Neural Pathways for Language in Autism
Neural Pathways for Language in Autism
Language deficits represent the core diagnostic characteristics of autism, and some of these individuals never develop functional speech. The language deficits in autism may be due to structural and functional abnormalities in certain language regions (e.g., frontal and temporal), or due to altered connectivity between these brain regions. In particular, a number of anatomical pathways that connect auditory and motor brain regions (e.g., the arcuate fasciculus, the uncinate fasciculus and the extreme capsule) may be altered in individuals with autism. These pathways may also provide targets for experimental treatments to facilitate communication skills in autism. We propose that music-based interventions (e.g., auditory–motor mapping training) would take advantage of the musical strengths of these children, and are likely to engage, and possibly strengthen, the connections between frontal and temporal regions bilaterally. Such treatments have important clinical potential in facilitating expressive language in nonverbal children with autism.
Impairments in language and communication skills represent the core diagnostic features of autism or autism spectrum disorders. The linguistic ability of individuals on the autism spectrum varies greatly. Up to 25% of individuals with autism spectrum disorders lack the ability to communicate with others using speech sounds. Others have adequate linguistic knowledge coupled with abnormalities of nonliteral language, such as the comprehension of idioms, and some individuals display impairments in the understanding of language in context. At present, there appears to be no evidence-based intervention that consistently produces significant improvements in expressive language in individuals with autism. Deficits in communication thus present a persistent and life-long challenge for individuals with autism and their families.
To elucidate the language deficits in autism, researchers have used structural and functional imaging and neurophysiological techniques to examine potential abnormalities in classical language areas in the brain, such as the posterior inferior frontal gyrus (pIFG; i.e., Broca's region) and the posterior superior and middle temporal gyri (i.e., Wernicke's region). In this article, we review studies that have reported abnormalities in these key brain regions and the connections between them, and present a new experimental intervention that may provide an alternative medium to engage a network that might be abnormal, impaired or underdeveloped. It is inevitable that verbal individuals will be over-represented in this literature, so the work reviewed here may not be ideal for illuminating the mechanisms underlying the complete absence of speech, as is observed in some individuals with autism. We argue that interventions that engage the network of frontal and temporal brain regions bilaterally, such as using alternative methods, may have important clinical potential, specifically in facilitating expressive language in otherwise nonverbal individuals, as well as in strengthening the underlying connections. Finally, we present a music-based intervention (termed auditory–motor mapping training) and provide a rationale of why it may serve as a viable therapeutic tool in assisting individuals with autism to develop speech.
Abstract and Introduction
Abstract
Language deficits represent the core diagnostic characteristics of autism, and some of these individuals never develop functional speech. The language deficits in autism may be due to structural and functional abnormalities in certain language regions (e.g., frontal and temporal), or due to altered connectivity between these brain regions. In particular, a number of anatomical pathways that connect auditory and motor brain regions (e.g., the arcuate fasciculus, the uncinate fasciculus and the extreme capsule) may be altered in individuals with autism. These pathways may also provide targets for experimental treatments to facilitate communication skills in autism. We propose that music-based interventions (e.g., auditory–motor mapping training) would take advantage of the musical strengths of these children, and are likely to engage, and possibly strengthen, the connections between frontal and temporal regions bilaterally. Such treatments have important clinical potential in facilitating expressive language in nonverbal children with autism.
Introduction
Impairments in language and communication skills represent the core diagnostic features of autism or autism spectrum disorders. The linguistic ability of individuals on the autism spectrum varies greatly. Up to 25% of individuals with autism spectrum disorders lack the ability to communicate with others using speech sounds. Others have adequate linguistic knowledge coupled with abnormalities of nonliteral language, such as the comprehension of idioms, and some individuals display impairments in the understanding of language in context. At present, there appears to be no evidence-based intervention that consistently produces significant improvements in expressive language in individuals with autism. Deficits in communication thus present a persistent and life-long challenge for individuals with autism and their families.
To elucidate the language deficits in autism, researchers have used structural and functional imaging and neurophysiological techniques to examine potential abnormalities in classical language areas in the brain, such as the posterior inferior frontal gyrus (pIFG; i.e., Broca's region) and the posterior superior and middle temporal gyri (i.e., Wernicke's region). In this article, we review studies that have reported abnormalities in these key brain regions and the connections between them, and present a new experimental intervention that may provide an alternative medium to engage a network that might be abnormal, impaired or underdeveloped. It is inevitable that verbal individuals will be over-represented in this literature, so the work reviewed here may not be ideal for illuminating the mechanisms underlying the complete absence of speech, as is observed in some individuals with autism. We argue that interventions that engage the network of frontal and temporal brain regions bilaterally, such as using alternative methods, may have important clinical potential, specifically in facilitating expressive language in otherwise nonverbal individuals, as well as in strengthening the underlying connections. Finally, we present a music-based intervention (termed auditory–motor mapping training) and provide a rationale of why it may serve as a viable therapeutic tool in assisting individuals with autism to develop speech.
