Lobes of the Brain

Overview

• The cerebral cortex is the outermost layer of the brain, characterized by its wrinkly appearance.
• It is divided into two hemispheres connected by the corpus callosum.
• Traditionally, these hemispheres are divided into four lobes:
  • Frontal
  • Parietal
  • Temporal
  • Occipital
• Brain functions rely on various regions, but each lobe typically handles specific functions.

Brain Structures

• Gyri: Bumps on the brain's surface.
• Sulci: Grooves or fissures dividing the lobes.
• Folding increases surface area, allowing more cerebral cortex to fit within the skull.

Frontal Lobe

• Separated by the central sulcus from the parietal lobe and the lateral sulcus from the temporal lobe.
• Functions:
  • Higher executive functions such as emotional regulation, planning, reasoning, and problem-solving.
  • Contains the primary motor cortex for voluntary movement.
• Pathology:
  • Changes in personality often indicate frontotemporal dementia.
  • Notable case: Phineas Gage, who experienced personality changes after a brain injury.

Parietal Lobe

• Located behind the frontal lobe, separated by the central sulcus.
• Responsible for integrating sensory information (touch, temperature, pressure, pain).
• Function Test: Two-point discrimination, which evaluates the ability to sense distinct points on the skin.

Temporal Lobe

• Separated by the lateral fissure from the frontal lobe.
• Functions:
  • Primary auditory cortex processes auditory information.
  • Visual processing (faces, scenes).
  • Memory formation, especially in the hippocampus.

Occipital Lobe

• Primary area for visual processing.
• Contains the primary visual cortex (V1) which interprets visual information such as depth, distance, and object identity.

Additional Information

• Central Nervous System: Includes the brain and spinal cord.
• Neurons: Basic unit of the nervous system.
• Glia: Supportive cells in the nervous system.
• Neurogenesis: The process of generating new neurons.
• Synaptic Plasticity: The ability of synapses to strengthen or weaken over time.