Mod 6

Module Six: Brain Regions and Structures

Overview of Brain Divisions

• Three Main Divisions:

  • Hindbrain: Controls essential survival functions (breathing, sleeping, arousal, coordination, balance)

  • Midbrain: Connects hindbrain with forebrain; controls movement and transmits sensory information

  • Forebrain: Manages complex cognitive functions, sensory processing, associative functions, and voluntary motor activities

Hindbrain Structures

• Brain Stem:

  • Central core of the brain, includes pons and medulla; responsible for autonomic survival functions such as heartbeat and breathing.

  • Medulla: Located at base of brain stem; controls heartbeat and breathing.

  • Pons: Sits above medulla; assists in controlling movement and sleep.

• Thalamus:

  • Above brain stem; directs sensory messages to the cortex and transmits replies to cerebellum and medulla.

• Reticular Formation:

  • Nerve network through brainstem; filters information; important for controlling arousal and alertness.

• Cerebellum:

  • Rear of brain stem; processes sensory information, coordinates movements, balance, and non-verbal learning.

Forebrain Structures

• Limbic System:

  • Located mostly in the forebrain; associated with emotion and drives, includes:

    • Hypothalamus: Controls the pituitary gland, regulates bodily maintenance functions (hunger, thirst, temperature) and pleasure/reward systems.

    • Amygdala: Linked to aggression, fear, and emotional responses. Dysfunction associated with criminal behavior.

    • Hippocampus: Processes conscious memories; involved in memory formation and storage.

Cerebral Cortex

• Overview:

  • Thin layer of interconnected neurons covering cerebral hemispheres; ultimate control and information processing center.

  • Each hemisphere has four lobes:

    • Frontal Lobe: Involved in speaking, muscle movements, planning, and judgment.

    • Parietal Lobe: Processes sensory information from various body parts.

    • Occipital Lobe: Receives and processes visual information.

    • Temporal Lobe: Receives and processes auditory information.

Functions of the Cortex

• Motor Cortex:

  • Controls voluntary movements; electrically stimulating this area can cause body parts to move.

  • Mapped by researchers such as Gustav Fritsch, Edouard Hitzig, and Jose Delgado.

• Somatosensory Cortex:

  • Registers and processes body touch and movement sensations; located behind the motor cortex.

• Visual and Auditory Cortex:

  • Visual Cortex: Located in occipital lobes; processes incoming visual information.

  • Auditory Cortex: Located in temporal lobes; processes incoming auditory information.

Myth about Brain Usage

• Common Misconception: Only 10% of our brain is used.

  • Reality: Studies show that all areas of the brain are active, especially during mental tasks.

  • Association areas, not involved in primary functions, are crucial for higher mental processes like learning, memory, thinking, and speech.

Importance of Association Areas

• Found across all lobes; allow integration of information.

• Damage to these areas results in significant cognitive deficits.

Case Study: Phineas Gage

• Discussed in module; illustrates the impact of brain damage on personality and behavior.

Conclusion

• Review module content, take time to understand terms, and utilize diagrams and figures for better comprehension.