The ability of a newly developed measure of information processing to detect deficits in cognitive functioning associated with multiple sclerosis (MS) was investigated. The Computerized Tests of Information Processing (CTIP; Tombaugh, T., & Rees, L. (1999). Computerized Tests of Information Processing (CTIP). Unpublished test. Ottawa, Ontario, Canada: Carleton University) was administered to 60 clinically definite MS patients and 60 healthy controls. MS patients responded significantly slower than controls on the reaction time tests composing the CTIP. Moreover, as the CTIP tests became more difficult (i.e. as processing demands increased), the difference between the performances of the two groups progressively increased. These results suggest the CTIP is sensitive to the cognitive deficits observed in MS and that this measure has the potential to serve as a viable alternative to traditional measures of information processing speed currently in use with MS patients.

Two experiments examined whether experience gained with a series of reaction time tests [Computerized Tests of Information Processing (CTIP); Tombaugh, T. N. & Rees, L. (in press). Computerized Tests of Information Processing (CTIP). Toronto, Canada: Multi-Health Systems Inc.] influenced the performance of individuals instructed to simulate the cognitive effects of a traumatic brain injury. Experience with the tests was manipulated by varying the order and number of tests administered for simulator and control groups. Simulators responded significantly slower and exhibited increased variability compared to controls. Performance was not affected by order or number of tests. The results of a third experiment showed that criterion scores could be established that correctly classified members of control, simulator, mild TBI, and severe TBI groups. Overall, the results suggest that the performance of the simulators was based on a context-free, absolute judgment and that reaction time measures show considerable promise for detecting low effort.