Observational studies of retarded children with multiple stereotyped movements

Stereotyped movements, such as body rocking and hand gesturing, are common among developmentally delayed children. However, very little is known concerning the naturally occurring circumstances that produce variability in this type of responding. Three relatively long-term observational studies, involving seven preschool children, each of whom exhibited multiple stereotypies, were conducted to determine the extent to which the type of activity or setting had any effect upon the rates of these responses. Repeated observations were made of each child during a variety of school activities. In two studies, adult-child interactions were also recorded. The results showed that, in general, the particular activity greatly affected rates of stereotyped behavior, although there were some marked individual differences. Moreover, in two studies variability was apparent across sessions within a particular setting. For some of the children, there was evidence that their multiple stereotypies were functionally interrelated. Adult interactions, as recorded in one study, appear to be both quantitatively and qualitatively different for stereotyping as contrasted with nonstereotyping children. An environmental analysis employing a sequential model indicated that there were teacher behaviors that affected the frequency and/or conditional probability of the child's aberrant behavior.This research was supported by P.H.S. Grant No. HD-00973.     

WHISTLING IN THE DARK:

Abstract— Terror management theory posits that cultural worldviews function to provide protection against anxiety concerning human vulnerability and mortality and that their effectiveness as buffers against such anxiety is maintained through a process of consensual validation. Two field experiments were conducted to test the hypothesis that incidental reminders of one's mortality increase the need to believe that others share one's worldview. In both studies, passersby on city streets were asked to estimate the extent of social consensus for culturally relevant attitudes, 100 m before passing a funeral home, 100 m after passing a funeral home, or directly in front of a funeral home. In the first study, conducted in Germany, subjects were asked to estimate the percentage of Germans who shared their opinions about a proposal to change the German constitution to restrict the immigration of foreigners, in the second study, conducted in the United Stales, subjects were asked to estimate the percentage of Americans who shared their opinions about the teaching of Christian values in the public schools. In both studies, subjects who held the minority position on the issue estimated greater consensus for their opinions when interviewed directly in front of a funeral home than when interviewed either before or after passing it.     

Switching or sharing in dual-task line-length discrimination?

In two experiments, we tested whether subjects switched or shared attention between two simultaneously relevant line-length discrimination tasks. Switching models that allowed within- as well as between-trial switching were considered. In the first experiment, stimulus duration was varied randomly from trial to trial. With varied durations, many switching models predict negative contingencies: for a given duration and attentional allocation, accurate responses on one task should be associated with inaccurate responses on the other task. The results, however, showed no negative contingencies, which is consistent with sharing models. In the second experiment, stimulus duration was reduced to 20 msec, yet responses were more than 75% correct overall. This implies that information was obtained about both of the tasks within single trials, contradicting those switching models which predict that information can be obtained from, at most, one task within a period of 20 msec or less. In short, the results of both experiments support sharing models.     

Macintosh analogue of the rotary pursuit task

Pursuit tracking, a perceptual motor-skill task, has had wide application in many areas of psychology. The task is usually administered with a mechanical device in which subjects try to maintain a contact between a stylus and a disk on a rotating platter. A pursuit-tracking task that can be administered on a Macintosh computer is described. Subjects try to keep a crosshair cursor on top of a moving circular target. The cursor can be controlled by commonly used Macintosh ADB devices such as a joystick. The computer version has several important advantages: it offers more task flexibility and more accurate dependent measures of performance, and it is inexpensive.     

Terror Management and Meaning: Evidence That the Opportunity to Defend the Worldview in Response to Mortality Salience Increases the Meaningfulness of Life in the Mildly Depressed

Previous terror management research has demonstrated that mildly depressed participants show a greater increase in worldview defense in response to reminders of their mortality than do nondepressed participants. Because the cultural worldview is posited to provide a meaningful conception of life, we hypothesized that mildly depressed participants who defend their worldview in response to mortality salience (MS) would increase their perception that the world is meaningful. A preliminary study first examined the Kunzendorf No Meaning Scale as a measure to assess perceptions of meaning. In the primary study, mildly depressed and nondepressed participants contemplated their own mortality or a neutral topic, evaluated two targets in a manner that either allowed them to defend their worldview or that did not, and then completed the Kunzendorf No Meaning Scale. As predicted, mildly depressed participants who had the opportunity to defend their worldview in response to mortality salience reported greater meaning in life than did mildly depressed participants who did not have the opportunity to defend their worldview, or mildly depressed participants not exposed to mortality salience. Implications for understanding and treating depression are briefly discussed.     

Improving instruction for adults with developmental disabilities: Evaluation of a staff training package

Improvements in adaptive behavior among adults with developmental disabilities often depends on the quality of instruction delivered by direct-care staff. The present study evaluated the effectiveness of a multifaceted package for improving the quality of instructional interactions among three staff/adult dyads. Instructional interactions were first analyzed to identify areas for improvement. A multifaceted intervention package consisting of inservice training, participative management, and on-going feedback was then implemented in a multiple-baseline design across dyads. The package trained staff to increase their use of time delay and reinforcement strategies and these changes were associated with greater independence in a sandwich making task among two of the three participating adults. The results suggest direct observation of existing instructional interactions may provide valuable information when training staff to implement effective habilitative programs for adults with developmental disabilities.     

Bars and lines: A study of graphic communication

Interpretations of graphs seem to be rooted in principles of cognitive naturalness and information processing rather than arbitrary correspondences. These predict that people should more readily associate bars with discrete comparisons between data points because bars are discrete entities and facilitate point estimates. They should more readily associate lines with trends because lines connect discrete entities and directly represent slope. The predictions were supported in three experiments--two examining comprehension and one production. The correspondence does not seem to depend on explicit knowledge of rules. Instead, it may reflect the influence of the communicative situation as well as the perceptual properties of graphs.     

Joint consistency of nonparametric item characteristic curve and ability estimation

The simultaneous and nonparametric estimation of latent abilities and item characteristic curves is considered. The asymptotic properties of ordinal ability estimation and kernel smoothed nonparametric item characteristic curve estimation are investigated under very general assumptions on the underlying item response theory model as both the test length and the sample size increase. A large deviation probability inequality is stated for ordinal ability estimation. The mean squared error of kernel smoothed item characteristic curve estimates is studied and a strong consistency result is obtained showing that the worst case error in the item characteristic curve estimates over all items and ability levels converges to zero with probability equal to one.     

Constant versus variable response signal delays in speed--accuracy trade-offs: effects of advance preparation for processing time

In two experiments, we used response signals (RSs) to control processing time and trace out speed--accuracy trade-off(SAT) functions in a difficult perceptual discrimination task. Each experiment compared performance in blocks of trials with constant and, hence, temporally predictable RS lags against performance in blocks with variable, unpredictable RS lags. In both experiments, essentially equivalent SAT functions were observed with constant and variable RS lags. We conclude that there is little effect of advance preparation for a given processing time, suggesting that the discrimination mechanisms underlying SAT functions are driven solely by bottom-up information processing in perceptual discrimination tasks.