Tuesday, October 28, 2014

Musical skills in individuals with autism, who are not savants

In the chapter 7 of Robert Jourdains´s book entitled “Music, the brain and ecstasy”, the author relates the story of Blind Tom, a musical savant, who had a phenomenal music memory for about five thousand pieces, despite his low level of general cognitive ability [1]. As a child psychiatrist, my curiosity about neurodevelopmental disorders leads me to investigate about musical skills in individuals with autism who are not savants. Nowadays research in music cognition in autism is a familiar topic, however, back in 1997 when Jourdain had his book released, this topic was not pursued by researchers.

To begin with, autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by impairments in social functioning, communication, and repetitive behaviors and restricted interests [2]. It has an estimated prevalence of 1 in 88 children aged 8 years [3]. Individuals with ASD also exhibit sensory disturbances and can therefore display atypical reactions to the sensory environment [4].

The history of ASD has shown that the individuals with this disorder give increased attention to music. Leo Kanner, the doctor who first described the term “infantile autism” in 1943, reported several instances of “extraordinary music memory” in his clinical group. In fact 6 out of 11 individuals described exhibited music-related behaviors, which were considered extraordinary given their developmental levels. An outstanding example was case number 9, who showed an unusual enjoyment and appreciation for music and was able to discriminate between 18 symphonies and identify their composers by 18 months of age [5].

Despite these interesting reports, the first study to assess musical skills in non-savant children with autism only took place 36 years after, in 1979.  Applebaum and his colleagues observed that children with autism had a superior performance on reproducing atonal melodies than children with typical development and who had higher levels of musical experience [6]. The following study in this field was performed by Heaton et al. in 1998. They examined absolute pitch (AP) ability (the ability to produce or identify specific pitches without reference to an external standard) in musically naive children with autism. Results showed superior recall for the tone/animal pairings in the autism group relative to IQ matched neurotypical controls [7]. Subsequent studies in pitch perception have also been consistent indicating that short and long term pitch memory and labelling are superior in autism [8, 9, 10, 11]. According to Brown [12], the incidence of AP among individuals with autism is estimated to be 1 in 20. It is of interest to note that enhanced pitch perception in this population exists especially in those individuals with a history of delayed speech onset. Nevertheless, the causal relationship between language impairment and superior pitch perception is yet unclear [13].

With respect to the perception of other low-order music features such as loudness, my clinical experience within this population supports my idea that individuals with ASD are hypersensitive to loud sounds, causing them great distress and aversive responses. In fact, few studies have investigated loudness processing in ASD, but typically, results indicated enhanced loudness sensitivity which declines with age and also normal performance on intensity discrimination tasks [14].

Regarding the processing of music´s higher order characteristics, such as emotion, despite the fact that the individuals with autism are impaired in social domains (as in face processing recognition), research has shown that they can recognize emotion in music in childhood and adulthood. In 1999, Heaton et al. were the first to report that children with autism could understand music´s emotional connotation, by examining perception of music mode. In their study, children with autism were as likely to pair fragments of major mode music with happy faces and fragments of minor mode music with sad faces as controls were [15]. More recently, Molnar-Szakacs and his colleagues also showed that children with autism identified the emotional musical excerpts as well as the typical developing control participants [16].

Nevertheless, Temple Grandin, a well-known high-functioning woman with autism, self-reported insensitivity to the affective aspects of music [17]. In my opinion this difference can be due to a disorder named type II alexithymia which is characterized by difficulties in identifying and describing one’s own feelings. This disorder has recently been observed in adults with high functioning autism, and may explain some empathy deficits associated with ASD [18].

Then a question is posed: why do individuals with autism like listening to music? As Kanner initially reported in 1943, music seems to elicit special attention for children with autism. This evidence also occurs when comparing to other auditory stimuli such as speech and environmental noise [18]. But which aspect of music is more attractive? Is it timbre, pitch, loudness, rhythm, mode, harmony, etc.?

One study investigated about motivation for music listening in ASD population, and results did not differ from those of people with typical development. Some of the motivational reasons outlined were “feeling of belonging, satisfying emotional needs”, which generally suggest that the individuals with autism are able to appreciate music [17].

