Prelude or requiem for the 'Mozart effect'?
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Cognition↗
Biomedical subjects
I Peretz
Publications and source records attributed to I Peretz.
Processing prosodic and musical patterns: a neuropsychological investigation.
To explore the relationship between the processing of melodic and rhythmic patterns in speech and music, we tested the prosodic and musical discrimination abilities of two "amusic" subjects who suffered from music perception deficits secondary to bilateral brain damage. Prosodic discrimination was assessed with sentence pairs where members of a pair differed by intonation or rhythm, and musical discrimination was tested using musical-phrase pairs derived from the prosody of the sentence pairs. This novel technique was chosen to make task demands as comparable as possible across domains. One amusic subject showed good performance on both linguistic and musical discrimination tasks, while the other had difficulty with both tasks. In both subjects, level of performance was statistically similar across domains, suggesting shared neural resource for prosody and music. Further tests suggested that prosody and music may overlap in the processes used to maintain auditory patterns in working memory.
Adult↗
Music and emotion: perceptual determinants, immediacy, and isolation after brain damage.
This study grew out of the observation of a remarkable sparing of emotional responses to music in the context of severe deficits in music processing after brain damage in a non-musician. Six experiments were designed to explore the perceptual basis of emotional judgments in music. In each experiment, the same set of 32 excerpts taken from the classical repertoire and intended to convey a happy or sad tone were presented under various transformations and with different task demands. In Expts. 1 to 3, subjects were required to judge on a 10-point scale whether the excerpts were happy or sad. Altogether the results show that emotional judgments are (a) highly consistent across subjects and resistant to brain damage; (b) determined by musical structure (mode and tempo); and (c) immediate. Experiments 4 to 6 were designed to asses whether emotional and non-emotional judgments reflect the operations of a single perceptual analysis system. To this aim, we searched for evidence of dissociation in our brain-damaged patient, I.R., by using tasks that do not require emotional interpretation. These non-emotional tasks were a 'same-different' classification task (Expt. 4), error detection tasks (Expt. 5A,B) and a change monitoring task (Expt. 6). I.R. was impaired in these non-emotional tasks except when the change affected the mode and the tempo of the excerpt, in which case I.R. performed close to normal. The results are discussed in relation to the possibility that emotional and non-emotional judgments are the products of distinct pathways.
Adult↗
Contribution of different cortical areas in the temporal lobes to music processing.
Music processing ability was studied in 65 right-handed patients who had undergone unilateral temporal cortectomy for the relief of intractable epilepsy, and 24 matched normal controls. The ability to recognize changes in note intervals and to distinguish between different rhythms and metres was tested by presentation of sequences of simple musical phrases with variations in either pitch or temporal dimensions. The responses (right or wrong) enabled us to determine in which component of the music processing mechanism the patients had deficits and hence, knowing the positions of the surgical lesions, to identify their separate cerebral locations. The results showed that a right temporal cortectomy impaired the use of both contour and interval information in the discrimination of melodies and a left temporal cortectomy impaired only the use of interval information. Moreover, they underlined the importance of the superior temporal gyrus in melody processing. The excision of a part of the auditory areas (posterior part of the superior temporal gyrus) was found to be most detrimental for pitch and temporal variation processing. In the temporal dimension, we observed a dissociation between metre and rhythm and the critical involvement of the anterior part of the superior temporal gyrus in metric processing. This study highlights the relevance of dissociating musical abilities into their most significant cognitive components in order to identify their separate cerebral locations.
Adult↗
Exposure effects on music preference and recognition.
In three experiments, the effects of exposure to melodies on their subsequent liking and recognition were explored. In each experiment, the subjects first listened to a set of familiar and unfamiliar melodies in a study phase. In the subsequent test phase, the melodies were repeated, along with a set of distractors matched in familiarity. Half the subjects were required to rate their liking of each melody, and half had to identify the melodies they had heard earlier in the study phase. Repetition of the studied melodies was found to increase liking of the unfamiliar melodies in the affect task and to be best for detection of familiar melodies in the recognition task (Experiments 1, 2, and 3). These memory effects were found to fade at different time delays between study and test in the affect and recognition tasks, with the latter leading to the most persistent effects (Experiment 2). Both study-to-test changes in melody timbre and manipulation of study tasks had a marked impact on recognition and little influence on liking judgments (Experiment 3). Thus, all manipulated variables were found to dissociate the memory effects in the two tasks. The results are consistent with the view that memory effects in the affect and recognition tasks pertain to the implicit and explicit forms of memory, respectively. Part of the results are, however, at variance with the literature on implicit and explicit memory in the auditory domain. Attribution of these differences to the use of musical material is discussed.
