Concerning the effect of shock for right responses in visual discrimination learning.

Motivation in learning: X. Comparison of electric shock for correct turns in a corrective and a non-corrective situation.

“…His statement that in his experiment "learning of the shockright animals was retarded rather than facilitated" (8, p. 279) is based on differences of what he calls "trials" and "errors" in the no-shock and shock-right groups. As the senior author has pointed out (6), Wischner's use of the term "trial" is not the same as that of the Colorado experimenters, and his conclusions are therefore not directly comparable to ours in terms of "trials." In terms of errors or wrong turns his shock-right group was poorer than the no-shock group.…”

“…In previous studies (1,4,5) it has been shown that electric shock for correct turns after the point of choice has an accelerating effect upon white rats learning a black-white discrimination in a corrective situation. Using a non-corrective situation, where an animal was not permitted to retrace his entry into the wrong alley, Wischner recently (8) obtained results which, if stated in terms of reinforcement (6), also indicated a slight accelerating effect of shock for correct turns. Since Wischner did not have a corrective situation as a control condition it is impossible to say whether the smallness of the accelerating effect was due to the non-corrective as contrasted with the corrective condition, where the accelerating effect might be expected to be large, or to the particular apparatus used which differed in some respects considerably from the one used by us.…”

“…But a slight accelerating effect of shock-right is apparent if his results are stated in terms of the number of reinforcements required to reach the criterion of learning, as was done in the reports from the Colorado laboratory. This whole issue has been discussed recently (6,8). Further reference to Wischner's use of the terms "trial" and "error" will be found below.…”

The effect of shock on the rat's choice of a path to food.

“…This difference may be accounted for in part by the fact that in the corrective situation the rat must experience a shock-food sequence on every trial while in the noncorrective situation he does not. Both Wischner (1947) and Muenzinger (1948) have pointed out the rapid decline in errors when the shock-right 5s finally begin to learn. This is to say that the positive effects of shock on learning take place mainly in the later trials.…”

Escape learning and "vicious circle" behavior under partial and continuous reinforcement

“…Studies in which electric shock administered after a choice point was found to facilitate learning (Muenzinger, 1934(Muenzinger, , 1948Drew, 1938) are also relevant. While Muenzinger concluded that shock does not inhibit the punished response, but instead makes the animal more sensitive to the cues to be discriminated, other explanations have been offered.…”