Discriminative and associative aspects of retroactive inhibition

Original learning of paired drawings of meaningful objects or of modified Chinese characters was followed by interpolated learning in which details of drawings were changed in one of two degrees with or without rearrangement of the original pairings. Subjects were tested for accuracy of identification of the original drawings and for associative matching of the original pairs. Identification errors were attributed jointly to confusion between original and interpolated drawings, and to unlearning of those features of original drawings which were in conflict with comparable features of interpolated drawings. Rearrangement of pairs during interpolated learning produced not only associative interference on the matching test, but also additional discriminatory interference on the identification test. Effects of associative and discriminative interference upon individual drawings were uncorrelated for meaningful material and only slightly correlated for meaningless material.     

Anxiety and retrieval inhibition: support for an enhanced inhibition account

Retrieval inhibition of negative associations is important for exposure therapy for anxiety, but the relationship between memory inhibition and anxiety is not well understood—anxiety could either be associated with enhanced or deficient inhibition. The present study tested these two competing hypotheses by measuring retrieval inhibition of negative stimuli by related neutral stimuli. Non-clinically anxious undergraduates completed measures of trait and state anxiety and completed a retrieval induced forgetting task. Adaptive forgetting varied with state anxiety. Low levels of state anxiety were associated with no evidence for retrieval inhibition for either threatening or non-threatening categories. Participants in the middle tertile of state anxiety scores exhibited retrieval inhibition for non-threatening categories but not for threatening categories. Participants in the highest tertile of state anxiety, however, exhibited retrieval inhibition for both threatening and non-threatening categories with the magnitude of retrieval inhibition being greater for threatening than non-threatening categories. The data are in line with the avoidance aspect of the vigilance–avoidance theory of anxiety and inhibition. Implications for cognitive behavioural therapy practices are discussed.     

Stimulus imagery and the effect of response categorization on recall in retroactive inhibition

This study deals with the interaction between characteristics of stimulus-response encoding and the effect of response categorization on recall in an A-B, A-C paradigm. After a discussion of the results of previous experiments by the present author a ‘restricted-constraint hypothesis’ is formulated. It states that category information will be used if the stimulus provides for an amount of constraint that is not sufficient for direct retrieval but still enough for identifying the response after the list as a whole has been retrieved. In the case of a high amount of constraint however, direct retrieval of the response is possible and category cues are bypassed. This hypothesis is tested by varying the Imagery-value of the noun-stimulus. A first experiment is inconclusive since the categorization effect fails to materialize. The second experiment comes out as predicted.