Tonal cognition.

This article presents a self-organizing map (SOM) neural network model of tonality based on experimentally quantified tonal hierarchies. A toroidal representation of key distances is recovered in which keys are located near their neighbors on the circle of fifths, and both parallel and relative major/minor key pairs are proximal. The map is used to represent dynamic changes in the sense of key as cues to key become more or less clear and modulations occur. Two models, one using tone distributions and the other using tone transitions, are proposed for key-finding. The tone transition model takes both pitch and temporal distance between tones into account. Both models produce results highly comparable to those of musically trained listeners, who performed a probe tone task for ten nine-chord sequences. A distributed mapping of tonality is used to visualize activation patterns that change over time. The location and spread of this activation pattern is similar for experimental results and the key-finding model.

Cross-cultural music cognition: cognitive methodology applied to North Sami yoiks.

This article is a study of melodic expectancy in North Sami yoiks, a style of music quite distinct from Western tonal music. Three different approaches were taken. The first approach was a statistical style analysis of tones in a representative corpus of 18 yoiks. The analysis determined the relative frequencies of tone onsets and two- and three-tone transitions. It also identified style characteristics, such as pentatonic orientation, the presence of two reference pitches, the frequency of large consonant intervals, and a relatively large set of possible melodic continuations. The second approach was a behavioral experiment in which listeners made judgments about melodic continuations. Three groups of listeners participated. One group was from the Sami culture, the second group consisted of Finnish music students who had learned some yoiks, and the third group consisted of Western musicians unfamiliar with yoiks. Expertise was associated with stronger veridical expectations (for the correct next tone) than schematic expectations (based on general style characteristics). Familiarity with the particular yoiks was found to compensate for lack of experience with the musical culture. The third approach simulated melodic expectancy with neural network models of the self-organizing map (SOM) type (Kohonen, T. (1997). Self-organizing maps (2nd ed.). Berlin: Springer). One model was trained on the excerpts of yoiks used in the behavioral experiment including the correct continuation tone, while another was trained with a set of Finnish folk songs and Lutheran hymns. The convergence of the three approaches showed that both listeners and the SOM model are influenced by the statistical distributions of tones and tone sequences. The listeners and SOM models also provided evidence supporting a core set of psychological principles underlying melody formation whose relative weights appear to differ across musical styles.

Rhythm and pitch in music cognition.

Rhythm and pitch are the 2 primary dimensions of music. They are interesting psychologically because simple, well-defined units combine to form highly complex and varied patterns. This article brings together the major developments in research on how these dimensions are perceived and remembered, beginning with psychophysical results on time and pitch perception. Progressively larger units are considered, moving from basic psychological categories of temporal and frequency ratios, to pulse and scale, to metrical and tonal hierarchies, to the formation of musical rhythms and melodies, and finally to the cognitive representation of large-scale musical form. Interactions between the dimensions are considered, and major theoretical proposals are described. The article identifies various links between musical structure and perceptual and cognitive processes, suggesting psychological influences on how sounds are patterned in music.

An exploratory study of musical emotions and psychophysiology.

A basic issue about musical emotions concerns whether music elicits emotional responses in listeners (the 'emotivist' position) or simply expresses emotions that listeners recognize in the music (the 'cognitivist' position). To address this, psychophysiological measures were recorded while listners heard two excerpts chosen to represent each of three emotions: sad, fear, and happy. The measures covered a fairly wide spectrum of cardiac, vascular, electrodermal, and respiratory functions. Other subjects indicated dynamic changes in emotions they experienced while listening to the music on one of four scales: sad, fear, happy, and tension. Both physiological and emotion judgements were made on a second-by-second basis. The physiological measures all showed a significant effect of music compared to the pre-music interval. A number of analyses, including correlations between physiology and emotion judgments, found significant differences among the excerpts. The sad excerpts produced the largest changes in heart rate, blood pressure, skin conductance and temperature. The fear excerpts produced the largest changes in blood transit time and amplitude. The happy excerpts produced the largest changes in the measures of respiration. These emotion-specific physiological changes only partially replicated those found for nonmusical emotions. The physiological effects of music observed generally support the emotivist view of musical emotions.

