THE BRAIN PART II-A

The scans that we are going to discuss involve: Diagnosing Psychological Disorders Determining How Drugs Affect the Brain and Body Assessing the usefulness of hypnosis Examining whether the unconscious processes affects behavior Exploring the Interaction of Sensation and Perception

RECORDING THE BRAIN’S ELECTRICAL ACTIVITY You may have heard of an EEG: electroencephalogram. It is an amplified readout of soundwaves. Studying an EEG of the brain is like studying a car engine by listening to its hum. By presenting a stimulus repeatedly and having a computer filter out brain activity unrelated to the stimulus, one can identify the electrical wave evoked by the stimulus

THIS IS WHAT IT LOOKS LIKE

IN THE PREVIOUS PICTURE… The girl in the picture is a 4-year-old girl suffering from epilepsy. The EEG is recording her brain activity.

CT SCAN A series of X-Ray photographs taken from different angles and combined by computer to into a composite representation of a slice through the body. Sometimes called a CAT Scan. CT Scans can reveal brain damage. CT=Computed Tomography

PET SCAN

Depicts brain activity by showing each brain area’s consumption of it’s chemical fuel, the sugar glucose. Active neurons are glucose hogs. After a person receives temporary radioactive glucose, the PET scan detects where this “food for thought” goes by locating radioactivity. Rather like weather radar showing rain activity, PET scan “hot spots” show which brain areas are most active as the person performs mathematical calculations, looks at images of faces, or daydreams.

MRI Magnetic Resonance Imaging A technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue. MRI Scans show brain anatomy.

MRI OF 2 BRAINS, BRAIN ON R ENLARGED AND FLUID - FILLED DUE TO SCHIZOPHRENIA

OLDER BRAIN STRUCTURES Brainstem: begins where the spinal cord swells slightly after entering the skull; the brainstem is responsible for automatic survival functions. Medulla: Base of the Brainstem. Controls heartbeat and breathing.

THE THALAMUS The brain’s sensory switchboard, located on top of the brainstem. It directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

THE CEREBELLUM The “little brain.” The cerebellum exists at the rear of the brain stem; functions include processing sensory input and coordinating movement and balance.

MORE ON THE CEREBELLUM Myers says: “When David Beckham fires the ball into the net with a perfectly timed kick, give his cerebellum some credit. If you injured your cerebellum, you would have difficulty walking, keeping your balance, or shaking hands. Your movements would be jerky and exaggerated. Under alcohol’s influence on the cerebellum, walking may lack coordination, as many a driver has learned after being pulled over and given a roadside test.”

THE LIMBIC SYSTEM Neural System which includes the hippocampus, amygdala, and hypothalamus. Located below the cerebral hemispheres; associated with emotions and drives.

LIMBIC SYSTEM

Hypothalamus: directs several maintenance activities (eating, drinking, and body temp). Helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward. Amygdala: 2 clusters in the limbic system linked to emotion. Hippocampus: linked to memory