PubMed Health⌕ Search

Biomedical subjects

James T Townsend

Publications and source records attributed to James T Townsend.

8 recordsLinked to original sources
PubMed2006

Building bridges between neural models and complex decision making behaviour.

Diffusion processes, and their discrete time counterparts, random walk models, have demonstrated an ability to account for a wide range of findings from behavioural decision making for which the purely algebraic and deterministic models often used in economics and psychology cannot account. Recent studies that record neural activations in non-human primates during perceptual decision making tasks have revealed that neural firing rates closely mimic the accumulation of preference theorized by behaviourally-derived diffusion models of decision making. This article bridges the expanse between the neurophysiological and behavioural decision making literatures specifically, decision field theory [Busemeyer, J. R. & Townsend, J. T. (1993). Decision field theory: A dynamic-cognitive approach to decision making in an uncertain environment. Psychological Review, 100, 432-459], a dynamic and stochastic random walk theory of decision making, is presented as a model positioned between lower-level neural activation patterns and more complex notions of decision making found in psychology and economics. Potential neural correlates of this model are proposed, and relevant competing models are also addressed.

Action Potentials↗
PubMed2006

On the costs and benefits of faces and words: process characteristics of feature search in highly meaningful stimuli.

The authors present a comprehensive consideration of the process characteristics of visual search in contexts that vary in their meaningfulness. The authors frame hypotheses regarding process architecture, stopping rule, capacity, and channel independence, using analytic results and a rigorously specified dynamic system to characterize a set of alternative hypotheses that vary along all of these dimensions. Results of the tests of these hypotheses suggest that process architecture and the stopping rule do not distinguish the processing of meaningful and meaningless forms. The major distinction between configural and nonconfigural processing was with regard to processing capacity, potentially implicating channel interdependencies. All of these conclusions hold for both faces and words.

Face↗
PubMed2005

Contrast effects or loss aversion? Comment on Usher and McClelland (2004).

M. Usher and J. L. McClelland (2004) recently proposed a new connectionist type of model to explain context effects on preferential choice including the similarity, attraction, and compromise effects. They compared their model with an earlier connectionist type model for these same effects proposed by R. Roe, J. R. Busemeyer, and J. T. Townsend (2001) and raised several new issues. The authors address these issues and point out the main theoretical differences between the 2 explanations for context effects.

Choice Behavior↗
PubMed2004

A theory of interactive parallel processing: new capacity measures and predictions for a response time inequality series.

The authors present a theory of stochastic interactive parallel processing with special emphasis on channel interactions and their relation to system capacity. The approach is based both on linear systems theory augmented with stochastic elements and decisional operators and on a metatheory of parallel channels' dependencies that incorporates standard independent and coactive parallel models as special cases. The metatheory is applied to OR and AND experimental paradigms, and the authors establish new theorems relating response time performance in these designs to earlier and novel issues. One notable outcome is the remarkable processing efficiency associated with linear parallel-channel systems that include mutually positive interactions. The results may offer insight into perceptual and cognitive configural-holistic processing systems.

Cognition↗
PubMed2004

Parallel versus serial processing and individual differences in high-speed search in human memory.

Many mental tasks that involve operations on a number of items take place within a few hundred milliseconds. In such tasks, whether the items are processed simultaneously (in parallel) or sequentially (serially) has long been of interest to psychologists. Although certain types of parallel and serial models have been ruled out, it has proven extremely difficult to entirely separate reasonable serial and limited-capacity parallel models on the basis of typical data. Recent advances in theory-driven methodology now permit strong tests of serial versus parallel processing in such tasks, in ways that bypass the capacity issue and that are distribution and parameter free. We employ new methodologies to assess serial versus parallel processing and find strong evidence for pure serial or pure parallel processing, with some striking apparent differences across individuals and interstimulus conditions.

Adult↗
PubMed2004

The serial-parallel dilemma: a case study in a linkage of theory and method.

The question as to whether humans perceive, remember, or cognize psychological items simultaneously (i.e., in parallel) or sequentially (i.e., serially) has been of interest to philosophers and psychologists since at least the 19th century. The advent of the information-processing approach to cognition in the 1960s reopened the inquiry, initiating a flood of experiments and models in the literature. Surprisingly for so elemental an issue, persuasive experimental tests have, until recently, proven rather elusive. Several decades of theoretical, methodological, and experimental effort, propelled and shaped by a meta-theoretical perspective, are leading to powerful strategies for assessing this and related cognitive issues. The present article reviews the theoretical and empirical history of these inquiries and details situations in which decisive experimental tests are possible.

Cognition↗