Dichotic listening as an index of lateralization of speech perception in familial risk children with and without dyslexia

Abstract

Atypical language lateralization has been marked as one of the factors that may contribute to the development of dyslexia. Indeed, atypical lateralization of linguistic functions such as speech processing in dyslexia has been demonstrated using neuroimaging studies, but also using the behavioral dichotic listening (DL) method. However, so far, DL results have been mixed. The current study assesses lateralization of speech processing by using DL in a sample of children at familial risk (FR) for dyslexia. In order to determine whether atypical lateralization of speech processing relates to reading ability, or is a correlate of being at familial risk, the current study compares the laterality index of FR children who did and did not become dyslexic, and a control group of readers without dyslexia. DL was tested in 3rd grade and in 5/6th grade. Results indicate that at both time points, all three groups have a right ear advantage, indicative of more pronounced left-hemispheric processing. However, the FR-dyslexic children are less good at reporting from the left ear than controls and FR-nondyslexic children. This impediment relates to reading fluency.

Auditive training effects from a dichotic listening app in children with dyslexia

“…There was no correlation to the RAN and DS scores in the untrained CnT group (however, the near to significant correlation between DS and ASI post is noteworthy). That this lack of relationship was also seen in the DT group, is in line with the findings of Hakvoort et al () who found no relationship between LI scores and measures of phonological processing in dyslexia, arguably because the LI measure, being primarily a measure of laterality of speech processing, was not refined enough to relate to phonological processes. The individual changes from pre to post ASI scores seen in the dyslexia group (Figure ) indicate that the ASI score is a very sensitive measure of attentional change in language processing.…”

“…However, the scores of the two control groups indicate a language preference for the left hemisphere as seen in typical samples (Bless et al, ; Hugdahl, ). The lack of ear advantage in the dyslexia group is in line with what is often reported in dyslexia (Helland et al, ; Helland & Asbjørnsen, ; Hugdahl et al, ; Moncrieff & Black, ), but not in all studies (Hakvoort et al, ).…”

“…A few studies have addressed the relationship between DL scores and benchmark WM measures in dyslexia. In a study of right‐handed controls and children with dyslexia, no significant correlations between an LI and phonological processing measures were found (Hakvoort et al, ). The findings were tentatively explained by the different levels of processing, i.e., that the phonological measures assessed processing at the lexical level, while the DL tasks were primarily sublexical tasks.…”

“…The analyses of DL can be complex, as some studies indicate that handedness, age, and gender may interact with the DL scores (Hakvoort et al, ; Obrzut, Boliek, & Bryden, , ). However, in a large scale study of subjects ranging from age 10 to older adults, it was concluded that handedness did not affect any of the findings, and no sex differences were seen in children and older adults (Hirnstein, Westerhausen, Korsnes, & Hugdahl, ).…”

A primer on dichotic listening as a paradigm for the assessment of hemispheric asymmetry

“…This interpretation finds support in a series of studies showing a behavioural dissociation between the "attend right" and the "attend left" condition. For example, compared to healthy controls, individuals with Alzheimer's disease (Gootjes et al, 2006), attention-deficit/hyperactivity disorder (Dramsdahl, Westerhausen, Haavik, Hugdahl, & Plessen, 2011), dyslexia (Hakvoort et al, 2016), Klinefelter syndrome (Kompus et al, 2011), and schizophrenia (Green, Hugdahl, & Mitchell, 1994) show an impaired ability to selectively attend the left-ear stimulus, whereas their performance is unaltered for attending to the right ear. Studies in healthy ageing indicate that older compared to young individuals exhibit a reduced ability to follow the instruction to attend to left-ear stimulus while no differences are found in the "attend right" condition (Takio et al, 2009;Westerhausen, Bless, Passow, Kompus, & Hugdahl, 2015b).…”