Lateralisation of function

Two stacked errors. Muddling the hemispheres: language gets placed in the right, spatial in the left. Anchor it — left = language — and the right takes the non-verbal work. A difference answered as two definitions is one mark; a connective (whereas) earns the second. Watch the contralateral trap: the left hemisphere controls the right side, not the left.

The documented zero-scoring answer. Asked about the corpus callosum, candidates treat it as another structure with its own job — it controls memory, it makes decisions. It is not a processing area; it is a connection — a bundle of nerve fibres carrying information between the hemispheres. Give both parts: what it is and what it does.

Bullet e is what examiners single out, and two failures recur. No research evidence: there is evidence for this cannot be credited — use brain-scanning studies of language activity and the split-brain findings (4.2.2). Identification without justification: a strength is it is scientific is a label. Each point needs the point, the reason and the consequence.

Two ideas with similar names. Lateralisation is specialisation between the two hemispheres — which half does a job. Localisation (4.1.1) is which region within a hemisphere does it — which lobe. A hemispheres question wants lateralisation; a frontal or occipital lobe question wants localisation. Mixing the levels — the occipital lobe is the right hemisphere — loses marks.

Asymmetrical function means the halves specialise to different degrees — not that the brain works as two separate halves. They are joined by the corpus callosum and constantly share information, so an intact brain is one system. Lateralisation is about which side does more, not one side working while the other rests.

The popular version says logical people are left-brained, creative people right-brained. Not so: functions are more specialised in one hemisphere, not exclusive to it, and both are active in almost every task. Sharper AO3 than nobody is only left-brained: lateralisation is a matter of degree that varies between individuals, so an average says little about one person.

Bullet e reports an average tendency, and candidates turn it into a rule about individuals. Hold three things apart: level (an average, not a fact about one person); size (within-sex variation exceeds the between-sex difference); cause (a relationship, not proof one produced the other). So the explanation generalises poorly to any individual, and it is socially sensitive.