Integrative processing of perception and reward in an auditory localization paradigm

Under natural conditions, human beings routinely have to choose among multiple alternatives which are associated with specific outcomes of varying desirability. Typically, decisions are based upon the processing of perceptual input, which introduces additional noise to the system. Bayesian decision theory (BDT) allows us to formalize decision under risk and to predict statistically optimal choice behavior. In the present study, human observers performed a classification task characterized by an extensive amount of perceptual uncertainty (auditory localization). In addition, a spatial reward function was imposed on the task. We set up a BDT model with no free parameters to serve as a benchmark for statistically optimal choices, and tested it against a purely perceptual model and a hybrid, heuristic model. In addition, we tested these three models with free rather than fixed parameters for the perceptual uncertainty and the peak of the reward function. The log likelihoods of the models given the empirical data were determined by means of Monte Carlo simulations. Bayesian model comparison (BMC) revealed that the BDT model with two free parameters was the most plausible among the tested models. The fitted parameter values for the peak of the reward function were consistently smaller than the actual peak reward communicated to the participants. The results are discussed in the context of an internal underweighting of the reward function.     

RTbox: A device for highly accurate response time measurements

Although computer keyboards and mice are frequently used in measuring response times (RTs), the accuracy of these measurements is quite low. Specialized RT collection devices must be used to obtain more accurate measurements. However, all the existing devices have some shortcomings. We have developed and implemented a new, commercially available device, the RTbox, for highly accurate RT measurements. The RTbox has its own microprocessor and high-resolution clock. It can record the identities and timing of button events with high accuracy, unaffected by potential timing uncertainty or biases during data transmission and processing in the host computer. It stores button events until the host computer chooses to retrieve them. The asynchronous storage greatly simplifies the design of user programs. The RTbox can also receive and record external signals as triggers and can measure RTs with respect to external events. The internal clock of the RTbox can be synchronized with the computer clock, so the device can be used without external triggers. A simple USB connection is sufficient to integrate the RTbox with any standard computer and operating system.     

On quoting the empty expression

Roy Sorensen has argued that a certain technical use of quotation marks to name the empty string supports a revised version of Davidson’s theory of quotation. I point out that Sorensen’s considerations provide no support for Davidson’s original theory, and I show that at best they support the revised Davidsonian theory only to the same extent that they support a simpler revised version of a Tarskian theory.     

Hierarchical Bayes Models for Response Time Data

Human response time (RT) data are widely used in experimental psychology to evaluate theories of mental processing. Typically, the data constitute the times taken by a subject to react to a succession of stimuli under varying experimental conditions. Because of the sequential nature of the experiments there are trends (due to learning, fatigue, fluctuations in attentional state, etc.) and serial dependencies in the data. The data also exhibit extreme observations that can be attributed to lapses, intrusions from outside the experiment, and errors occurring during the experiment. Any adequate analysis should account for these features and quantify them accurately. Recognizing that Bayesian hierarchical models are an excellent modeling tool, we focus on the elaboration of a realistic likelihood for the data and on a careful assessment of the quality of fit that it provides. We judge quality of fit in terms of the predictive performance of the model. We demonstrate how simple Bayesian hierarchical models can be built for several RT sequences, differentiating between subject-specific and condition-specific effects.     

Conceptualizations of valence and instrumentality: A fourfold model

Within the framework of valence-instrumentality (VI) theory, a fourfold model is developed to predict the contribution which is made by one outcome of an alternative to the valence of that alternative. The proposed model uses four subjective conditional probabilities which are based on the presence and absence of an alternative, and on the occurrence and nonoccurrence of an outcome. Valence is defined as the difference between the attractiveness values of the occurrence of an alternative (or an outcome) and the nonoccurrence of an alternative (or an outcome). Also, differences between subjective probabilities replace instrumentalities. Alternative valence-instrumentality formulations are analyzed in relation to the proposed fourfold model. The proposed model can be understood as a consistent application of Vroom's model (1964, Work and motivation, New York: Wiley), while other models are judged to be relatively deficient. The fourfold model, in combination with a matrix formulation of expectancy concepts, addresses a number of criticisms of VI theory and makes possible a test of the theory within the limits of its own assumptions.     

Scientific empathy,American buddhism,and the ethnography of religion

This paper examines some of the current ideas and methods that have problematised the study of religion within a globalised community. Religion and culture cannot be considered bounded entities, to be described as unchangeable. However, their constant process of change is not something new. It becomes new due to writing patterns and contemporary ideas on the relevance of religion or the creativity of culture. By analysing some discussions on possession cults, the paper suggests that ritual and performance constitute the moments when culture and religion are mediated. It is through ritual that religious practices are adapted, and it is in a ritual performance where culture is contested and challenged. Religion becomes ‘confused culture’, that once again is re‐organised and made orderly by reflection on ritual practices. Finally, the paper suggests that the agenda for an anthropology of religion for this new century is two‐fold. Firstly, to try to become more conversant with ever changing localised practices of ritual, and secondly, to try to converse about those practices with other practitioners and scholars from different fields and in different fields.     

The Dyadic Relationships Test: Creation and Validation of a Model-Derived,Visual-Verbal Instrument to Evaluate Couples Part I of II

Abstract

In Part I of this article, background and rationale for the construction of a Selfhood model-derived visual-verbal Dyadic Relationships Test (DRT) is presented. Results from studies covering its reliability and verification of its psychometric properties are presented. Construct validity was evaluated through research with competing theoretical models. In Part II, results from studies are reported through discriminant and concurrent validity analyses in adoptive and traditional couples. A revision evaluated its construct validity with measures of negotiation, intimacy, and communication, and through relational and emotional life at different stages of the life cycle, including empty nest and retirement. Results from these studies tend to support the psychometric properties of this instrument and, indirectly, the validity of the Selfhood model underlying its construction.     

When sex primes love: subliminal sexual priming motivates relationship goal pursuit

The studies reported here provide, for the first time, experimental evidence to support the claim that sexual interest and arousal are associated with motives to form and maintain a close relationship. In five studies, sex-related representations were cognitively primed, either subliminally or supraliminally, by exposing participants to erotic words or pictures as compared with neutral words or pictures. The effects of "sexual priming" on the tendencies to initiate and maintain a close relationship were assessed using various cognitive-behavioral and self-report measures. Supporting the hypotheses, subliminal but not supraliminal exposure to sexual primes increased (a) willingness to self-disclose, (b) accessibility of intimacy-related thoughts, (c) willingness to sacrifice for one's partner, and (d) preference for using positive conflict-resolution strategies. The article discusses implications of these findings for the role of sex in close relationships and offers a conceptualization of possible relational motives of the sexual behavioral system.