Mean recovery rate: A simple measure of recovery uncontaminated by the carryover effect

Assessment of recovery is important for the investigation of stress but has been compounded by difficulties, in particular contamination by the carryover effect. In the present study, the mean recovery rate ( MRR ) was used in order to overcome this difficulty. First, the validity of the MRR was demonstrated theoretically. Second, it was demonstrated experimentally, when a comparison was made with the validity of the mean recovery per se. In the experiment, data on beat-by-beat systolic blood pressure, obtained from 18 participants before, during, and after mental arithmetic, were used as a typical sample. The implications of these results for the understanding of recovery measures are discussed.     

A different look at perceptual defense for taboo words

Hober has concluded from previous work that meaningfulness, frequency, and related stimulus variables directly affect the clarity of letters of words. To examine whether the letters of taboo words would be harder to see, 12 taboo words were matched in length to 12 very frequent and 12 very rare neutral words. Each word was shown an unpredictable number of times. Three groups of 8 Ss each were required, respectively, either to name the letters they saw on each flash, name the letters and then guess the word, or guess the word only. While no differences were found among the three groups, the clarity of the letters of the frequent words exceeded that for the rare words, which in tum was higher than that of the taboo words. This difference was apparent on even the first flash, supporting the interpretation of a perceptual defense effect.     

Recognition without perceptual identification: A measure of familiarity?

Previous work has shown that when items in a perceptual identification task are presented too quickly to identify, participants can still discriminate between studied and unstudied items. Such recognition without perceptual identification (RWPI) has been shown to occur in a variety of situations, including the false recognition of semantic associates of studied items. The present study investigated the utility of the RWPI paradigm for isolating instances of recognition that are familiarity based from those that are recollection based. Toward this end, the magnitude of the RWPI effect was compared in item versus associative recognition and in short versus long lists. The RWPI effect was larger in item than in associative recognition, and larger with short than with long study lists. These results are interpreted within the context of a dual-process approach to recognition and support the notion that RWPI taps familiarity-based recognition.     

On the automaticity of pure perceptual sequence learning

We investigated the automaticity of implicit sequence learning by varying perceptual load in a pure perceptual sequence learning paradigm. Participants responded to the randomly changing identity of a target, while the irrelevant target location was structured. In Experiment 1, the target was presented under low or high perceptual load during training, whereas testing occurred without load. Unexpectedly, no sequence learning was observed. In Experiment 2, perceptual load was introduced during the test phase to determine whether load is required to express perceptual knowledge. Learning itself was unaffected by visuospatial demands, but more learning was expressed under high load test conditions. In Experiment 3, we demonstrated that perceptual load is not required for the acquisition of perceptual sequence knowledge. These findings suggest that perceptual load does not mediate the perceptual sequence learning process itself, supporting the automaticity of implicit learning, but is mandatory for the expression of pure perceptual sequence knowledge.