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Biomedical subjects

D W Massaro

Publications and source records attributed to D W Massaro.

At least 19 recordsLinked to original sources

Discovery and expository methods in teaching visual consonant and word identification.

An experiment was conducted to examine the processes involved in lipreading as well as to investigate an optimal approach to teaching lipreading skill. We compared discovery and expository methods of learning to lip-read. Twenty-six college students with normal hearing were trained over 3 days to lip-read consonant-vowel (CV) syllables. The training material consisted of a prerecorded videotape of four different talkers. The task was a forced-choice procedure with feedback. Subjects learned with training, but there was no difference between the two learning methods. As a retention measure, subjects returned 4 weeks later and repeated the training. There were significant savings of the original learning. Three weeks after the retention phase, subjects were tested with a 10-item forced-choice monosyllabic word task. Those subjects who had extensive training on CV syllables did no better on identifying the monosyllabic words than did a control group of 9 subjects with no training. Nevertheless, performance for all three groups (discovery, expository, and no training) improved during training in the word identification task.

Adolescent

Integration versus interactive activation: the joint influence of stimulus and context in perception.

Empirical results from both reading and speech perception indicate that stimulus and context information have independent influences on perceptual recognition. Massaro (1989) argued that these data are inconsistent with an interactive activation and competition (IAC) model (McClelland & Rumelhart, 1981), and consistent with the fuzzy logical model of perception (FLMP) (Massaro, 1979; 1989). McClelland (1991) than modified the interactive activation model to be stochastic rather than deterministic and to use a best one wins (BOW) decision rule, allowing it to predict independent influences of stimulus and context. When tested against real data, however, the network proposed by McClelland and extended by us gives a poorer description of actual empirical results than the FLMP. To account for the dynamics of information processing, the SIAC model, an interactive model based on the Boltzmann machine, and the FLMP are formulated to make quantitative predictions of performance as a function of processing time. It is shown that the dynamic FLMP provides a better description of the time course of perceptual processing than does interactive activation. The SIAC and Boltzmann models have difficulty predicting 1) context effects given little processing time and 2) a strong stimulus influence given substantial processing time. Finally, we demonstrate that the FLMP predicts that context can improve the accuracy of performance, in addition to providing a bias to respond with the alternative supported by context. In summary, there is now both empirical and theoretical evidence in favor of the FLMP over SIAC models of pattern recognition. We therefore argue that interactive activation is both less consistent with empirical results and not necessary to describe the joint influence of stimulus and context in language perception.

Algorithms

Integration of orthographic and semantic information in memory retrieval.

Our central goal was to determine how multiple sources of information are evaluated and integrated during memory retrieval. An expanded factorial design was used to vary two sources of information independently of one another and to present each source alone. Subjects solved crossword-like puzzles with varying numbers of orthographic and semantic cues. The results of the experiment indicated that (a) performance is better given two sources of information relative to just one; (b) evaluation of each source of information provides continuous rather than just categorical (all-or-none) information; and (c) the two sources are integrated multiplicatively rather than simply used independently of one another as claimed by nonintegration models. A fuzzy logical model of perception (FLMP)-taken from the pattern recognition domain--gave a good description of the memory results. A single channel model, an averaging model, and an adding model produced poor descriptions of the results.

Adult

Models of integration given multiple sources of information.

Several models of information integration are developed and analyzed within the context of a proto-typical pattern-recognition task. The central concerns are whether the models prescribe maximally efficient (optimal) integration and to what extent the models are psychologically valid. Evaluation, integration, and decision processes are specified for each model. Important features are whether evaluation is noisy, whether integration follows Bayes's theorem, and whether decision consists of a criterion rule or a relative goodness rule. Simulations of the models and predictions of the results by the same models are carried out to provide a measure of identifiability or the extent to which the models can be distinguished from one another. The models are also contrasted against empirical results from tasks with 2 and 4 response alternatives and with graded responses.

Arousal

Before you see it, you see its parts: evidence for feature encoding and integration in preschool children and adults.

Preschool children and adults were compared in two experiments examining the basic issue of whether perceptual representations of objects are built-up from independent features along the dimensions of size and brightness. Experiment 1 was a visual search experiment. Subjects searched for targets which differed from distractors either by a single feature or by a conjunction of features. Results from preschoolers were comparable to those from adults, and were consistent with Treisman and Gelade's (1980, Cognitive Psychology, 12, 97-136) feature-integration theory of attention. Their theory states that independent features are encoded in parallel and are later combined with a spatial attention mechanism. However, children's significantly steeper conjunctive search slope indicated a slower speed of feature integration. In Experiment 2, four mathematical models of pattern recognition were tested against classification task data. The findings from both age groups were again consistent with a model assuming that size and brightness features are initially registered, and then integrated. Moreover, the data from Experiment 2 imply that perceptual growth entails small changes in the discriminability of featural representations; however, both experiments show that the operations performed on these representations are the same developmentally.

Adult

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.

