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.     

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.     

A new measure for determining children's subjective organization of speech

A new technique for determining children's subjective organization of speech is described. The technique consists of teaching a child a sentence and then repeatedly (1) reading the sentence up to a selected point, (2) sounding a tone, and (3) having the child supply the next word. The time from the tone to the onset of the child's voice is the dependent variable. In the first study 6- and 8-year-old children memorized the following sentence: “John likes to feed the little puppies in the barn.” Their response times suggested that the dominant segmentation pattern consisted of four phrases: a subject phrase, a verb phrase, an object phrase and a modifier phrase. Within each phrase differences between reaction times were on the order of 30 msec. Across phrases they were on the order of 120 msec. The same trend emerged for subsamples of the children with various short-term memory sizes, and for adults. It also appeared for subsamples of the total scores (e.g., first six trials and last six trials). In order to provide further evidence of the technique's validity, different sentences of the same general type were presented to children with short-term memory spans of either 3, 4, or 5. As predicted, it was found that when children's spans corresponded to the number of hypothesized chunks (i.e., 4), they could repeat the sentences verbatim on the first exposure. They could not do so, however, when their spans were lower than that value or when the number of phrases was increased. It was concluded that the new technique is a promising one for assessing young children's patterns of speech segmentation.     

The effects of expected future interaction and prior group support on the conformity process

Previous results indicate that people conform more to group judgments when they have received unanimous group support for their opinions than when they have received no support. The present study tested the hypothesis that these differences would be attenuated when future interaction with the group members was anticipated. The 70 male subjects were tested in a Crutchfield-type conformity situation, where prior group support (100 vs 0%) and anticipation of future interaction (alone vs group) were manipulated. Predictions were based on an examination of conformity incentives that considered normative and informational sources of social influence, as well as Hollander's model of idiosyncracy credit. Consistent with predictions, conformity in the 0% prior support condition was greater when subjects anticipated future group interaction than when they did not, whereas the reverse was true in the 100% prior support condition. In addition, conformity was correlated negatively with both confidence in task ability and feelings of group acceptance when future interaction with the group was anticipated. These data suggest that when future group activity is expected, the tendency to reciprocate past treatment from the group is reduced.     

An investigation of the arousal model of interpersonal intimacy

In a study designed to test Patterson's arousal model of nonverbal intimacy, the heartrate, gaze, smiles, body orientation, and body lean of each of 40 female subjects who interacted with an accomplice were measured. Within a factorial design, subjects were induced to view more or less favorably the accomplice, who subsequently increased or maintained the same level of nonverbal immediacy as she did in an earlier session. It was hypothesized that (1) an increase in the accomplice's immediacy would effect an increase in subjects' arousal (heartrate) which, in turn, (2) would lead to either reciprocal or compensatory nonverbal adjustments by subjects, depending on whether they viewed the accomplice more or less favorably, respectively. The results supported the first but not the second hypothesis. However, interpretation of the results suggests, nevertheless, that they may be consistent with the arousal model.     

Semantic differential studies of children's language development: Some methodological problems

A semantic differential study of development of antonym meanings revealed methodological problems (e.g., concept-scale interaction and developmental changes in scale-checking style) not fully considered in previous semantic differential investigations of child language development. Twenty adjectives were rated on 10 scales by subjects from grades K to 5 (approximately 6 through 11 years old) and adults. Analyses by means, polarity ratings, and average sums of squared differences failed to yield consistent developmental trends. Subjects' choices of scale ratings did show clear age-related differences: Grades K and 1 chose extreme ratings almost exclusively; grades 2 through 4 showed an increase in neutral choices and decreases in extreme ratings; grades 4 and 5 and adults chose extreme ratings least often, neutral choices most often, and more intermediate ratings than any younger subjects. Results show that scale choice is a crucial factor in designing semantic differential studies with children, there is a low correlation between mean scores and ratings given by individual children, and shifts in scale-checking style should be considered when interpreting apparent developmental changes in children's semantic differential ratings.     

Robust estimation of ability in the Rasch model

Estimating ability parameters in latent trait models in general, and in the Rasch model in particular is almost always hampered by noise in the data. This noise can be caused by guessing, inattention to easy questions, and other factors which are unrelated to ability. In this study several alternative formulations which attempt to deal with these problems without a reparameterization are tested through a Monte Carlo simulation. It was found that although no one of the tested schemes is uniformly superior to all others, a modified jackknife stood out as the best one in general, it was also super efficient (more efficient than the asymptotically optimal estimator) for tests with forty or fewer items. It is proposed that this sort of jackknifing scheme for estimating ability be considered for practical work.This research was funded through a grant from the Law Enforcement Assistance Administration (78-NI-AX-0047) to the Bureau of Social Science Research, Howard Wainer, Principal Investigator. We would like to thank Ronald Mead, Anne Morgan and James Ramsay for kind, generous, and invaluable help at various stages of the project.     

Environmental dispositions and the evaluation of architectural interiors

The Environmental Response Inventory (ERI) was developed, in part, to assess dispositions toward everyday physical environments and to aid in explaining variance in response to settings. The eight ERI scales were examined and resultant hypotheses were tested in a design involving evaluative ratings of 10 everyday public building interiors briefly presented in sequences of color slides to 118 participants. Settings were arranged in three levels of generality. Results support the ERI as a promising tool. Biographical items also correlate with ratings. Environment evaluation is discussed as a complex phenomenon, in which rater differences play a significant part.