NEUROPLASTICITY

PSYC 233

What is neuroplasticity?

Brain changes at cellular and global levels caused by changes in neural pathways and synapses. Occurs with development, learning/environment, after injury.

Sprouting and Pruning

Sprouting = growth of new synapses. Useful after damage eg. stroke

Pruning = removal of weak synapses. Hebb: Used = Strengthen, Not used = Removed

Synaptic plasticity

Changes in strength of synaptic connections. LTP strengthen, LTD weaken.

Reorganisation

Cellular changes alter whole functional brain system. Cortical maps reorganise after major change. Can be beneficial/maladaptive

Advantageous - Learning

Maguire (2000): taxi drivers → Larger hipocampi

Gaser + Schlaug (2003): pianists → Larger grey matter in somatomotor/auditory cortices.

Shows experience can alter brain structure

Advantageous - Stroke

After lesion, secondary paths carry signals around damage. Sprouting and synaptic upregulation support recovery.

Maladaptive plasticity

• Phantom Limb: Somatosensory cortex reorganises after amputation

• Chronic pain: Repeated activation → Pain paths over sensitive → Central sensitisation

Evaluation

Effects depend on what change and circumstances