Perceptual Narrowing - Neural Mechanisms

Neural Mechanisms

Brain plasticity is responsible for this "tuning" of infants’ perceptual ability. While plasticity is evident throughout the human lifespan, it occurs most often at younger ages, during sensitive periods of development. This is a function of synaptic pruning, a mechanism of plasticity where the overall number of neurons and neural pathways are reduced, leaving only the most commonly used—and most efficient—neural pathways. These pathways are also more myelinated which increases the speeds at which processing occurs. Evidence suggests that perceptual narrowing, especially phoneme distinction, is heavily reliant on infants' social interaction with the adults in their environment; this is referred to as the "Social Gating Hypothesis". The Social Gating Hypothesis suggests that social interaction creates an optimal learning environment for infants, an environment that introduces learning through social context. Social Gating might function in a number of ways; for example, by increasing infants' attention or arousal, increasing infants' sense of relationship, and by strengthening an infant's link between perception and action.