Recognition memory for words and pictures at short and long retention intervals

In two experiments, subjects studied a long series of words and pictures for recognition. Retention intervals varied from several minutes to a few months. The complicated testing procedures in Experiment I required the use of a traditional correction for guessing to obtain estimates of subjects' memory performance. A comparable, but simpler, design in Experiment II permitted the calculation of sensitivity and bias measures. In both studies, pictorial memory was superior to verbal memory at all retention intervals tested, and this advantage was essentially constant over time. In addition, the experiments identified an increasing tendency to call verbal test items "old" over time. Bias scores in Experiment H revealed that subjects adopted a more lenient criterion in responding to words than to pictures, and increased leniency was noted for both item types over time. Explanations of the results are offered in terms of differences in initial encoding and of a loss of discrimination between experimental and extraexperimental materials.     

Group caution at the race track

McCauley, Stitt, Woods and Lipton's finding that groups were more conservative than individuals when betting at a race track has been criticized on statistical and methodological grounds. The present study which does not suffer the shortcomings for which McCauley et al. were legitimately criticized does, nonetheless, sustain their general results and conclusions. Groups were significantly more cautious than individuals when wagering $2.00 on a horse race.     

Component processes of an overt rehearsal strategy in young children

The locus of facilitation due to rehearsal was investigated in three experiments with first-grade children. Several different overt acquisition strategies in a four-item sequential memory task were compared, including ordered repetition, item repetition, item labeling, and free strategy conditions. Experiment 1 showed that ordered repetition yields most of the facilitation due to rehearsal, and Experiment 2 demonstrated that the facilitation cannot be attributed to spaced practice. Experiment 3 showed that retrieval practice during study may improve memory performance but that the facilitation due to ordered repetition and retrieval practice is relatively short term. Mere repetition and labeling were not found to be significant component processes of rehearsal in any of the experiments. These results were discussed in terms of their relevance to rehearsal training studies and a differentiation between maintenance and elaborative rehearsal.     

Conditioning in human opiate addicts

Eight volunteers maintained on daily methadone participated in a classical conditioning procedure to determine which if any of the elements of narcotic withdrawal could be conditioned. The unconditioned stimulus was the injection of a small dose of naloxone. The unconditioned response was a brief precipitated withdrawal syndrome. The conditioning stimulus was a tone, odor, and injection of saline. Conditioning was successful in the pilot study in 5 of 8 subjects. The conditioned response consisted of tearing, yawning, lacrimation, systolic blood pressure increase, respiratory irregularities and subjective feelings of narcotic withdrawal sickness (nausea, muscle aches, chills). A second group of 8 subjects showed, in addition to the above, evidence of conditioning of heart rate, respiratory rate and skin temperature decrease. These laboratory findings support the clinical reports of a conditioned withdrawal syndrome and suggest ways to improve treatment results by detecting and extinguishing or modifying conditioned responses.     

Stimulus probability and same-different classification

Three experiments investigated the effect of stimulus probability on same-different classification time. In Experiments I and II, subjects made same responses on the basis of name matches of simultaneously presented letters. Half of the same trials involved letters that were also physically identical. Experiment I showed that the presentation probability of specific letters affected name matches and different responses, but not physical matches. Experiment II varied stimulus contrast as well as probability. Contrast had a main effect but did not interact with probability at any level of processing. In Experiment III, subjects were switched to the physical level of processing. Stimuli that now had the same name but differed in case were called different. In this condition, the probability effects obs(irved in Experiment II disappeared. These results are interpreted as demonstrating that stimulus probability has its effect during the process that derives the name of the stimulus from the visual representation. This process takes place before the name comparison is made, and the name comparison process precedes the determination of the different response.     

Auditory evoked potentials during selective listening to dichotic speech messages

The sensitivity of the scalp-recorded, auditory evoked potential to selective attention was examined while subjects monitored one of two dichotically presented speech passages for content. Evoked potentials were elicited to irrelevant probe stimuli (vowel sounds) embedded in both the right- and the leftear’s message. The amplitude of the evoked potential was larger to probe stimuli embedded in the attended message than to probe stimuli in the unattended message. Recall performance was unaffected by the presence of the probes. The results are interpreted as supporting the hypothesis that this evoked potential sensitivity reflects an initial “input selection” stage of attention.     

A comparison of the predictive validity of typical and maximal personality measures

Most personality tests are based on concepts assessing typical performance, and tests of this sort have not been generally successful in predicting criterion behaviors with useful levels of efficiency. Ability tests, which call for maximal performance, have been much more successful as predictors of criterion outcomes. Following a model derived from ability tests, predictors requiring separate typical and maximal self-reports of emotional expressivity were compared to measures of typical and maximal emotional expression in the laboratory. For angry expression, self-reports of maximal expressivity tended to outpredict self-reports of typical expressivity for both typical and maximal laboratory measures of angry expression. Although similar trends were observed for elation, the advantage of maximal self-report measures over typical self-report measures was negligible. Results were discussed in terms of both experimental and clinical implications.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.