Neural systems for evaluating speaker (Un)believability

Abstract

Our voice provides salient cues about how confident we sound, which promotes inferences about how believable we are. However, the neural mechanisms involved in these social inferences are largely unknown. Employing functional magnetic resonance imaging, we examined the brain networks and individual differences underlying the evaluation of speaker believability from vocal expressions. Participants (n = 26) listened to statements produced in a confident, unconfident, or "prosodically unmarked" (neutral) voice, and judged how believable the speaker was on a 4-point scale. We found frontal-temporal networks were activated for different levels of confidence, with the left superior and inferior frontal gyrus more activated for confident statements, the right superior temporal gyrus for unconfident expressions, and bilateral cerebellum for statements in a neutral voice. Based on listener's believability judgment, we observed increased activation in the right superior parietal lobule (SPL) associated with higher believability, while increased left posterior central gyrus (PoCG) was associated with less believability. A psychophysiological interaction analysis found that the anterior cingulate cortex and bilateral caudate were connected to the right SPL when higher believability judgments were made, while supplementary motor area was connected with the left PoCG when lower believability judgments were made. Personal characteristics, such as interpersonal reactivity and the individual tendency to trust others, modulated the brain activations and the functional connectivity when making believability judgments. In sum, our data pinpoint neural mechanisms that are involved when inferring one's believability from a speaker's voice and establish ways that these mechanisms are modulated by individual characteristics of a listener. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc.

Prefrontal Cortex: Role in Language Communication during Social Interaction

“…One future perspective is to examine the functional coupling between prefrontal regions and other parts of the brain that support the social inference via linguistic cues (e.g., vocal cues [100]) and the individual differences that modulate the strength of the functional coupling. Despite growing recent evidence with behavioral measures showing that language communication is deeply grounded in sociocultural conventions [84], few neuroimaging studies have dedicated to how culturally related linguistic and speech cues (e.g., linguistic accent) can contribute to the understanding of the role of the medial prefrontal cortex in perceiving sociocultural groups [100]. Another related question is how the knowledge regarding prefrontal cortex can illuminate the neural underpinnings of the socio-communicative deficits in special populations such as autism and schizophrenia, with a particular interest in the various types of pragmatic and social language processing as the medium for indexing their social interactive ability.…”

“…The involvement of the medial prefrontal cortex and precuneus in a range of social functions suggests that the ability of a listener to relate to a speaker and to understand the content of a real-world narrative seems to rely on the higher-level social processing, including the reward-based learning and memory, empathy, and ToM (for mPFC), and first-person perspective taking and experience of agency (for precuneus). In particular, the inference of another's intention through verbal cues plays an essential role during exchange of information between the speaker and the listener and is integral to the success of real-world communication [84].…”

Neural bases of social communicative intentions in speech

“…Similarly, adult conversation contains distinct prosodic markers for various interpersonal attitudes ( Aubergé et al , 2003 ; Jiang and Pell, 2015 , 2016 ) and intentions such as criticism, wish or suggestion ( Hellbernd and Sammler, 2016 ). What remains unresolved so far is how prosody translates into social meaning at the neurocognitive level ( Jiang et al , 2017 ; Lavan et al , 2017 ). On the one hand, distinct prosodic signatures make it plausible to assume auditory prosodic categorization processes that may link conventionalized acoustic feature configurations to communicative meaning.…”

Differences in the Evaluation of Prosocial Lies: A Cross-Cultural Study of Canadian, Chinese, and German Adults

“…Moreover, as Chao and Moon (2005) concluded, each individual has a "unique collage of multiple cultural identities" which results in non-homogeneous cultural groups. Thus, greater attention needs to be paid to how individual participant characteristics simultaneously influence social perception and pragmatic language processing in context (e.g., Matsumoto, 2007;Rothermich and Pell, 2015;Jiang et al, 2017). Within our Canadian sample in particular, several participants were first-generation Canadians who had likely experienced heterogeneity in their exposure to different cultural practices.…”