Neurocircuits Involved in Speech Production

Many individuals with autism produce little or no speech, yet by many measures their receptive language is adequate for many functional interactions with family members and caregivers. Many persons with autism can communicate with sign language, augmentative speech devices, and gesture. There is also the common observation that individuals with autism can speak and enunciate properly up to about three years of age after which this ability is lost. On the face of it, this would seem to suggest that the main problem has to do with loss of the control of movement, i.e. interference with the patterning of the extensive set of muscle activations needed to produce even the simplest of utterances. It is also possible that the sense of hearing is impaired and the auditory cortex subsequently fails to produce a coherent output map for the primary motor cortex to use during speech imitation, a crucial step in learning language. In the earliest stages of learning a native language, many cortical subsystems must contribute to giving saliency to self-produced babbling sounds. As the infant experiences the propagation of self-generated sound through bones and other tissues, responds to the gestures and touches of those around him, and attaches emotional meaning to human interaction, a neurally encoded syllabary forms.

Cognitive Neuroscience represents an attempt to treat the mind as a set of distributed processing centers or ‘modules’ that communicate along nerve fibers on time scales ranging from milliseconds to seconds. During periods of attentive listening, these centers can become entrained by brain rhythms that regulate the chunking of sensory information into syllables, words, and meaningful concepts. Impressive advances in neuroimaging now make it possible to test various theories about how language appears in the brain and gets mapped onto the neuromuscular apparatus of speech production. It is to be hoped that these concepts and tools can be used to answer fundamental questions about the nature of autism. A Boston Club held on November 14, 2008 titled “Neurocircuits Involved in Speech Production” focused on this area of inquiry.

Matthew Anderson, MD, Ph.D., Beth Israel Deaconess Medical Center

Susan Birren, Ph.D., Brandeis University

Al Galaburda, MD, Beth Israel Deaconess Medical Center

Matthew Goodwin, Ph.D.,Massachusetts Institute of Technology

Investigating the neural bases of normal and disordered speech 
Frank Guenther, Ph.D., Boston University

Tal Kenet, Ph.D., Massachusetts General Hospital

Katherine Martien, MD, Massachusetts General Hospital

Rosalind Picard, Sc.D., Massachusetts Institute of Technology

Electrophysiological Signatures of Language Impairment in Autism Spectrum Disorders
Timothy P.L. Roberts, Ph.D., Children’s Hospital of Philadelphia

The Human Speechome Project: Applications for Autism
Deb Roy, Ph.D., Massachusetts Institute of Technology

Gottfried Schlaug, MD, Ph.D., Beth Israel Deaconess Medical Center

Language in Autism: Developmental and Neuroimaging Research
Helen Tager-Flusberg, Ph.D., Boston University

Contributions of Memory Brain Systems to Language: Implications for Autism
Michael Ullman, Ph.D., Georgetown University

2008

The Nancy Lurie Marks Family Foundation, Wellesley , MA