Project Summary/Abstract This project will investigate a topic of significance in advancing linguistic research in ASD: the ability to navigate across-talker variability in speech prosody (e.g., rhythm, intonation, tones). Although the importance of studying receptive prosody in ASD has been recognized for decades, the literature remains relatively small and findings often inconclusive. One fundamental aspect of receptive prosody, which has so far been largely overlooked, is the variability of human speech. Depending on their age, gender, and other physiological and cultural factors, talkers can differ substantially in how they use prosody to express meaning. Receptive prosody therefore needs to be adaptive, compensating for these differences. This insight has significant implications for individuals with ASD, whose perception has been found to be highly accurate locally and less impacted by top-down knowledge and global changes in statistics. If their receptive prosody is not appropriately modulated according to the across-talker variability that is ubiquitous in natural language, it would severely limit the accuracy of their comprehension. This is the hypothesis we test, for the first time, in this proposal. Experiments proposed here capitalize on a recent innovation made by our team, testing adaptation of receptive grammatical and pragmatic prosody in large samples of neurotypical (NT) adults. Our research demonstrates that, when exposed to a novel talker whose prosodic productions are slightly different from what is normally expected given the general statistics of the input, adult listeners robustly recalibrate how they categorize the talker’s meaning (e.g., Is this a statement or a question?) after only 10 minutes of exposure. Building on this innovation, we will examine similar abilities to perceive, categorize, and adapt to subtle acoustic variations in receptive prosody in adolescents with ASD and matched NT controls. To better account for heterogeneity among individual subjects, as well as examine possible ASD subgroups (e.g., with and without language impairment), we will obtain the same measurements locally via laboratory-based testing as well as nationwide, by leveraging a new web-delivered testing paradigm launched under this project. This will be the largest perceptual experiment of receptive prosody to date, providing the foundation of a novel research framework for investigating core mechanisms underlying receptive prosody in ASD and the causes of deficits hampering their linguistic and pragmatic communication. Beyond expanding conceptual understanding, the new knowledge about adaptivity and plasticity of receptive prosody in adolescents with ASD can inform the development of novel intervention programs. The web-delivered experiments will serve as a prototype for future research in our labs and beyond, facilitating effective testing of a diverse population across the country. This paradigm can be further developed to facilitate e...