Thinking About Psychology:

The Science of Mind and Behavior

Charles T. Blair-Broeker

Randal M. Ernst

The Brain

Module 07

Lower-Level Brain Structures:

The Brainstem

Module 7: The Brain

Brainstem

• The oldest part of the brain• Is responsible for automatic survival

functions• Located where the spinal cord swells

and the brain just begins

Medulla

• The base of the brainstem• Controls life-supporting functions like

heartbeat and breathing• Damage to this area can lead to death.

Medulla

• Life Support: Controls…–Breathing / Respiration–Heart rate–Blood Pressure–Digestion–Swallowing, coughing, vomiting etc.

Medulla

• Injury to this area can cause death…–Hanging – pathways severed–Karate Chops - dangerous–Whiplash

• Kennedy shot in medulla• Christopher Reeves - damaged

Reticular Formation

• A nerve network extending up and down the spinal cord into the brain

• Controls an organism’s level of alertness–Driving – sleepy, snaps us awake – deer!

• Damage to this area can cause a coma.

Thalamus

• Sits atop the brainstem

• The brain’s sensory switchboard -- directs messages to the sensory receiving areas in the cortex (all senses except smell)

• Thalamus is Greek for “inner chamber.”

• If spinal cord damaged, thalamus can not work

Cerebellum

• Latin for the “little brain”

• Located in the rear of the brain

(Looks like “cauliflower”)

• Coordination and Balance–Precise movement, posture and muscle tone

• Injury: relearn eating and walking

Cerebellum

• If damaged, the person could perform basic movements but would lose fine coordination skills.

• Alcohol consumption affects this area– “Under the influence”, may stagger and not

be able to walk a straight line or stand on one foot

Pons

• Connects Cerebellum to rest of brain

• Regulates sleeping, waking, dreaming

• Blow to head – effects this area

Lower-Level Brain Structures:

The Limbic System

Module 7: The Brain

Limbic System

• A ring of structures around the thalamus; at the border of the brainstem and cerebral cortex

• Helps regulate memory, aggression, fear, hunger, and thirst

• Includes the hypothalamus, hippocampus, and amygdala

Hypothalamus

• Small bean-shaped; thumbnail size

• Master controller of emotions (pleasure center)– Hunger and thirst– Body temperature (sweating or shivering)– Urination– Sleep and wakefulness

Hypothalamus

• Triggers “Fight or flight response”

• Stress – causes hands to get cold, blood flows to vital organs

Hippocampus

• Wraps around the back of the thalamus

• Plays a role in processing new memories for permanent storage

• Alzheimers patients have problems in this area

• Looks something like a seahorse–Hippo is Greek for “horse.”

Amygdala

• Two almond shaped structures

• Controls emotional responses such as fear and anger

The Cerebral Cortex

Module 7: The Brain

Cerebral Cortex

• The body’s ultimate control and information processing center

• Covers the brain’s lower level structures

• Contains an estimated 30 billion nerve cells

• Divided into four lobes

Corpus Callosum

• The large band of neural fibers that connects the two brain hemispheres and carries messages between them

• Is sometimes cut to prevent seizures

• “Contra Lateral Control” – opposite hemispheres control opposite sides of body

Longitudinal Fissure

• The crevice that divides the brain into two halves or hemispheres

• This and other fissures in the brain create major divisions in the brain called lobes

Frontal Lobes

• The portion of the cerebral cortex lying just behind the forehead

• Primary function in planning, thinking, creativity, speech etc…

• Damaged: alter personality

Parietal Lobes• Behind the frontal lobes

• Regions available for general processing, including mathematical reasoning– Puzzles, drink from straw etc…

• Designated as the association lobes– Recognize objects by touch and sight

• Damaged: cause “Visual Agnosia”– Inability to name common objects by sight

Occipital Lobe

• Located in the back of the head

• The primary visual processing area

• Color, lines and movement

• Damaged: blindness can occur

Temporal Lobes• Located roughly above the ears

• Includes the auditory cortex where sound information is processed

• Language comprehension

• Right temporal lobe– Perception of music and tone– Spatial relationships, complex visual images and

facial expressions

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex