Paralinguistic processing in children with callosal agenesis: Emergence of neurolinguistic deficits

Abstract

Recent research revealed impaired processing of both nonliteral meaning and affective prosody in adults with agenesis of the corpus callosum (ACC) and normal intelligence. Since normal children have incomplete myelination of the corpus callosum, it was hypothesized that paralanguage deficits in children with ACC would be less apparent relative to their peers. The Familiar and Novel Language Comprehension Test (FANL-C) and Prosody Test were given to 18 children with ACC and normal intelligence and 17 controls matched for age (7-13 years), education, and IQ (83-122). When controlling for age, children with ACC were significantly poorer in comprehension of the precise meaning of both literal and nonliteral items on the FANL-C. Adults with ACC had previously been shown to have difficulty only on nonliteral items. The effect size for nonliteral comprehension in children with ACC was smaller than that seen in adults. There was only a trend for the child ACC group to perform worse on the recognition of affective prosody. Thus, while deficits in paralinguistic processing were apparent, children with ACC were not as clearly different from age peers as adults, and were equally deficient at comprehending literal and nonliteral expressions. The differences in results between adults and children with ACC are thought to reflect incomplete callosal development in normal children, and the importance of the corpus callosum in the early stages of the development of the ability to process literal language.

Bilateral language function in callosal agenesis

“…DTI did not show any increased numbers of fibres crossing the anterior commissure or other interhemispheric connections above the pyramidal tract decussation ( Figure 1b). In contrast to a recently published study demonstrating neurolinguistic deficits in subjects with ACC [5], extensive neurological and neuropsychological examinations in our patient, including a standardized aphasia test battery (Aachen Aphasia Test, evaluation of various samples of spontaneous speech production and perception, repetition of sentences and words, speech comprehension) and an intelligence scale [6, verbal IQ: 108, execution IQ: 115) yielded normal findings without any evidence of stuttering. An established test battery revealed uncompromised cross-hemisphere transfer capabilities for tactile, visual and auditory information [7].…”

Social and Behavioral Problems of Children with Agenesis of the Corpus Callosum

“…A number of studies have demonstrated that individuals with ACC have difficulty on tasks involving complex novel problem solving [13,14,[23][24][25][26][67][68][69]. In addition, individuals with ACC have deficits in comprehension of the second-order meanings of language [33][34][35].…”

“…As of yet, the pattern of consistent cognitive deficits in ACC has not been fully described. However, our results thus far, and those appearing in the research literature, suggest that high-functioning adults with ACC typically have moderate but detectable deficits in the following areas: interhemispheric transfer of complex sensory information and learning [15][16][17][18][19][20]; bimanual motor coordination [18,21,22]; complex novel problem-solving [13,14,[23][24][25][26]; processing of subtle phonetic and semantic aspects of language [13,[27][28][29][30][31][32]; comprehension of second-order meanings of language [33][34][35]; and psychosocial understanding and behavior [14,35]. Since the individuals with ACC that we have studied have complete ACC, normal IQs, and few, if any, other structural brain abnormalities, we refer to this form of ACC as Primary ACC.…”

“…O'Brien's survey [12] of the behavioral consequences of ACC found ''meaningless/out of place'' speech to be characteristic of nearly the entire group. Problems in social communication in persons with ACC could be related to deficits in comprehension of nonliteral language expressions or in use of linguistic pragmatics [34,35,44].…”

Agenesis of the corpus callosum: symptoms consistent with developmental disability in two siblings

“…Problem solving, mathematics, and pragmatic language skill deficits are documented in a large proportion of cases, and deficits in social awareness and perspective-taking skills are common (Chiappedi & Bejor, 2010;Paul, 2011;Paul et al, 2007;Siffredi et al, 2013). Notably, problem-solving impairment becomes more evident with increasing task complexity, which when combined with pragmatic language deficits poses challenges for social communication (Brown & Paul, 2000;Brown, Symington, VanLancker-Sidtis, Dietrich, & Paul, 2005;Paul, 2011;Stickles, Schilmoeller, & Schilmoeller, 2002). In particular, social relatedness may be an area of weakness for many individuals with AgCC, including deficits in social insight, fluent reciprocal social interaction, and development of peer relationships (Badaruddin et al, 2007;Brown & Paul, 2000;Paul, 2011;Paul et al, 2007;Paul, Schieffer, & Brown, 2004).…”