Brain Structure & Function (AQA GCSE Psychology)

• The brain is divided into two hemispheres, left and right and is covered by a thin layer known as the cerebral cortex
• The brain has four main lobes, each of which regulates and controls specific functions:
  • The frontal lobe
  • The parietal lobe
  • The occipital lobe
  • The temporal lobe

• Each lobe is divided between the two hemispheres i.e. there is symmetry in the brain, with each lobe mirroring itself on the right/left hemisphere
• As each hemisphere is responsible for different functions then each lobe is also responsible for different functions too 

Function of the frontal lobe

• It is located at the front of the brain 
• Responsible for:
  • motor coordination i.e. voluntary movement (located in the motor cortex of the frontal lobe)
  • language production (particularly Broca’s area which is located in the left hemisphere of the frontal lobe)
  • executive functioning e.g. planning, reasoning, impulse-control (specifically the job of the prefrontal cortex)

Function of the parietal lobe

• It is located at the top of the brain
• It is responsible for:
  • enabling people to understand sensory information detected via touch e.g. heat/cold, vibrations, pressure, pain (located in the somatosensory cortex of the parietal lobe)
  • enabling people to understand where parts of their body are i.e. even with your eyes closed you still know where your left ankle or right shoulder is

Function of the occipital lobe

• It is located at the back of the brain
• It is responsible for:
  • sight (located in the visual cortex of the occipital lobe)
  • decoding visual information sent from the eyes and turning it into forms that can be used to navigate and interpret the environment (the process of sight, in other words)
  • regulating a range of other visual functions including spatial processing, perception (distance and depth), face recognition

Function of the temporal lobe

• It is located on either side of the brain (around where the ears are located on the head)
• It is responsible for:
  • auditory processing e.g. hearing (located in the auditory cortex)
  • language comprehension  (particularly Wernicke's area which is located in the left hemisphere of the temporal lobe)
  • memory retrieval and the processing of emotions

• The cerebellum plays a  vital role in movement and balance, receiving messages from the spinal cord as to how to move
• It contains around half the total neurons in the brain even though it is a small structure (it means ‘little brain’ in Latin)
• It coordinates bodily movements, maintaining posture, muscle tone and voluntary actions 
• The cerebellum uses sensory information for example:
• it receives messages from the eye muscles about environmental conditions
• the message could be, ‘I need more light to read by’
• the cerebellum can then adjust head movement by turning towards the light source
• The cerebellum also plays a role in some cognitive functions e.g.  language and memory, attention

Research which investigates brain structure

• Maguire et al. (2000): increased grey matter in the brains of taxi cab drivers was found in the hippocampus which is located in the temporal lobe
• Draganski et al. (2006): participants who had learnt a juggling routine showed more grey matter in their temporal lobe
• Raine et al. (1997) found that impulsive murderers did not use their prefrontal cortex located in the frontal lobe when engaged in a cognitive task