17 research outputs found

    Failure to apply signal detection theory to the Montreal Battery of Evaluation of Amusia may misdiagnose amusia

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    This article considers a signal detection theory (SDT) approach to evaluation of performance on the Montreal Battery of Evaluation of Amusia (MBEA). One hundred fifty-five individuals completed the original binary response version of the MBEA (n = 62) or a confidence rating version (MBEA-C; n = 93). Confidence ratings afforded construction of empirical receiver operator characteristic (ROC) curves and derivation of bias-free performance measures against which we compared the standard performance metric, proportion correct (PC), and an alternative signal detection metric, d ′. Across the board, PC was tainted by response bias and underestimated performance as indexed by Az , a nonparametric ROC-based performance measure. Signal detection analyses further revealed that some individuals performing worse than the standard PC-based cutoff for amusia diagnosis showed large response biases. Given that PC is contaminated by response bias, this suggests the possibility that categorizing individuals as having amusia or not, using a PC-based cutoff, may inadvertently misclassify some individuals with normal perceptual sensitivity as amusic simply because they have large response biases. In line with this possibility, a comparison of amusia classification using d ′- and PC-based cutoffs showed potential misclassification of 33% of the examined cases

    Revising the diagnosis of congenital amusia with the Montreal Battery of Evaluation of Amusia

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    This article presents a critical survey of the prevalent usage of the Montreal Battery of Evaluation of Amusia (MBEA; Peretz et al., 2003) to assess congenital amusia, a neuro-developmental disorder that has been claimed to be present in 4% of the population (Kalmus and Fry, 1980). It reviews and discusses the current usage of the MBEA in relation to cut-off scores, number of used subtests, manner of testing, and employed statistics, as these vary in the literature. Furthermore, data are presented from a large-scale experiment with 228 German undergraduate students who were assessed with the MBEA and a comprehensive questionnaire. This experiment tested the difference between scores that were obtained in a web-based study (at participants’ homes) and those obtained under laboratory conditions with a computerized version of the MBEA. In addition to traditional statistical procedures, the data were evaluated using Signal Detection Theory (SDT; Green and Swets, 1966), taking into consideration the individual’s ability to discriminate and their response bias. Results show that using SDT for scoring instead of proportion correct offers a bias-free and normally distributed measure of discrimination ability. It is also demonstrated that a diagnosis based on an average score leads to cases of misdiagnosis. The prevalence of congenital amusia is shown to depend highly on the statistical criterion that is applied as cut-off score and on the number of subtests that is considered for the diagnosis. In addition, three different subtypes of amusics were found in our sample. Lastly, significant differences between the web-based and the laboratory group were found, giving rise to questions about the validity of web-based experimentation

    Word stress perception by congenital amusics

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    Congenital Amusia is a developmental disorder that is defined by diffi- culties with the perception of pitch and rhythm. While it used to be described as a disorder of musical pitch perception, recent publications have shown that congeni- tal amusia also affects linguistic pitch perception. In this chapter we report the first study of word stress processing by congenital amusics. We designed a behav- ioral identification task and a mismatch negativity study using German minimal stress pairs as basis for our stimuli. We considered the acoustic parameters funda- mental frequency (pitch), duration, intensity and spectral slope. Behavioral results surprisingly revealed no pitch processing difficulties for word stress in the amusic group in comparison to controls, and amusics also showed a better usage of dura- tional cues. The electrophysiological results revealed that amusics consistently have an MMN, though it is smaller than that of controls. The present results war- rant further investigation of the use of linguistic cues by congenital amusics

    Auditory imagery in congenital amusia

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    Congenital amusia is a neurogenetic disorder affecting various aspects of music and speech processing. Although perception and auditory imagery in the general population may share mechanisms, it is not known whether previously documented perceptual impairments in amusia are coupled with difficulties in imaging auditory objects. We employed the Bucknell Auditory Imagery Scale (BAIS) to assess participants’ self-perceived voluntary imagery and a short earworm questionnaire to gauge their subjective experience of involuntary musical imagery. A total of 32 participants with amusia and 34 matched controls, recruited based on their performance on the Montreal Battery of Evaluation of Amusia (MBEA), filled out the questionnaires in their own time. The earworm scores of amusic participants were not statistically significantly different from those of controls. By contrast, their scores on vividness and control of auditory imagery were significantly lower relative to controls. Overall, results suggest that the presence of amusia may not have an adverse effect on generating involuntary musical imagery—at the level of self-report—but still significantly reduces the individual’s self-rated voluntary imagery of musical, vocal, and environmental sounds. We discuss the findings in the light of previous research on explicit musical judgments and implicit engagement with music, while also touching on some statistical power considerations
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