Abstract
This chapter examines how the core deficits discussed in Chapter 2 account for the linguistic deficits discussed in Chapter 1. It explains why diminished attention to speech and diminished joint attention behaviors impede linguistic immersion, potentially limiting the acquisition of vocabulary and syntactic structures. It discusses echolalia and how it reflects limitations in syntactic understanding. It also discusses how difficulty interpreting facial expressions and social interactions impedes the acquisition of socio-emotional vocabulary. It then turns to social communication, also known as pragmatics, as well as to comprehension, and explains why these aspects of language are, to varying degrees, universally impaired across the autism spectrum. Finally, it offers further discussion of non-speaking autism: why it often correlates with nonverbal autism and what the underlying issues appear to be. It concludes with 13 takeaways related to language and literacy acquisition in autism that will inform later chapters.
TopConnecting The Core Deficits To The Linguistic Deficits
How Early Perceptual Deficits Stymie the First Stages of Language Acquisition
As we saw in Chapter 2, there is a diminished tendency in autism to selectively attend to speech sounds. Here, the connection to language is immediately clear: not attending to speech sounds reduces the amount of language one absorbs.
Aggravating this is the tendency of autistic children not to attend to faces. Not attending to faces means that, even on occasions when one is attending to a speech sound, one is not attending to the mouth that produces it. Indeed, several studies show that young children diagnosed (or later diagnosed) with autism have difficulty integrating speech sounds with lip movements (Guiraud et al., 2012; Kissine et al., 2021; Righi et al., 2018). Guiraud et al. found such difficulties in infants as young as nine months old. Difficulty integrating speech sounds with lip movements, in turn, has been found to impede both speech perception and speech production (Desjardins et al., 1997; Patterson et al., 1999)—the latter by diminishing opportunities to learn from others how speech sounds are produced. In addition, both reduced attention to speech sounds and reduced awareness of people’s lips as they produced them limits opportunities to learn about the concept of a human speaker deliberately using speech in a communicative activity.
Related to this are three additional factors. First, speech sounds, even when attended to, tend not to be selectively processed as speech sounds, as distinct from environmental sounds. Second, there is evidence of a deficit in phonological processing: in making sense of the distinctive speech sounds that contribute to meaning—e.g., vowels and consonants. Finally, an examination of neurological wiring in autism suggests that there is a lower signal to noise ratio when processing sound: in other words, that there is less filtering out of irrelevant noise (Groen et al., 2008).
What all this means is that children with autism derive less linguistic information from the auditory environment, and less linguistic clarity, than their non-autistic counterparts do—even on occasions when they do attend to speech. While the most obvious effects of this are on speech perception and comprehension, there are also effects on speech production. Young et al. (2009), for example, report a correlation between face-scanning and later expressive language. Relatedly, Kim et al. (2014) report a recent study that found that infants and toddlers with autism, compared to non-autistic counterparts, produce a much higher proportion of non-speech vocalizations—suggesting that failing to selectively take in speech sounds results in a failure to selectively produce speech sounds.
Finally, the tendency in autism to preferentially orient to objects over people, in limiting one’s awareness of interpersonal interactions, further reduces one’s awareness of language—language being one of the primary ways in which people interact. Indeed, Campbell et al. (2014) found that diminished attention to social scenes at age two predicts worse linguistic outcomes at age three.
Key Terms in this Chapter
Receptive Language: Comprehension of language produced by others, whether spoken, written, or signed. Receptive language tends to exceed spoken language, but is an area of disproportionate weakness in autism.
Non-Speaking: Unable to articulate words, perhaps because of Apraxia of Speech or other oral-motor difficulties, or perhaps because of lack of access to speech sounds (e.g., because of hearing loss). Non-speaking individuals may be able to use alternative linguistic media like sign language or written language. In autism, however, non-speaking often means non-verbal.
Syntax: The subset of grammar that includes word order and the embedding of phrase and clauses within sentences.
Grammar: A language’s rules for word order and word endings, including singular and plural, verb tense, function words, embedded clauses, and question syntax.
Gestalt Processing: A way that listeners may process language when it exceeds their syntactic understanding. In gestalt processing, multiple words are memorized as wholes, with no sense of internal syntactic and semantic structure. Those words may later be repeated verbatim rather than recombined into novel sentences.
Pragmatics: Communicative uses of language and the interpretation of language in communicative context. Pragmatics includes conversational interactions, implied meanings, figurative language, and reading between the lines.
Nonverbal: Unable to produce language in any linguistic medium: speech, sign language, or written language. Approximately 20% of autistic individuals are thought to be nonverbal.
Apraxia of Speech: An oral-motor disorder that interferes with the ability to plan and execute speech sounds.
Expressive Language: Actively produced language, whether by speaking, typing, handwriting, or signing (cf. receptive language).
Echolalia: The immediate or delayed parroting back of words and phrases, typically with the intonation in which they were originally heard, including words and phrases that one does not fully understand.