Discussion: We found strong effects of semantic role predictability on the use of pronouns/zeros (supporting Rosa, in prep). We found no support for an audience design mechanism. If the predictability from the listener’s perspective were the primary determinant of reference form, we should see strong effects of gesture on reference form, but we saw none. Instead, goal continuations were more fluent, more tightly connected with the previous discourse, and faster to initiate. These suggest that predictability contributes to the accessibility of discourse information and/or the ease of planning and formulating the utterance.

Sandra A. Zerkle, Elise C. Rosa, & Jennifer E. Arnold

Do addressee gestures influence the effects of predictability on spoken reference form?

Background:Semantic role predictability increases pronouns/zeros, controlling for effect of grammatical role: Goal referents are pronominalized more than source referents (Rosa, in prep.)

Why does this occur? • Audience design explanation: Speakers use names to help listeners when the referent is unpredictable. • Speaker-internal processes: Predictable goal referents may be more accessible and easier to produce.

Current question: Gestures form part of face-to-face communication, and can facilitate comprehension (Kelly et al., 2009). Does gestural feedback modulate the effects of semantic-role predictability on reference form?

Task design: • Pairs of sentences and illustrations about a murder mystery• Storyboards with magnetic movable characters/props displayed between speaker and addressee (detective)1. Participant previewed a comic story on a computer screen2. Confederate described part of the scene (establishing the key semantic role of predictability) and acted it out3. Confederate made an anticipatory gesture towards one of the characters in the scene after speaking

• Gesture either towards character who held subject position in first sentence, or neutral gesture (hand off)• Example: (counterbalanced conditions of grammatical role, semantic role stays same by item)

Analysis: Data were analyzed using multilevel logistic regressions with SAS proc glimmix, including full random effects (N=24). Models included control predictors when they predicted the dependent variables, e.g. order of presentation.

Results:

Rosa, E. (in preparation). Semantic Role Affects Referential Expression. Ph.D. dissertation, UNC Chapel Hill.; Kelly, S. D., Özyürek, A., & Maris, E. (2009). Two Sides of the Same Coin Speech and Gesture Mutually Interact to Enhance Comprehension. Psychological Science.

Do speakers use more reduced forms for predictable referents (goals)?

More pronouns for goals vs. sources (p=0.0003) and subjects vs. objects (p<0.0001)YES

Funded by NSF Grant 1348549 to J.A.

Confederate: “Lady Mannerly handed the picnic basket to Sir Barnes”

4. Then participant described the next (critical) action (“and then Sir Barnes threw it behind him”), and confederate acted it out. Speech was recorded and transcribed, and then analyzed for use of pronouns/zeros, use of connector words, disfluencies, and latency to begin speaking.

Confederate: “Sir Barnes took the picnic basket from Lady Mannerly”

Does audience design explain the predictability effect?

Goal continuations are easier to talk about and are more tightly connected to the prior discourse:

More connectors used for continuations that are both goal and subject (p=0.04)

Fewer disfluencies(more fluent) for goal continuations (p=0.03)

Goal continuations are initiated more quickly, but latency does not mediate reference form (directly):

• Goal continuations are faster than source continuations (p=0.002)

• Interaction of goal continuation x subject continuation (p=0.02)

• Three-way interaction of subject continuation/goal continuation/gesture condition (p=0.045)

Does utterance planning explain the predictability effect?

NO No effects/interactions with gesture (all p’s > 0.4)

Participant previews scene on computer screen

or