The development of adaptive specificity in learning and memory

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PROJECT SUMMARY Many forms of psychopathology that emerge or peak in prevalence in adolescence, including anxiety and depression, are associated with overgenerality in value-based learning and episodic memory. Understanding developmental change in the specificity of value-based learning computations and memory representations may provide insight into periods of heightened risk for the onset of psychopathology. Critically, to effectively guide behavior across diverse contexts, learning and memory systems should flexibly adapt to the environment, representing information more generally when the reward statistics of similar states converge and with a higher degree of granularity when more detailed representations are needed to guide behavior. In adulthood, interactions between the hippocampus and medial prefrontal cortex support both specific representations of individual exemplars as well as more abstract representations that guide generalization during learning. While prior studies of value-based learning and episodic memory suggest that children represent information with less specificity than adults, no research has examined how the cognitive and neural mechanisms that support the flexible adaptation of value-learning computations and memory representations to the demands of varied contexts change over development. The proposed work will use a novel reinforcement learning task, coupled with advanced computational modeling and neuroimaging methods, to address this question. Specific Aim 1 will examine age-related change in context-invariant biases toward more specific or more general value associations during learning, as well as in their flexibility to adapt to the reward statistics of different contexts. Specific Aim 2 will probe how the specificity of value-learning associations influences the specificity of memory for information encountered during learning, both immediately and over time. Finally, Specific Aim 3 will examine how the reward statistics of the learning environment influence the granularity of representations within the hippocampus and medial prefrontal cortex across development. We hypothesize that normative learning and memory development may be marked both by increases in the specificity of neurocognitive representations that emerge across contexts, and in their flexibility to adapt to the reward statistics of varied learning environments. The proposed work will elucidate the mechanistic relations between specificity in value-based learning and in memory across development, enhancing our understanding of potential neurocognitive risk factors for the emergence of psychopathological symptoms associated with overgeneralization.