Psychology Chapter 2
  1. Lower-Level Brain Structures
    1. The Brainstem
      1. The brain stem is the oldest and innermost region where the spinal cord enters the skull and swells slightly.
      2. The medulla is what controls your heartbeat and breathing.
      3. Inside the brain stem between the ears is the reticular formation. It’s a finger shaped network of neurons that extends from the spinal cord to the thalamus.
      4. The reticular formation filters incoming stimuli and relays important information to other areas. It also helps control arousal.
    2. The Thalamus
      1. Above the brainstem is the brain’s sensory switchboard, a joined pair of egg-shaped structures called the thalamus.
      2. It receives all the information from the senses except for smell. It also directs orders from the higher brain regions.
      3. It also coordinates the brain’s electrical oscillations slowing down during sleeping and speeding up when awake.
    3. The Cerebellum
      1. The cerebellum extends from the rear of the brainstem and is like two wrinkled hemispheres.
      2. It enables one type of nonverbal learning and memory but it also coordinates voluntary movement.
      3. An injured cerebellum could lead to difficulty in walking, keeping balance, or shaking hands.
    4. The Limbic System
      1. The doughnut shaped neural system that is at the border of the brain’s older parts and cerebral hemisphere is the limbic system.
        1. The Amygdala
          1. The two almond-shaped neural clusters are called the amygdala. They influence aggression and fear.
        2. The Hypothalamus
          1. The structure that lies just below the thalamus is called the hypothalamus. The hypothalamus monitors blood chemistry and takes orders from other parts of the brain.
  2. The Cerebral Cortex
    1. Structure of the Cortex
      1. The cerebral cortex is an intricate covering of interconnected neural cells that form a thin surface layer on your cerebral hemispheres. It is the control and information-processing center.
      2. 80% of the brain’s weight is the ballooning of the right and left hemispheres.
      3. Glial cells guide neural connections, provide nutrients and insulating myelin, and mop up ions and neurotransmitters.
      4. The frontal lobes are behind the forehead and the parietal lobes are at the top and to the rear. The occipital lobes are at the back of the head and the temporal lobes are just above the ears.
      5. Each lobe carries out many functions that require the interplay of several lobes.
    2. Functions of the Cortex
      1. Motor Functions
        1. Stimulation only caused movement when applied to an arch-shaped region at the back of the frontal lobe.
        2. When stimulating specific body parts they move on the opposite side of the brain.
        3. The brain has no sensory receptors.
        4. The body parts that require the most control have larger surface areas Penfield’s Sensory Map.
        5. Sensory Functions
        6. The area parallel to the motor cortex and behind it at the front of the parietal lobes is the sensory cortex.
        7. Sounds are processed by the auditory areas in the temporal lobes.
      2. Association Areas
        1. Association Areas are the areas of the cerebral cortex that are not involved in primary motor or sensory functions.
        2. Electrically probing the association areas doesn’t trigger any observable response.
        3. The association areas are not dormant.
        4. The association areas interpret, integrate, and act on information processed by the sensory areas.
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