Selectivity, scope, and simplicity of models: a lesson from fitting judgments of perceived depth.

When comparing psychological models a researcher should assess their relative selectivity, scope, and simplicity. The third of these considerations can be measured by the models' parameter counts or equation length, the second by their ability to fit random data, and the first by their differential ability to fit patterned data over random data. These conclusions are based on exploration of integration models reflecting depth judgments. Replication of Massaro's (1988a) results revealed an additive model (Bruno & Cutting, 1988), and Massaro's fuzzy-logical model of perception (FLMP) fit data equally well, but further exploration showed that the FLMP fit random data better. The FLMP's successes may reflect not its sensitivity in capturing psychological process but its scope in fitting any data and its complexity as measured by equation length.     

Testing between the TRACE model and the fuzzy logical model of speech perception

The TRACE model of speech perception (McClelland & Elman, 1986) is contrasted with a fuzzy logical model of perception (FLMP) (Oden & Massaro, 1978). The central question is how the models account for the influence of multiple sources of information on perceptual judgment. Although the two models can make somewhat similar predictions, the assumptions underlying the models are fundamentally different. The TRACE model is built around the concept of interactive activation, whereas the FLMP is structured in terms of the integration of independent sources of information. The models are tested against test results of an experiment involving the independent manipulation of bottom-up and top-down sources of information. Using a signal detection framework, sensitivity and bias measures of performance can be computed. The TRACE model predicts that top-down influences from the word level influence sensitivity at the phoneme level, whereas the FLMP does not. The empirical results of a study involving the influence of phonological context and segmental information on the perceptual recognition of a speech segment are best described without any assumed changes in sensitivity. To date, not only is a mechanism of interactive activation not necessary to describe speech perception, it is shown to be wrong when instantiated in the TRACE model.     

A pattern recognition account of decision making

In the domain of pattern recognition, experiments have shown that perceivers integrate multiple sources of information in an optimal manner. In contrast, other research has been interpreted to mean that decision making is nonoptimal. As an example, Tversky and Kahneman (1983) have shown that subjects commit a conjunction fallacy because they judge it more likely that a fictitious person named Linda is a bank teller and a feminist than just a bank teller. This judgment supposedly violates probability theory, because the probability of two events can never be greater than the probability of either event alone. The present research tests the hypothesis that subjects interpret this judgment task as a pattern recognition task. If this hypothesis is correct, subjects’ judgments should be described accurately by the fuzzy logical model of perception (FLMP)—a successful model of pattern recognition. In the first experiment, the Linda task was extended to an expanded factorial design with five vocations and five avocations. The probability ratings were described well by the FLMP and described poorly by a simple probability model. The second experiment included (1) two fictitious people, Linda and Joan, as response alternatives and (2) both ratings and categorization judgments. Although the ratings were accurately described by both the FLMP and an averaging of the sources of information, the categorization judgments were described better by the FLMP. These results reveal important similarities in recognizing patterns and in decision making. Given that the FLMP is an optimal method for combining multiple sources of information, the probability judgments appear to be optimal in the same manner as pattern-recognition judgments.     

Ambiguity in perception and experimentation

Bruno and Cutting (1988) varied four monocular cues to perceived depth in a factorial design. Subjects judged the distance between test objects. Given main effects in the analysis of variance, the authors concluded that the perceivers integrated the four different sources of information, as opposed to simply selecting a single source. Given no interactions in the analysis of variance, the authors concluded that the integration process was additive rather than multiplicative. The ambiguity inherent in Bruno and Cutting's experiments and analyses is discussed. As presented, their results did not provide evidence for integration of depth cues or evidence for additivity, independence, and parallel processing of the cues. An additional analysis of the distribution of the rating judgments given by their subjects, however, provides some evidence for integration of the cues. The fuzzy logical model of perception (FLMP) is extended to describe perceptual recognition of depth. The model assumes independence of the cues during feature evaluation and a nonadditive integration process in which the least ambiguous cues have the greatest impact on the judgment. The FLMP is contrasted with a model assuming additivity of the cues. Because both models describe the results equally well, it remains for future researchers to provide definitive tests between the models.     

Measuring model flexibility with parameter space partitioning: an introduction and application example

A primary criterion on which models of cognition are evaluated is their ability to fit empirical data. To understand the reason why a model yields a good or poor fit, it is necessary to determine the data-fitting potential (i.e., flexibility) of the model. In the first part of this article, methods for comparing models and studying their flexibility are reviewed, with a focus on parameter space partitioning (PSP), a general-purpose method for analyzing and comparing all classes of cognitive models. PSP is then demonstrated in the second part of the article in which two connectionist models of speech perception (TRACE and ARTphone) are compared to learn how design differences affect model flexibility.     