Isolating the dynamic attributes of musical timbre.

Three experiments examined the dynamic attributes of timbre by evaluating the role of onsets in similarity judgments. In separate experiments, subjects heard complete orchestral instrument tones, the onsets of those tones, and tones with the onsets removed ("remainders"). Ratings for complete tones corresponded to those for onsets, indicating that the salient acoustic attributes for complete tones are present at the onset. Ratings for complete tones also corresponded to those for remainders, indicating that the salient attributes for complete tones are present also in the absence of onsets. Subsequent acoustic analyses demonstrated that this pattern of similarity was due to the centroid frequencies and amplitude envelopes of the tones. The results indicate that the dynamic attributes of timbre are not only present at the onset, but also throughout, and that multiple acoustic attributes may contribute to the same perceptual dimensions.

Pitch and rhythmic patterns affecting infants' sensitivity to musical phrase structure.

The present studies were undertaken to learn more about the nature of the cues that underlie infants' perception of musical phrase structure. Experiment 1 demonstrated that infants in Krumhansl and Jusczyk's (1990) study were responding to the phrase structure instead of to the beginnings and endings of Mozart minuet stimuli. Experiment 2 showed that infants treat musical passages with pauses inserted at phrase boundaries much as they do unaltered versions of the same passages. Experiments 3 and 4 indicated that the direction of change in pitch height and tone duration is critical to obtaining longer orientation times to musical passages that are segmented at phrase boundaries. Finally, Experiment 5 demonstrates that different effects found for the forward and reversed versions of the passages with inserted pauses are not the result of an intrinsic preference for the forward versions.

Perceptual interactions between musical pitch and timbre.

These experiments examined perceptual interactions between musical pitch and timbre. Experiment 1, through the use of the Garner classification tasks, found that pitch and timbre of isolated tones interact. Classification times showed interference from uncorrelated variation in the irrelevant attribute and facilitation from correlated variation; the effects were symmetrical. Experiments 2 and 3 examined how musical pitch and timbre function in longer sequences. In recognition memory tasks, a target tone always appeared in a fixed position in the sequences, and listeners were instructed to attend to either its pitch or its timbre. For successive tones, no interactions between timbre and pitch were found. That is, changing the pitches of context tones did not affect timbre recognition, and vice versa. The tendency to perceive pitch in relation to other context pitches was strong and unaffected by whether timbre was constant or varying. In contrast, the relative perception of timbre was weak and was found only when pitch was constant. These results suggest that timbre is perceived more in absolute than in relative terms. Perceptual implications for creating patterns in music with timbre variations are discussed.

Memory for musical surface.

This study of memory for music presented listeners with the first half of a short piano piece, O. Messiaen's Mode de valeurs et d'intensités. The piece is written according to a unique compositional principle that rigidly couples values of pitch (chroma and octave), duration, and dynamics. Listeners heard test excerpts, which were judged in terms of whether or not they might have come from the piece (either from the part they had heard or from the remainder of the piece). Even in the first block of trials, listeners were able to recognize segments from the part of the piece they had heard, suggesting surprisingly accurate memory for surface characteristics. Listeners were also able to generalize to the rest of the piece, accurately judging segments from the part of the piece they had not heard. However, performance on four kinds of transformed segments showed that the abstraction of a piece's surface characteristics adopts rather loose criteria. Even highly trained professional musicians informed of the compositional constraints before the experiment were not sensitive to the specific couplings between musical parameters. Rather, listeners appeared to be sensitive to contour (the pattern of increasing and decreasing pitch) and global correlations between pitch height and duration, dynamics, and interval size. Performance did not change with repeated hearings of the music.

Mental representations for musical meter.