Adult

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.

Cues

Evaluation and integration of speech and pointing gestures during referential understanding.

Two experiments investigated the relative influence of speech and pointing gesture information in the interpretation of referential acts. Children averaging 3 and 5 years of age and adults viewed a videotape containing the independent manipulation of speech and gestural forms of reference. A man instructed the subjects to choose a ball or a doll by vocally labeling the referent and/or pointing to it. A synthetic speech continuum between two alternatives was crossed with the pointing gesture in a factorial design. Based on research in other domains, it was predicted that all age groups would utilize gestural information, although both speech and gestures were predicted to influence children less than adults. The main effects and interactions of speech and gesture in combination with quantitative models of performance showed the following similarities in information processing between preschoolers and adults: (1) referential evaluation of gestures occurs independently of the evaluation of linguistic reference; (2) speech and gesture are continuous, rather than discrete, sources of information; (3) 5-year-olds and adults combine the two types of information in such a way that the least ambiguous source has the most impact on the judgment. Greater discriminability of both speech and gesture information for adults compared to preschoolers indicated small quantitative progressions with development in the ability to extract and utilize referential signals.

Adult

Developmental changes in visual and auditory contributions to speech perception.

Previous research has demonstrated that listeners make use of both auditory and visual information in bimodal speech perception. Preschool children appear to evaluate and integrate the two sources of information in the same manner as adults, but the children are less influenced by the visual source. The current experiments test a possible explanation of this difference and extend the question to younger children. It is possible that children are poorer lip-readers than adults and thus have less complete information about the visual source. Children and adults were tested with both auditory and visual sources and were also required to identify speech events on the basis of only the visual source. In addition to replicating the previous findings in the bimodal situation, the current experiments found that children are poorer lip-readers than adults. Furthermore, a positive correlation was observed between lip-reading ability and the size of the visual contribution to bimodal speech perception. A fuzzy logical model of speech perception provided a good quantitative description of the results even with the assumption that the visual information was equivalent in both the bimodal and lip-reading conditions. The results also contradict the categorical perception of speech events and any nonindependence in the evaluation of auditory and visual information in speech perception.

Adolescent

Similarity effects in backward recognition masking.

Auditory backward recognition masking refers to the ability of a masking sound to terminate further perceptual resolution of a test sound presented slightly earlier in time. The present experiments were conducted to determine whether mask/test tone similarity effects in backward recognition masking could be reliably demonstrated. Although similarity effects were found in Experiments 1 and 2, only about 60% of the subjects demonstrated these effects. Experiment 3 was designed to isolate which stage of information processing is responsible for similarity effects. It was hypothesized that similarity effects are due to mask interference with the synthesized auditory memory of the test tone rather than to selective overwriting of a preperceptual auditory store: previous research has shown that interference in synthesized auditory memory depends on the similarity of the interfering stimulus to the items held in memory. By independently varying the backward masking interval and the interfering effect of the mask on the test tone memory, it was possible to demonstrate that similarity effects are indeed caused by mask interference in synthesized memory. The implications of these results are considered in the framework of auditory and visual masking.

Auditory Perception

Letter information and orthographic context in word perception.

Theories of word perception in reading can be categorized in terms of the assumption made about whether or not a word context modifies the feature analysis of its component letters. Independence theories assume that the visual information passed on by feature analysis is independent of word context. Nonindependence theories assume that a word context directly influences visual analysis. Some nonindependence theories have assumed that word context enhances feature analysis of letters, others have assumed that word context overrides feature analysis of letters, and some have assumed that word context directs which letters are analyzed. The present experiment provided a critical test between the two classes of theories by independently varying orthographic context and visual letter information in a letter recognition task. The results contradict the qualitative predictions of the class of nonindependence theories and are accurately described by a quantification of independence theory.

Discrimination Learning

Orthographic regularity, positional frequency, and visual processing of letter strings.

Previous research has demonstrated that familiarity with the orthographic structure within a letter string can facilitate the processing of the component letters. The current research was directed at discovering the psychologically relevant properties of this structure. Two fundamental descriptions were independently varied in the construction of six-letter nonword strings. A probabilistic description based on the frequency of occurrence of letters in each position was factorially combined with a rule-governed description defined in terms of graphemic and phonological constraints. College sophomores and sixth-grade readers were asked to indicate whether or not a predesignated target letter was present in these strings. For both groups of readers, orthographic regularity and summed positional frequency were found to have only a small facilitative effect on reaction time (RT). In contrast, RTs to say "no" increased dramatically with increases in the number of letters in the catch string that were physically similar to the target letter. In another experiment, the letter string was presented for a short duration, followed immediately by masking stimulus and then the target letter. College students indicated whether or not the target was present in the test string. Accuracy of performance was critically dependent on the orthographic regularity and summed positional frequencies of the letters in the test string. No effect of letter similarity was observed. The large differences that were observed between these two tasks were accounted for in terms of the stages of processing that are critical for performance in the tasks.

Adult