Cognistat
Cognistat
Definition
The Cognistat is a standardized neurobehavioral screening test. It is a test that examines neurological (brain and central nervous system) health in relation to a person’s behavior.
Purpose
As a screening test, the Cognistat may be administered to identify basic strengths and weaknesses so that further tests (if necessary) can be selected, and the data provided by the Cognistat can then be used as preliminary data against which scores from other tests given may be compared. Cognistat results have been used in a number of arenas, most notably in behavioral medicine. For example, Cognistat results may be useful to track cognitive decline (decreased thinking and reasoning abilities) in patients with organic brain disorders, to develop helpful strategies for cognitive problems associated with schizophrenia, and to help distinguish among terminally ill cancer patients those with depression and anxiety versus those with cognitive impairment.
Precautions
The Cognistat is more sensitive than many similar tests, but considers a limited sample of behavior at a brief point in time. Thus, its results are not generalizable and should not be viewed as conclusive indicators of the areas being assessed. It is important that the examiner be properly trained in the use of the test. Test takers may be affected by test-related discomfort or performance anxiety. This may be particularly true when prior to testing, the examinee was not fully aware of his or her deficits, especially deficits that become more apparent as testing progresses. The test’s reliability has not been fully documented. Further research and standardization data is needed.
Description
The Cognistat usually takes less than 45 minutes to complete, and the test explores, quantifies, and describes performance in central areas of brain-behavior relations: level of consciousness, orientation, attention, language, constructional ability, memory, calculations and reasoning. The sub-areas of language are spontaneous speech, comprehension, repetition, and naming. The sub-areas of reasoning are similarities and judgment. Exploration occurs through interactive behavioral tasks that rely on perception, cognitive processing, and motor skills. The test is more quickly administered to higher than lower functioning individuals by providing a difficult screening item at the beginning of each section. Only when a screening item is missed are the metric, or more remedial, items applied, usually from easiest to most difficult within that section.
The test begins with the examiner asking general questions of the test taker (name, address, age, etc.), and while these questions are being answered, the examiner is subjectively assessing the test taker’s level of consciousness. Then, the examiner asks general questions to confirm the test taker’s level of orientation, meaning that the test taker is correctly oriented to place and time—he or she knows what day it is and where he or she is. To test the examinee’s attention and memory, the test taker will be asked to repeat a series of digits and the first part of a verbal memory task will be given. (This task will be asked about again later in the test.)
The language section begins with a sample of spontaneous speech derived by asking for a description of a detailed line drawing. The language comprehension section requires responses to simple commands that involve manipulation of common objects placed before the examinee. In the language repetition subtest, the test taker is asked to repeat short phrases and simple sentences. In naming, the last of the language subtests, the screening item differs in form from the metric (easier) items. In the screening item, the examiner holds up an object and asks the test taker to name its four major parts, as the examiner points to them one after another. If the test taker fails, he or she is asked to name eight separate objects, one after another represented by line drawings.
In the next section, constructional ability, the screening item is a visual memory task wherein a stimulus sheet is presented for ten seconds, and the examinee is asked to draw the stimuli from memory. The test taker is then asked to assemble plastic tiles into designs, one after another, as each is shown on a card. Faster completion yields greater points. After the constructional items, the test taker is asked to recall the verbal memory items presented earlier. For items he or she cannot recall, the examiner provides prompts, or clues.
The calculations section is composed of simple verbal mathematics, and is followed by the reasoning section, which includes two subtests. The first consists of associative thinking items known as similarities. In similarities items, the examinee is asked to explain how two concepts are alike. Greater points are awarded if their concept is abstract rather than concrete. The final subtest on the Cognistat is the judgment subtest of the reasoning section. In the judgment subtest, the examinee is asked to answer questions that demonstrate practical judgment in solving basic problem scenarios. Scores for this subtest are weighted based on their appropriateness. There is only one fully appropriate response to each item.
KEY TERMS
Screening test —A test given as a preliminary tool, that helps to later target a more thorough analysis.
Standardized test —A test that follows a regimented structure, and each individual’s scores may be compared with those of groups of people. In the case of the Cognistat, test taker’s scores can be compared to groups of young adults, middle-aged adults, the geriatric, and people who have undergone neurosurgery.
The test booklet provides space for listing medications, and for noting comments about any physical deficits and the examinee’s impression of his or her own performance.
Results
When test administration is complete, the examiner tallies the points earned in each section, and plots them on the cognitive status profile located on the front of the test booklet. On the profile, numerical scores are described to fall within the normal or impaired range. The impaired range is broken down into mild, moderate and severe. An individual’s scores can also be compared to standardization group data, and their profile may be compared to five case study profiles presented in the test guide. The few items that do not allow for quantitative analysis—the sample of spontaneous speech, for example—are factored into the interpretation of results by the examiner. There is no mechanism for transforming raw scores into percentiles or standard scores, and the test is not designed to generate one main score.
Resources
BOOKS
The Northern California Neurobehavioral Group, Inc. Manual for the Neurobehavioral Cognitive Status Examination. Fairfax, CA.
PERIODICALS
Kiernan, R., J. Mueller, W. Langston, and C. Van Dyke. “The Neurobehavioral Cognitive Status Examination: A brief but differentiated approach to cognitive assessment.” Annals of Internal Medicine 107 (1987): 481–485.
Logue, P., L. Tupler, C. D’Amico, and F. Schmitt. “The Neurobehavioral Cognitive Status Examination: Psychometric properties in use with psychiatric inpatients.” Journal of Clinical Psychology 49 (Jan. 1993): 80–89.
Geoffrey G. Grimm, Ph.D., LPC