CERの測定

Abstract

Brady and others measured the effects of convulsive shock on behavior using CER (Conditioned Emotional Response). But the nature of the CER has not thoroughly been examined, although there were many experiments cencerning the problem since it was first reported by Estes and Skinner in 1941. The present study was designed to investigate the nature of CER.About 120 albino rats were trained in the Skinner box. After the accomplishment of the bar-pressing learning, they were conditioned the fear by the combination of buzzer (CS) and the electric shock (UCS) in a grid box. The effects of the following two variables were examined. The first was the duration of the CS (buzzer) which was changed from 15 to 180sec. The second was the number of shock which was changed from 2 to 8. Sixteen groups, consisted of 7 rats each, were used owing to the combination of the two variables.After the conditioning of the fear response, Ss were given extinction trials in the Skinner box presenting only the CS. Results were given in the inflexion ratio of the number of the bar-pressing. A modified formula was used in computing the IR. The IR may represent the direct effect of CS and IR′ the post effect.The main results were as follows:1) IR and IR′ increase as the function of the duration of the buzzer. They increase as the duration increases and reach the maximum at 30sec., and then decrease as the duration increases.2) IR reaches the maximum when the number of shock is four, and IR′ reaches the maximum when the number is two. Both IR and IR′ decrease when the number of the shock increases.3) There may be the optimal points of the duration and number of CS for the effects of CER. Insufficiency as well as excess of the duration and the number of CS the decrease of the effects may result from.