Major Brain Regions and Their Functions in Psychology

Major Brain Regions

Brainstem

The brainstem is the oldest part of the brain, responsible for basic life functions such as breathing and sleep. It acts as a relay center, receiving information and sending it to other brain areas.

• Hindbrain: Includes the cerebellum, reticular formation, pons, and medulla.

• Midbrain: Contains dorsal (sensory) and ventral (motor) areas.

• Diencephalon: Composed of the hypothalamus and thalamus, located below the hypothalamus.

• Basal Ganglia: Involved in motor coordination and learning.

Hindbrain

The hindbrain is the oldest part of the brain and is essential for motor functions and balance.

• Functions: Motor functions (e.g., breathing, sleep), balance

Midbrain

The midbrain serves as a relay center for information between higher and lower brain regions.

• Relay center for information between higher and lower brain regions

Diencephalon

The diencephalon acts as a relay center and sends information up and down the brain.

• Relay center

• Sends information up and down the brain

Cerebellum

The cerebellum is involved in coordinating voluntary movements and emotional control.

• Motor movement: Coordinates voluntary movements (e.g., playing sports)

• Emotional control: Influences cognitive effects and attention span

• Location: At the base, on the brainstem and cortex

• Ventral = closer to the back of the neck

Medulla

The medulla controls breathing and is essential for life.

• Controls breathing

• Essential for life

Pons

The pons is the largest, smooth white structure in the brainstem and controls automatic body movements.

• Controls automatic body movements (e.g., sneezing, vomiting)

Dorsal (Superior) vs. Ventral (Inferior)

These terms describe anatomical directions in the brain.

• Dorsal (Superior): Top, sensory information, like the fin of a fish

• Ventral (Inferior): Bottom, motor function

Basal Ganglia

The basal ganglia are deep brain structures involved in motor coordination and learning.

• Motor coordination

• Smooth motion

• Associated learning

Limbic System

The limbic system is a group of structures located deep within the brain, involved in motivation, emotion, and memory.

• Medial location (towards the center)

• Motivational behavior

• Memories:

  • Amygdala: Responsible for fear responses, anxiety, and PTSD

  • Hippocampus: Shaped like a seahorse, involved in long-term memory (e.g., studying), located internally

Thalamus and Hypothalamus

• Thalamus:

  • Sensory relay center (except smell)

  • Auditory center

  • Located in the middle of the brain

  • Olfactory (smell) information bypasses the thalamus

• Hypothalamus:

  • Regulates the "four F's": Flight, Flee, Feed, Fornication

  • Controls temperature

  • Involved in forms of emotional behavior

The Brain (Cortex)

The cortex is the outer layer of the brain, involved in higher-order functions such as perception, thought, and decision-making.

Summary Table: Major Brain Regions and Functions

Region	Main Function(s)	Location
Midbrain	Relay center for sensory/motor info	Above hindbrain
Diencephalon	Relay center, includes thalamus/hypothalamus	Central brain
Cerebellum	Motor coordination, balance, emotional control	Base, behind brainstem
Basal Ganglia	Motor coordination, learning	Deep within cerebral hemispheres
Limbic System	Emotion, motivation, memory	Medial, deep brain
Thalamus	Sensory relay (except smell)	Center of brain
Hypothalamus	Homeostasis, emotion, drives	Below thalamus
Medulla	Breathing, heart rate	Base of brainstem
Pons	Automatic movements	Above medulla
Reticular Formation	Sleep, alertness	Runs through brainstem
Amygdala	Fear, anxiety, PTSD	Limbic system

Key Terms and Definitions

• Relay center: Area that transmits information between different brain regions

• Homeostasis: Regulation of internal body conditions (temperature, hunger, etc.)

Example Applications

• Damage to the hippocampus can result in difficulty forming new long-term memories (anterograde amnesia).

• Overactivity of the amygdala is associated with anxiety disorders and PTSD.

• Lesions in the basal ganglia can cause movement disorders such as Parkinson's disease.