Forced-Attention Dichotic Listening With University Students With Dyslexia

Abstract

Rapidly changing environments in day-to-day activities, enriched with stimuli competing for attention, require a cognitive control mechanism to select relevant stimuli, ignore irrelevant stimuli, and shift attention between alternative features of the environment. Such attentional orchestration is essential to the acquisition of reading skills. In the present forced attention dichotic listening study, adults with moderate and severe dyslexia and nondisabled adults were tested on their ability to switch attention between ears for immediate recall. Blocks of pairs of consonant-vowel syllables were counterbalanced into left-ear first or right-ear first ordered conditions. Significant order effects showed that only those with severe dyslexia were poorer in switching attention to the left ear, whereas both groups with dyslexia were poorer switching attention to the right ear. Shifting left appears to be a normative function of reading level, whereas inferior ability to disengage attending to the left ear to report from the right ear qualifies as a dysfunctional facet of dyslexia with etiological significance. No support was found for the traditional proposition that dyslexia may be associated with atypical left hemisphere lateralization. Combining these results with previous dichotic and neuroimaging research implicates a dysfunctional frontostriatal cognitive control network in dyslexia. With due caution, the results suggest that a neurobiological feature of dyslexia may be a lack of control in downwardly modulating excessive left inferior frontal cortex activations. The results are consistent with impoverished connectedness between left anterior and posterior language areas and, pending future confirmation of these findings, suggest the need for a reconceptualization of remedial programming.

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

“…However, it should be noted that there was a larger, but insignificant Re score over Le score in both conditions. This could be attributed to specific difficulties with this task, which is also in line with the findings in other dyslexia samples (Hugdahl, ; Hugdahl & Helland, ; Kershner, ).…”

“…Alternatively, it could be the case that dyslexia is not associated with atypical left hemisphere lateralisation, although the pretest scores indicated NEA for the DL group. The latter interpretation would be in line with a study of DL performance in university students with dyslexia (Kershner, ).…”

“…This was not the case, which supports arguments that brain architecture for language in children with dyslexia is lateralised in the same way as in children without dyslexia (Bishop, ). But, as proposed by Kershner (), it is the ability to modulate attention that seems to be dysfunctional.…”

“…Other studies have shown impairments within executive functions in dyslexia subgroups (Beneventi, Tønnessen, Ersland, & Hugdahl, 2010;Helland & Asbjørnsen, 2000;Smith-Spark & Fisk, 2007), and with increasing problems especially in more demanding tasks (Reiter, Tucha, & Lange, 2005). In his study of students with dyslexia, Kershner (2014) concluded that the dysfunction relates to impaired processes in left inferior frontal gyrus, in line with what was found in 8-year-olds in an fMRI-study from the Bergen Longitudinal Dyslexia Study (Morken, Helland, Hugdahl, & Specht, 2017). Another functional and structural imaging study (Hoeft et al, 2011) found that their participants with dyslexia depended on a right hemisphere pathway as a compensation for an impaired left-hemisphere pathways in frontal regions.…”

A Mini-Review: Toward a Comprehensive Theory of Dyslexia

“…My colleagues and I have provided a more direct test in a programmatic series of forced attention dichotic studies. We found evidence of dysfunctional frontostriatal cognitive control in dyslexia in four replications with different samples, consisting of children and adults and including males and females [64,66,67]. Two of these studies included readinglevel controls, which discounts the possibility that the deficit in cognitive control may be a secondary consequence rather than a cause of their reading disability.…”