Neuroplasticity

Neuroplasticity is the brain’s ability to change its connections and functioning in response to experience. During childhood, experience-dependent plasticity allows activity generated by sensations, movement, learning and social interaction to strengthen, weaken or reorganise connections between neurons.

How experience changes neural connections

Neurons communicate at junctions called synapses. Experiences activate particular networks of neurons, and patterns of activity help determine which connections become more effective and which are weakened.

• Synaptic strengthening makes communication between particular neurons more effective. Repeated, appropriately coordinated activity can produce lasting increases in synaptic strength, helping support learning and memory.
• Synaptic weakening reduces the effectiveness of some connections. Plasticity therefore involves selective adjustment, not simply adding more connections.
• Experience can also alter the structure of connections, including the formation and elimination of synapses and changes in dendritic spines, which receive many excitatory inputs.
• Synaptic pruning removes some connections during development, helping refine initially extensive networks into more selective circuits.

Why childhood is especially responsive

Developing neural circuits are particularly responsive to environmental input. Genetic programmes guide their initial formation, while experience helps refine their organisation and function.

• During sensitive periods, particular circuits are especially responsive to relevant experiences. These periods differ across functions rather than forming one universal window for brain development.
• Normal visual input, for example, helps organise developing visual pathways; severe early deprivation can disrupt their development.
• Childhood is not the only period when the brain can change. Plasticity continues throughout life, although its extent and mechanisms vary with age, brain region and the function involved.

How everyday experiences shape development

Childhood experiences influence which neural pathways are repeatedly activated. Their effects depend on timing, duration and the child’s developmental circumstances, rather than on exposure alone.

• Responsive interaction, language exposure, play and practice provide activity through which developing circuits supporting communication, movement and learning are refined.
• Prolonged severe stress or deprivation can adversely affect developing systems involved in memory, attention and emotional regulation.
• Plasticity supports adaptation and recovery, but it does not make the brain infinitely changeable. Early adversity does not determine every later outcome, and supportive experiences can improve development without necessarily reversing every effect.