The brain

• The brain consists of the hindbrain, midbrain, forebrain and cerebral cortex
• The cerebral hemispheres are covered by the cerebral cortex
• The corpus callosum is a thick band of nerve fibres that allow information to travel between the two hemispheres
• The hemispheres are partially connected via the corpus collosum
• The cerebrum contains two cerebral hemispheres
• hemispheric specialisation is the dominance of one hemisphere over another in the control of particular functions
• the cerebral cortex covers the outer region of the left and right cerebral hemispheres
• the cerebral cortex is the convoluted (folded) outer layer of the brain, which gives room for additional neurons
• cerebral cortex is made up of 4 parts: the frontal, parietal, temporal and occipital lobes
• Primary motor cortex (25% of cortex):

  Receive and process sensory/motor information
• Association area (75% of cortex)

  Integrate and coordinate information from motor and sensory areas

  Higher mental processes
• frontal lobe the largest lobe in each hemisphere
• the frontal lobe makes up 20% of the cerebral cortex
• the frontal lobe is responsible for:

  • Voluntary movement of the skeletal muscles
  • Higher-order thinking: planning, reasoning
  • Speech production
  • Personality emotion
• damage to the frontal lobe can cause changes to personality and emotions
• Primary motor cortex: Arch of tissue over the top of the brain at the back of the frontal lobe
• Role of primary motor cortex: Responsible for voluntary skeletal muscle movement
• The left motor cortex controls the right side of the body and vice versa
• The top of the motor cortex controls the bottom of the body & vice versa
• Body parts that require very fine movements are more highly presented on the motor cortex
•  Broca's Area: Located in the left frontal lobe
• Roles of the Broca's area:

  • Movement of muscles required to articulate speech
  • Allows us to produce clear and fluent speech
  • Grammatical structure of sentences
• Damage: Broca's aphasia, difficulty producing clear and articulate speech but their ability to comprehend speech is largely unaffected
• Parietal lobe: Located behind the frontal lobe and in front of the occipital lobe
• The parietal lobe is responsible for:

  • Receiving and processing body sensations - touch, temperature and pressure
  • Spatial reasoning - puzzles, map reading, rotating 3D objects
  • Spatial awareness - the body's position in space
• Damage to the parietal lobe: spatial neglect, unlikely to point to their own body parts, difficulty remembering where something is located in a room
• The  somatosensory cortex is an arch of tissue over the top of the brain at the front of the parietal lobe
• The somatosensory cortex role is to be responsible for receiving and processing body sensations
• The left somatosensory cortex receives and processes sensory information from the right side of the body and vice versa (contralateral control)
• Parts of the body are sequentially placed on the cortex. The top of the somatosensory cortex receives sensations from the bottom of the body & vice versa
• Body parts that are very sensitive (contain more sensory receptors) are more highly presented on the somatosensory cortex
• The occipital lobe is located at the rear of each cerebral hemisphere
• Roles of the occipital lobe:

  • Receiving and processing visual information
  • Interacts with other association areas to organise and interpret visual information in a meaningful way
• Damage to the occipital lobe can cause: gaps in vision, inability to visually recognise things
• The primary visual cortex in the occipital lobe is located at the base of each occipital lobe
• The primary visual cortex in the occipital lobe is responsible for receiving and processing visual information
• Neurons located in the primary visual cortex (occipital lobe) are specialised to respond to different feature of visual information
• damage to the primary visual cortex (occipital lobe) can result in being unable to process any visual stimuli
• The temporal lobe is located low in the brain (just above the ears)
• The temporal lobe is responsible for:

  • Receiving and processing auditory information
  • Language comprehension
  • Facial recognition
  • Memory of emotional responses