Nordic SAMSPEL Dyslexia as a musical problem Kai Karma – [email protected] The Sibelius Academy, Finland: It has been long known that musical abilites and linguistic abilities are correlated. This is especially evident in language impairments, like dyslexia. Persons with low musical ability often also have problems in reading and writing, and musical exercises often help in training linguistic skills (Hanshumaker 1980). The closer nature of this relationship is not clear, however. This is so partly because both musical aptitude and dyslexia are unclear constructs as such and the mechanisms operating in them are partly unknown or not agreed upon. It is thus pertinent to first briefly describe both constructs to form a basis for later discussion. Musical aptitude Hardly any systematic and comprehensive theories about musical ability exist. Different writers emphasize different characteristics assumed to be parts of musical aptitude or perception; different tests and test items are constructed to measure the hypothesized aspects of the construct. The emphasis may be on the cognitive or on the emotional sides of musical perception as well as on more atomistic or holistic ways of hearing. The atomistic way of thinking concentrates on a person’s ability to hear the elemental characteristics of sound. This may lead, for instance, to tests where the abilities to hear small differences in pitch, intensity, duration and timbre are measured. The holistic approach stresses the importance of bigger wholes in music; these are often seen as essential from the point of view of the meaning or emotion in music. The atomistic approach often ignores the structural aspects of music while the holistic approach often uses subjective and culture-dependent structures, such as samples from the music of one culture. These are used as examples or measures of musical principles which are intended to be general in nature. To avoid these extremes, Karma (1973) defined musical aptitude as an ability to structure auditive material or an auditory structuring ability. This means a general ability to relate sounds with each other; sets of these relationships are structures. This definition includes any kinds of sounds, not just “musical” sounds. There is no reason to limit a psychological construct according to culture-dependent and changing ideas about what “music” or “musical sounds” are. The perception is defined by the state of the listener rather than the quality of the stimulus; any sound patterns can be heard “musically”. One important class of sounds usually not seen as “musical” are phonemes, the sounds of language. It is important to understand that hearing sounds separately, unrelated, is not the same as hearing sound patterns or structures. One may hear the pitches, intensitites, durations, or ___________________________________________________________________________ ISME2002 timbres of sounds very accurately without having a good idea about the structures they form. In the same way, it is possible to have a very good idea about the patterns even if the hearing of the absolute qualities of the sounds is not perfect. The differences between the elements have to be heard, however. Patterns are composed of differences; without differences there are no patterns. Reasonable sensory acuity should thus be seen as a necessary but not sufficient condition for auditory structuring. Dyslexia Different cases of reading impairment may have very dissimilar primary causes. Difficulties may be caused by low intelligence, poor linguistic environment, or emotional disturbances, for instance. Even if extraneous variables like these are ruled out, the remaining cases, which may be seen as representing "developmental dyslexia", form a heterogenous group (Tallal 1980, Duane 1983). The assumed causes of developmental dyslexia may be classified in numerous ways. One basic continuum that dyslexias often can be placed on can be described as linguistic vs. perceptional (Bakker 1983). At one end of the continuum the difficulties would thus be symptoms caused by a broader language impairment, at the other consequences of dysfunction in perception. Even dyslexia that seems to be linguistic in nature may have its origins in perception, however. A hearing deficit, for instance, may lead to an unclear or incorrect memory store for spoken language. There are many reasons why some cases of dyslexia can be seen as mainly linguistic in nature. According to Tallal (1980), children diagnosed as reading-impaired may often actually be cases of receptive and/or expressive language delay. Duane (1983) lists several reasons why reading disability can be seen as a symptom of a general language impairment: the delay in speech production milestones in reading impaired population, slow rate of speech production, disturbances of body schema that have strong verbal components, difficulty in aquiring a second language and strong and persistent correlations found between reading and language underachievement. When dyslexia is believed to be mainly a consequence of perceptual impairments, it is natural to see it as primarily either visual or auditory (Hicks & Spurgeon 1982), or as a problem in audiovisual cross-modal functioning (Hicks 1981). Early theories tended to use predominantly visual explanations as depicted by the term "word blindness". The focus of interest has moved towards auditory/temporal explanations, however. There are several resons for this. Purely visual training has often been unproductive (Hicks & Spurgeon 1982). Also, the problem may not be in visual perception as such, but rather in later processing of the perception, like labelling (Crispin et al. 1984). Auditory reading impairment, again, can be classified in several ways. One classification useful from the point of view of this article is to see the causes in three groups: sensory disrimination, structuring the auditory elements, or the speed of perception. The term discrimination is not used quite consistently, it may mean either hearing the differences between elemental qualities, like different phonemes, or hearing the differences between higher order qualities, like phoneme structures, words and sentences. The writer of this article feels that it is clearer to use the term discrimination in the first sense; this would mean hearing the differences between elemental qualities like phonemes, intensities, and durations. When one is expected to hear the differences between words, sentences, rhythms, or melodies, a discrimination task is used to measure structuring abilities. Spoken languages can be decomposed into limited, often rather small, sets of phonemes which are used to form expressions like words and sentences. Hearing the differences ___________________________________________________________________________ ISME2002 between these phonemes, i.e. sensory discrimination, is not sufficient for understanding speech, however. The semantic content of an expression is mostly conveyed by the way the elements have been put together, i.e. sequential structures of the available phonemes. This means that in order to understand an expression one has to be able to conceive its phoneme structure. Compared with discrimination, structuring is further processing of the perceived sounds. Terms like auditory organisation and rhythmic ability can be understood as meaning approximately the same thing as structuring in the sense it is used here. In addition to discrimination and stucturing problems, slowness of auditory processing can also be seen as a cause of reading impairments. Many studies, both behavioral and physiological, support the view that it does have a significant share in explaining dyslexic problems (Tallal 1980, Merzenich et al. 1996). The awareness of speech sounds, phonological or phonemic awareness, has been a central construct in language research for some time. Today it is often seen as one of the most important predictors, or even the most important predictor of reading achievement. Phonological and phonemic awareness are often used interchangeably as describing the same construct. Awareness of speech sounds is not a homogenous thing, however. It seems to consist of parts which have quite different roles in learning to read and write. Onset and rime, for instance, are usually easy for children to perceive and manipulate and are good predictors of learning to read and write. Analysis of words phoneme by phoneme, on the other hand, is usually difficult for young children and is mainly a consequence of learning to read, not a predictor of it. (Goswami & Bryant 1990). Using different words for these different functions would be very desirable. Phonological awareness could mean the general sense or feeling of the sound structures in language; phonemic awareness would then mean the accurate knowledge of the language sounds phoneme by phoneme. Although the division auditory/visual may be useful and may describe the phenomena adequately, it is also possible that it masks something more basic. Although there are many exceptions, hearing is the most natural sense for temporal and vision for spatial perception. It may be as good or even better to divide the impairments into temporal/sequential on one hand and spatial on the other instead of auditory and visual. Many writers do this or mention the possibility (Payne & Holzman 1983). Karma (1994) studied the possibility to understand musical aptitude as a general temporal structuring ability rather than an ability to process sound. In addition to being a problem in either visual