Adult↗
Role of familiarity in auditory discrimination of musical instrument: a laterality study.
Normal subjects were presented with dichotic pairs of sounds differing in pitch-timbre combination. Their task was to detect a fixed target sound that occurred randomly but equally often in the right and the left ear in two-thirds of the trials. Half the subjects performed this task with sounds produced by familiar natural instruments (violin, flute, guitar and drum), and the other subjects performed the same task but with the sounds played backwards, hence being less recognizable. Subjects were quicker and more accurate in discriminating forwards than backwards played sounds, hence exhibiting sensitivity to familiarity with musical instrument sounds. Recourse to this knowledge was, however, not associated to a shift in laterality. For both familiar and unfamiliar sounds, a robust left-ear advantage (LEA) was observed.
Acoustic Stimulation↗
Recognition of music in long-term memory: are melodic and temporal patterns equal partners?
The notion that the melody (i.e., pitch structure) of familiar music is more recognizable than its accompanying rhythm (i.e., temporal structure) was examined with the same set of nameable musical excerpts in three experiments. In Experiment 1, the excerpts were modified so as to keep either their original pitch variations, whereas durations were set to isochrony (melodic condition) or their original temporal pattern while played on a single constant pitch (rhythmic condition). The subjects, who were selected without regard to musical training, were found to name more tunes and to rate their feeling of knowing the musical excerpts far higher in the melodic condition than in the rhythmic condition. These results were replicated in Experiment 2, wherein the melodic and rhythmic patterns of the musical excerpts were interchanged to create chimeric mismatched tunes. The difference in saliency of the melodic pattern and the rhythmic pattern also emerged with a music-title-verification task in Experiment 3, hence discarding response selection as the main source of the discrepancy. The lesser effectiveness of rhythmic structure appears to be related to its lesser encoding distinctiveness relative to melodic structure. In general, rhythm was found to be a poor cue for the musical representations that are stored in long-term memory. Nevertheless, in all three experiments, the most effective cue for music identification involved the proper combination of pitches and durations. Therefore, the optimal code of access to long-term memory for music resides in a combination of rhythm and melody, of which the latter would be the most informative.
Adult↗
[Dissociations between music and language functions after cerebral resection: A new case of amusia without aphasia].
We present the neuropsychological study of a patient, I.R., who sustained bilateral damage to the temporal lobes and to the right frontal lobe as a result of successive brain surgeries that occurred ten years earlier. The patient is 40 years old and right-handed; she had no special training in music or in language, representing, therefore, the large majority of listeners. Her performance is compared to that of four neurologically intact subjects who are closely matched in terms of education, sex and age. In the present study, we report I.R.'s performance on various tests aiming at assessing her general cognitive functioning with a particular focus on auditory aspects. The results show that, despite extensive damage to her auditory cortex, I.R.'s speech abilities are essentially intact (see Tables 1 and 2). The only impairments that are detected in the language domain are related to a short-term memory deficit, to some abnormal sensitivity to retroactive interference in long-term memory (see Table 3) and to articulation. These difficulties do not, however, affect linguistic communication, which is obviously undisturbed I.R. is not aphasic). Similarly, I.R. does not experience any difficulty in the recognition and memorization of familiar sounds such as animal cries, traffic noises and the like (see Tables 5 and 7). In contrast, I.R. is severely impaired in most musical abilities: She can no longer discriminate nor identify melodies that were once highly familiar to her; she can no longer discriminate nor memorize novel melodies (see Table 4). Her pattern of musical losses is compatible with a basic and severe perceptual deficit that compromises access to and registration in memory systems. The observation that the auditory impairment affects music and spares language and environmental sounds refers to a neuropsychological condition that is known as music agnosia. I.R. represents, to our knowledge, the fourth case of music agnosia available in the literature (Peretz et al., 1994; Griffiths et al., 1997). The existence of such cases suggests that music processing is not mediated by a general-purpose auditory architecture but by specialized cortical subsystems. Not only does I.R. suffer from music agnosia, but she is also impaired in the discrimination and recognition of musical instruments and of human voices (see Table 5). These latter two deficits probably do not result from the music agnosic condition. Rather, they seem to reflect damage to adjacent brain areas that are specialized in timbre processing (see Peretz. et al., 1994, for the relevant discussion). It is also worth mentioning that I.R. appears to be impaired in musical expressive abilities as well: I.R. can no longer sing a single note. Thus, her losses are rather general in the musical domain, hence justifying the classification of her case as amusia. Cases of amusia without aphasia are relatively frequent in the neuropsychological literature. However, all of these reported cases are anecdotal. Thus, in the present study, special focus is given to the measurement and direct comparison of performance in the language and music domain; in both domains, task characteristics and materials were as similar as possible. To this aim, the lyrics and the tune of the same popular song excerpts were used. The musical and the spoken parts were presented separately in a primed familiarity decision task and in a memory recognition task. In both situations, I.R. performs at or close to chance when she has to deal with music, whereas she recognizes easily and performs normally on the spoken material (see Tables 6 and 7). These results clearly argue for the autonomy of music and language in the processing of auditory information.
