Recent research on disorders such as autism has allowed us to reframe pragmatic communication as belonging to the larger domain of social cognition, defined as the thought processes involved in social understanding. Social-cognitive functions include those that appear specific to the social domain—such as theory of mind—as well as domain-general functions such as working memory and executive function. We have studied both types of functions in adolescents and adults with traumatic brain injury (TBI), typically injuries to brain regions thought to be critical for social cognition.

There is emerging evidence that pragmatic errors by individuals with TBI result from a combination of domain-specific and domain-general impairments. For example, adults and adolescents with TBI had significantly lower scores than uninjured peers on tests requiring the identification of emotions from the eye region of faces (Turkstra, 2007). They also had lower scores on video-based tests requiring judgments about the degree of acquaintance of two conversation partners, their sincerity, predictions about their future actions, or other pragmatic inferences (Turkstra, 2007; Turkstra, McDonald, & DePompei, 2001).

Adolescents with TBI also used fewer mental-state terms in social conversations than did their peers (Stronach & Turkstra, in press). This difference suggests that they might not always access both stated and implied information in a dynamic interaction, perhaps reflecting domain-general impairments; for example, conversations might be more demanding of working memory, which might limit the individual's ability to process multiple types of information simultaneously. Consistent with these limitations, both adolescents and adults made more errors on items requiring them to keep information in mind while they answered other questions, and also on items that required them to inhibit their initial responses (Turkstra, 2007).

These social-cognitive impairments are in marked contrast to knowledge about social norms and behaviors, which are generally preserved in individuals with TBI. For example, we found that adolescents with TBI were indistinguishable from peers in their descriptions of "appropriate" social behavior, regardless of any differences in actual social performance (Turkstra, Dixon, & Baker, 2004). These findings suggest that didactic social-skills training is likely to be less effective than strategies that focus on reducing the cognitive load of a conversation and making thoughts and feelings more explicit. The results of studies in TBI have inspired new questions about the social lives of adolescents with other communication disorders, such as adolescents with language-based learning disabilities (LLD). It has long been known that adolescents with LLD perform poorly on social-cognitive tests such as tests of emotion recognition (Wiig & Harris, 1974), and there is evidence that they experience poorer social outcomes than their peers, at least those with more severe language impairments (Clegg, Hollis, Mawhood, & Rutter, 2005).

What is not well understood, however, is the role of domain-specific vs. domain-general social-cognitive processes. In a recent study, adolescents with specific language impairment (SLI) reported more executive function-related social problems in daily living than did their peers, and their parents described them as having many more social problems than peers (Hughes, Turkstra, & Wulfeck, 2007). Consistent with this finding, adolescents with SLI had lower scores than their peers on tests of social cognition, working memory, and linguistic inference, despite being within the normal range on overall language test scores (Turkstra, Evans, & Pollak, 2007). Thus, in this group—as in individuals with TBI—domain-general and domain-specific social-cognitive impairments are likely to affect pragmatic communication.

The research described here has influenced our approach to assessment and intervention for individuals with pragmatic communication disorders. It also has shown us how much work remains to be done to maximize participation in meaningful social life for the individuals we serve.