The brain

• The brain is split into two halves called the cerebral hemispheres, one on the left and one on the right
• The two hemispheres are contralateral, meaning each hemisphere senses and controls the opposite side of the body
• Cerebral cortex


  • It's the outside layer of the brain, also called gray matter as it's mostly cell bodies doing the processing of the brain
  • The inside or white matter is mostly axons and these are the connections between the neurons
  • The cerebral cortex is wrinkly and folded to increase the brain surface area allowing more space for processing
• Cerebral hemispheres divided into four lobes

  • Temporal lobe - understands and produces spoken language
  • Frontal lobe - involved in conscious for planning memory and logical tasks like problem-solving, also regulate social behavior
  • Parietal lobe - processes sensations from around the body and brings together information from other parts of the brain
  • Occipital lobe - processes visual information coming from the eyes
• Cerebellum


  • Found at the base of the brain, responsible for functions like balance and coordination
• Localization of function


  The brain's abilities are not evenly spread across the brain but are located in particular places
• Specific brain areas and their functions


  • Motor cortex - controls voluntary movement
  • Somatosensory cortex - detects touch sensation from the opposite side of the body
  • Visual cortex - processes visual information
  • Auditory cortex - processes sound information
  • Broca's area - controls speech production
  • Wernicke's area - for understanding speech
• Penfield's work


  • Developed a brain surgery called the Montreal procedure to treat epilepsy
  • Electrically stimulated various parts of the brain in conscious patients and recorded the sensations they experienced
  • Found that stimulating the same areas of the brain in different people produced consistent results
  • Concluded that many brain functions are localized
  • Suggested the interpretive cortex contains a perfect recording of memories that can be fully recovered
• Penfield's suggestion that the interpretive cortex contains a perfect recording of memories that can be fully recovered is seen as a myth, as the evidence was weak
• Penfield's findings have been largely confirmed by later research using modern brain scanning techniques