Auditory Sequence/artif Icial Grammar Learning

language experience, attention allocation, and working memory resources influence lower-level auditory orocessing at the level of the brainstem and even at ihe level ofthe cochlea. These are known as top-down influences because a higher level of processing-higher in the sense of being further from the periphery of the central nervous system and also in the sense of being more cognitive-influences a level that is lower, or earlier, in the process. For example, phonological awareness rnay influence backward masking performance; auditory brainstem responses can be affected by musical training or by a persont choice of what stimulus to attend to. Thus, the causal direction of auditory processing deficits is not clear. Although perceptual deficits could cause problems in spoken and written language, as well as verbal working memory, attention, and other cognitive functions, problems with these higher functions could also influence perception. In summary the relationship between auditory processing and language impairments is difficult to characterize. There is a large body of evidence showing that auditory processing deficits are common in children with SLI or SRD. However, it seems unlikely that these deficits play causal roles in spoken and written language impairments. The auditory processing deficits are diverse in nature, and no single type of auditory processing difficulty has been found consistently across studies. Regardless of the auditory processing task, group differences are not always found, and even when they are, not all individuals with SLI or SRD demonstrate de6cits. Furthermore, alternattve explanations of the observed deficits are plausible. Interventions that aim to improve auditoiy processing have little effect on language or reading, and audltory processing is not consistently predictive of tanguage and academjc outcomes. There remain, however, avenues of research that may reveal the nature of the relationshiDs between a-uditory processing and language, causai or otherwtse. Our understanding of the exceedingly complex a,udrtory system, and its interactive relationship with rhe language processing system, continues to grow. ^I the applied level of ameliorating SLI and SRD, most auditory training interventions investigaled so rdr nave been based on a tcmporal processing deficit account. Other hypotheses that focus on brainstem uming or cortical oscillations may lead to different intervention rechniques that are more effective. rxplaining the entire neurodevelopmental pathway from the perception of the speech signal to the representation of phonological, lexical, and syntactic aspects oflanguage is an ambitious goal but one that is worth pursuing.