Aphasia is an acquired language disorder resulting from trauma or injury to language areas of the brain. Despite extensive research on the impact of aphasia on traditional forms of communication, little is known about the impact of aphasia on computer-mediated communication (CMC). In this study we asked whether the well-documented language deficits associated with aphasia can be detected in online writing of people with aphasia. We analyzed 150 messages (14,754 words) posted to an online aphasia support forum, by six people with aphasia and by four controls. Significant linguistic differences between people with aphasia and controls were detected, suggesting five putative linguistic HCI markers for aphasia. These findings suggest that interdisciplinary research on communication disorders and CMC has both applied and theoretical implications.

This paper examines how different forms of linguistic similarity in a text-chat environment relate to the establishment of interpersonal trust. Sixty-two pairs played an iterative social dilemma investment game and periodically communicated via Instant Messenger (IM). Novel automated and manual analysis techniques identify linguistic similarity at content, structural and stylistic levels. Results reveal that certain types of content (some positive emotion words, task-related words), structural (verb tense, phrasal entrainment), and stylistic (emoticons) similarity characterize high trusting pairs while other types of similarity (e.g., negative emotion words) characterize low trusting pairs. Contrary to previous literature, this suggests that not all similarity is good similarity.

We report on a new kind of culturally-authentic embodied conversational agent more in line with the ways that culture and ethnicity function in the real world. On the basis of the careful analysis of a corpus of verbal and nonverbal behavior, we found that children shift dialects and ways of using their body depending on social context and task. Based on these results, we implemented a culturally authentic African American virtual peer capable of "code-switching" between African American English and Mainstream American English, and of using nonverbal behavior differently, depending on context. An evaluation of the agent revealed that the virtual peer elicited the same style changes in real children as real children did in one another.