Do the mentally retarded have poor memory?

The hypothesis that mentally retarded persons have a short-term memory deficit whixh is due to inadequate rehearsal strategies is reexamined. A reevaluation of results of a number of experiments suggests that normal and retarded persons differ on short-term memory tasks, and the superiority of normals is present from the time of initial stimulus exposure. While some evidence for slope differences in retention curves is found in a few tasks, it is not strong support for memory differences. The hypothesis that “memory” differences are due to differential encoding as a result of more adequate rehearsal by the normal subjects is unacceptable. If this were the case, some differences in slope of retention curves could be expected unless rehearsal beyond the encoding stage was totally precluded. The review points to a need for an empirical reevaluation of the issue with a full recognition that deficits in particular processes may characterize some retarded persons and not others.     

The consequences of noncooperation for the target of third party instigated aggression

Consequences for a new target as a function of noncooperation was investigated in the instigative aggression paradigm. Subjects instigated partners to aggress against an opponent by suggesting what shock intensity to deliver. The partner was either cooperative (i.e., complied with the suggestion) or noncooperative (i.e., refused to set high shocks). Subsequently, subjects were given the opportunity to be directly aggressive by actually setting the shocks themselves. During this phase a new target who was nonprovocative was introduced. Subjects aggressed alone, in the presence of their partner, or in the presence of a new person. Results revealed that noncooperation reduced the level of instigative aggression and carried over to the second phase of the experiment. Subjects who had had cooperative partners were more aggressive toward the new target than were subjects who had had noncooperative partners. The presence or absence of the partner was not significant.     

Neuroelectrical correlates of hemisphere and handedness factors in a cognitive task

Principal-components analysis was performed on a set of averaged evoked potentials in order to extract components of cerebral activity functionally related to hemisphere, handedness, processing task, and stimulus feature variables. Eight such components were isolated. Degree of dextrality, hemispheric differences, and cognitive operations in processing distinct stimulus characteristics were identified as reflected in functionally distinct components of brain activity.     

Attention demands of movements as a function of their duration and velocity

The attention demands of initiating and controlling discrete movements were examined as a function of their movement time (MT) and average movement velocity. Experiment 1 showed that the attention required to execute a movement decreased as MT decreased, although Experiment 2 through independently manipulating MT and movement velocity, revealed that movement velocity is the key determiner of attention demands rather than MT. The attention demands of preparing a high velocity movement are greater than during its execution with the reverse being the case for relatively slow velocity movements. The results are compatible with the view that it is the initiation of error corrections that are attention demanding (Keele 1973).     

Alcohol consumption by college women following exposure to unsolvable problems: Learned helplessness or stress induced drinking?

Three experiments were intended to examine the relationship between alcohol, depression and learned helplessness. In Study I, more female undergraduate heavy drinkers than light drinkers were found to have critically elevated scores on a depression index. A sex difference in the relationship between drinking and depression is suggested since male depressives were equally distributed among drinking categories. In Studies II and III, female undergraduates were given unsolvable problems in a learned helplessness paradigm. Relative to controls these subjects reported increased depressive and hostile affect and drank more beer in a taste rating task. However, we failed to find deficits in anagram solution with those subjects given the learned helplessness manipulation. Specific questions are raised regarding the boundary conditions of learned helplessness while implications bearing on stress-related alcohol consumption are discussed.     

Infant search tasks reveal early concepts of containment and canonical usage of objects

It is difficult to gain unambiguous evidence on the use of concepts by infants. Many results can be accounted for in terms of action-based strategies. The evidence reported here fulfils the minimal criteria for the operation of working concepts in infants. Search tasks are used with a filled interval which forces memory-search, and the object is hidden in containers which fulfil their customary job or violate it. Infants treat an upright cup as a more reliable location marker than an inverted one. A series of experiments probes the phenomenon. The results indicate that the infants have a working concept of containment which can be triggered by the provision of containers in their canonical orientation. Even “object permanence tasks” lead infants to access their knowledge of the relationships into which things typically enter in the world outside the laboratory.     

Development of comprehension of sentences with “because” or “if”

The comprehension of sentences with “because” or “if” was investigated in children aged 2;9–11;11. Imitation, comprehension (choosing one of two picture sequences to go with a sentence), recognition (judging sentences with connective or structure differences as heard before or not), and synonymy (judging equivalence of meaning in sentences with different connectives or structures) tasks were administered, along with logical ordering, reversibility, and classification tasks. Above-chance responding in the comprehension task occurred by age 8, and in recognition and synonymy by age 10. Cognitive performance predicted 28.4% of the variance in the linguistic scores and cognitive success was concurrent with or preceded linguistic success. Comprehension of “because” and “if” appears to develop gradually, and is related to the development of certain operative rules.     

Active and passive observers' attraction to a self-disclosing other

Active observer (participant) subjects were induced to make either a high or a low intimacy disclosure about themselves to a partner. Their (videotaped confederate) partner then disclosed either intimately or non-intimately in return. The impressions and attributions of these subjects were compared to the predictions of passive observer subjects (non-participants) who were each furnished with the original instructions, heard a tape recording of a different active observer's disclosure, and watched the same videotape of the confederate that person had seen. As expected, both active observers' responses and passive observers' predictions indicated a preference for the intimate partner. In addition, passive observers' attraction predictions were less positive than active observers' reports. But contrary to the hypotheses, passive observers predicted that active observers would attribute the partner's disclosure more to personalistic causes than was actually the case, and guessed inaccurately that active observers would interpret the partner's intimacy as an indicator of attraction. The methodological implications of these active-passive observer differences for research in self-disclosure and relationships are discussed.     

Statistical significance tests for binormal ROC curves

Statistical significance tests are derived and evaluated for measuring apparent differences between an obtained and an expected binormal ROC curve, between two independent binormal ROC curves, and among groups of independent binormal ROC curves. A binormal ROC curve is described by two parameters which represent the spread of the means and the ratio of the standard deviations of the two underlying Gaussian decision variable distributions. To test the significance of apparent differences between or among ROC curves, approximate χ² statistics for each of the three tests were constructed from maximum likelihood estimates of the two parameters defining the binormal ROC curve. The performance of each test statistic was evaluated by simulating five-category rating scale data with equal numbers of noise and signal-plus-noise trials (set at 50, 250, and 500) for each of three typical ROC curves. For the significance test involving only one ROC curve, rating scale data were generated from the chance diagonal of the ROC space also. Although test performance was found to be somewhat dependent on the number of trials and on the location of the ROC curve in the ROC space, comparisons of the obtained and expected fractions of (falsely) significant results at various α levels showed the proposed statistical significance tests to be reliable under practical experimental conditions.