Imitation Accuracy Research Articles

Pattern Typicality and Dimensional Interactions in Pianists' Imitation of Expressive Timing and Dynamics

Success in an imitation task may be defined in absolute terms (how well the reproduction matches the model) or in relative terms (how much better the reproduction matches the model than the imitator's spontaneous production matches the model). In the present study of expressive music performance, it was hypothesized that absolute imitation success would decrease but relative imitation success would increase as the model pattern diverges more and more from the typical pattern of spontaneous production, within reasonable limits. This hypothesis received support in Experiment 1, which required pianists first to play a musical excerpt spontaneously and then to imitate model performances instantiating different patterns of expressive timing or dynamics, with the other dimension held constant at a typical pattern. The typical expressive pattern for a given musical passage seems to function as a cognitive schema that biases perception, memory, and (re) production of expressive nuances. The results also suggested that imitation of different dynamic patterns affects expressive timing (louder tones were followed by longer interonset intervals), whereas imitation of different timing patterns had little effect on produced dynamics. The latter findings were replicated in Experiment 2, which presented models that differed in both timing and dynamics. Attention to both dimensions simultaneously also reduced imitation accuracy, especially for timing.

A procedure for an automated measurement of song similarity

Assessment of vocal imitation requires a widely accepted way of describing and measuring any similarities between the song of a tutor and that of its pupil. Quantifying the similarity between two songs, however, can be difficult and fraught with subjective bias. We present a fully automated procedure that measures parametrically the similarity between songs. We tested its performance on a large database of zebra finch, Taeniopygia guttata, songs. The procedure uses an analytical framework of modern spectral analysis to characterize the acoustic structure of a song. This analysis provides a superior sound spectrogram that is then reduced to a set of simple acoustic features. Based on these features, the procedure detects similar sections between songs automatically. In addition, the procedure can be used to examine: (1) imitation accuracy across acoustic features; (2) song development; (3) the effect of brain lesions on specific song features; and (4) variability across different renditions of a song or a call produced by the same individual, across individuals and across populations. By making the procedure available we hope to promote the adoption of a standard, automated method for measuring similarity between songs or calls.

Listeners and disguised voices: the imitation and perception of dialectal accent

This paper presents an experimental investigation into whether a group of speakers could produce convincing text readings in various dialectal accents of Swedish, and the performance of listeners in identifying the accents and determining whether the accents were natural or a disguise. It was observed that individual speakers vary greatly in their ability to produce plausible imitations of accents and to mask their own dialectal background. Examination of the listeners' perceptual strategies contributes an important dimension to the understanding of reasoning processes in earwitnesses. The linguistically trained listeners were found to use combinations of accent markers as cues to the degree of naturalness, although some of the judgements reflected misconceptions or preconceived ideas about the possible forms of specific accents. The hazards of using speakers with certain accent features in voice line-ups and the potential problems associated with earwitness accent identification are discussed.

Effect of a Pragmatic Context on Elicited Imitation

Elicited imitation is often used to measure the linguistic performance of elementary school children. Conflicting results have been reported regarding the effect of context vs no context on children's elicited imitation behavior. In the present study, Carrow's Elicited Language Inventory was administered in its standardized form and in an experimental form using discourse cues to 8 boys and 1 girl who were language-disordered. Ages ranged from 5:4 to 7:11. Significant differences were noted in linguistic performance, as measured by accuracy of imitation, between pragmatic context and no-context conditions of test. The findings indicated that the pragmatic context improved linguistic accuracy of imitation for the language-disordered children. Diagnostic implications are discussed.

Categorical tendencies in imitating self-produced isolated vowels

An earlier experiment requiring literal imitation of synthetic isolated vowels from [u]-[i] and [i]-[æ] continua [8] was replicated using as stimuli vowels produced by the subjects themselves. Even though imitation accuracy was much improved, the responses deviated from the stimuli in ways similar to those observed previously with synthetic stimuli. That is categorical tendencies (nonlinear stimulus-response mappings of formant frequencies, nonuniform response variability across each continuum, and peaks in formant frequency distributions) were obtained even with stimuli that matched the subjects articulatory capabilities. This rules out one possible explanation of the observed categorical tendencies, viz., that they arise in the perceptual translation of synthetic stimuli into a talker's production space.

