We assessed the goodness of fit of three models of vocabulary growth, with varying sensitivity to the structure of the environment and the learner's internal state, to estimated vocabulary growth trajectories in autistic and non-autistic children. We first computed word-level acquisition norms that indicate the vocabulary size at which individual words tend to be learned by each group. We then evaluated how well network growth models based on natural language co-occurrence structure and word associations account for variance in the autistic and non-autistic acquisition norms. In addition to replicating key observations from prior work and observing that the growth models explained similar amounts of variance in each group, we found that autistic vocabulary growth also exhibits growth consistent with "the lure of the associates" model. Thus, both groups leverage semantic structure in the learning environment for vocabulary development, but autistic vocabulary growth is also strongly influenced by existing vocabulary knowledge.

An important aspect of human cognition is our ability to adapt our behavior to changing situations and contexts. Semantic control is generally broken into two different modes acting at varying levels of domain specificity: general rule-based selection or contextually-altered semantic space. The current study examines how context shifts influence associative behavior across three context domains. We instructed participants to make word associations as if they were interacting with a toddler (i.e. child condition), interacting with a peer (i.e. peer), or to just produce short words. We found that participants in the child condition produced more child-directed speech than the other conditions. Specifically, these responses were shorter, acquired earlier, and higher frequency and contextual diversity. Additionally, the child condition resulted in different representational similarity structure than the other two conditions, providing evidence for a context-effect that is less rule based and more akin to a flexible shifting of semantic space.

Previous research indicates that Autism Spectrum Disorder (ASD) is associated with altered production of co-speech gestures. However, little research has examined whether ASD impacts the processes involved in interpreting observed gestures. We collected meaningfulness ratings and one-word interpretations for 165 video-recorded gestures of varying ambiguity from individuals with and without an ASD diagnosis. The resulting dataset contains insights into gesture processing in individuals with and without ASD, including the number and variability of interpretations assigned to gestures as well as tendencies to endorse ambiguous gestures as meaningful. We also used a subset of these stimuli to identify the neural mechanisms by which gestures enhance memory in neurotypical adults. This collection of videos, as well as the interpretations and ratings from each group, will be made available through the Open Science Framework for use in future research.