas of association cortex that exhibit decision-related activity. Second, a person’s preferences can fluctuate even for repetitive decision scenarios. Using functional magnetic resonance imaging (fMRI) and behavioral experiments in humans, this project explored how these distinct sources of variability impact choice evaluation, localization of valuation in the brain, and the links between valuation and other cognitive phenomena. Group-level findings suggest that valuation processes share a neural representation with the “default network” (DN) in medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC). Study 1 examined brain network variability in an open dataset of resting-state fMRI (n=100) by quantitatively testing the hypothesis that the spatial layout of the DN is unique to each person. Functional network topography was well-aligned across individuals in PCC, but highly idiosyncratic in mPFC. These results highlighted that the apparent overlap of cognitive functions in these areas should be evaluated within individuals. Study 2 examined variability in the integration of rewards with subjective costs of time and effort. Two computerized behavioral experiments (total n=132) tested how accept-or-reject foraging decisions were influenced by demands for physical effort, cognitive effort, and unfilled delay. The results showed that people’s willingness to incur the three types of costs differed when they experienced a single type of demand, but gradually converged when all three were interleaved. The results could be accounted for by a computational model in which contextual factors altered the perceived cost of temporal delay. Finally, Study 3 asked whether the apparent cortical overlap between valuation effects and the DN persisted after accounting for individual variability in brain topography and behavior. Using fMRI scans designed to evoke valuation and DN-like effects (n=18), we reproduced the idiosyncratic network topography from Study 1, and observed valuation-related effects in individually identified DN regions. Collectively, these findings advance our taxonomic understanding of higher-order cognitive processes, suggesting that seemingly dissimilar valuation and DN-related functions engage overlapping cortical mechanisms.

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