Friday, 9 May 2014

The enigma of dyslexic musicians

Can a musician be dyslexic? The question might seem an odd one, but its relevance becomes clear when you look at auditory theories of dyslexia. We've known for several decades that most dyslexics are poor at phonological processing – segmenting and identifying speech sounds and linking these to written letters. Some researchers argue that this is a language-specific deficit, but others have amassed evidence to suggest that the phonological difficulties are downstream consequences of a broader problem with auditory perception. In a recent paper, Weiss and colleagues turned this issue on its head and looked at dyslexia in people who ought to be very good at auditory perception, i.e., musicians.

A frustrating aspect of the study was that we don't know how common dyslexia is in musicians. The authors mention that Nigel Kennedy and John Lennon were dyslexic, but the evidence is anecdotal and there appear to have been no proper surveys to compare the prevalence of dyslexia in musicians with other types of expert.

Be this as it may, Weiss et al managed to recruit a group of 24 professional musicians who reported difficulty reading, who were compared with other musicians matched for age, musical education and reasoning skills. They screened these individuals to confirm that the dyslexic group were poor on reading measures, whereas the control group was not. The study did also include parallel groups of dyslexics and controls who were not musicians, but these were recruited from a different study and they did not complete all of the same experimental measures.

Musicians with dyslexia were impaired on measures of auditory working memory
The principal findings were that the musicians did well on tests of auditory discrimination, regardless of whether or not they were dyslexic. On the other hand, the two groups of musicians differed significantly on tests of auditory working memory, with dyslexics impaired on measures of memory span for syllables, melodic patterns and rhythmic patterns.

So can we conclude from this study that problems in basic auditory perception are not implicated in dyslexia? Well, things are not so simple. Few people would accept that all dyslexia is the same: it is likely that there are multiple reasons for reading failure. So showing that someone is dyslexic despite good auditory perception is not all that informative: their dyslexia might arise from another cause. It would be more interesting if one could show that someone was not dyslexic despite poor auditory perception. In fact, there are such instances in the literature: Ayotte et al (2002), for instance, described eleven individuals with congenital amusia, who reported no learning difficulties except with music. And our group have studied children with mild-moderate hearing loss who had age-appropriate literacy scores despite poor auditory discrimination. So there are reasons to question whether the auditory deficit observed in many (non-musician) dyslexics is a causal factor. It therefore is interesting to ask whether the dyslexic musician data might suggest alternative approaches.

Given that auditory perceptual problems were not at the root of the dyslexia in musicians, then what is? The authors proposed that deficient auditory memory was the culprit. The dyslexic musicians seemed to have a generic problem with short-term retention of all kinds of auditory material, be it verbal or nonverbal. This suggests one of two possible interpretations: first, there could be two kinds of dyslexia: one (seen in non-musicians) due to impaired auditory discrimination, and the other (seen in musicians) to poor auditory memory. Alternatively, the notion of an auditory discrimination deficit could be a red herring, with auditory memory a more salient reason for poor reading in all people, both musicians and non-musicians. It is unfortunate that data on the nonverbal auditory memory tasks was not available for the non-musicians, as this might have helped distinguish these possibilities.

Nevertheless, there are reasons to be cautious in interpretation of these results. The memory limitations found in the dyslexic musicians were surprising, because one might have anticipated that such a deficit would be a handicap for a professional musician. One question that this study raises is whether the specific auditory tasks used in this study might have elicited specific strategies in those with musical training which could confound interpretation of them as pure memory measures. There may have been benefit in mentally encoding the materials in memory tasks by verbal labels or visualising a musical score. It is possible that the dyslexic vs non-dyslexic musicians differed in the ease with which they adopted such strategies, and that this, rather than any more fundamental memory deficit, led to group differences.

Altogether this is an intriguing study that is far from conclusive but does raise further questions about the relationship between verbal and nonverbal auditory processing, as well as suggesting that auditory memory may be a more crucial component of dyslexia than basic auditory discrimination. And it opens a new line of research into dyslexia in musicians, who are a fascinating group because of their prolonged training in aspects of auditory perception.

_________________________________ ResearchBlogging.org
Weiss, A., Granot, R., & Ahissar, M. (2014). The enigma of dyslexic musicians Neuropsychologia, 54, 28-40 DOI: 10.1016/j.neuropsychologia.2013.12.009

Post written for the BPS Research Digest by guest host Dorothy Bishop, Professor of Developmental Neuropsychology and a Wellcome Principal Research Fellow at the Department of Experimental Psychology in Oxford, Adjunct Professor at The University of Western Australia, Perth, and a runner up in the 2012 UK Science Blogging Prize for BishopBlog.

2 comments:

  1. Anonymous1:22 pm

    An very interesting article. My son who is severely dyslexic (he has extremely poor short term memory) is also a very talented musician (he was offered a contract with a leading orchestra recently but it is not his profession). He struggled to read for many years and getting the written word down on paper is a great challenge - never really overcome despite being now in his 20's.

    He started learning when he was 10 and we didn't realise it at the time when he chose the trumpet it was the ideal instrument. He has since tried keyboard and guitar. Reading 1 line of music is a challenge for him let alone 2 as in piano music. In fact reading music full stop is difficult. He really has to hear the tune before he can interpret the printed notes. He used to practise using cd's which came with 2 versions of a tune with and without the main theme ie backing only that he could play along with. The first grade he took he got 0 points on theory and almost max on the practical pieces. Expecting him to remember a rhythm and to repeat it back during the exam or remember sequences as in scales was nigh near impossible. Yet he has an inbuilt musicality which allowed him to overcome the dyslexia. He has good auditory skills, his english teacher commented that he was better at listening to stories etc than most others. Whether these skills came as a result of learning music or not I don't know.

    Incidentally my daughter is also dyslexic but doesn't have any musical ability at all - although she does appreciate music. She has much better short term memory abilities than her brother. It is most definitely an intriguing subject.

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    1. Anonymous11:51 am

      I too am and have been fascinated by this subject as I too have an extremely talented musical son who is ...well lets say....neurodiverse...as dyslexia doesn't quite seem to fit the bill. He is a professional classical singer who studied music at Guildhall achieving a 2:1 which was pretty good considering he had not 'studied' music before and finds reading music quite hard. I am a dyslexia specialist who although not dyslexic myself has an Adult ADD husband, and 3 sons 2 of whom are on the same continuum. My singer son has a big organisational problem but particularly severe short term memory problem. He can remember a tune and sing it pitch perfect instantly. His understanding and deep love of music (many genres) is not in question, he lives and breathes it. But he still takes longer than his musician friends to read music and learns in much the same way the previous commenter talked of.

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