Combination Scores for the Humm-Wads-Worth Temperament Scale

In an attempt to assess the degree to which specific stimulus-response associations are gradually acquired in learning a serial list, the order of the middle items was altered during acquisition. Five groups with 16 Ss per group had either no items switched, two items switched after four or eight test trials, or four items switched after four or eight test trials. The nonsense syllables were presented with slide projectors by means of standard serial anticipation procedures. Contrary to hypotheses, there were no overall differences between the four experimental groups and the control in trials to criterion or in total errors. However, although few experimental Ss reported noticing the switch, they made more errors on the trials immediately following the switch in comparison with the control group. These results are interpreted as disconfirming continuous, stimulus-specific association assumptions and supporting noncontinuous, nonassociative approaches.