Kaufman Short Neurological Assessment Procedure
Kaufman Short Neurological Assessment Procedure
The Kaufman Short Neurological Procedure, often abbreviated as K-SNAP, is a brief test of mental functioning appropriate for adolescents and adults between the ages of 11 and 85 years. It is administered on an individual basis, and measures mental functioning at varying levels of cognitive complexity as well as addressing possible neurological damage.
The K-SNAP is intended as a short measure of mental functioning and is sometimes preferable to other longer mental status and intelligence exams. Compared to the Kaufman Adolescent and Adult Intelligence Test (KAIT), which is given to people in the same age range and takes over an hour to complete, the K-SNAP takes only 20-30 minutes. The K-SNAP provides a measure of general mental status, as well as addressing specific mental abilities. It also allows for assessment of damage to the nervous system.
The K-SNAP was developed by Alan S. Kaufman and Nadeen L. Kaufman. Other Kaufman tests include the KAIT and the Kaufman Assessment Battery for Children (K-ABC). The Kaufmans based their tests on Horn and Cattell’s formulation of the distinction between fluid and crystallized intelligence, sometimes referred to as the Gf-Gc Theory. Gf refers to such general fluid abilities as problem solving and reasoning. Fluid intelligence is thought not to be influenced by a person’scultural experience and education. Gc refers to such general crystallized abilities as acquired knowledge. Crystallized intelligence, unlike fluid intelligence, is thought to be shaped by a person’scultural experience and education.
Because the K-SNAP provides a measure of possible neurological impairment, it is often preferable to other measures of mental status and intelligence. If the doctor suspects that a patient may have a disorder of the nervous system, the doctor can use the K-SNAP as a short initial assessment. Depending on the results of the K-SNAP, the doctor can give more specific tests.
One should be careful when using the results of the K-SNAP to assess neurological impairment. It should be used as a supplement to other more extensive and more specific measures of neuropsychological functioning.
The K-SNAP is primarily a test of mental and neuropsychological functioning. Although it measures cognitive skills, it should not be used to measure some-one’soverall intelligence.
The K-SNAP consists of four subtests administered in the following order of complexity: Mental Status; Gestalt Closure; Number Recall; and Four-Letter Words. Each subtest contains between 10 and 25 items.
The Mental Status subtest assesses the test taker’s alertness, attentiveness, and orientation to the environment. In this subtest, the examiner asks the examinee to answer verbal questions. It is the easiest and shortest of the four subtests, containing only 10 items.
The Gestalt Closure subtest provides an assessment of visual closure and simultaneous processing. In this subtest, the examinee is shown partially completed inkblot pictures and is asked to name the objects in the pictures.
The Number Recall subtest assesses sequential processing and short-term auditory memory. In this subtest, the examiner recites series of numbers and the examinee repeats the numbers.
The Four-Letter Words subtest measures the test taker’s ability to solve problems and make plans. In this subtest, the examinee is asked to guess a secret word by analyzing a series of four-letter words that provide clues to the answer. It is the most complex of the subtests.
The K-SNAP is a relatively easy test to administer. Except for the Mental Status subtest, the test items are presented on an easel, which is visually appealing to many test takers. Also, because the test is brief and includes a variety of tasks, the test takers often find the test engaging and interesting.
The K-SNAP is considered to be useful in evaluating elderly people, especially with regard to decline in fluid intelligence. The Mental Status subtest can also detect possible age-related impairment in mental functioning.
Compared to other neurological and cognitive assessments, there are smaller than usual differences in K-SNAP performance between African-American and Caucasian individuals, especially with regard to fluid intelligence. This cultural neutrality makes the K-SNAP a preferred method for testing African-Americans.
The K-SNAP yields several scores, including raw scores, scaled scores, a composite score, and an impairment index. Raw scores and scaled scores are calculated for each of the four subtests. Raw scores are calculated first; they refer simply to the number of points that the examinee scored on a particular subtest. The raw scores are converted to scaled scores to simplify comparisons between the subtests and between examinees. The subtest scaled scores are standardized to have a mean of 10 and a standard deviation of three.
One composite score is obtained on the K-SNAP. The composite score has a mean of 100 and a standard deviation of 15 and is based on the scores of the four subtests.
The results of the Mental Status subtest are primarily of interest when working with middle-aged or elderly people, as well as people with neurological or cognitive impairments. Most people find the mental Status subtest very easy, and they get most, if not all, of the items correct.
Gestalt —A German word that means “form”or “structure.” The Gestalt Closure subtest on the K-SNAP measures a person’s ability to identify a whole object from a partially completed drawing of its form.
Mean —The mathematical average of all scores in a set of scores. The K-SNAP Composite Score has been standardized to have a mean of 100. The K-SNAP subtests have been standardized to have a mean of 10. The means are based on a comparison to others in the same age group. Standardizing in this way then allows the scores to be comparable across age groups.
Orientation —In psychiatry, the ability to locate oneself in one’s environment with respect to time, place and people.
Reliability —The ability of a test to yield consistent, repeatable results.
Standard deviation —A measure of variability in a set of scores. The K-SNAP Composite Score has been standardized to have a standard deviation of 15. The subtests have been standardized to have a standard deviation of three. The standard deviations are based on a comparison to others in the same age group. Standardizing in this way then allows the scores to be comparable across age groups.
Standardization —The administration of a test to a sample group of people for the purpose of establishing scoring norms. Prior to the publication of the K-SNAP, it was standardized in 1988 using a sample of 2,000 adults and adolescents.
Validity —The ability of a test to measure accurately what it claims to measure.
Some of the interpretation of the K-SNAP involves comparisons of performance on tasks of varying complexity. For example, Gestalt Closure is considered a less complex task than Number Recall. Someone who performs better on the more difficult Number Recall subtest may exhibit some kind of brain dysfunction. On the other hand, that person may simply prefer sequential processing tasks.
An impairment index is also calculated and provides an objective measure of cognitive and neurological impairment. The impairment index is based on the following four factors: the K-SNAP composite score; the test taker’s performance on the Mental Status subtest; the difference between the scaled scores on the Number Recall and Gestalt Closure subtests; and the difference between the actual composite score and the predicted composite score based on the test taker’s level of education. These four factors determine whether a more comprehensive assessment of impairment is necessary. For example, if an examinee has a composite score below 70, a low score on the Mental Status subtest, a large difference in performance in the Number Recall and Gestalt Closure subtests, and a difference of at least 24 points between the predicted and actual composite scores, there may be indications of impairment. One example of such impairment is damage to one hemisphere of the brain.
Overall, the K-SNAP has above-average to good reliability. As a mental status examination, it has been shown to have good validity as well. There have been no studies, however, demonstrating the K-SNAP’s validity as a measure of neuropsychological impairment. Because the K-SNAP is based on similar theories and on the same standardization sample as other Kaufman tests, such as the KAIT, interpretation across the range of Kaufman tests is easier than comparing results from the K-SNAP to results from tests designed by other persons.
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Ali Fahmy, Ph.D.