How Psychologists Study the Brain

Accidents Brain damage due to: Psychologists/Doctors examine: Whiplash: aka – diffuse axonal injury Stretching, twisting, damage to the axon Isotropic Stress: high speed change scenarios Car crash, explosions, sky-diving, etc Creates a “pressure wave” or pulse Causes damage to neurons Psychologists/Doctors examine: Loss of Vision Loss of Hearing Loss of Memory Confusion

Lesions Def: cutting the brain, removing portions of the brain Commonly done in the past Today: lobotomy Last resort, experimental surgery McDreamy Observe and document changes Animal experimentation commonly performed Are correlations reliable and valid? Harvesting brains of the dead Concussion victims, dementia, Alzheimer's, schizophrenia, etc

Electroencephalogram (EEG) Why would you get one? Sleep Disorder Having Seizures (epilepsy) Determine “brain death” How does it work? Electrodes attached to the scalp (exterior) Perform mental function or physical action Brain waves produced & recorded

EEG Readings

Electrical Brain Stimulation (EBS) How: Electrodes attached, inserted in the brain (interior) Charge emitted Measure results performed by patient Findings Specific regions of the brain linked to sensory or motor cortex regions Ventral Nerves: neurons sending messages to the brain Epilepsy patients OCD subjects

Computerized Axial Tomography (CAT) Scan aka – CT scan Why would you get one? Car accident Suspected concussion Locate blood clot, infection, or tumor How is it done? X-ray of the brain Brain absorbs radiation and computer produces an image Can be done on any organ

CAT Scans Healthy Brain Scans Abnormal Brain Scans

Magnetic Resonance Imaging (MRI) Why would you get one? CAT Scan inconclusive Looking for a tumor or aneurism Examine bleeding in the brain Damage to optic or auditory nerves How does it work? Brain produces “energy” Computer measures radio waves Looking for abnormalities, “hotspots”

MRI Images Healthy Brain A Brain on “MS”

Positron Emission Tomography (PET) Scan Why would you have one? To confirm CAT Scan To measure blood flow Diagnose: Alzheimer’s, Parkinson’s, MS, ALS, or Cancer (lymphoma) How does it work? Chemical injected (glucose) Chemical “lights-up” Image captured PET & CT Machines often are the same

PET Scan Images Schizophrenia Experiment Alzheimer’s Patient PET scans of five normal individuals (left); each row is one person, and each image is a slice from five different levels of the person's brain. The red areas show regions of the brain that are activated when a person performs a memory task. In PET scans of five individuals with schizophrenia (right), each row represents a different person, with comparable slices. Clearly, the patients with schizophrenia do not generate the dramatic brain activity in the circuits of the brain critical to the memory task.