From temporal processing to developmental language disorders: mind the gap

Abstract

The ‘rapid temporal processing’ and the ‘temporal sampling framework’ hypotheses have been proposed to account for the deficits in language and literacy development seen in specific language impairment and dyslexia. This paper reviews these hypotheses and concludes that the proposed causal chains between the presumed auditory processing deficits and the observed behavioural manifestation of the disorders are vague and not well established empirically. Several problems and limitations are identified. Most data concern correlations between distantly related tasks, and there is considerable heterogeneity and variability in performance as well as concerns about reliability and validity. Little attention is paid to the distinction between ostensibly perceptual and metalinguistic tasks or between implicit and explicit modes of performance, yet measures are assumed to be pure indicators of underlying processes or representations. The possibility that diagnostic categories do not refer to causally and behaviourally homogeneous groups needs to be taken seriously, taking into account genetic and neurodevelopmental studies to construct multiple-risk models. To make progress in the field, cognitive models of each task must be specified, including performance domains that are predicted to be deficient versus intact, testing multiple indicators of latent constructs and demonstrating construct reliability and validity.

Enhancement of brain event-related potentials to speech sounds is associated with compensated reading skills in dyslexic children with familial risk for dyslexia

“…However, there is still a gap in the chain of reasoning between auditory and speech processing deficits and manifestation of dyslexia or reading difficulties ( Figure 1, page 17; for a review, see Protopapas, 2014). The evidence gained from the current research supports a bottom-up route from auditory and speech processing deficits via deficient speech sound (phonological) representations, that leads to phonological problems, and further to dyslexia or reading difficulties.…”

“…The ERP responses to syllables with changes in vowel or consonant duration reveal differences between children at risk for dyslexia and control children already at birth and early childhood Guttorm, Leppänen, Tolvanen, & Lyytinen, 2003;, and differences continue in childhood and adulthood (e.g., . However, gateway which connect problems in speech perception with the manifestation of dyslexia are still partly unknown (for a review, see Protopapas, 2014). Theories have been proposed to explain the route from auditory and speech processing deficits to reading problems (bottom-up route, see Figure 1).…”

How Does Parental Reading Influence Children’s Reading? A Study of Cognitive Mediation

“…Nevertheless, it may be that all (reliable) variance in reading performance will never be completely captured by any set of cognitive skills. Explained variance would also have increased by using multiple indicators per cognitive construct (Protopapas, 2013). However, our set of tasks already explained more than half of the reading variance, and we do not expect a huge increase with multiple indicators as the reliability of our measures was high.…”

When words fail us: insights into language processing from developmental and acquired disorders

“…R. Soc. B 369: 20120403 phonological deficit [64] and how it interacts with other factors to predict outcome [71]. Also, as noted above, the strength of this relationship may depend on the phonological task employed [5].…”

“…They showed, however, that phonological deficits are seen only in certain tasks, and may be unimpaired when a task does not tax speed or short-term memory or involve conscious judgements. In a similar vein, Protopapas [64] notes that a child may fail the so-called phonological tests for reasons other than poor phonology, such as problems with EFs of attention and inhibition. These authors emphasize the importance of analysing task demands rather than just taking at face value the label given to a language task.…”