THE INTERPRETATION OF ELICITED SENTENCE IMITATION IN A STANDARDIZED CONTEXT

Elicited imitation has been used to study language acquisition and ability, language disorders, and nonstandard dialects While it was initially assumed that elicited imitation reflected knowledge of grammar, later work suggests considerable variability in performance, e.g., children do not always imitate sentences they are known to have spontaneously produced at another time. This paper reviews research on elicited sentence imitation, distinguishing naturalistic and standardized applications of the technique. A six‐year program of research is summarized which suggests that elicited imitation in a standardized context yields highly stable individual difference scores, improvement with age in accuracy of imitation, superior performance by middle class students, correlations between “imitation” tests and natural environment language performances, significant correlations between elicited imitation and widely used tests of general verbalability, and statistical evidence that elicited imitation reflects knowledge of grammar, short‐term memory, and knowledge of vocabulary The inconsistency of child imitations noted by some researchers may be a function of age and nonstandardized observation procedures.

Relationship of reinforcement by student clinicians and peers to accuracy of imitated grammatical constructions during language training.

Percentages of correctly imitated grammatical constructions were examined within a framework of reinforcement theory. Four small treatment groups, each of 4 language-delayed children, were repeatedly observed interacting with different student-clinicians. The Therapy Reinforcement Schedule was used to obtain frequency counts of verbal and non-verbal reinforcements so that within each language group the students could be objectively divided into those who frequently and infrequently were reinforcing, and the children into those for whom peer-reinforcement was high or low. The resulting 4 groups were compared for proportions of accurately imitated constructions with a repeated-measures analysis of variance design (student-clinicians' reinforcement x peers' reinforcement x trials). Correctly scored imitations increased significantly over trials. In addition, children interacting with frequently reinforcing students received higher imitation scores than those with infrequently rewarding ones. Significant main effects of reinforcement by the peer group were not observed, although a reliable interaction of student-clinicians' reinforcement x peers' reinforcement was present. Regression analyses indicated the importance of certain types of reinforcements in predicting accuracy of imitation.

Measuring musical abilities of autistic children.

Three normal children with reported musical ability and three autistic children were tested for the ability to imitate individual tones and series of tones delivered by voice, piano, and synthesizer. Accuracy of imitation was judged by two independent observers on the basis of pitch, rhythm, and duration. The autistic children overall performed as well as or better than the age-matched normal children. These results are discussed and their implications for future neurological and clinical research are considered.

Facilitating accuracy of imitative articulation through reception training

Accuracy of imitation of nonsense words was examined in first- and second-grade children (65–99 months of age) as a function of prior reception training. Two experiments were conducted, involving within-subject comparisons. In the first, one group of words was trained as labels for nonsense objects, a second received noncontingent feedback yoked to the labeling words, a third was presented an equal number of times to control for exposure, and a fourth group was not included in the training phase. Testing involved accuracy of imitation of all four groups of words. Both the feedback and exposure words were imitated less accurately than the labeling words, but more accurately than the nonexposure controls. The second experiment examined the length of the label-object association, using an overtraining procedure. Words which came under the discriminative control of objects for greater numbers of trials were imitated more accurately than those meeting only a minimum discrimination criterion.

Feedback and fidelity: Effects of contingent consequences on accuracy of imitation

Accuracy of imitation by sixty kindergarten subjects was examined using a task in which a female adult modeled a series of pegboard patterns and delivered accuracy-contingent feedback. Four methods of feedback and a nofeedback control were compared. All four feedback groups were more accurate than the control group. The feedback conditions were: positive only, negative only, positive and negative, and negative with correction. The last condition resulted in greater accuracy than the others, which did not differ. All groups, including the control, improved significantly over trials. Accuracy of performance on interspersed, nonfeedback trials was maintained by feedback to the other patterns. Finally, imitation of repeating stimulus patterns did not differ from performance with nonrepeating patterns.

The effects of social isolation and characteristics of the model on accent imitation in fourth-grade children

This study investigated some possible determinants of sociolinguistic change through the use of an experimental analog. General American speakers were asked to learn the role of a British character in a puppet play under varying motivational conditions. In the absence of any instruction to do so, children who were exposed to a tape recorded model presented as nurturant and powerful imitated the model's British accent to a greater extent than did children who heard the some model presented as helpless. The effect of preceding social isolation interacted with the sex of the child and/or that of the model.