Introductory Psychology Biological Bases of Behavior AP PSYCHOLOGY

Introductory Psychology: Biological Bases of Behavior AP PSYCHOLOGY: UNIT II Topic: Research Methods

Research Methods: Lesioning PART ONE

Methods: Lesioning The natural or experimental destruction of brain tissue An electrode passes a high frequency current through the structure Burns & disables the targeted tissue Use? Victims of severe brain injury Parkinson’s patients? Schizophrenic patients? OCD patients?

Methods: Lesioning

Research Methods: Electrical Recordings PART TWO Hans Berger German Psychiatrist 1929

Research: Electrical Recordings Electroencephalograph (EEG) Monitors brainwave patterns produced by electrical activity on the surface of the brain EEG electrodes amplify electric potential Use? Sleep stages Seizure disorders Presence of tumors Active areas of brain

Research Methods: Electrical Stimulation PART THREE

Methods: Electrical Stimulation of the Brain (ESB) A process in which a weak electrical current is sent into a brain structure in order to stimulate it Delivered by an electrode Simulates normal signals in the brain & activates the structure in question Use? Animal research Humans in some surgical situations

Research Methods: Transcranial Stimulation PART FOUR

Methods: Transcranial Stimulation Transcranial Magnetic Stimulation (TMS) New technique Permits scientists to temporarily enhance or depress activity in a specific area of the brain; 2 cm “Virtual lesions” Limitations?

Research Methods: Brain-Imaging Procedures PART FIVE

Methods: Brain-Imaging Computer Tomography (CT) Brain-imaging method that utilizes computercontrolled x-rays of the brain; gives a composite representation (map) of brain slices Use? Stroke damage Blood clots Tumors Injuries Abnormal brain structure

Methods: Brain-Imaging Positron Emission Tomography (PET) Brain-imaging method is which a radioactive glucose is injected into the subject A computer compiles color-coded images of brain activity, with lighter colors indicating more activity

Very high activity High activity Medium activity Low activity No activity

Methods: Brain-Imaging

Methods: Brain-Imaging Magnetic Resonance Imaging (MRI) A technique that uses magnetic fields and radioactive waves to produce computer generated images that distinguish among different types of soft tissue Allows us to see smaller details & structures within the brain

Methods: Brain-Imaging CT versus MRI? Cost CTs are generally less expensive than MRIs Testing Ability CTs are less sensitive to patient movement CT scans CAN be performed in the presence of an implanted medical device Side Effects MRI contrast materials used for image enhancement have very low incidence of side effects

Methods: Brain-Imaging Functional MRI (f. MRI) A new variation on MRI technology that monitors blood flow and oxygen consumption in the brain to identify areas of high activity As opposed to a traditional MRI, the f. MRI allows neuroscientists to study brain ACTIVITY