Dominic W. Massaro

Backward recognition masking

Backward recognition masking refers to the interference of a second sound on recognition of another sound presented earlier in time. Previous experiments have demonstrated backward recognition masking in an absolute judgment task. In those experiments, all of the experimental conditions were varied randomly within a test session. In the first experiment reported here, backward‐masking functions generated between blocks of trials were compared to those determined within an experimental session. The results showed backward masking using both experimental procedures. The next two experiments evaluate backward‐masking effects in a two‐interval forced‐choice task and a successive‐comparison task. Backward masking was observed in both experiments. The final experiment showed that selectively attending to the ear of the test tone presentation does not attenuate the backward‐masking effects of a second tone presented to the opposite ear.Subject Classification: 65.22, 65.58, 65.75.

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.

A bidimensional model of pitch in the recognition of melodies

Pitch can be conceptualized as a bidimensional quantity, reflecting both the overall pitch level of a tone (tone height) and its position in the octave (tone chroma). Though such a conceptualization has been well supported for perception of a single tone, it has been argued that the dimension of tone chroma is irrelevant in melodic perception. In the current study, melodies were subjected to structural transformations designed to evaluate the effects of interval magnitude, contour, tone height, and tone chroma. In two transformations, the component tones of a melody were displaced by octave intervals, either preserving or violating the pattern of changes in pitch direction (melodic contour). Replicating previous work, when contour was violated perception of the melody was severely disrupted. In contrast, when contour was preserved the melodies were identified as accurately as the untransformed melodies. In other transformations, a variety of forms of contour information were preserved, while eliminating information for absolute pitch and interval magnitude. The level of performance on all such transformations fell between the levels observed in the other two conditions. These results suggest that the bidimensional model of pitch is applicable to recognition of melodies as well as single tones. Moreover, the results argue that contour, as well as interval magnitude, is providing essential information for melodic perception.

Speech Perception: A Framework for Research and Theory

Publisher Summary This chapter discusses a psychological framework for speech perception. Scientists sometimes overcome complexity by analyzing an unmanageable problem into manageable subproblems. A naive speech perception model appears to give a reasonable description of the various processes and structures involved in a number of important phenomena. Faced with a speech stimulus, the listener must evaluate features of the sensory input and match these to pattern descriptions in memory. In accounting for certain phenomena, it is important to assume that the listener has information about the degree to which each feature is present in the speech sound. Similarly, the complexity of the sensory input argues for propositional descriptions of speech patterns and corresponding logical integration rules. This general framework allows for a natural description of the powerful contribution of both auditory and linguistic context. Whether or not this model proves to be ultimately correct, it should certainly serve as a valuable heuristic framework for research and theory in speech perception.

Selective perception without confounding contributions of decision and memory.

Previous research has demonstrated that decision processes and short-term memory limitations contribute to the observed limitation in the span of apprehension in tachistoscopic experiments. The present study addresses the question of whether perceptual factors also contribute to this limitation. Observers were asked to indicate which of four target letters occurred in a four-item test display. The irrelevant background items were either highly confusable or completely nonconfusable with the target letters. The target detection task is designed to bypass short-term memory limitations. In order to eliminate differences in decision processing, the location of the target letter was indicated either slightly before or shortly after the display presentation. The indicator was either an arrow cue or a pattern mask. Performance decreased with increases in the delay of the arrow cue only when the background items were confusable. The pattern mask yielded standard masking functions, but performance with the nonconfusable background items improved more rapidly with increases in processing time than did performance with the confusable background items. These results conform to the hypothesis that attention operates at the perceptual stage of processing. The results were accurately described by a quantification of attentional effects in a general information processing model.

The role of lateral masking and orthographic structure in letter and word recognition

Abstract The present experiments evaluated the contribution of orthographic structure and lateral masking in the perception of letter, word, and nonword test displays. Performance was tested in a backward recognition masking experiment in which a masking stimulus followed the test display after a variable blank interstimulus interval. In agreement with previous findings across different experiments, words were recognized better than single letterd at short interstimulus intervals, but the opposite was the case at long intervals. Performance on the nonwords resembled performance on letters at short masking intervals and performance on words at long masking intervals. The quantitative results were described by a processing model that incorporates the effects of lateral masking and orthographic structure in the dynamic processing of letter strings. Lateral masking tends to lower the potential perceptibility of letters whereas orthographic structure can reduce the uncertainty of the candidate letters in the letter sequence. The present model predicts that the quantitative contribution of each of these processes to performance is critically dependent upon the processing time available before the onset of the masking stimulus.

Tone chroma is functional in melody recognition

Musical notes can be defined both in terms of their fundamental frequencies (tone height) and their positions in the musical octave (tone chroma). Although there is some evidence indicating that hoth tone height and chroma can contribute to tone perception, Deutsch 11969, 1972) suggested that chroma is not functional in melody recognition. By systematically transforming melodies so as to preserve one or another type of information, Idson and Massaro (1978) de~nonstrated that chroma was also functional in melody recognition. However, in the Idson and Massaro study, subjects repeatedly heard the same melodies and were asked to identify them out of a limited set of possibilities (forced-choice procedure). The repetition of melodies and the forced-choice procedure might have encouraged subjects to develop special recognition strategies. To preclude this possibility, subjects in the present experiments heard each melody only once and were not informed in advance of the possible melodies. When systematic transformations similar to those used by Idson and Massaro were applied to familiar melodies, similar results were found. Therefore, it is unlikely that special recognition strategies were responsible for the results of the Idson and Massaro (1978) study: tone chroma contributes to melody recognition in both types of experimental procedures. The functional role of tone chroma in melody recognition is consistent with the idea that octave generalization not only applies to l:he perception of single tones but also occurs in the perception of successive intervals.

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.

Dividing attention between auditory and visual perception

To what extent is simultaneous visual and auditory perception subject to capacity limitations and attentional control? Two experiments addressed this question by asking observers to recognize test tones and test letters under selective and divided attention. In Experiment 1, both stimuli occurred on each trial, but subjects were cued in advance to process just one or both of the stimuli. In Experiment 2, subjects processed one stimulus and then the other or processed both stimuli simultaneously. Processing time was controlled using a backward recognition masking task. A significant, but small, attention effect was found in both experiments. The present positive results weaken the interpretation that previous attentional effects were due to the particular duration judgment task that was employed. The answer to the question addressed by the experiments appears to be that the degree of capacity limitations and attentional control during visual and auditory perception is small but significant.

The role of tone height, melodic contour, and tone chroma in melody recognition.

The present experiments assessed the contribution of tone height, melodic contour, and tone chroma to melody recognition. Rather than using highly familiar folk songs as in earlier studies, subjects were taught new melodies. Novel melodies were used to (a) more precisely control potential cues (e.g., rhythm) that are not of present interest, (b) eliminate unison intervals that cannot be transformed appropriately, (c) provide a direct analysis of the nature of confusion errors, (d) test whether recently learned melodies are recognized differently than highly overlearned melodies, and (e) evaluate the extent to which practice in the experimental task alters the process of recognition. The results replicate previous studies using familiar folk songs. Transformations of the original melodies were accurately recognized when tone height was violated, but both melodic contour and tone chroma were maintained. Violating both tone height and contour while maintaining chroma produced extremely poor recognition. Performance was intermediate when just melodic contour was preserved. There is now good evidence to support the idea that melodic contour and tone chroma, in addition to tone height, contribute to recognition of both highly familiar and recently learned melodies.