Addressee Backchannels Influence Overhearers' Comprehension of Dialogue

Addressee Backchannels Influence Overhearers’ Comprehension of Dialogue Jackson Tolins (jtolins@ucsc.edu) Jean E. Fox Tree (foxtree@ucsc.edu) Psychology Department, University of California Santa Cruz Santa Cruz, CA 95064 USA Abstract We tested whether overhearers made use of the relationship between specific (e.g. really, oh) and generic (e.g. uh huh, mhm) backchannels and speakers’ talk in online dialogue comprehension. In Experiment 1 we found that words that followed specific backchannels were recognized more slowly than words that followed either generic backchannels or pauses. In Experiment 2 we found that the type of backchannel and the discourse relationship between the speaker’s subsequent and previous turn predicted overhearer’s recall of words that preceded backchannels and pauses. When the turn was a continuation of the narrative preceding the test point, specific backchannels resulted in faster responses. When the turn was an elaboration of the narrative preceding the test point, specific backchannels resulted in slower responses. We conclude that overhearers make use of the predictive relationship between listener backchannels and speakers’ discourse in comprehending dialogue. Keywords: Dialogue; Comprehension; Backchannels; Overhearers; Narratives; Elaborations; Continuations Introduction Observing others in interaction is a common means of communication, from political debates and television dramas to overhearing conversations at work or at the bus stop. According to the collaborative theory of language use (Clark, 1996), all active participants play a role in shaping a conversation, no matter whether they contribute multi-turn utterances, short utterances like uh huh, facial expressions, or postural responses. While early understanding of how the collaborative theory affected third party dialogue comprehension demonstrated both enhanced and decreased performance for overhearers of interactions (Fox Tree, 1999), increasing evidence has shown that overhearers view interactive dialogue holistically. For example, children used overheard conversation to learn novel words (Akhtar, Jipson, & Callanan, 2001) and adults used information created through dialogue to enhance success in referential tasks (Branigan, Catchpole, & Pickering, 2011; Fox Tree, 1999). In the current experiments, we demonstrate that non- interruptive addressee responses also influence overhearers’ comprehension of speakers’ talk in two-party dialogue. Speakers, Addressees, and Overhearers In our studies, we treat speakers as the conversational participants who produced the principal narratives in our experimental materials. We treat addressees as listeners of the narratives, who in our cases contributed backchannels such as uh huh to the ongoing dialogue. Overhearers are listeners who do not actively participant in the talk. Addressees can make significant contributions to the development of ongoing talk. Speakers actively monitor their audience and dynamically adjust their speech accordingly (Clark & Krych, 2004). Rather than being passive recipients of information, listeners actively participate in the construction of ongoing dialogue, even when they are only using backchannels rather than full turns at talk. The type of backchannels provided may change the course of the dialogue, for example, influencing how well stories are told (Bavelas, Coates, & Johnson, 2000). Backchannels can also influence the way narratives develop turn by turn, leading people to make predictions about what will happen next in a conversation (Tolins & Fox Tree, submitted). At the level of discourse construction, when addressees provide generic backchannels such as mhm and uh huh, displaying attention and understanding, participants expected speakers to continue their subsequent talk with new events, or continuations. However, when addressees respond with context specific backchannels such as oh and really, it was expected that the next turn would be an explanation of the prior talk, or elaboration. That is, the type of backchannel the addressee displayed may modulate not only global features of narration such as quality and story structure (Bavelas et al., 2000), but also the utterance- by-utterance development of the speaker’s talk (Tolins & Fox Tree, submitted). In addition to speakers and addressees, any particular conversation may have a number of other individuals involved. For example, a conversation could have ratified and unratified side listeners, such as an audience listening in on an interview (ratified) or a child listening to parents through a door (unratified; Goffman, 1981). Similarly based on participation status, listeners can be divided into addressees and overhearers (Schober & Clark, 1989), with addressees participating in the conversation and overhearers not participating. Overhearers can be further divided into those whom the conversational participants are aware of, bystanders, and those whom the conversational participants are not aware of, eavesdroppers (cf Clark & Schaefer, 1987; Schober, 1998). The speakers whose communication was tested in our studies knew they were being recorded for potential future comprehension experiments, thus making our listeners ratified overhearers of the bystander sort, which we will henceforth refer to as overhearers. Overhearers understand talk differently from direct addressees. Because they are unable to participate in the process of grounding, they have reduced access to the jointly maintained mutual knowledge (Garrod & Anderson, 1987). As such, they fare worse on a number of tasks