This lecture focused on the primary sensory and motor areas of the cerebral cortex. Here’s a summary of the key points:

  • Location:

    • The brain is divided into two hemispheres (left and right).
    • The lecture focused on the left hemisphere for illustration.
  • Primary Motor Cortex (M1):

    • Located in the frontal lobe, in a strip anterior to the central sulcus.
    • Controls voluntary movements on the opposite side of the body.
    • For example, the left M1 controls the right hand.
  • Primary Somatosensory Cortex (S1):

    • Located posterior to the central sulcus in the parietal lobe.
    • Receives sensory information from the opposite side of the body.
    • For example, the left S1 receives touch information from the right hand.
  • Special Cases:

    • Auditory Cortex (A1): Located in the temporal lobe.
      • Receives input from both ears, with a slight bias towards the opposite ear.
    • Visual Cortex(V1): Located mostly on the medial surface of the occipital lobe.
      • Receives information from the opposite visual field.
      • So, the left visual cortex sees everything on the right side of the world, regardless of which eye it originates from.
  • Hemispheric Specialization:

    • The sensory and motor cortices are mostly contra-lateralized.
    • This means one hemisphere controls the opposite side of the body.
    • However, there are exceptions for auditory and visual processing.
  • Language Lateralization:

    • Language processing is primarily located in the left hemisphere.
    • Damage to the left hemisphere can lead to aphasia, a language disorder.

Additional Notes:

  • The lecture mentions Brodmann areas for each region, but doesn’t go into detail. You can find more information about these Brodmann areas in resources on cortical organization.

Aphasia