ABSTRACT –Using the results from 485 patients with various forms of cerebral dysfunctions and from 60 hospitalized controls, it was shown that measurement of continuous reaction times (CRT) is sensitive to cerebral lesions. Reaction times were more impaired by progressive than by non‐progressive brain diseases. The test did not distinguish between patients with right‐ or left‐hemisphere lesions and was not influenced either by etiology, chronicity, age or sex.Our conclusion is that CRT is useful as a “screening” test for the presence of cerebral dysfunction and is especially sensitive to progressive diseases. Its discrimination power is equivalent to more sophisticated and complex psycholo