Resistance to the impact of interruptions during multitasking by healthy adults and dysexecutive patients

Two experiments (one with healthy adult volunteers and the other with controls and dysexecutive patients) assessed the impact of interruptions on a novel test of multitasking. The test involved switching repeatedly between four tasks (block construction, bead threading, paper folding, alphabetical searching) over a 10 min period. In Experiment 1, there were four groups of 20 healthy participants. One group attempted multitasking with no interruption, a second group was interrupted early in the test, a third group late in the test and a fourth group was interrupted both early and late. Interruption involved carrying out a fifth, unexpected task for a period of 1 min before returning to the four main tasks. There was no difference in multitasking performance between the groups. In Experiment 2 the participants were seven dysexecutive patients and 14 age-matched controls. A repeated measures approach was employed to assess the impact of two interruptions (early and late) for both groups. Contrary to predictions, the patients as well as controls were resistant to the effects of interruptions, despite their clearly impaired multitasking performance. These results suggest that the ability to deal with interruptions may be separable from the ability to organise and execute multiple tasks within a limited time frame.     

A microswitch program to foster simple foot and leg movements in adult wheelchair users with multiple disabilities

This study assessed a microswitch program to foster simple foot and leg movements in 2 adult wheelchair users with multiple disabilities. The participants' mood (indices of happiness) was recorded throughout the study. Data showed that participants rapidly increased the target foot and leg movements and maintained those movements during the course of the study, which lasted about 4.5 months. With regard to indices of happiness, 1 participant showed a fairly modest increase during the intervention while the other participant showed a substantial increase. Implications of the findings are discussed.     

Autism: beyond “theory of mind”

The theory of mind account of autism has been remarkably successful in making specific predictions about the impairments in socialization, imagination and communication shown by people with autism. It cannot, however, explain either the non-triad features of autism, or earlier experimental findings of abnormal assets and deficits on non-social tasks. These unexplained aspects of autism, and the existence of autistic individuals who consistently pass false belief tasks, suggest that it may be necessary to postulate an additional cognitive abnormality. One possible abnormality - weak central coherence - is discussed, and preliminary evidence for this theory is presented.     

Dimensions of health‐related dispositions in elderly people: relationships with health behaviour and personality traits

The principal aim of this study was to examine a health‐related disposition construct in elderly Italians by explorative factor analysis of the Multidimensional Health Questionnaire. The questionnaire had a two‐factor structure. The first factor was loaded by cognitive variables such as Health‐Efficacy, Health Control, Optimism, etc.; it predicted compliance with self‐rating health seeking behaviours and it was correlated with personality traits such as Emotional Stability and the Lie scale. The second factor comprised emotional dispositions including Health Anxiety, Health Depression, Health Preoccupation, etc. and it was negatively associated with Conscientiousness and Energy. Interesting results emerged for sex by age differences in both health factors. Moreover, men and women showed different correlation patterns between the health factors and the Five Factor Model. Copyright © 2000 John Wiley & Sons, Ltd.     

Assisted ambulation and activity for restless or passive persons with profound multiple disabilities: assessing performance and preferences

Two adults with profound multiple disabilities and restlessness or passivity were exposed to two occupational conditions involving (a) robot‐assisted ambulation and activity in a fairly large area and (b) unassisted ambulation and activity in a small area. The aim was to examine the participants' performance (independent activities, ambulation, and challenging behavior) in the two conditions and their possible preferences between those conditions. Data showed that the participants had higher percentages of independent activities, higher percentages of ambulation, and somewhat lower percentages of challenging behavior in the condition with the robot. The participants also seemed to prefer this condition over the one without the robot. Implications of the findings were discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Improving accepting and giving compliments with individuals with developmental disabilities

Individuals with developmental disabilities, such as autism spectrum disorder, typically exhibit conversation skill deficits, with two prevailing deficits including giving and accepting compliments. The current study used an individualized approach to assess and teach accepting and giving compliments specific to performance, possession, and appearance with three adolescents and young adults with developmental disabilities. We taught these skills using behavioral skills training and prompting during conversations utilizing a multiple-baseline design across participants. We also observed generalization and treatment extension of the participants' skills in conversations with adults not associated with teaching and in the absence of any teaching procedures. The results support the efficacy of the procedures used toward improving giving and accepting compliments within the context of a conversation. We discuss considerations to improve the social acceptability of and refinements to the teaching procedures and acquired skills.     

Promoting fluency of performance during morning dressing by two persons with multiple disabilities

This study investigated the possibility of promoting fluency of performance, i.e., a performance independent of caregiver's guidance and without serious interruptions, during morning dressing in two adults with multiple disabilities. The intervention program relied on the use of assistive technology including optic and pressure sensors to monitor the participants' task responding and tape players to present preferred stimuli in relation to such responding, as well as messages of encouragement. Analysis showed that the intervention program was effective with both participants. In fact, they became capable of performing the dressing sequence with only occasional guidance from research assistants, and the time they required for dressing dropped significantly from baseline levels. Implications of the results are discussed.     

A technique for simulating visual field losses in virtual environments to study human navigation

The following paper describes a new technique for simulating peripheral field losses in virtual environments to study the roles of the central and peripheral visual fields during navigation. Based on Geisler and Perry's (2002) gaze-contingent multiresolution display concept, the technique extends their methodology to work with three-dimensional images that are both transformed and rendered in real time by a computer graphics system. In order to assess the usefulness of this method for studying visual field losses, an experiment was run in which seven participants were required to walk to a target tree in a virtual forest as quickly and efficiently as possible while artificial head and eye-based delays were systematically introduced. Bilinear fits were applied to the mean trial times in order to assess at what delay lengths breaks in performance could be observed. Results suggest that breaks occur beyond the current delays inherent in the system. Increases in trial times across all delays tested were also observed when simulated peripheral field losses were applied compared to full FOV conditions. Possible applications and limitations of the system are discussed. The source code needed to program visual field losses can be found at lions.med.jhu.edu/archive/turanolab/Simulated_Visual_Field_Loss_Code.html.     

Working memory components and imagery instructions in the elaboration of a spatial mental model

The paper investigates the involvement of verbal and visuo-spatial working memory during the processing of spatial texts via a dual-task paradigm. Subjects were presented with three texts describing locations from a route perspective, and had either to imagine themselves moving along a route in surroundings or to rehearse verbal information. Concurrently they had to perform a spatial tapping task, an articulatory task, or no secondary task. Performance on a verification test used to assess the product of comprehension showed that the concurrent tapping task impaired performance in the imagery instructions group but not in the repetition instructions group, and caused the beneficial effect of imagery instructions to vanish. This result was not observed with the articulatory task, where interference effects were similar in both instructions groups. Performance on the concurrent tasks confirmed the pattern obtained with the verification test. In addition, results seem partly dependent on the capacity of spatial working memory as measured by the Corsi Blocks Test. We argue that these results clarify the processes of the construction of a spatial mental model, and confirm that the visuo-spatial working memory is involved in mental imagery.     

Doing the opposite to what another person is doing

The three studies presented here aim to contribute to a better understanding of the role of the coordinate system of a person's body and of the environment in spatial organization underlying the recognition and production of gestures. The paper introduces a new approach by investigating what people consider to be opposite gestures in addition to identical gestures.