Chapter 5 - Research Flashcards
Contrast X-ray techniques
use to visualize the brain -How is done? by injecting into one compartment of the body a substance that absorbs X-rays either less than or more than the surrounding tissues
Cerebral angiography
uses the infusion of a radio-opaque dye into a cerebral artery to visualize the cerebral circulatory system during X-ray photography
Computed tomography
is a computer- assisted X-ray procedure that can be used to visualize the brain and other internal structures of the living body
magnetic resonance imaging (MRI)
procedure in which high-resolution images are constructed from the measurement of waves that hydrogen atoms emit when activated by a radio-frequency waves in a magnetic field
Spatial resolution
ability to detect and represent differences in spatial location
positron emission tomography (PET)
first brain-imaging technique to provide images of brain activity rather than images of brain structure
2-deoxyglucose
provides color coding for PET - acts similar to glucose since is rapidly taken up by active cells- but instead of being consume its broken down
carotid artery
an artery of the neck that feeds the ipsilateral cerebral hemisphere
ligands
ions or molecules that bind to other molecules during investigation
Functional MRI
produces images representing the increase in oxygen flow in the blood to actives areas of the brain
BOLD signal
signal recorded by fMRI - blood-oxygen-level-dependent signal
temporal resolution
ability of a recording technique to detect differences in time (i.e. pinpoint when an event occurred)
Diffusion tensor imaging
a method of identifying those pathways along which water molecules rapidly diffuse … provides image of major tracts
Transcranial magnetic stimulation (TMS)
technique that can turn off an area of the cortex by creating a magnetic field under a coil positioned next to the skull
psychological recording methods
methods of recording physiological activity from the surface of the human body
Electroencephalogram (EEG)
is a measure of the gross electrical activity of the brain and is recorded through a large electrode by a device called an electroencephalograph (EEG machine)
electroencephalography
technique use to measure the gross electrical activity of the brain
alpha waves
are regular, 8-12-per second, high amplitude waves that are associated with relaxed wakefulness
event-related potentials
EEG waves that accompany certain psychological events
Sensory evoked potential
change in the cortical EEG signal elicited by the momentary presentation of a sensory stimulus
Component of a sensory stimulus
response to the stimulus & ongoing background EEG activity (noise)
Signal averaging
method used to reduce the noise of the background EEG
Average evoked potentials (AEPs)
analysis that focuses on the various waves in the averaged signal
P wave
positive waves that are measure in milliseconds and are recorded after a momentary stimulus that have meaning for the subject