SCOTOPIC ACUITY AND KNOWLEDGE OF RESULTS

The purpose of the present experiment was to determine the effect of knowledge of results (KR) when introduced separately from any change in motivation. That is, the object was to determine how much of the improvement reported by Shvarts is due to a learning process specific to the stimulus used, and how much is due to a general excitation of cerebral centres, which according to Shvarts, transfers to the discrimination of other stimuli. The following changes in the procedures described by Shvarts were made. First, KR was intruduced some time after the effect of the motivation variable had been measured. These two variables were confounded in Shvarts' study. Secondly, to distinguish training effects from motivation effects, the level of discrimination was determined independently on a Landolt ring before and after the experiment, in which the training stimulus was a letter E. (Author)
Reprint from Perceptual and Motor Skills, 18, pp. 505-508, 1964. (Copies not supplied by DDC)