Hemispheric Lateralisation
Hemispheric lateralisation in psychology refers to the functional differences between the two brain hemispheres. This concept is a key topic in AQA A-level Psychology, particularly in the study of biopsychology.
Definition: Hemispheric lateralisation is the idea that the two brain hemispheres are functionally different, with certain processes and behaviors mainly controlled by one hemisphere.
The document outlines the key features of hemispheric lateralisation:
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Left hemisphere dominance:
- Language and speech
- Words, letters, and language sounds
- Verbal memory
- Grammar rules
- Reading and writing
- Arithmetic
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Right hemisphere dominance:
- Visual-motor tasks
- Geometric patterns and faces
- Emotional expression
- Non-language sounds and music
- Non-verbal memory
- Emotional tone of speech
- Spatial abilities (geometry, sense of direction, distance, mental rotation of shapes)
Highlight: Information received in one hemisphere is sent to the other through bundles of nerve fibers, such as the corpus callosum.
The concept of hemispheric lateralisation was derived from studies on split-brain patients, typically those with epilepsy. In these patients, surgeons cut the corpus callosum to prevent violent activity from crossing between hemispheres.
The document presents several critical evaluations (AO3 points) regarding hemispheric lateralisation:
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Lateralisation increases neural processing activity:
Example: Rogers et al. found that in domestic chickens, lateralisation enhanced the ability to perform two tasks simultaneously: finding food and being vigilant for predators.
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Lateralisation changes with age:
Quote: "Szaflarki et al found language was more lateralised with increasing age in children but after 25 it decreased with each decade of life."
These points provide valuable insights for students preparing to discuss localisation of function in the brain (16 marks) or answer questions about hemispheric lateralisation in A-level Psychology.