Adult↗
Atypical hemispheric specialization in intellectual deficiency.
In order to determine the relation between hemispheric specialization for language and intellectual deficiency, two groups of lower-IQ subjects were compared to normal-IQ controls on word-dichotic listening tasks. Two conditions in which stimuli differed by their level of phonological complexity were used. Normal controls showed the expected right-ear advantage in both conditions. Moreover, they showed a greater magnitude of ear difference on the condition requiring higher-order phonological processing. In the mentally deficient group, almost half the subjects exhibited a left-ear advantage and they showed no difference between the two conditions in terms of the magnitude of ear difference. These results point to the presence of atypical hemispheric specialization in mentally deficient subjects.
Adolescent↗
Left ear advantage in pitch perception of complex tones without energy at the fundamental frequency.
Normal right-handed subjects were required to make pitch comparisons of complex tones in which the fundamental frequency was either present or absent. In both conditions, tones were presented monaurally. An increase in left-ear superiority was observed in the response time measurements when the fundamental was absent. These findings support the notion that the right hemisphere possesses a special mechanism for pitch computation.
Adult↗
Examination of the working memory components in normal aging and in dementia of the Alzheimer type.
The verbal and attentional components of working memory were examined in patients with Alzheimer's disease, normal elderlies, and young controls. Patients with Alzheimer's disease, showed a reduced span but were sensitive to word length. This is indicative of a functional rehearsal procedure. However, the effect of phonological similarity on immediate recall was smaller in patients with Alzheimer's disease and these patients showed a depressed performance in tasks of phonological analysis. There was also a significant decrement in a task that assessed the attentional component of working memory. Examination of individual patterns of performance showed that the phonological deficiency was severe in a subgroup of patients while the attentional deficit was more general.
Adolescent↗
Perceiving the tonal ending of tune excerpts: the roles of pre-existing representation and musical expertise.
In this study, sensitivity to tonal relations was assessed by using real melodies instead of traditional scales or chords. Two groups of listeners-one trained, one untrained-rated the goodness of fit of each of the 12 tones of the chromatic scale as the final note of familiar and unfamiliar tune excerpts. The unfamiliar excerpts were the mirror forms in pitch and time of the familiar tunes. The results showed that musicians and nonmusicians exhibited responses that were governed by tonal relations with both familiar and unfamiliar tunes. These findings were corroborated by multiple-regression analysis, which revealed that the pattern of ratings reflected knowledge of the musical structure, beyond the contribution of surface features such as note frequency or pitch proximity between the two last tones.
Adolescent↗
[Musical excerpts: indices relating to familiarity, age of acquisition and verbal associations].
The objective of the present study was to establish estimates of familiarity, of age of acquisition, and of verbal associations in relation to 144 musical excerpts drawn from the repertoire of tunes that is expected to be shared by all French-speaking Québec university students. The excerpts were synthesized monophonic lines (which can be found in Appendix B) that were tape recorded. A first group of 60 university students were required to indicate their degree of familiarity (on a 5-point scale) with each excerpt and the age period at which they learned the excerpt. A second group of 60 students indicated whether the original tune was vocal or instrumental as well as the first words that came to mind. In each group, half the subjects were presented with the 144 excerpts in a different order. Overall, the material was found to be highly familiar and to have been mostly learned between the ages of 5 and 15. Most of the excerpts were easily categorized as vocal or instrumental with the exception of 26 excerpts, which were accordingly classified as ambiguous. Finally, 57% of the excerpts elicited verbal responses. There was a high level of agreement in some of the verbal responses provided, referred to as dominant responses. In contrast, 21 excerpts gave rise to very little verbal recall, hence specifying a subset of "purely" musical material. All indices of familiarity, of acquisition age, and of verbal responses (specifying the overall rate of verbal responding, the content of the dominant response as well as its frequency of occurrence) are provided for each excerpt in Appendix A. Finally, the most interesting aspect of the present study was revealed by the analysis of the errors in verbal recall. Subjects tended to fill in missing elements by words that fitted the meaning of song lyrics as well as the temporal structure of the music. For instance, instead of providing "MON BEAU SAPIN", subjects would provide "mon grand sapin". The use of such a procedure is consistent with the notion that music serves as a memory aid which facilitates the communication of news and ideas.
