Context dependence of the event-related brain potential associated with reward and punishment

The error-related negativity (ERN) is an event-related brain potential elicited by error commission and by presentation of feedback stimuli indicating incorrect performance. In this study, the authors report two experiments in which participants tried to learn to select between response options by trial and error, using feedback stimuli indicating monetary gains and losses. The results demonstrate that the amplitude of the ERN is determined by the value of the eliciting outcome relative to the range of outcomes possible, rather than by the objective value of the outcome. This result is discussed in terms of a recent theory that holds that the ERN reflects a reward prediction error signal associated with a neural system for reinforcement learning

State Lotteries and the New American Dream

This paper analyzes state lotteries in the economic and cultural context of the late twentieth century. As access to traditional meritocratic advancement declined, many Americans perceived lotteries as new means of attaining increasingly elusive upward mobility. Their turn to lotteries was facilitated by grassroots coalitions as well as lottery advertisers who claimed lotteries as effective means of making money. The relationship of lotteries and social mobility reveals the full implications of lottery playing in the United States and the reasons this form of gambling has assumed new importance as providing access to the American Dream

Male circumcision in the United States: The History, an analysis of the discourse, and a philosophical interpretation

Routine neonatal circumcision is at the present time a procedure on the decline in the United States. This is largely due to the lack of medical justification for the surgery, as medical organizations today do not recommend the procedure. Despite the statements of medical boards, the subject of male circumcision is frequently discussed in the media, and portrayed as an ongoing and controversial debate. This thesis analyzes this discourse to attempt an understanding of what this discourse can show us about our culture and our understanding of the sexual nature of the human body. A review of the history of male circumcision is given. The theories of Michel Foucault are used to help understand a loss of knowledge concerning human sexuality that occurred in the 19th century, and how this loss of knowledge enabled a practice of male circumcision which, though appearing scientific in the discourse, resulted instead from moral concerns. Male circumcision as a routine practice gained traction at a time when medicine was gaining authority over the body at the expense of religious authority, but often utilizing moral, unscientific concerns to increase the authority of medicine. Finally, the philosophies of Nietzsche and Freud are used to cast suspicion on current understanding of the practice of male circumcision, questioning the assumption that male circumcision is easily understood by conscious thought, and attempting a deeper and more relevant understanding of the cultural implications of the practice of male circumcision

Measuring time preferences

We review research that measures time preferences—i.e., preferences over intertemporal tradeoffs. We distinguish between studies using financial flows, which we call “money earlier or later” (MEL) decisions and studies that use time-dated consumption/effort. Under different structural models, we show how to translate what MEL experiments directly measure (required rates of return for financial flows) into a discount function over utils. We summarize empirical regularities found in MEL studies and the predictive power of those studies. We explain why MEL choices are driven in part by some factors that are distinct from underlying time preferences.National Institutes of Health (NIA R01AG021650 and P01AG005842) and the Pershing Square Fund for Research in the Foundations of Human Behavior

Evolutionary game dynamics of controlled and automatic decision-making

We integrate dual-process theories of human cognition with evolutionary game theory to study the evolution of automatic and controlled decision-making processes. We introduce a model where agents who make decisions using either automatic or controlled processing compete with each other for survival. Agents using automatic processing act quickly and so are more likely to acquire resources, but agents using controlled processing are better planners and so make more effective use of the resources they have. Using the replicator equation, we characterize the conditions under which automatic or controlled agents dominate, when coexistence is possible, and when bistability occurs. We then extend the replicator equation to consider feedback between the state of the population and the environment. Under conditions where having a greater proportion of controlled agents either enriches the environment or enhances the competitive advantage of automatic agents, we find that limit cycles can occur, leading to persistent oscillations in the population dynamics. Critically, however, these limit cycles only emerge when feedback occurs on a sufficiently long time scale. Our results shed light on the connection between evolution and human cognition, and demonstrate necessary conditions for the rise and fall of rationality.Comment: 9 pages, 7 figure

A martingale analysis of first passage times of time-dependent Wiener diffusion models

Research in psychology and neuroscience has successfully modeled decision making as a process of noisy evidence accumulation to a decision bound. While there are several variants and implementations of this idea, the majority of these models make use of a noisy accumulation between two absorbing boundaries. A common assumption of these models is that decision parameters, e.g., the rate of accumulation (drift rate), remain fixed over the course of a decision, allowing the derivation of analytic formulas for the probabilities of hitting the upper or lower decision threshold, and the mean decision time. There is reason to believe, however, that many types of behavior would be better described by a model in which the parameters were allowed to vary over the course of the decision process. In this paper, we use martingale theory to derive formulas for the mean decision time, hitting probabilities, and first passage time (FPT) densities of a Wiener process with time-varying drift between two time-varying absorbing boundaries. This model was first studied by Ratcliff (1980) in the two-stage form, and here we consider the same model for an arbitrary number of stages (i.e. intervals of time during which parameters are constant). Our calculations enable direct computation of mean decision times and hitting probabilities for the associated multistage process. We also provide a review of how martingale theory may be used to analyze similar models employing Wiener processes by re-deriving some classical results. In concert with a variety of numerical tools already available, the current derivations should encourage mathematical analysis of more complex models of decision making with time-varying evidence