Database results:
examBoard: AQA
examType: GCSE
lessonTitle: Localisation of Function
Your brain might look like a wrinkly lump of jelly, but it's actually organised like a really sophisticated computer, with different parts handling specific jobs. This organisation is called localisation of function and it's one of the most important ideas in understanding how our brains work.
Key Definitions:
Understanding which brain areas control specific functions helps doctors diagnose and treat brain injuries and diseases. For example, if someone has trouble speaking after a head injury, doctors can predict which part of their brain might be damaged. It also helps scientists understand how our thoughts, feelings and behaviours are created by our brains.
While different brain regions have specialised functions, they don't work in isolation. Your brain is a network where different areas communicate constantly. Think of it like a football team - each player has a specific position, but they all work together to win the match!
The cerebral cortex (the wrinkly outer layer of the brain) is divided into four main sections called lobes. Each lobe has specialised functions:
Location: Front of the brain
Functions: Decision-making, planning, personality, higher thinking, movement control and Broca's area (speech production)
Location: Side of the brain
Functions: Hearing, memory formation, language comprehension and Wernicke's area (understanding speech)
Location: Back of the brain
Functions: Visual processing - interpreting what we see
Location: Top/middle of the brain
Functions: Sensory information processing (touch, temperature, pain), spatial awareness and body position sense
Broca's area: Located in the frontal lobe, responsible for speech production. Damage can cause Broca's aphasia - difficulty speaking fluently.
Wernicke's area: Located in the temporal lobe, responsible for language comprehension. Damage can cause Wernicke's aphasia - difficulty understanding speech.
Scientists have discovered localisation of function through several types of evidence:
Some of the strongest evidence comes from studying people with brain injuries. When specific brain areas are damaged, particular abilities are lost, showing that those areas controlled those functions.
In 1848, a railway worker named Phineas Gage had an iron rod shoot through his skull in an accident, damaging his frontal lobe. Amazingly, he survived, but his personality changed dramatically. Once responsible and polite, he became impulsive, rude and unable to hold down a job. This case provided early evidence that the frontal lobe controls personality and social behaviour.
After having parts of his temporal lobes removed to treat severe epilepsy in 1953, HM developed severe amnesia. He couldn't form new long-term memories (anterograde amnesia) but could still remember things from before his surgery and could learn new skills. This showed that the temporal lobes, particularly the hippocampus, are crucial for forming new memories.
Modern technology allows scientists to see the brain in action and identify which areas are active during different tasks.
Shows which parts of the brain are active by detecting changes in blood flow. When neurons are working, they need more oxygen, so more blood flows to that area. fMRI can create colourful images showing which brain regions "light up" during specific tasks like reading, solving maths problems, or looking at pictures.
Measures electrical activity in the brain using electrodes placed on the scalp. It can show which brain areas are active during different mental states (like sleep vs. wakefulness) or when performing different tasks.
Neurosurgeons like Wilder Penfield electrically stimulated different parts of patients' brains during surgery (while patients were awake but under local anaesthetic). When he stimulated specific areas, patients reported specific sensations or memories, or their bodies moved in particular ways. This helped create detailed maps of brain function.
Your brain has two halves (hemispheres) that look similar but handle different types of thinking:
Specialises in:
Controls the right side of the body
Specialises in:
Controls the left side of the body
Roger Sperry studied patients who had their corpus callosum (the connection between the two hemispheres) cut to treat severe epilepsy. These "split-brain" patients showed fascinating results in experiments. For example, if an image was shown only to their left visual field (processed by the right hemisphere), they couldn't name what they saw (because the language centres in the left hemisphere couldn't access the information). However, they could pick out the object with their left hand. This research earned Sperry the Nobel Prize and provided strong evidence for hemisphere specialisation.
While localisation of function is a useful way to understand the brain, it has some limitations:
Understanding localisation of function has important real-world applications:
Neurosurgeons use brain mapping to plan surgeries, avoiding damage to critical areas. For example, before removing a brain tumour, surgeons might map nearby language areas to avoid causing speech problems. Understanding localisation also helps in diagnosing and treating conditions like stroke, epilepsy and brain injuries.
Knowledge about brain specialisation can inform teaching methods. For example, multisensory learning approaches engage multiple brain areas, potentially improving learning outcomes. Understanding how memory works in the brain can also help develop more effective study techniques.
Log in to track your progress and mark lessons as complete!
Login NowDon't have an account? Sign up here.