Pruning recurrent neural networks replicates adolescent changes in working memory and reinforcement learning

Abstract

Significance Adolescence is a period during which there are important changes in behavior and the structure of the brain. In this manuscript, we use theoretical modeling to show how improvements in working memory and reinforcement learning that occur during adolescence can be explained by the reduction in synaptic connectivity in prefrontal cortex that occurs during a similar period. We train recurrent neural networks to solve working memory and reinforcement learning tasks and show that when we prune connectivity in these networks, they perform the tasks better. The improvement in task performance, however, can come at the cost of flexibility as the pruned networks are not able to learn some new tasks as well.

Attractor dynamics reflect decision confidence in macaque prefrontal cortex

“…The dynamical systems models also agreed with direct numerical reconstructions of the energy landscapes, which also reflected choice consistency. This association between energy landscapes and choice consistency has been predicted with computational models 19,21,22 . Intuitively it follows from the assumption that steeper landscapes will more likely lead to consistent decisions given the inherent stochasticity in neural activity.…”

Navigating Pubertal Goldilocks: The Optimal Pace for Hierarchical Brain Organization

“…1, beyond bone development, the refinement of brain structure is also part of the anatomical changes associated with puberty and adolescence. One of the significant maturational events during this phase is the targeted elimination of synapses, known as synaptic pruning [45][46][47][48] (Fig. 1b), which occurs in various species 49,50 and across the nervous system 45 during development to adapt to environmental conditions 48,50 .…”

“…One of the significant maturational events during this phase is the targeted elimination of synapses, known as synaptic pruning [45][46][47][48] (Fig. 1b), which occurs in various species 49,50 and across the nervous system 45 during development to adapt to environmental conditions 48,50 . This process is vital for optimal brain function and shaping a healthy adult brain 47,51 .…”

Microbiome depletion prior to repeat mild TBI differentially alters social deficits and prefrontal cortex plasticity in adolescent and adult rats

“… 9 Although changes in social and emotional function following TBI are commonly reported in adult populations, as they have adverse consequences for return to work, familial relationships, and the maintenance of intimate relationships, 10 the influence of RmTBI on social behavior deficits is underrepresented in the literature on adolescents. 11 Of importance, adolescence represents a period of significant neurological maturation, particularly pertaining to synaptic pruning 12 and myelination, 13 within the cortical regions that makeup the social brain network (SBN). 14 The SBN encompasses a network of brain regions that underpin social functioning, which include, but are not limited to, the medial prefrontal cortex (mPFC) and orbital frontal cortex (OFC).…”