Methods of Mapping the Brain Flashcards
What is the purpose of Neuropsychology?
Neuropsychology refers to the study of functions and behaviors associated with specific regions of the brain.
When typically applied in research settings, researchers attempted to associate very specific areas in the brain to behavior. When applied in a clinical settings, it is used to treat brain lesions on patients.
What methods are typically used for studying the relationship between brain regions and behaviors?
- ) Studying brain lesions in lab animals
- ) Electrically stimulating and recording brain activity
- ) Noninvasive computerized scanning devices
What advantages come from the method of “studying brain lesions in lab animals”?
The advantage of this approach is that precisely defined brain lesions can be created in animal through extirpation or by inserting tiny electrodes inside the brain and selectively applying intense heat, cold or electricity to specific regions of the brain. Such process has greatly increased our understanding of comparable neural structures in humans.
What advantages come from the method of “electrically stimulating and recording brain activity”?
The advantage of this approach is that it is a non-invasive procedure which can be used on human subjects. A small electrode is used to stimulate a patient’s cortex causing individual neurons to fire and thereby activating the behavioral or perceptual processes associated with those neurons, ultimately creating cortical maps. Depending on where they are implanted, electrodes can elicit sleep, sexual arousal, rage or terror; behaviors cease once the electrode is turned off.
Additionally, the electrodes can be used to record electrical activity via Electroencephalogram (EEG).
What is Regional Cerebral Blood Flow (rCBF) and what advantages come from using this method?
Regional Cerebral Blood Flow (rCBF) is a technique used to record patterns of neural activity based on blood flow to different areas of the brain measured using detection of inhaled radioactive markers.
The advantage of this approach is that it is a non-invasive mapping procedure which can be used on human subjects.
What is an Electroencephalography and what advantages come from using this method?
Electroencephalography (EEG) is a test used to study the electrical patterns of the brain under varying conditions and consists of multiple electrodes placed on the scalp. EEGs are noninvasive procedures that can be used on human subjects.
Characteristics EEG patterns include beta, alpha, theta & delta waves, as well as patterns associated with REM sleep.
EEGs are commonly used with human subjects to study sleep, seizures and brain lesions.
What are cortical maps?
A cortical map is topographical representation of arrays of sensory receptors or motor effectors (muscle units) in the cerebral cortex.
Aside from rCBF, what are other common scanning devices/methods used for brain imaging visualization?
- ) CT (Computerized Tomography)
- ) PET (Positron Emission Tomography) scan
- ) MRI (Magnetic Resonance Imaging)
- ) fMRI (Functional Magnetic Resonance Imaging)
What is a CT (Computerized Tomography)?
A CT scan is a method of visualization used for brain imaging in which multiple X-rays are taken at different angles and processed by a computer to cross-sectional slice images of the tissue.
What is a PET (Positron Emission Tomography) scan?
A PET scan is a method of visualization used for brain imaging in which a radioactive sugar is injected and absorbed into the body and its dispersion and uptake throughout the target issue is imaged.
What is an MRI (Magnetic Resonance Imaging) scan?
An MRI scan is a method of visualization used for brain imaging which uses a magnetic field to interact with hydrogen and map out hydrogen dense regions of the body.
MRI techniques are dependent on the reaction of hydrogen to a magnetic field, and the scientific principles behind MRI scans are also applied in NMR techniques.
What is an fMRI (Functional Magnetic Resonance Imaging) scan?
An fMRI scan is a method of visualization used for brain imaging which uses the same base technique as MRI but specifically measures changes associated with blood flow.
This is especially useful for monitoring neural activity, since increased blood flow in regions of the brain is typically coupled with neuronal activation.
MCAT Concept Check:
What are some of the methods used for mapping the brain?
- ) Studying the brains of lab animals
- ) Electrical stimulation and recording brain activity
- ) Noninvasive imaging such as MRI, CT, PET, fMRI
