Virtual reality in the rehabilitation of the upper limb after stroke: the user's perspective.

Our group has developed a relatively low-cost virtual reality (VR) system for rehabilitation of the upper limb following stroke. Our system is immersive in that the participant views a representation of their arm and hand, reaching and retrieving objects in the virtual environment (VE), through a head-mounted display (HMD). This is thought to increase the participant's sense of presence in the VE and may lead to improved rehabilitation outcomes. However, use of immersion, particularly with our low-cost system, may increase the incidence of side effects reported. Therefore, the aim of this project was to assess the interaction of healthy users and those following stroke, in terms of their experience of presence in the VE and the rate of self-reported side effects. Differences in rates of perceived exertion, levels of enjoyment, and sense of control between both groups were also explored.     

Attention demands in balance recovery following lower limb amputation

The attention demands in balance control after damage to the peripheral sensorimotor system were studied in 12 persons with a recent lower limb amputation. The interference of an arithmetic task with two postural tasks of different complexity (quiet standing and active weight shifting) was examined several times during their rehabilitation while the subjects stood on a force platform. Control data were obtained from healthy subjects. For both postural tasks, persons with amputation performed worse than controls. Quiet standing, a relatively simple task, revealed clear dual-task interference only in the amputation group. Evidence was found for a reduction in dual-task interference as rehabilitation progressed. In contrast, voluntary (feedback-controlled) weight shifting, a more complex task, revealed an equal amount of dual-task interference in persons with amputation and in controls, without changes in interference over the period of rehabilitation. The results indicate that attentional mechanisms may be involved in postural control, depending on both the novelty and complexity of the task. Moreover a reduction in attention demands of quiet standing may reflect a central adaptation of the postural organization to the peripheral sensorimotor impairments caused by lower limb amputation.     

Apparent changes in the visual threshold as a function of subliminal stimulation: A preliminary report

A methodological difficulty in the traditional perceptual defence experiment is that of trying to use verbal reports as a measure of threshold changes. The following experiment handles this difficulty by using the method of closed loop control. The design involves obtaining from the subject a continuous record of his awareness threshold for light entering the left eye while verbal material, dichotomized regarding emotional value, is presented, below threshold to the right eye. The data from this first stage of the research provide some support for the hypothesis that the threshold of awareness will vary as a function of sub-threshold presentations.     

Vitamin D and executive function: a preliminary report

The aim of this study was to investigate the relationship between vitamin D levels and cognition, both executive and nonexecutive functions, in men incarcerated in a Norwegian prison. Participants were divided into high vitamin D and low vitamin D groups based on established criteria (high level > or = 50 nmol/L; low level < 50 nmol/L). The mean vitamin D concentration was 69 (SD = 12) and 38 (SD = 9) nmol/L in the high-level group (n = 14) and the low level group (n = 11), respectively. Results revealed that the high vitamin D group had significantly more correct responses than the low vitamin D group on the executive function task. There was no difference between the groups on the nonexecutive function task. The reaction time data indicated that the high levels of correct responses in the high vitamin D group on the executive function tasks were not due to a speed-accuracy trade-off.     

Antidepressive behaviour: A preliminary report

Outside the psychological literature it is common knowledge that when people feel depressed they ordinarily try to do something about it. In the clinical literature, this commonplace fact is in danger of being forgotten. Using an empirically-derived checklist of activities consensually identified as being ‘the thing to do when feeling depressed’, the present study examines (1) the distribution of reported antidepressive behaviour (ADB) in a group consisting of depressed and non-depressed psychiatric patients and normals and (2) the relationship between an individual's sex, personality (locus of control), and patient status and (a) the amount of ADB he reports and (b) how much of it he regards as helpful. All Ss reported some ADB but not all reported any that was helpful. In an analysis of variance, no main effects of sex, personality or patient status were found, but sex interacting with personality was significantly related both to the overall amount of ADB reported and to the amount found helpful. The findings have implications for the sorts of concepts that a theoretical formulation of ADB will require as well as for the ways in which clinicians conceptualize depressed patients.     

Kinematic analysis of limb movements in neuropsychological research: subtle deficits and recovery of function

In this brief review, we argue that a detailed analysis of the spatial and temporal characteristics of visually guided limb movements can provide important insights into the nature of neuropsychological deficits and the functional organization of the brain. In particular, we will show how kinematic analysis of a simple aiming movement can reveal differences that might not be apparent clinically in the behaviour of patients with unilateral brain lesions. We will argue that the subtle but distinctive deficits that follow damage to the left or right hemisphere can be related to the clinical syndromes of manual apraxia and hemispatial neglect, respectively. The fact that these deficits are apparent only with kinematic analysis demonstrates the potential of these techniques for evaluating recovery of function.     