Adult↗
Functional dissociations following bilateral lesions of auditory cortex.
We present two patients with bilateral lesions of the superior temporal cortex who manifested a number of functional dissociations in the auditory domain. The perception of speech and environmental sounds were preserved; yet, the perception of tunes, prosody and voice was impaired. As the processing of melodic but not rhythmic variations in musical sequences was selectively disturbed, the deficit cannot be attributed to a general impairment in auditory memory or sequential processing. These findings suggest that melody processing is not mediated by a general-purpose auditory architecture but by specialized cortical subsystems residing within the lesioned areas. Current taxonomies of auditory agnosia and models of normal music cognition are evaluated in light of the functional dissociations manifested by these patients.
Adult↗
Boundaries of separability between melody and rhythm in music discrimination: a neuropsychological perspective.
The detailed study of a patient who suffered from a severe amelodia without arhythmia as a consequence of bilateral temporal lobe damage revealed that the processing of melodic information is at least partially separable from the processing of rhythmic information. This dissociation was replicated across different sets of material, was supported by the presence of a reversed association, and was maintained in conditions that promote integration in the normal brain. These results argue against the view that melody and rhythm are treated as a unified dimension throughout processing. At the same time, they support the view that integration takes place after early separation of the two dimensions.
Adult↗
The role of contour and intervals in the recognition of melody parts: evidence from cerebral asymmetries in musicians.
The left hemisphere (LH) has been shown to be involved in tasks requiring interval-based procedures, and the right hemisphere (RH) in task allowing a contour-based approach in melody recognition. Support for this distinction was obtained by studying contour properties at the level of whole melodies and interval characteristics at the level of individual tones. The purpose of the present study was to extend the validity of this two-component model at the level of melody parts. It was predicted that both the LH interval-based procedure and the RH contour-based approach contribute to melody part recognition, but that their respective efficiency will depend on the structure of the parts used as recognition probes. To address this question along the lines of prior work Bever and Chiarello, Science 185, 537-539, 1974), a probe recognition task was presented monaurally to right-handed musicians. The recognition probes that corresponded to one of the melody parts were found to be far more accurately and quickly recognized than the probes that bridged across the contour-defined boundary. On the latter, subjects performed initially at about chance level. They improved, however, after some exposure to the task, that is on the second half of the test material in Experiment 1 and on the second half of Experiment 2, and displayed the predicted interaction between laterality and probe type. Subjects recognized the probes that coincided with a part delineated by contour boundaries in the left ear (or the RH) more easily; whereas they recognized more easily the probes which crossed contour boundaries in the right ear (or the LH). These findings justify the consideration of contour as an important grouping factor in pitch sequences and emphasize the usefulness of laterality effects.
Adult↗
Contribution of articulatory rehearsal to short-term memory: evidence from a case of selective disruption.
We describe a brain-damaged patient with disturbed articulatory rehearsal in whom all predictions derived from a working memory model were fulfilled. The patient showed a reduced verbal span, no word-length effect on immediate recall in both the visual or the auditory modalities, no phonological similarity effect in the visual modality, and no effect of articulatory suppression. A slowed overt articulation rate provided independent evidence for disrupted articulatory rehearsal. The other components of working memory, the visuospatial scratch-pad, phonological storage system, and central executive, were functional. The selectivity of the deficit can be taken as evidence for the specific role of articulatory rehearsal in working memory.
Aphasia↗
Processing of local and global musical information by unilateral brain-damaged patients.
Melody processing in unilaterally brain-damaged patients was investigated by manipulating the availability of contour and metre for discrimination in melodies varying, respectively, on the pitch dimension and the temporal dimension. On the pitch dimension, right brain-damaged patients, in contrast to left brain-damaged patients and normal controls, were found to be little affected by the availability of contour as a discrimination cue. However, both brain-damaged groups were impaired on tasks requiring consideration of pitch interval structure. These findings are consistent with hierarchical contribution of the cerebral hemispheres, with the right hemisphere being primary in representing the melody in terms of its global contour and the left hemisphere by filling in the intervallic structure. On the temporal dimension, only the discrimination of durational values (the rhythm) was found to be impaired by a lesion in either hemisphere, which spared, however, the metric interpretation of the musical sequences. These latter results are discussed in the light of current models of temporal processing. Finally, evidence of double dissociation between the processing of the pitch dimension and the processing of rhythm was obtained, providing further support for the need to fractionate musical perceptual abilities in order to arrive at a theory as to how the two hemispheres cohere to produce a musical interpretation of the auditory input.
Adult↗