Grounding models of category learning in the visual experiences of young children

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PROJECT SUMMARY Early word learning is a major developmental achievement that rests on a foundation of visual category learning: to learn that the word “dog” refers to a category dog that includes chihuahuas and excludes wolves, children must make an impressive visual generalization. However, deep neural networks—our best models of category learning—are unable to learn from the same visual diet as children, limiting our ability to construct mechanistic accounts of early category and word learning. While infants learn the categories that words refer to while experiencing a few categories (e.g., spoons, cups) dramatically more often than others (and while experiencing certain categories as drawings or illustrations), current models learn from uniform distributions of categories where exemplars are photos taken from the adult perspective. The proposed work will overcome these limitations and use deep neural networks to understand how children’s everyday visual experiences interact with statistical learning mechanisms to yield the category representations that support early word learning. In Aim 1 (K99 phase), I will determine how variability in children’s visual experiences relates to early word learning outcomes. To do so, I will collect a representative dataset of the categories in the infant view using a parent-report measure and photographs taken from the infant perspective, and determine whether variance in visual experience with different categories predicts which words are learned earlier in development. In Aim 2 (K99/R00 phase) I will evaluate how well current models and infants learn from diverse sets of realistic visual inputs using looking-time experiments and model simulations, evaluating whether networks with more neurally plausible architectures are better predictors of infant learning. In Aim 3 (R00 phase), I will adapt an existing deep neural network for infant categorization. To do so, I will build output layers on top of a state-of-the-art unsupervised model of object segmentation to identify the categories in the infant view and to make principled generalizations from frequently experienced to infrequently experienced but similar categories—much like young children in early development. The empirical findings and resulting computational model will provide insight into the relevant visual experiences for learning the categories that words refer to. This understanding of how typically-developing children learn rapidly and efficiently in everyday environments is essential to improve interventions for children struggling to learn the categories that words refer to, including late talkers, children with ASD, and children recovering from blindness (e.g., after cataract surgery). This award will build upon my strong background in visual category recognition and provide me with relevant training in both early language acquisition and deep neural networks via interdisciplinary workshops, coursework, and the scientific expertise of a team of mentors and consultants. This award will thus facilitate my transition to become an independent investigator at the forefront of cognitive development, vision science, and machine learning.