Patterns of desynchrony in agoraphobia: A preliminary report

Changes in heart rate in three moderate to severe agoraphobic women were monitored by a Holter Recorder, used for obtaining portable EKGs. These data were collected before, half-way through, and at the end of a 12 session, group therapy program consisting of exposure and cognitive restructuring while subjects walked, or in one case, were driven along a standard 1.2 km course leading away from the treatment setting. Self-reports of anxiety were collected simultaneously. Despite substantial behavioral improvement in all cases, markedly different patterns of synchrony or desynchrony were noted between heart rate and self-reports of anxiety and substantial increases in heart rate were noted in one subject.     

Taxonomies of aggressive behavior: A preliminary report

It has been widely and regularly suggested that aggression is not a unitary concept but rather an omnibus term concealing important and distinct subclasses of behavior. Psychologists have offered various categorical schemes highlighting motivation and form as distinguishing criteria. Many writers have also noted the social relativity of dermitions of classes of aggression and called for a consideration of lay conceptions of aggressive behavior. The present paper explores the correspondence between psychologists' and laypersons' categorizations of aggressive acts. Ten short scenarios of aggression were generated to embody systematic permutations of form and motive as suggested by the published work of social psychologists. Subjects rated every pairwise combination in terms of perceived similarity. The data were subjected to three-factor, multidimensional scaling. The resulting structure indicated that subjects' ratings were not random and reflected consideration of motive (hostile, normative, instrumental, status) and of direct versus indirect form. The data were thus in close correspondence with the classifications generated by psychologists. The desirability of refining this technique and extending it to other cultural and subcultural groups is discussed.     

A method to monitor upper limb movement direction encoding in the corticomotor pathway

ABSTRACT Abnormal shoulder and elbow muscle coactivation patterns, or muscle synergies, are commonly present following stroke and may arise through dysfunctional descending neural control from the cortex. The authors evaluated a novel technique for examining corticomotor movement encoding of the upper limb in three dimensions. A 6-degree-of-freedom loadcell recorded arm twitch responses in healthy adults following stimulation over the cortex or over Erb's point in the periphery. Stimuli were delivered while the arm generated a 5 N preload in each of the 6 axial directions. The initial force twitch response to stimulation was used to construct twitch direction vectors for each preload direction. General linear mixed model analyses were used to determine the influence of stimulation location, preload direction, posture, and stimulation intensity on twitch direction. Cortical stimulation gave rise to arm twitch responses that were predictably modified by preload direction. Peripheral stimulation elicited stereotypical twitches that were not influenced by preload. Our stimulation, recording, and analysis techniques were able to capture movement encoding of the upper limb in three dimensions. Such techniques could be utilized in the stroke population to determine and monitor the presence of upper limb synergies during muscle activation.     

Patterns of spontaneous recovery in aphasic groups: A study of adult stroke patients

The recovery of 31 aphasic stroke patients in the first three months postonset was investigated. Improvements on eight comprehension, repetition, and expression tasks were documented for four groups. These groups, retrospectively defined on the basis of initial scores on a fluency and a comprehension task, were: Low Fluency/Low Comprehension (LFLC), Low Fluency/High Comprehension (LFHC), High Fluency/Low Comprehension (HFLC), and High Fluency/High Comprehension (HFHC). Examination of each group's recovery revealed (1) equal improvement on nearly all language tasks for the two High Comprehension groups and (2) a more selective improvement largely in comprehension and imitation tasks for the two Low Comprehension groups. Implications of this selective improvement in initially low comprehending aphasics are discussed.     

Portable delayed auditory feedback device: A preliminary report

This writing is a preliminary report describing a prototype of a portable delayed auditory feedback device called the DYSTECH 1000. This writing and our observations are presented to stimulate review and feedback by our colleagues of the DYSTECH 1000 as a clinical and generalization tool.     

Patterns of apraxia associated with the production of intransitive limb gestures following left and right hemisphere stroke

The model of apraxia proposed by Roy (1996) states that three patterns of apraxia should be observed across pantomime and imitation conditions. In the present analysis the frequency and severity of each pattern of apraxia were examined in a consecutive sample of left-(LHD) and right-hemisphere-damaged (RHD) patients during the production of intransitive limb gestures. The results indicated that a significant proportion of LHD and RHD patients were selectively impaired in formulating the ideational component of intransitive limb gestures.     

Group training in communication skills for couples: A preliminary report

Abstract

This article reports on the initial development and evaluation of a group skill-training program for couples. The program, entitled the Communication Skills Workshop (CSW), aims at improving communication and problem-solving skills within the context of relationships. The orientation of the CSW is preventive and educational in that it (a) serves couples prior to the onset of serious relationship discord, and (b) focuses on the learning of general communication skills and problem-solving strategies rather than the amelioration of specific relationship conflicts.