Evidence of Audience Design in Amnesia: Adaptation in Gesture but Not Speech

Abstract

Speakers design communication for their audience, providing more information in both speech and gesture when their listener is naïve to the topic. We test whether the hippocampal declarative memory system contributes to multimodal audience design. The hippocampus, while traditionally linked to episodic and relational memory, has also been linked to the ability to imagine the mental states of others and use language flexibly. We examined the speech and gesture use of four patients with hippocampal amnesia when describing how to complete everyday tasks (e.g., how to tie a shoe) to an imagined child listener and an adult listener. Although patients with amnesia did not increase their total number of words and instructional steps for the child listener, they did produce representational gestures at significantly higher rates for the imagined child compared to the adult listener. They also gestured at similar frequencies to neurotypical peers, suggesting that hand gesture can be a meaningful communicative resource, even in the case of severe declarative memory impairment. We discuss the contributions of multiple memory systems to multimodal audience design and the potential of gesture to act as a window into the social cognitive processes of individuals with neurologic disorders.

Multimodal language in child-directed versus adult-directed speech

“…Our findings on iconic gesture use are compatible with earlier evidence that shows increased use of iconic gestures in CDS compared with ADS (Campisi & Özyürek, 2013; Clough et al, 2022; Molnar et al, 2021; Özçalışkan & Goldin-Meadow, 2011; Perry et al, 2018). In Campisi and Özyürek’s study (2013), they focused on iconic gesture production in terms of different addressees in one task.…”

“…Moreover, they produced gestures that were bigger and more informative to a child than an adult. Similar to this, a recent study investigated how patients with amnesia (i.e., hippocampal damage) adjust their multimodal utterances when describing how to complete everyday actions (e.g., how to tie a shoe) to an imagined child versus an adult (Clough et al, 2022). Complementing earlier evidence, they found that although patients with hippocampal damage did not change their speech when speaking to an imagined child versus an adult, they used more gestures to a child than an adult.…”

“…We wanted to control local adaptation for this study as it would dynamically affect speakers’ utterances and therefore used imaginary addressee which only influences global adaptation following Campisi and Özyürek’s (2013) study. Similar to earlier work (Campisi & Özyürek, 2013; Clough et al, 2022), we focused on speakers’ multimodal language; we used imaginary addressees and compared ADS and CDS in a within-subject design. Nevertheless, in addition to their study, we aimed to investigate how the types of gestures will change for ADS versus CDS conditions.…”

Teaching Audience Adaptation With Value Frameworks

“…Of course, communicators do sometimes adapt spontaneously. Psycholinguists, using concepts such as “audience design” (Clough et al., 2022) and “recipient design” (Valeiras-Jurado, 2020) have shown that speakers adjust their communication efforts (e.g., speaking louder or slower) in attempts to make their messages more accessible.…”

“…Research shows that, as human brains mature, persons begin to adapt their communication behavior based on how they perceive their target audience (Clough et al., 2022; Hoffmeister & Shettle, 1983). This “cognitive development model” (Rubin & Piché, 1979, p. 293) implies that audience adaptation will come more naturally to older students than to younger ones (or, perhaps, to a larger percentage of older students).…”