Categorization and decision making are combined in a task with photorealistic faces. Two different types of face stimuli were assigned probabilistically into one of two fictitious groups; based on the category, faces were further probabilistically assigned to be hostile or friendly. In Part I, participants are asked to categorize a face into one of two categories, and to make a decision concerning interaction. A Markov model of categorization followed by decision making provides reasonable fits to Part I data. A Markov (...) model predicting decision making followed by categorization is rejected. In Part II, a no-parameter model predicts decisions using categorization and decision responses collected in separate trials, suggesting that Part 1 results are not an artifact of the presentation of categorization and decision questions within a single trial. Decisions concerning interaction appear to be based on information from the category decision, and not from the face stimuli alone. (shrink)

The purpose of this study is to take preliminary steps to unify psychoacoustic techniques with reaction-time methodologies to address the perceptual mechanisms responsible for the detection of one vs. multiple sounds. We measured auditory redundancy gains for auditory detection of pure tones widely spaced in frequency using the tools of Systems Factorial Technology to evince the system architecture and workload capacity in two different scenarios. We adopted an experimental design in which the presence or absence of a target at each (...) of two frequencies was combined factorially with two stimulus levels. Replicating previous work, results did not allow an assessment of system architecture due to a failure to observe factor influence at the level of distribution ordering for dual-target stimuli for both SOFT and LOUD scenarios. All subjects demonstrated very modest redundancy gains for the dual-target compared to the single-target stimuli, and results were similar for both LOUD and SOFT. We propose that these results can be predicted by a mental architecture that falls into the class of integrated subadditive parallel systems, using a well-supported assumption that reaction time is driven by loudness. We demonstrate that modeled loudness of the experimental sounds is highly correlated with mean reaction time, and we provide a proof-of-concept model based on Steven’s Power law that predicts both a failure of distributional ordering for dual-target stimuli and very modest redundancy gains. (shrink)

We affirm the dynamical systems approach taken by Feldman and Levin, but argue that a more mathematically rigorous and standard exposition of the model according to dynamical systems theory would greatly increase readability and testability. Such an explication would also have heuristic value, suggesting new variations of the model. We present one such variant, a new solution to the redundancy problem.

Mealey's sociopathy model is an exemplar of popular diathesis-stress models. Although such models, when presented in descriptive language, offer the illusion of integrative explanation, their actual scientific value is very limited because they fail to make specific, quantitative, falsifiable predictions. Conceptual and quantitative weaknesses of such diathesis-stress models are discussed and the requirements for useful models are outlined.