The Signs of a Savant: Language against the Odds (review)

This book presents a case study of a middle-aged man named Christopher, an autistic savant who demonstrates an incredible ability to master multiple languages despite a below-average general IQ. The crux of this new book centers on a crucial question: How will an autistic man with a gift for languages and severe apraxia perform when taught signed language? As the study unfolds, we gain valuable insight into the modularity of the mind, particularly the cognitive and linguistic structures, which are intertwined.

Based on nearly twenty years of empirical observations and psychometric tests of the subject's abilities, the first chapter introduces us to Christopher, whose early diagnosis revealed developmental difficulties that would produce delays in speech fluency and motor coordination. Christopher exhibited an extremely low nonverbal performance, with artistic IQ ability in the 40-60 range. However, his linguistic IQ in English—120—stands in stark contrast. Moreover, his severe apraxia results in poor performance in the copying of nonrepresentational gestures. Although he was able to recognize conventional gestures (e.g., brushing teeth), he was not able to make the appropriate movements when prompted. Such severe motor limitations in the face of his savant linguistic abilities have led the authors to investigate how Christopher will perform when given an opportunity to learn British Sign Language (BSL). After laying out important theoretical assumptions based on Chomskyan linguistics, modularity, and Baddeley's memory model, the chapter ends with well-specified predictions about how Christopher will perform in BSL. The authors predicted that Christopher's limited cognitive ability to tie iconic signs to their referents would hamper his acquisition of lexical signs. He was also expected to perform better on the comprehension of lexical signs and grammatical devices than with facial expressions and sign production due to his inability to maintain eye contact with the signer, his apraxia, and his linguistic savant abilities.

The second chapter provides a comprehensive overview of the linguistic structure of BSL, covering the gamut of phonological, morpho syntactic, and facial elements of signed languages, as well as giving examples of signs that might be problematic for someone who avoids social eye contact (e.g., bos s and god are distinguished only by direction of eyegaze). The chapter tackles most of the critical literature on sign modality, iconicity, sign language acquisition, and sign topography. Aside from a few references to Christopher's performance in digit-span recall using signed stimuli, the entire chapter appears to stand independently of the study of Christopher's foray into signed language learning.

The third chapter, the methods section, details the training and data-collection phase of Christopher's signed language learning experience. Two hours a month of sign language learning for twelve months may not be an adequate training period for most learners, but it was more than twice the amount of time Christopher needed to master his other spoken languages. His training included morpho-syntactic structures of signed languages such as topic markers, aspect morphology, nonmanual markers, verb locative agreement, and narratives involving multiple characters. Then he was tested at five different intervals for his comprehension and production of lexical signs and manual grammatical devices, as well as his performance on facial markers. To compare Christopher's BSL learning to "normal" second language learning of BSL, forty hearing volunteers were recruited to learn BSL using the same curriculum as Christopher's, albeit in one-hour sessions over a twelve-week period.

Chapter 4 evaluates Christopher's lexical and syntactic development and that of the comparison group. Using their production and comprehension tests of iconicity, the authors found that Christopher did not utilize the relationship between iconic symbols and their referents as extensively as the comparator group did. They attributed this to Christopher's intellectual limitations and severe deficits in visuo spatial skills. As expected, Christopher's sign comprehension performance was nearly effortless as he reached peak plateau by...