Lateralisation of Brain Function

Lateralisation refers to the idea that the two hemispheres of the brain are not identical in function — certain cognitive processes are specialised in one hemisphere more than the other. The most important evidence for lateralisation comes from Sperry's split-brain studies.

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What is Lateralisation?

The brain has two hemispheres (left and right), connected by the corpus callosum — a thick bundle of nerve fibres that allows the two hemispheres to communicate and share information.

Lateralisation means that some functions are predominantly controlled by one hemisphere:

Left Hemisphere	Right Hemisphere
Language production (Broca's area)	Spatial awareness
Language comprehension (Wernicke's area)	Face recognition
Logical and analytical thinking	Creativity and imagination
Mathematical calculations	Processing emotions
Right side of the body	Left side of the body

Contralateral Control

Each hemisphere controls the opposite side of the body. This is called contralateral control:

• The left hemisphere controls the right side of the body
• The right hemisphere controls the left side of the body