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

Abstract

Acquired disorders of language represent loss of previously acquired skills, usually with relatively specific impairments. In children with developmental disorders of language, we may also see selective impairment in some skills; but in this case, the acquisition of language or literacy is affected from the outset. Because systems for processing spoken and written language change as they develop, we should beware of drawing too close a parallel between developmental and acquired disorders. Nevertheless, comparisons between the two may yield new insights. A key feature of connectionist models simulating acquired disorders is the interaction of components of language processing with each other and with other cognitive domains. This kind of model might help make sense of patterns of comorbidity in developmental disorders. Meanwhile, the study of developmental disorders emphasizes learning and change in underlying representations, allowing us to study how heterogeneity in cognitive profile may relate not just to neurobiology but also to experience. Children with persistent language difficulties pose challenges both to our efforts at intervention and to theories of learning of written and spoken language. Future attention to learning in individuals with developmental and acquired disorders could be of both theoretical and applied value.

Lexical learning and lexical processing in children with developmental language impairments

“…The distinction between proximal and distal is not clear cut (see [87] for further discussion) and how relevant pinpointing causality is to our understanding of the lexical nature of LI depends very much on the particular question being asked. If one is interested in underlying causes-what is the nature and origin of LI-then one needs to ask how language difficulties emerge from the genetic and environmental etiological factors that place children at risk for LI.…”

Genetics and the Language Sciences

“…As we discuss in greater detail below, it is not possible for a gene to specify an individual cognitive process, and we should not expect neurodevelopmental disorders to carve up cognition into clear-cut dissociable packages, each directed by a different gene (Fisher 2006). Certainly there are developmental impairments in which various speech and language abilities are disproportionately disturbed compared with other cognitive skills, and studies of these impairments can be very valuable (Bishop et al 2014). However, pure isolated impairments are seldom observed.…”

Executive Dysfunctions, Reading Disabilities and Speech-Language Pathology Evaluation

“…The study of EF processes is still evolving and to date lacks a clear unifying definition as those offered reflect perspectives from divergent fields within neurosciences and education [18,19,21,22,23]. Nonetheless, it is generally agreed that EF is not a unitary construct [17] but rather ‘an umbrella term for the complex cognitive processes that serve ongoing, goal-directed behaviors' [[22], p. 1, [10,20], [24]]; these processes are dynamic as they are highly sensitive to individuals' internal (biological) and external (environmental) context factors [25]. …”

“…EF deficits exist in diverse groups of youth such as those with acquired neurological impairments [10,24,36], deaf youth with cochlear implants [37,38], non-verbal learning disabilities [39], neurodevelopmental disorders such as ASD [35], specific language impairment (SLI) [40], SSD and dyslexia [17,41,42], reading comprehension disorders (RCD) [43,44], and ADHD [28,45]. …”

“…Finally, although in some regions speech-language pathologists may not engage directly in the diagnosis and management of reading and writing disorders, in many other regions difficulties in these are considered a communication disorder and so fall under their domain [16], even while remaining of significant interest to many other disciplines. In fact, it is commonly accepted that oral language is key to reading development, and while oral language difficulties predict reading impairment, its improvement positively impacts reading comprehension [17]. …”