In conclusion, individuals with autism who are not savants also possess some enhanced musical skills. Over the last decade the field of music cognition in autism has been growing. The increased attention and self-motivation to listen to music presented by these individuals can be used for educational purposes or in clinical care (e.g. music therapy or music medicine).

In my opinion, some studies will be rather difficult to design, especially those related to testing hypothesis on emotional processing of music in autism. Furthermore, the heterogeneity of the disorder can be a limitation, and participants should be clinically subgrouped according to characteristics such as history of language impairment, level of intellectual ability, the presence of other comorbidities and type of functioning autism.

[1] R. Jourdain, “Music, The Brain, And Ecstacy: How Music Captures Our Imagination”, Harper Perennial, New York, NY, (1997), p. 196-201
[2] Diagnostic and Statistical Manual of Mental disorders, 5th edition: DSM-5 American Psychiatric Association, Washington D.C., (2013).
[3] Autism and Developmental Disabilities Monitoring Network Surveillance Year 2008 Principal investigators; Centers for Disease Control and Prevention, (2012) “Prevalence of autism spectrum disorders – Autism and Development Disabilities Monitoring Network, 14 sites, United States , 2008”, MMWR Surveill Summ, 61: 1-19
[4] R.A. Stevenson, J. Siemann, et al., “Multisensory temporal Integration in Autism Spectrum Disorders” The Journal of Neuroscience, 34 (2014), 691-697.
[5] L. Kanner, “Autistic disturbances of affective contact”, Nervous Child, 2 (1943), 217-250.
[6] E. Applebaum et al. “Measuring musical abilities of autistic children”, Journal of Autism and Developmental Disorders, 9 (1979). 279-285.
[7] P. Heaton, B. Hermelin, L. Pring, “Autism and pitch processing. A percursor for savant musical ability?”,Music Perception, 15 (1998), 291-305.
[8] Bonnel et al, “Enhanced pitch sensitivity in individuals with autism. A signal detection analysis” Journal of Cognitive Neuroscience, 15 (2003), 226-235.
[9] P. Heaton, “Pitch memory, labelling and disembedding in autism”, Journal of Child Psychology and Psychiatry, 44 (2003), 543-551.
[10] P. Heaton, “Assessing musical skills in autistic children who are not savants”, Philosophical Transactions of the Royal Society, 364 (2009), 1443-1447.
[11] S. Stanutz, J. Wapnick, J.A. Burack, “Pitch discrimination and melodic memory in children with autism spectrum disorders”, Autism, 18 (2014), 137-147.
[12] W. Brown, K. Cammuso, H. Sacks et al. “Autism – related language, personality and cognition in people with absolute pitch: results of a preliminary study”, Journal of Autism and developmental Disorders, 33 (2003), 163-167
[13] A. Bonnel, S. McAdams, B. Smith, C. Berthiaume, A. Bertone, V. Ciocca, J.A. Burack, L. Mottron, “Enhanced pure-tone pitch discrimination among persons with autism but not Asperger syndrome”,Neuropsychologia, 48 (2010), 2465-2475.
[14] K. O’Connor, “Auditory processing in autism spectrum disorder: a review”, Neuroscience and Biobehavioral Reviews, 36 (2012), 836-854.
[15] P. Heaton, B. Hermelin, L. Pring, “Can children with autistic spectrum disorders perceive affect in music? An experimental investigation”, Psychological Medicine, 29 (1999), 1405-1410.
[16] I. Molnar- Szakacs, et al. “The neural correlates of emotional music perception: an fMRI study of the shared affective motion experience (SAME) model of musical experience”, presented at The Neurosciences and Music IV: learning and Memory, Edinburg, Scotland, UK, 2011.
[17] P. Heaton, R. Allen, “With concord of sweet sounds…:new perspective on the discovery of musical experience in autism and other neurodevelopmental conditions”, The Neuroscience and Music III-Disorders and Plasticity: Annals of the New York Academy of Sciences, 1169 (2009), 318-325
[18] I Molnar-Szakacs, P. Heaton, “Music: a unique window into the world of autism”, Annals of the New York Academy of Sciences, 1252 (2012), 318-324.

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