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