Cognitive Tests, Event-Related Potentials
Norm of Cognitive Tests, Event-Related Potentials
Normal recognition and reaction time.
Usage of Cognitive Tests, Event-Related Potentials
Alzheimer's disease, dementia, depression, Huntington's disease, multiple sclerosis, myoclonic dystrophy, post coma unawareness, psychiatric illnesses, and other clinical or experimental situations in which cognitive function disorders are suspected.
Description of Cognitive Tests, Event-Related Potentials
A test devised to measure perceptuomotor skills, sensory acuity, and ability to discriminate. Attention span is also tested because the client is asked to indicate it by pressing a button quickly after recognizing certain auditory or visual clues. When combined with evoked potential recordings, the test can give information about possible areas of error (such as a psychiatric disorder in which a hysterical loss of hearing shows positive brain response to sound but the client is unable to respond). Lack of expected response may be found to result from physical hearing loss rather than from psychiatric causes.
Professional Considerations of Cognitive Tests, Event-Related Potentials
Consent form NOT required.
Preparation
- Obtain earphones, a multichannel recorder with response button, and stimulus equipment.
Procedure
- This test is carried out in a specialized psychophysiology laboratory.
- The client is seated in a quiet environment in a comfortable chair.
- After headphones are placed over the client's ears, a pattern or patterns of auditory cues are given.
- The client must respond to the cues by pushing a button as quickly as possible to signify his or her recognition of the proper cue.
- Visual cues consisting of patterns of light flashes are also used. A multichannel recorder notes the stimulus and response so that the time lapse as well as correctness of response can be determined.
- In some tests, an evoked potential is also recorded and determined. One electrode (active) is placed between the vertex and the auditory meatus. Neutral electrodes are attached to the earlobes, and an evoked potential recording of the hearing test is obtained along with the above recordings.
Postprocedure Care
- Remove the headphones.
Client and Family Teaching
- You must cooperate if the results are to be of value. You will be asked to recognize certain demonstrated tones through earphones and respond by pressing the button provided.
Factors That Affect Results
- Hearing loss or visual disorders impair the client's ability to respond to the auditory and visual cues.
- The test is not helpful in clients who are unable to cooperate or comprehend the instructions.
- Noise or other distractions in the testing environment may interfere with the client's comprehension of the testing cues.
Other Data
- See also Brainstem auditory evoked potential.
