Selective attention.

106

Recent experiments using a variety of techniques have suggested that speech perception involves separate auditory and phonetic levels of processing. Two models of auditory and phonetic processing appear to be consistent with existing data: (a) a strict serial model in which auditory information would be processed at one level, followed by the processing of phonetic information at a subsequent level; and (b) a parallel model in which auditory and phonetic processing could proceed simultaneously. The present experiment attempted to distinguish empirically between these two models.Ss identified either an auditory dimension (fundamental frequency) or a phonetic dimension (place of articulation of the consonant) of synthetic consonant-vowel syllables. When the two dimensions varied in a completely correlated manner, reaction times were significantly shorter than when either dimension varied alone. This "redundancy gain" could not be attributed to speed-accuracy trades, selective serial processing, or differential transfer between conditions. These results allow rejection of a completely serial model, suggesting instead that at least some portion of auditory and phonetic processing can occur in parallel.

Section: Relation To Multidimensional Information Processingmentioning

confidence: 99%

Parallel processing of auditory and phonetic information in speech discrimination

Wood

1974

106

“…lftwo elements are not grouped into a single unit, then selective attention to either element should be easy. This assumption made it possible to look for organizational effects with processing tasks used in selective attention research (Egeth, 1967;Garner & Felfoldy, 1970). Here the subject is presented with several informational sources simultaneously (e.g .…”

mentioning

confidence: 99%

Grouping by proximity: Selective attention measures

Pomerantz

Schwaitzberg

1975

105

The role of element proximity in perceptual grouping was examined in tasks requmng speeded discrimination of two-element visual patterns. Grouping of two elements was defined as the failure of attention to be focused on one element selectively in filtering tasks where only that one element was relevant to the discrimination. Failure of selective attention was measured by the degree of interference caused by variation of the irrelevant element. Grouping was shown to diminish monotonically as the spacing between two elements was increased. At a given spacing, grouping could be reduced or eliminated by the introduction of a third element into the stimulus field, presumably because the addition of this element triggered a reorganization of the perceptual field into a new grouping structure. Grouping appeared to facilitate performance on condensation tasks requiring distributed attention, to the degree that the condensation tasks were actually easier than the filtering tasks at close proximities. Paradoxically, for some tasks, moving an irrelevant element away from a relevant one actually impaired performance, suggesting that paying attention to irrelevant information could be beneficial. This result, if generalizable, suggests that grouping be conceptualized not as an automatic process under preattentive control but as an optional process under strategic control. This paper is concerned with two aspects of the problem 01 perceptual organization of visual arrays (Wertheimer, 1923). The first is the degree to which perceptual organization is under the control of specitic parameters of the stimulus array, as opposed to cognitive (strategic) factors within the observer. The second is the establishment of experimental measures of organizational processes. This latter issue is much more than simply a methodological one, for in order to measure organization a theory is required that explains just what organization means, and how and where organization enters into the processing of perceptual information.The Gestalt "laws" of course represented an attempt to answer the first question. Certain stimulus variables. some well defined (proximity) and some not so well defined (similarity), can be shown to have clear effects on the wayan observer reports his perception of stimulus arrays. The conclusions one can draw from these demonstrations. as compelling as the perceptual effects may be, are limited, however. to the domain of phenomenology and say little about the underlying processes that shape our perceptual experiences. What is required are performance measures. rather than subjective reports. of perceptual organization. Pomerantz and Garner (1973) argued that if organization is more than an epiphenomenon. there

“…The study of selective attention in perceptual process has emphasized the need for obtaining a physics of stimulus domains studied and models for weighting ·the utility of these physical dimensions (Egeth, 1967). The results of the present study indicate the importance of an individual differences multidimensional scaling approach to the study of cue utilization in information processing.…”

Section: Resultsmentioning

confidence: 65%

An individual differences analysis of interdimensional additivity in multidimensional scaling

Forsyth

Shor

1974

Comparative judgments of the dissimilarity between schematic faces varying on 1, 4, 7, or 10 binary attributes were obtained under two instructional sets. Using the Tucker-Messick procedure, three subgroups of like-perceiving Ss were isolated and the nature of cue-utilization by each described. Perceptual independence of attributes was demonstrated both within and between instructional sets for Subgroup 1 and within instructional sets for Subgroup 2. The Subgroup 3 results indicated an interaction of the attributes. Data from the Shor cognitive elements test differentially characterized Subgroups 1 and 2, but did not uniquely characterize Ss requiring more complex models for the combination of attributes. The study illustrates the possible usefulness of an individual differences approach to the study of selective attention and information processing.Emphasis by many perceptual theorists (e.g., Gibson, 1966Gibson, , 1969Garner, 1970) that perception involves an active search for and selection of distinctive features of a stimulus array has led to a rapidly increasing literatureon processing information from multidimensional stimuli. Forsyth and Brown (l967) presented research supporting their proposition that there is a hierarchy of physical dimensions to which an individual attends in the perceptual process. It seemed to us that if weights could be attached to each physical dimension or stimulus attribute to reflect its relative utility, extremely good predictability of perceptual judgments could be achieved. The work by Tversky and Krantz (l969) suggested that an inter dimensional additivity model might be appropriate for combining dimensions in a prediction scheme for perceptual judgments. This model posits that the perceived dissimilarity between stimulus objects can be decomposed into the additive components of each attribute differing between the two stimuli. Tversky and Krantz (1969) provided some validation of this hypothesis using schematic faces varying on three features. Several aspects of this research led us to question the general utility of the model for perceptual judgments about faces. First, the small number of features permitted Tversky and Krantz's Ss to count the number of differing features to make a judgment. Second, Ss scaled stimulus pairs for overall dissimilarity rather than the more complex and more typical perceptual process of judging faces on a specific expression. A third concern was the substantial individual differences typical of multidimensional scaling tasks. Wender (l971), using a different stimulus domain and varying S's set for testing, failed to validate the