by Richard L. Doty, PhD
Time: 8-12 minutes
Sensitive to smell deficits caused by a wide range of medical, neurological, and psychiatric disorders, the SIT is useful in a variety of clinical, laboratory, and industrial settings. It has been used in occupational settings to screen persons working in hazardous manufacturing areas for their ability to smell; to evaluate the effect of occupational exposure to airborne chemicals on the ability to smell; to select members for sensory panels within the food and beverage industries; and to screen firemen, municipal gas works employees, plumbers, and others who are in potential danger from smoke or leaking natural gas. In addition, the SIT has been shown to be an excellent measure of frontal lobe dysfunction and has gained interest in the area of Schizophrenia, as it is one of a few neuropsychological measures that tracks the progression of the disease.
The SIT focuses on the comparative abilities of individuals to identify a number of odourants at the suprathreshold level. Test stimuli include a number of odourous components mimicking the types of stimuli usually experienced by individuals in the general population. An individual's test scores are compared to scores from normal persons of equivalent age and gender using tables provided in the manual. The resulting percentile score provides a measure of the individual's performance that is easy to interpret. The test-retest reliability of the SIT exceeds .90 and correlates well with other olfactory tests, including detection threshold tests.
One of the strengths of this unique test is its normative data base of nearly 4,000 individuals of all ages. Another strength is its means for detecting malingerers.