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R G Crowder

Publications and source records attributed to R G Crowder.

At least 19 recordsLinked to original sources
PubMed1992

The role of spectral and dynamic cues in imagery for musical timbre.

The musical quality of timbre is based on both spectral and dynamic acoustic cues. Four 2-part experiments examined whether these properties are represented in the mental image of a musical timbre. Experiment 1 established that imagery occurs for timbre variations within a single musical instrument, using plucked and bowed tones from a cello. Experiments 2 and 3 used synthetic stimuli that varied in either spectral or dynamic properties only, to investigate imagery with strict acoustic control over the stimuli. Experiment 4 explored whether the dimension of loudness is stored in an auditory image. Spectral properties appear to play a much larger role than dynamic properties in imagery for musical timbre.

Adult↗
PubMed1990

Schedules of presentation and temporal distinctiveness in human memory.

Recency, in remembering a series of events, reflects the simple fact that memory is vivid for what has just happened but deteriorates over time. Theories based on distinctiveness, an alternative to the multistore model, assert that the last few events in a series are well remembered because their times of occurrence are more highly distinctive than those of earlier items. Three experiments examined the role of temporal and ordinal factors in auditorily and visually presented lists that were temporally organized by distractor materials interpolated between memory items. With uniform distractor periods, the results were consistent with Glenberg's (1987) temporal distinctiveness theory. When the procedure was altered so that distractor periods became progressively shorter from the beginning to the end of the list, the results were consistent for only the visual modality; the auditory modality produced a different and unpredicted (by the theory) pattern of results, thus falsifying the claim that the auditory modality derives more benefit from temporal information than the visual modality. We distinguish serial order information from specifically temporal information, arguing that the former may be enhanced by auditory presentation but that the two modalities are more nearly equal with respect to the latter.

Auditory Perception↗
PubMed1990

Stimulus order effects in vowel discrimination.

In same-different discrimination tasks employing isolated vowel sounds, subjects often give significantly more "different" responses to one order of two stimuli than to the other order. Cowan and Morse [J. Acoust. Soc. Am. 79, 500-507 (1986)] proposed a neutralization hypothesis to account for such effects: The first vowel in a pair is assumed to change its quality in memory in the direction of the neutral vowel, schwa. Three experiments were conducted using a variety of vowels and some initial support for the hypothesis was obtained, using a large stimulus set, but conflicting evidence with smaller stimulus sets. Rather than becoming more similar to schwa, the first vowel in a pair seems to drift toward the interior of the stimulus range employed in a given test. Several possible explanations are discussed for this tendency and its relation to presentation order effects obtained in other psychophysical paradigms is noted.

Adult↗
PubMed1990

Physical interaction and association by contiguity in memory for the words and melodies of songs.

Three experiments were designed to investigate two explanations for the integration effect in memory for songs (Serafine, Crowder, & Repp, 1984; Serafine, Davidson, Crowder, & Repp, 1986). The integration effect is the finding that recognition of the melody (or text) of a song is better in the presence of the text (or melody) with which it had been heard originally than in the presence of a different text (or melody). One explanation for this finding is the physical interaction hypothesis, which holds that one component of a song exerts subtle but memorable physical changes on the other component, making the latter different from what it would be with a different companion. In Experiments 1 and 2, we investigated the influence that words could exert on the subtle musical character of a melody. A second explanation for the integration effect is the association-by-contiguity hypothesis, which holds that any two events experienced in close temporal proximity may become connected in memory such that each acts as a recall cue for the other. In Experiment 3, we investigated the degree to which simultaneous presentations of spoken text with a hummed melody would induce an association between the two components. The results gave encouragement for both explanations and are discussed in terms of the distinction between encoding specificity and independent associative bonding.

Adult↗
PubMed1989

Accuracy of temporal coding: auditory-visual comparisons.

