Poster E37, Saturday, August 18, 3:00 – 4:45 pm, Room 2000AB
Pragmatic language comprehension in the adolescent brain
Salomi S. Asaridou1, Özlem Ece Demir-Lira2, Julia Uddén3, Susan Goldin-Meadow2, Steven L. Small1;1Department of Neurology, University of California, Irvine, 2Department of Psychology, The University of Chicago, 3Department of Psychology, Stockholm University
Adolescence is a period during which social interactions, especially with peers, become increasingly important. Mastering pragmatic language comprehension, i.e. the ability to interpret language in its communicative context, is therefore a crucial part of adolescent development. Despite its behavioral significance, little is known about the neural underpinnings of pragmatic language understanding in adolescents. Here we aimed to identify the brain networks recruited when adolescent listeners make pragmatic inferences during discourse comprehension. We used dialogues consisting of questions and direct replies (requiring no inference) or questions and indirect replies (requiring inference with or without affect). Given the fact that social-cognitive skills (such as Theory of Mind, ToM), and social-affective skills (such as empathy) are necessary for pragmatic inferences, we hypothesized that listening to the indirect-affective replies would engage regions important in ToM and empathy, including the medial prefrontal cortex (mPFC) and the temporo-parietal junction (TPJ). We collected fMRI data from 23 typically developing adolescents (14 male, mean age 15y;8m) as they listened to short question-answer dialogues. While the answers were the same across conditions, the meaning differed as a function of the preceding question. We constructed three conditions: (1) Direct, requiring no inference (Q: “Why do people use baby shower gift lists?” A: “It is difficult to choose a present for a baby”). (2) Indirect-informative, requiring inference, but without affect (Q: “Do you know what gift you're getting for Matilda's baby shower?” A: “It is difficult …”). (3) Indirect-affective, requiring inference to save face (Q: “Did Matilda like the onesie I gave her at the baby shower?” A: “It is difficult …”). Participants’ empathy skills were assessed with the Adolescent Empathy Quotient and entered as a covariate in the analysis. A significant effect of indirectness (Indirect-Affective and Indirect-Informative vs. Direct replies) was found in the right superior temporal gyrus/sulcus (STG/STS) and right middle temporal gyrus (MTG). Contrasting affective with non-affective replies (Indirect-Affective vs. Indirect-Informative and Direct) revealed increased activation in the bilateral STG/STS, MTG, cerebellum, left superior frontal gyrus (lSFG), left angular and supramarginal gyri, right middle and inferior frontal gyri. Indirect replies that differed in affect (Indirect-Affective vs. Indirect-Informative), and thus controlled for inference, preferentially engaged the lSFG, right posterior cingulate, right supramarginal gyrus (rSMG), and the right mPFC/ACC. Additionally, adolescents with higher empathy skills showed decreased activation for affective vs. direct replies, in the rSMG. Conclusions. When listening to dialogues that require affective pragmatic inference, adolescents recruited a wider “social brain network,” including prefrontal areas such as the mPFC, SFG, and ACC. Furthermore, individual differences in empathy modulated brain activation to these dialogues in the rSMG (part of the right “TPJ”), an area involved in perspective-taking. Interpreting affective/face-saving replies elicited the strongest activation, reflecting how salient the opinions and perspectives of others are in adolescence. Although indirect replies overall elicited right-lateralized temporal activation, adolescent activity for affective-indirect replies was less lateralized than previously reported in adults. This suggests that the neural developmental trajectory from adolescence to adulthood may entail increasing hemispheric specialization for processing different aspects of communicative tasks.
Topic Area: Meaning: Discourse and Pragmatics