A comparison of computerized and standard versions of the Wisconsin Card Sorting Test.

The manual version of the Wisconsin Card Sorting Test (WCST) is the most frequently used neuropsychological instrument for differentiating normal from populations with frontal-lobe impairments. A number of computerized versions have become available, and their ability to accurately detect frontal-lobe dysfunction is based on the assumption of equivalence with the standard manual version. Accordingly, comparisons of the distribution properties of central tendency, variability, and shape between the manual version with four computerized versions of the WCST were performed (n = 22 per condition). None of the computerized versions were found to be equivalent to the manual version on all assessment measures. Given the discrepancies between the manual and computerized versions, it is concluded that the norms provided for the standard manual presentation method should not be used for the computerized versions, and for continued use of the computerized versions, new norms for computer versions need to be established. Thus, clinicians and experimenters must use caution when basing conclusions on scores from computer versions of the WCST.

Free-operant avoidance in the pigeon using a treadle response.

A free-operant avoidance schedule was used to establish and maintain foot-treadle responding by two Homing, one White King, and two Carneaux pigeons. In the absence of responding, the interval between shocks equaled 10 sec. Each time a treadle response occurred the shock was postponed for 32 sec. Pigeons appear to learn the treadle response more quickly and use it to avoid shock more successfully than do rats bar pressing on similar schedules. The treadle response becomes highly stereotyped and interresponse time distributions obtained from terminal behavior appear very similar to data obtained from rats. It is concluded that the difficulty in training pigeons to avoid electric shock is not in establishing avoidance behavior but in attempting to evaluate such behavior with the key-peck response.