GCSE-ready- Home
- Lessons
- GCSE Psychology
- Lateralisation of function
Lateralisation of function
🎬 The doodle video for this lesson is coming soon. Subscribe on YouTube to see it first.
The brain has two halves, or hemispheres. They look similar, but they do not do exactly the same jobs.
Two hemispheres
Lateralisation means that some functions are mainly controlled by one hemisphere.
Asymmetrical function: the two hemispheres are not equal in what they do.
Left hemisphere: in most people, specialises in language (speaking, understanding, reading and writing) and logical, step-by-step thinking. It controls the right side of the body.
Right hemisphere: specialises in spatial tasks, such as recognising faces and recognising emotions in others. It controls the left side of the body.
Asymmetrical function: the two hemispheres are not equal in what they do.
Left hemisphere: in most people, specialises in language (speaking, understanding, reading and writing) and logical, step-by-step thinking. It controls the right side of the body.
Right hemisphere: specialises in spatial tasks, such as recognising faces and recognising emotions in others. It controls the left side of the body.
The corpus callosum
The corpus callosum is a thick bundle of nerve fibres joining the two hemispheres.
It lets them share information, so the brain works as a whole. For example, if you see an object on your left (processed by the right hemisphere), the corpus callosum passes the information to the left hemisphere so you can name it.
If it is cut (as in Sperry's split-brain patients), the hemispheres cannot communicate.
It lets them share information, so the brain works as a whole. For example, if you see an object on your left (processed by the right hemisphere), the corpus callosum passes the information to the left hemisphere so you can name it.
If it is cut (as in Sperry's split-brain patients), the hemispheres cannot communicate.
Lateralisation and sex differences
Some research suggests males show greater lateralisation for language and spatial tasks, while females show more bilateral activity (using both hemispheres). McGlone (1980) reported that men were more likely than women to lose language abilities after damage to the left hemisphere. Brain-scanning studies of rhyming tasks have found more bilateral activity in females.
Strengths: supported by brain-scanning and brain-damage evidence; it could explain why some studies find small differences in verbal and spatial skills.
Weaknesses: differences are small, there is huge overlap between individuals, and findings are inconsistent. Experience can shape the brain (plasticity), so differences may come from nurture. Overstating differences risks stereotyping.
Strengths: supported by brain-scanning and brain-damage evidence; it could explain why some studies find small differences in verbal and spatial skills.
Weaknesses: differences are small, there is huge overlap between individuals, and findings are inconsistent. Experience can shape the brain (plasticity), so differences may come from nurture. Overstating differences risks stereotyping.
A person has a stroke in the left hemisphere. Which side of the body and which ability are most likely to be affected?
- Each hemisphere controls the opposite side of the body.
- The left hemisphere is usually specialised for language.
Answer: The right side of the body, and language (speech).
Lateralisation means some functions are mainly in one hemisphere. Left: language and logic, controls the right side. Right: spatial tasks, faces, emotions, controls the left side. The corpus callosum connects them. Males may be more lateralised than females, but differences are small and inconsistent.
Check you have got it
Answer 7 quick questions with instant marking. If you get one wrong, GCSE-ready shows you why and gives you another go. It is free, and you do not need an account.