Stereotyped movement disorder in an adult following acquired brain injury: Effect of environmental stimulation

In the present study, a naturalistic functional analysis procedure was used to assess the effect of environmental stimulation on the stereotypic behavior (body rocking) of an adult whose stereotypy appeared to be induced by an acquired brain injury. Environmental stimulation, operationalized in terms of both physical and social characteristics, resulted in only minimal changes in the occurrence of body rocking. Body rocking occurred in excess of 50% of the observations in all environmental stimulation conditions and in a naturally occurring baseline condition. To our knowledge, this is the first published report of a functional analysis of stereotypy associated with acquired brain injury.     

Case study: Examining the relationship between self-initiations of an individual with disabilities and directive behavior of staff persons in a residential setting

This case study examines the relationship between self-initiations of an adult woman with severe disabilities and the directive behavior of staff persons in a community residential setting. Hypotheses generated from functional assessment procedures indicated that (a) Susan's low self-initiations were very likely related to high directive behavior of staff persons, and (b) infrequent problem behaviors during the morning routine were maintained by escape from repeated staff demands. An intervention was implemented to enable Susan to increase self-initiation in choice and sequence of activities and simultaneously decrease staff directives. Results and discussion focus on the need for a contextual approach for addressing problematic situations and an affirmation of the effectiveness of the positive behavioral support technology for increasing adaptive behaviors in individuals with severe disabilities.     

Non-heart-beating organ donation: a reply to Campbell and Weber.

In the preceding commentary, Campbell and Weber raise two valid and important issues concerning non-heart-beating organ donation (NHBOD). First, because the procedure links withdrawal of life support and the potential for subsequent organ donation, the desire for organs may create a situation in which care of the dying individual has relatively less importance and the dying may receive suboptimal care. Second, even if concerns about care of the dying were dealt with adequately, there will not be enough non-heart-beating donors to significantly decrease the organ shortage that exists, making the procedure not worth the risk. We agree that attention to the important details of caring for the dying are, and must be, the primary concern of all health care workers caring for those individuals. Ensuring the patients' comfort, dignity, and autonomy, and providing for family and social support are the mainstays of this care. All policies for NHBOD should clearly support and mandate these concepts. Regarding the second concern, we agree that NHBOD is currently rare; however, evidence is increasing that this type of donation has great potential. Continued growth of the practice in this country will depend largely on public acceptance, which we believe will be directly influenced by whether the public perceives that care of the dying is not compromised by this procedure.     

Correlates of parent–child communication about specific sexual topics: A study of rural parents with school-aged children

Using data from 600 parents of children aged 5 to 18, and a context-oriented, developmental socialization conceptual framework, the interrelationships between parents' perceptions of themselves, their child, and their family relationships and the amount of parent–child discussion of 16 sexuality topics were explored. Canonical correlation analysis was used to demonstrate how circumstances and contexts influence the complexity of parent–child conversations for mother–daughter, mother–son, father–son, and father–daughter dyads. Results lend support to the conceptual framework used, as well as to previous studies of this topic area. The implications of these findings for parent–child relationships and for future research on parent–child communication about sexuality are discussed.     

Going beyond heart rate: autonomic space and cardiovascular assessment of mental workload

Psychophysiological assessment of pilot mental workload using heart rate should be augmented with an autonomic space model of cardiovascular function. This model proposes that autonomic nervous system influences on the heart may change with psychological processing in ways that are not evident in heart rate. A method of mental-workload assessment was proposed that used multiple psychophysiological measures of cardiovascular responsivity to derive the underlying sympathetic and parasympathetic information needed to represent the autonomic space for heart rate. Principal-components analysis was used to extract Sympathetic and Parasympathetic components from heart period, residual heart period. respiratory sinus arrhythmia, and Traube-Hering-Mayer wave in three experiments that manipulated perceptual/central processing and physical task demands. This initial evaluation of the method concluded that the autonomic components were valid and that the components had greater diagnosticity, and for some manipulations greater sensitivity, than heart rate. These results support the contention that the Sympathetic and Parasympathetic components provided increased precision for mental-workload assessment.     

Quantitative measurement of observed workload in the analysis of aircrew performance

A methodology for the quantitative evaluation of observed workload was proposed. The model was designed to provide point estimations of observed workload at any time during the performance of a set of tasks. The model was also designed to provide information about the task-scheduling strategies used to complete a set of tasks. The proposed model was then tested with data from a full mission flight simulation. The model predictions correlated significantly with expert ratings of workload management made during the flight simulation. The model was also able to distinguish between low- and high-performing aircrews when performance was based on the number of errors made during flight simulations.     

Vibrotactile pattern discrimination and communality at several body sites

In a series of experiments, the effects of spatial layout on vibrotactile pattern perception were explored by testing the ability to discriminate between two sequentially presented patterns that share active elements in the same spatial locations. Two-dimensional displays were used in order to examine the functional relationship between discrimination performance and patterncommunality, defined as the sharing elements, on different body sites. Accuracy of discrimination judgments was inversely proportional to communality, regardless of the number of pattern elements. For compact arrays fitted to the finger, palm, and thigh, the effects of communality appeared equivalent. The similarity between finger and thigh functions is remarkable, considering the dramatic differences between these sites in receptor components and structure. When these data were compared with those from arrays with distributed contactors, performance was substantially better with well-separated pattern elements. Such findings help to explicate how information from apposed patterns can best be delivered to the skin through tactile communication systems.     

Time,change, and motion: The effects of stimulus movement on temporal perception

The effects of stimulus motion on time perception were examined in five experiments. Subjects judged the durations (6–18 sec) of a series of computer-generated visual displays comprised of varying numbers of simple geometrical forms. In Experiment 1, subjects reproduced the duration of displays consisting of stationary or moving (at 20 cm/sec) stimulus figures. In Experiment 2, subjects reproduced the durations of stimuli that were either stationary, moving slowly (at 10 cm/sec), or moving fast (at 30 cm/sec). In Experiment 3, subjects used the production method to generate specified durations for stationary, slow, and fast displays. In Experiments 4 and 5, subjects reproduced the duration of stimuli that moved at speeds ranging from 0 to 45 cm/sec. Each experiment showed that stimulus motion lengthened perceived time. In general, faster speeds lengthened perceived time to a greater degree than slower speeds. Varying the number of stimuli appearing in the displays had only limited effects on time judgments. Other findings indicated that shorter intervals tended to be overestimated and longer intervals underestimated (Vierordt’s law), an effect which applied to both stationary and moving stimuli. The results support a change model of perceived time, which maintains that intervals associated with more changes are perceived to be longer than intervals with fewer changes.