Language and Functionality in Autism.

1. Language and Functionality in Autism. Underconnectivity in LFA What We Know About Language Processing and Production in the Brain. • ATL: anterior temporal lobe; Aud: auditory cortex (early processing stages); BA 45/44/6: Brodmann areas 45, 44, & 6; MTG/ITG: middle temporal gyrus, inferior temporal gyrus; PM: pre-motor, dorsal portion; SMG: supramarginal gyrus; Spt: Sylvian parietal temporal region (left only); STG: superior temporal gyrus; red line: Sylvian fissure; yellow line: superior temporal sulcus (STS). Adapted from: Hickok G, Poeppel D. The cortical organization of speech processing. Nat Rev Neurosci 2007;8(5):393–402. • Processing • Early stages of speech recognition and phonological processing bilaterally organized in the superior temporal gyrus. • Semantic/conceptual systems thought to be represented throughout the cerebral cortex. Inferior temporal gyrus (ITG) may be more involved in relating acoustic input to semantic knowledge. • Phonological and semantic information are thought to come together in confluence areas. • Posterior lateral and inferior temporal regions. These areas may be specialized to process acoustic input. • Grammatical processing less well know. Broca’s Area, frontal-basal ganglia circuits and the anterior temporal region thought to play a role in processing sentences/utterances. • Production • Left posterior superior temporal regions strongly implicated in phonological production. • Sylvian parietal-temporal area thought to be a sensory-motor integration area. • Autism is likely the result of a number of regulatory genes regulating connectivity and migration (NLGN3/4, GRIN2A). • Such regulator genes work in a graded fashion, with variable expression due to inherited and environmental factors. • LFA may be the result of similar gene expression as HFA, but with a higher “neural dose.” In other words, a more extreme case of cortical underconnectivity. • Language dysfunction is a core diagnostic component of autism spectrum disorders. • Spoken language skills is an important component of how a person with autism functions. • “Low-functioning autism” (LFA) is characterized by poorer functional language abilities (Boucher et al. 2007) • Spoken “language” in verbal LFA is not delayed but structurally atypical. We have termed this “quasilinguistic.” Cortical Underconnectivity and Quasilinguistic Vocal Communication in Low-Functioning Autism: a Hypothetical ModelBrian Roper Ph.D., M.S. CCC-SLP, Scientific AdvisorJose A. Ortiz M.A. CCC-SLP, Chief Technology OfficerPAL Software Underconnectivity Model of Quasilinguistic Vocal Communication in LFA Quasilinguistic Communication in LFA • Processing • Underconnection between superior temporal gyrus (STG) involved in phonological processing frontal areas (Broca’s). Utterances possibly processed on phonological level, but never parsed into syntactically governed units. • Difficulty parsing words from utterance could lead to whole invariant utterances associated with specific contexts, but not individual objects, actions or entities. • Production • Production mirrors processing. Overreliance “calls,” reminiscent of non-human primates (Vauclaire, 2003). • Contextually bound. • Lack of syntactical features. • Holistic and invariant. Much like gestures (Thumbs-up = ok! Half a thumbs-up means nothing.) • We use the term “quasilinguistic” describe a subset of LFA who are able to use spoken or verbal communication that is based on whole, indivisible units. • The LFA individual’s memorized utterances “denote but fail to connote” (Fay and Schuler 1980). • Reliance on grammatically correct scripts used as wholes (Boucher 2003). • Spontaneous language tends to be laborious and inefficient. • Failure to parse individual words into semantically meaningful units that are bound together by syntactical rules and regularities. • Utterances tend to be highly contextual and invariant in their form. Possible Implication ðəfɑrmərtʃeɪsɪzðədəklɪŋzɔnðəreɪniːdeɪz • Research • Language processing on LFA. • Assessment • Tools for: • Assessing the ability to parse acoustic signal into words. • Flexibility and grammatical features of spoken communication. • Intervention • Associative use of functional blocks of language. Skip grammatical training and vocabulary growth. Cortical Underconnectivity in Autism • Evidence is accumulating supporting the view of autism as a disorder of an underconnected cortical system (Just et al. 2012). • During a sentence comprehension task, Just et al (2004) found reduced activity in Broca’s area high-functioning autistic (HFA) subjects as well as decreased functional connectivity throughout the language system. • Kana et al. (2006) found greater activation of parietal-occipital areas and reduced synchronization with frontal areas during a sentence comprehension task in HFA subjects. Hickock, G. 2009. The functional neuroanatomy of language. Physics of Life Reviews 6, 121-143 Just, M. A., Cherkassky, V. L., Keller, T. A., Minshew, N. J., 2004. Cortical activation and synchronization during sentence comprehension in high-functioning autism: Evidence of underconnectivity. Brain 127, 1811-1821. Kana, R. K., Keller, T. A., Cherkassky, V. L., Minshew, N. J., Just, M. A., 2006. Sentence comprehension in autism: thinking in pictures with decreased functional connectivity. Brain 129, 2484-2493. Vauclaire, J. 2003. Would humans without language be apes? In J. Vasliner (Series Ed.) & A. Toomela (Volume Ed.), Cultural guidance in the development of the human mind: Vol. 7. Advances in Child Developemtn within Culturally Structured Environments (pp.9-26). Greenwich, CT: Ablex Publishing Corporation. “the farmer chases the ducklings on the rainy days”