Investigations of the psychological representation for musical meter provided evidence for an internalized hierarchy from 3 sources: frequency distributions in musical compositions, goodness-of-fit judgments of temporal patterns in metrical contexts, and memory confusions in discrimination judgments. The frequency with which musical events occurred in different temporal locations differentiates one meter from another and coincides with music-theoretic predictions of accent placement. Goodness-of-fit judgments for events presented in metrical contexts indicated a multileveled hierarchy of relative accent strength, with finer differentiation among hierarchical levels by musically experienced than inexperienced listeners. Memory confusions of temporal patterns in a discrimination task were characterized by the same hierarchy of inferred accent strength. These findings suggest mental representations for structural regularities underlying musical meter that influence perceiving, remembering, and composing music.

Independent temporal and pitch structures in determination of musical phrases.

In two experiments we addressed the roles of temporal and pitch structures in judgments of melodic phrases. Musical excerpts were rated on how good or complete a phrase they made. In Experiment 1, trials in the temporal condition retained the original temporal pattern but were equitonal; trials in the pitch condition retained the original pitch pattern but were equitemporal; and trials in the melody condition contained both temporal and pitch patterns. In Experiment 2, one pattern (pitch or temporal) was shifted in phase and recombined with the other pattern to create the pitch and temporal conditions. In the melody condition, both patterns were shifted together. In both experiments, ratings in the temporal and pitch conditions were uncorrelated, and the melody condition ratings were accurately predicted by a linear combination of the pitch and temporal condition ratings. These results were consistent across musicians with varying levels of experience.

Tonal hierarchies in the music of north India.

Cross-culturally, most music is tonal in the sense that one particular tone, called the tonic, provides a focus around which the other tones are organized. The specific organizational structures around the tonic show considerable diversity. Previous studies of the perceptual response to Western tonal music have shown that listeners familiar with this musical tradition have internalized a great deal about its underlying organization. Krumhansl and Shepard (1979) developed a probe tone method for quantifying the perceived hierarchy of stability of tones. When applied to Western tonal contexts, the measured hierarchies were found to be consistent with music-theoretic accounts. In the present study, the probe tone method was used to quantify the perceived hierarchy of tones of North Indian music. Indian music is tonal and has many features in common with Western music. One of the most significant differences is that the primary means of expressing tonality in Indian music is through melody, whereas in Western music it is through harmony (the use of chords). Indian music is based on a standard set of melodic forms (called rags), which are themselves built on a large set of scales (thats). The tones within a rag are thought to be organized in a hierarchy of importance. Probe tone ratings were given by Indian and Western listeners in the context of 10 North Indian rags. These ratings confirmed the predicted hierarchical ordering. Both groups of listeners gave the highest ratings to the tonic and the fifth degree of the scale. These tones are considered by Indian music theorists to be structurally significant, as they are immovable tones around which the scale system is constructed, and they are sounded continuously in the drone. Relatively high ratings were also given to the vadi tone, which is designated for each rag and is given emphasis in the melody. The ratings of both groups of listeners generally reflected the pattern of tone durations in the musical contexts. This result suggests that the distribution of tones in music is a psychologically effective means of conveying the tonal hierarchy to listeners whether they are familiar with the musical tradition. Beyond this, only the Indian listeners were sensitive to the scales (thats) underlying the rags. For Indian listeners, multidimensional scaling of the correlations between the rating profiles recovered the theoretical representation of scales described by theorists of Indian music.(ABSTRACT TRUNCATED AT 400 WORDS)

Independent processing of visual form and motion.

Rotating or stationary targets were presented simultaneously with a random-dot mask which was itself either rotating or stationary. Observers were required to judge both the form of the target and its motion; these target attributes were manipulated orthogonally in the experiment. The results support the hypothesis that under these conditions figural information is encoded independently from motion information. On a trial-by-trial basis within conditions of target and mask motion combinations, performance in the two tasks was independent. Across conditions, different effects were observed in the two dependent measures. Form judgments were generally more accurate for rotating than for stationary targets, particularly when the mask was stationary. Motion judgments showed frequent intrusions from the motion of the mask, so that most errors occurred when target and mask were dissimilar in terms of their motion. The results show differential interference of the random-dot mask on the encoding of the two independent stimulus attributes, and support the possibility of separate processing of figural and motion information.