Three experiments were designed to decide whether temporal information is coded more accurately for intervals defined by auditory events or for those defined by visual events. In the first experiment, the irregular-list technique was used, in which a short list of items was presented, the items all separated by different interstimulus intervals. Following presentation, the subject was given three items from the list, in their correct serial order, and was asked to judge the relative interstimulus intervals. Performance was indistinguishable whether the items were presented auditorily or visually. In the second experiment, two unfilled intervals were defined by three nonverbal signals in either the auditory or the visual modality. After delays of 0, 9, or 18 sec (the latter two filled with distractor activity), the subjects were directed to make a verbal estimate of the length of one of the two intervals, which ranged from 1 to 4 sec and from 10 to 13 sec. Again, performance was not dependent on the modality of the time markers. The results of Experiment 3, which was procedurally similar to Experiment 2 but with filled rather than empty intervals, showed significant modality differences in one measure only. Within the range of intervals employed in the present study, our results provide, at best, only modest support for theories that predict more accurate temporal coding in memory for auditory, rather than visual, stimulus presentation.

Adult↗
PubMed1986

Auditory and temporal factors in the modality effect.

Subjects in five experiments read nine-digit memory lists from a cathode ray tube for immediate recall. Reading aloud always produced a localized and reliable advantage for the last item, compared to reading silently. Two experiments on whispered and mouthed lists, with or without simultaneous broadband noise, falsified expectations derived from the theory of precategorical acoustic storage. Three additional experiments showed no enhancement of recency in the silent conditions when the digits were drawn or spelled gradually on the screen, a result that is inconsistent with the changing-state hypothesis. The classic auditory-visual modality effect is large and reliable, but still poorly understood.

Humans↗
PubMed1983

The purity of auditory memory.

Recent evidence from experiments on immediate memory indicates unambiguously that silent speech perception can produce typically 'auditory' effects while there is either active or passive mouthing of the relevant articulatory gestures. This result falsifies previous theories of auditory sensory memory (pre-categorical acoustic store) that insisted on external auditory stimulation as indispensable for access to the system. A resolution is proposed that leaves the properties of pre-categorical acoustic store much as they were assumed to be before but adds the possibility that visual information can affect the selection of auditory features in a pre-categorical stage of speech perception. In common terms, a speaker's facial gestures (or one's own) can influence auditory experience independently of determining what it was that was said. Some results in word perception that encourage this view are discussed.

Feedback↗
PubMed1982

Decay of auditory memory in vowel discrimination.

Two experiments on same-different vowel discrimination are reported. In each, the main variable was the duration of a silent delay between the two items being judged. As would be expected from the assumption that such judgements depend at least partly on auditory sensory memory, longer delays led to poorer discrimination than shorter delays. The auditory memory loss seems to be asymptotic at about 3 sec, whether it is measured by correct discrimination of (as in one part of Experiment 2) by the contextual influence of the first vowel on identification of the second.

Adult↗
PubMed1979

Categories and context in the perception of isolated steady-state vowels.

The noncategorical perception of isolated vowels has been attributed to the availability of auditory memory in discrimination. In our first experiment, using vowels from an /i/-/I/epsilon) continuum in a same-different (AX) task and comparing the results with predictions derived from a separate identification test, we demonstrated that vowels are perceived more nearly categorically if auditory memory is degraded by extending the interstimulus interval and/or filling it with irrelevant vowel sounds. In a second experiment, we used a similar paradigm, but in addition to presenting a separate identification test, we elicited labeling responses to the AX pairs used in the discrimination task. We found that AX labeling responses predicted discrimination performance quite well, regardless of whether auditory memory was available, whereas the predictions from the separate identification test were more poorly matched by the obtained data. The AX labeling reponses showed large contrast effects (both proactive and retroactive) that were greatly reduced when auditory memory was interfered with. We conclude from the presence of these contrast effects that vowels are not perceived categorically (that is, absolutely). However, it seems that by taking the effects of context into account properly, discrimination performance can be quite accurately predicted from labeling data, suggesting that vowel discrimination, like consonant discrimination, may be mediated by phonetic labels.

Adult↗