Conditioned inhibition is not the symmetrical opposite of conditioned excitation: A test of the Rescorla-Wagner model

Rescorla and Wagner's (1972) linear associative model of learning predicts that a neutral stimulus will become weakly excitatory if it is paired with a conditioned inhibitor and the compound is not reinforced. If the inhibitor is not allowed to extinguish during these pairings, the model predicts that the neutral stimulus will become strongly excitatory. Rescorla (1971) has presented some evidence to support the former prediction of a weak effect. Experiment I tested the latter prediction of a strong effect using rats in a conditioned emotional response paradigm, and found no evidence that the pairings made the neutral stimulus excitatory. Experiment II replicated Rescorla's results, but showed that even on a relearning test the experimental group learned no faster than a novel stimulus control group.     

Involvement and response language effects in attitude scaling

An analytic procedure was developed for separating the effects of involvement from the number of response language categories the subject employs in judging a set of sentence stimuli. The procedure treats category usage as an independent variable and an aspect of the subject's response language. Category usage was shown to have significant influence on several attitudinal judgment processes: Informational complexity, mean judgment functions, and a successive intervals analysis testing Thurstone's assumption of the effect of involvement on equal category spacing. The decrement in scale responding typically associated with involvement is shown to depend on category usage operating either singly or in interaction with involvement. Some tentative conclusions about category usage as a response language variable are discussed.     

Aversive CSs suppress lever pressing for food but not the eating of free food

Forty rats received CER acquisition, half “on the baseline” (response lever present), half “off the baseline.” During initial CER extinction, Ss received: (a) normal CER extinction (lever available), (b) free food during CSs only (no lever), (c) free food during non-CSs only (no lever), or (d) free food during both CS and non-CS periods (no lever). While normal extinction Ss were highly suppressed in the presence of the CS, all free food groups readily ate but did not differ in eating latencies. On subsequent CER extinction trials on the baseline, those Ss which received free food during the CSs were no less suppressed than other Ss. These data offer no support for Estes' (1969) reciprocal inhibition explanation of CER and punishment, nor do they support a fear interpretation of CER.     

Stimulus probability and prediction outcome as determinants of choice reaction time: Some procedural considerations

Effects of stimulus probability and prediction outcome on two-choice reaction speed (CRS) were determined when a frequency imbalance was reversed half-way through 300 samples of a 70/30 stimulus distribution and when the same 70/30 distribution was sampled for 1200 trials. Prior to each presentation Ss made a prediction; following each presentation Ss identified the stimulus by pressing a right-hand or left-hand trigger. CRS was faster to correctly predicted stimuli, and faster to the more probable stimulus. Ss who were informed of the frequency imbalance reacted significantly faster than Ss who were not. Both practice and boredom effects were demonstrated by using the extended number of trials. CRS was faster during the second session of 300 trials than during the first; after two sessions, CRS was slower during the second half of two additional sessions.     

Relationships among measures of visual imagery

As a step toward the development of an objective measure of visualization ability, five tasks which yielded seven separate measures were administered to 74 Ss and intercorrelated. The tasks were: paired associate recall improvement (RI), recognition memory (RM), the Bett's Questionnaire on Mental Imagery (QMI) as revised by Sheehan (1967a, b), a task calling for the production of visual images (PVI) where rated vividness and latency of image attainment were measured, and a task requiring the imagining of emotional scenes (ES) where rated vividness and rated anxiety were measured. The results indicated that although paired associate learning scores per se were related to RM, neither of the memory measures of visualization (RI and RM) were related to any of the other visualization measures. A cluster of intercorrelations was obtained among self-ratings of image vividness on the QMI, PVI and ES tasks. This cluster also included a measure of latency of report of “best image” attainable derived from the PVI task. None of the measures correlated with anxiety ratings on the ES task. These findings were discussed in relation to previous studies and the potential value of the latency measure as an adjunct measure of visualization ability was noted.     

Different memory functions for consonants and vowels

Different memory functions were obtained for consonants (C) and vowels (V) in a serial recall task. In general, the most recently heard vowels in a sequence were easier to recall than the most recently heard consonants. This effect was observed for auditorily presented sequences of CV or VC syllables, but was not observed for visually presented stimuli. The results were explained in terms of a limited capacity acoustic storage in which vowels are preserved longer than consonants. Retrieval of the last vowels from this storage was presumed to cause the vowel recency effect.