Crossmodal integration in the identification of consonant segments

Although speechreading can be facilitated by auditory or tactile supplements, the process that integrates cues across modalities is not well understood. This paper describes two “optimal processing” models for the types of integration that can be used in speechreading consonant segments and compares their predictions with those of the Fuzzy Logical Model of Perception (FLMP, Massaro, 1987). In “pre-labelling” integration, continuous sensory data is combined across modalities before response labels are assigned. In “post-labelling” integration, the responses that would be made under unimodal conditions are combined, and a joint response is derived from the pair. To describe pre-labelling integration, confusion matrices are characterized by a multidimensional decision model that allows performance to be described by a subject's sensitivity and bias in using continuous-valued cues. The cue space is characterized by the locations of stimulus and response centres. The distance between a pair of stimulus centres determines how well two stimuli can be distinguished in a given experiment. In the multimodal case, the cue space is assumed to be the product space of the cue spaces corresponding to the stimulation modes. Measurements of multimodal accuracy in five modern studies of consonant identification are more consistent with the predictions of the pre-labelling integration model than the FLMP or the post-labelling model.     

The motor theory of speech perception revisited

Galantucci, Fowler, and Turvey (2006) have claimed that perceiving speech is perceiving gestures and that the motor system is recruited for perceiving speech. We make the counter argument that perceiving speech is not perceiving gestures, that the motor system is not recruitedfor perceiving speech, and that speech perception can be adequately described by a prototypical pattern recognition model, the fuzzy logical model of perception (FLMP). Empirical evidence taken as support for gesture and motor theory is reconsidered in more detail and in the framework of the FLMR Additional theoretical and logical arguments are made to challenge gesture and motor theory.     

Specificity of autobiographical memory and mood disturbance in adolescents

The combined perception of affective information provided by seeing a facial expression and hearing a tone of voice presents us with a phenomenon that has received little systematic attention in the laboratory. We argue that although the FLMP appears good at modelling the presently available data, more complex theoretical questions must be raised. We discuss the theoretical shortcomings of the FLMP and envisage two other theoretical frameworks that could guide future research.     

Perceiving speech from inverted faces

We examined whether the orientation of the face influences speech perception in face-to-face communication. Participants identified auditory syllables, visible syllables, and bimodal syllables presented in an expanded factorial design. The syllables were /ba/, /va/, /δa/, or /da/. The auditory syllables were taken from natural speech whereas the visible syllables were produced by computer animation of a realistic talking face. The animated face was presented either as viewed in normal upright orientation or inverted orientation (180° frontal rotation). The central intent of the study was to determine if an inverted view of the face would change the nature of processing bimodal speech or simply influence the information available in visible speech. The results with both the upright and inverted face views were adequately described by the fuzzy logical model of perception (FLMP). The observed differences in the FLMP’s parameter values corresponding to the visual information indicate that inverting the view of the face influences the amount of visible information but does not change the nature of the information processing in bimodal speech perception     

One or two dimensions in spontaneous classification: a simplicity approach

When participants are asked to spontaneously categorize a set of items, they typically produce unidimensional classifications, i.e., categorize the items on the basis of only one of their dimensions of variation. We examine whether it is possible to predict unidimensional vs. two-dimensional classification on the basis of the abstract stimulus structure, by employing Pothos and Chater's simplicity model of spontaneous categorization [Pothos, E. M., & Chater, N. (2002). A simplicity principle in unsupervised human categorization. Cognitive Science, 26, 303-343]. The simplicity model provides a quantitative measure of how intuitive a particular classification is. With objects represented in two dimensions, we propose that a unidimensional classification will be preferred if it is more intuitive than all possible two-dimensional ones, and vice versa. Empirical results supporting this proposal are reported. Implications for Goodman's paradox are discussed.     

Father identification,achievement, and occupational behavior of rural youth: 10-year follow-up

Males from rural economically deprived school districts, who had previously been surveyed as high school seniors, again 1 year after graduation, and again 5 years after graduation, were surveyed a fourth and final time 10 years after high school graduation concerning their occupational status and aspirations, their marital status, their spouses' educational and occupational achievements, the importance of life roles, and their occupational and personal satisfactions. In the original study the participants had been divided into two groups, low-identification males (LIM) and high-identification males (HIM) based on independent evaluators' judgments of the adequacy of their fathers as identification models. Each group's responses to the survey were compared. The results indicate that there were no statistically significant differences between the two groups on the variables of optimism about the future, spouses' occupational achievements, role importance, occupational satisfaction, and personal satisfaction. There were statistically significant differences on the variables of occupational status, occupational aspirations, educational achievements, educational plans, marital status, and spouses' educational achievements. The results are discussed in the context of the three previous surveys. Over the 10-year period the occupational and educational achievements and aspirations have been significantly higher for the HIM group than for the LIM group. Equally consistent is the finding that over the 10-year period there has been no differences between the two groups in satisfaction with status.