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
far-field potentials
EEG signals recorded in attenuated form at the scalp b/c they originate far away- for example in the brain stem
magnetoencephalography (MEG)
measures changes in magnetic fields on the surface of the scalp that are produced by changes in underlying patterns of neural activity
Electromyography
usual procedure for measuring muscle tension
electromyogram (EMG)
record from electromyography measurement …. usually recorded between two electrodes taped to the surface of the skin over the muscle of interest
electrooculography
electrophysiological technique for recording eye movements …. based on the fact that a steady potential difference exits between the front (positive) and back (negative)
electrooculogram (EOG)
resulting record of electrooculography
electrodermal activity
conduction of electricity in the skin
Skin conductance level (SCL)
steady level of skin conductance associated with a particular situation
Skin conductance response (SCR)
the transient change in skin conductance associated with a brief experience
cardiovascular system
two parts: the blood vessels and the heart… is responsible for distributing oxygen and nutrients to tissues of the body…. removing metabolic wastes and transmitting chemical messages
electrocardiogram (ECG or EKG)
records the electrical signal associated with each heartbeat through electrodes place on chest
Systole
measurement of the peak pressure during the periods of heart contraction
Diastoles
measurement of the minimum pressure during the periods of relaxation
Hypertension
A chronic blood pressure as a serious health hazard
sphygmomanometer
device compose of hollow cuff, and rubber bulb to inflate and a pressure gauge for measuring the pressure in the cuff – used to measure blood pressure
Plethysmography
refers to various technique for measuring changes in the volume of blood in a particular part of the body
stereotaxic surgery
means by which experimental devices are precisely positioned in the depths of the brain
Stereotaxic atlas
used to locate brain structures in much the same way that a geographic atlas is used to locate geographic
bregma
point on the top of the skull where two of the major sutures intersect
stereotaxic instrument
has two parts: head holder- firmly holds the subject’s brain in the prescribed position and orientation
electrode holder: holds the device to be inserted