Aptitude and dyslexia

Aptitude and dyslexia

Carroll (1965) proposed the construct of phonemic coding ability for the component of aptitude concerned with the processing of sound, that is, the ability to analyze sound as this influences how sounds can be retained for more than a few seconds. In slight contrast, Pimsleur (1968) proposed a sound-symbol association ability, a simpler ability which only reflects the capacity to learn and operate new sound-symbol mappings. This area has been developed considerably but from a different direction since the initial formulation. Sparks and colleagues (Sparks and Ganschow, 1991; Sparks et al., 1992) have argued that tests of phonemic coding ability bear a close relationship to tests for mild dyslexia. In each case, the focus seems to be on how there are differences in the ways sound is processed and how it is related to symbol. Essentially, Carroll’s notion of analyzing sound so that it can be retained is close to how symbols can be used to impose some structure on sound that is heard, in such a way that the dual coding involved enables more robust memory. With L2 learners, problems in this area may not mean that there is poorer “raw” discrimination, but rather that sound is not processed efficiently, presumably not being segmented so effectively into words, and certainly not being analysed into a state of distinctness so that it can be more easily retained. With mild dyslexics there is a problem in linking sound representations to the symbols on the page which have to be read. All this seems to argue that it is advantageous to be able to link sound and symbol. With dyslexics, the lack of connection with (well understood native language) sounds means that the symbols on the page have less meaning and processability. With L2 learners it may be the other way around–the sounds do not link with a representational system in another modality. Sparks and Ganschow (1991) propose the Linguistic Coding Deficit hypothesis to account for these two types of difficulty.

Critical period hypothesis:

• Lenneberg’s (1967) assumption that increasing lateralization was to blame is no longer viable, as more recent research has shown that lateralization is complete by early infancy if not at birth

• Lenneberg clearly realized that adults can learn a foreign language well, but that this does not contradict the critical period hypothesis because

• these individuals, by definition, have the advantage of having learned a language already, which means that some of the most fundamental principles do not have to be learned at a later age,

• being cognitively more mature, they are good at learning specific aspects of the L2 through mechanisms that adults or adolescents are good at (explicit learning), even though this means more effort, and

• in spite of this cognitive maturity and this effort, the results tend to fall short of native-speaker standards, which is especially obvious in the area of pronunciation