Kinematic motion analysis and muscle activation patterns of continuous reaching in survivors of stroke

Coordinated reaching requires continuous interaction between the efferent motor output and afferent feedback; this interaction may be significantly compromised following a stroke. The authors sought to characterize how survivors of stroke generate continuous, goal-directed reaching. Sixteen survivors of stroke completed functional testing of the stroke-affected side and a continuous reaching task between 2 targets with both sides. Motion analysis and electromyography data were collected to determine segmental contributions to reach (e.g., amount of compensatory trunk), spatiotemporal parameters (e.g., peak velocities), and muscle activation patterns (MAP). Repeated measures analyses of variance compared how survivors of stroke reach with the stroke-affected versus less affected sides. Correlations were determined between kinematic outcomes and functional ability. Participants used significantly more trunk movement and less shoulder flexion and elbow extension when reaching with the stroke-affected side. This corresponded with less muscle activity in the proximal musculature including the anterior, middle, and posterior deltoid on the stroke-affected side. There were significant correlations between the segmental contributions to reach, functional ability, and MAPs. Survivors of stroke generate reduced MAPs in the stroke-affected side corresponding to altered segmental kinematics and function ability. These findings suggest that impairments in the ability to generate sufficient MAPs may contribute to the difficulty in generating continuous reaching motions.     

The association between self-concealment from one's partner and relationship well-being

In two studies the authors examined whether self-concealment from one's partner is associated with lower relationship well-being. In Study 1, participants who were in a romantic relationship (N = 165) completed an online survey. Self-concealment from one's partner was associated with lower relationship satisfaction and commitment. Furthermore, results were consistent with this relationship being mediated by autonomy and relatedness needs. In Study 2, couples (N = 50) completed daily records for 14 consecutive days. Multilevel analyses indicated that daily self-concealment from one's partner was associated with daily relationship satisfaction, commitment, and conflict. Lagged analyses also showed that self-concealment from one's partner predicted lower relationship well-being on the following day. Moreover, results supported that thwarted basic needs mediated the association between daily self-concealment and relationship well-being. Finally, actor-partner interdependence model over time analyses indicated that, apart from one's own self-concealment, one's partner's self-concealment was associated negatively with one's own relationship well-being.     

Attributing illness to 'old age:' consequences of a self-directed stereotype for health and mortality

Stereotypic beliefs about older adults and the aging process have led to endorsement of the myth that 'to be old is to be ill.' This study examined community-dwelling older adults' (N?=?105, age 80+) beliefs about the causes of their chronic illness (ie, heart disease, cancer, diabetes, etc.), and tested the hypothesis that attributing the onset of illness to 'old age' is associated with negative health outcomes. A series of multiple regressions (controlling for chronological age, gender, income, severity of chronic conditions, functional status and health locus of control) demonstrated that 'old age' attributions were associated with more frequent perceived health symptoms, poorer health maintenance behaviours and a greater likelihood of mortality at 2-year follow-up. The probability of death was more than double among participants who strongly endorsed the 'old age' attribution as compared to those who did not (36% vs. 14%). Findings are framed in the context of self-directed stereotypes and implications for potential interventions are considered.     

Focal spatial attention can eliminate inhibition of return

Inhibition of return (IOR) is an orienting phenomenon characterized by slower responses to spatially cued than to uncued targets. In Experiment 1, a physically small digit that required identification was presented immediately following a peripheral cue. The digit could appear in the cued peripheral box or in the central box, thus guaranteeing a saccadic response to the cue in one condition and maintenance of fixation in the other. An IOR effect was observed when a saccadic response to the cue was required, but IOR was not generated by the peripheral cue when fixation was maintained in order to process the central digit. In Experiment 2, IOR effects were observed when participants were instructed to ignore the digits, whether those digits were presented in the periphery or at fixation. These findings suggest that behaviorally manifested, cue-induced IOR effects can be eliminated by focal spatial attentional control settings.     

Selective lesions of the dentate gyrus produce disruptions in place learning for adjacent spatial locations

The hippocampus (HPP) plays a known role in learning novel spatial information. More specifically, the dentate gyrus (DG) hippocampal subregion is thought to support pattern separation, a mechanism for encoding and separating spatially similar events into distinct representations. Several studies have shown that lesions of the dorsal DG (dDG) in rodents result in inefficient spatial pattern separation for working memory; however, it is unclear whether selective dDG lesions disrupt spatial pattern separation for reference memory. Therefore, the current study investigated the role of the dDG in pattern separation using a spatial reference memory paradigm to determine whether the dDG is necessary for acquiring spatial discriminations for adjacent locations. Male Long-Evans rats were randomly assigned to receive bilateral intracranial infusions of colchicine or saline (control) into the dDG. Following recovery from surgery, each rat was pseudo-randomly assigned to an adjacent arm or separate arm condition and subsequently tested on a place-learning task using an eight-arm radial maze. Rats were trained to discriminate between a rewarded arm and a nonrewarded arm that were either adjacent to one another or separated by a distance of two arm positions. Each rat received 10 trials per day and was tested until the animal reached a criterion of nine correct choices out of 10 consecutive trials across 2 consecutive days of testing. Both groups acquired spatial discriminations for the separate condition at similar rates. However, in the adjacent condition, dDG lesioned animals required significantly more trials to reach the learning criterion than controls. The results suggest that dDG lesions decrease efficiency in pattern separation resulting in impairments in the adjacent condition involving greater overlap among the distal cues. Conversely, in the separate condition, there was less overlap among distal cues during encoding and less need for pattern separation. These findings provide further support for a critical role for the dDG in spatial pattern separation by demonstrating the importance of a processing mechanism that is capable of reducing interference among overlapping spatial inputs across a variety of memory demands.     

Competence to make treatment decisions in anorexia nervosa: thinking processes and values

This paper explores the ethical and conceptual implications of the findings from an empirical study of decision-making capacity in anorexia nervosa. In the study, ten female patients aged 13 to 21 years with a diagnosis of anorexia nervosa, and eight sets of parents, took part in semi-structured interviews. The purpose of the interviews was to identify aspects of thinking that might be relevant to the issue of competence to refuse treatment. All the patient participants were also tested using the MacCAT-T test of competence. This is a formalised, structured interviewer-administered test of competence, which is a widely accepted clinical tool for determining capacity. The young women also completed five brief self-administered questionnaires to assess their levels of psychopathology.The issues identified from the interviews are described under two headings: difficulties with thought processing, and changes in values. The results suggest that competence to refuse treatment may be compromised in people with anorexia nervosa in ways that are not captured by traditional legal approaches or current standardised tests of competence.     

EVALUATION OF A TRAINING MANUAL FOR THE ACQUISITION OF BEHAVIORAL ASSESSMENT INTERVIEWING SKILLS

Two procedures were used to teach behavioral assessment interviewing skills: a training manual and one-to-one instruction that included modeling, rehearsal, and feedback. Two graduate students and two advanced undergraduates were trained with each procedure. Interviewing skills were recorded in simulated assessment interviews conducted by each student across baseline and treatment conditions. Each training procedure was evaluated in a multiple baseline across students design. The results showed that both procedures were effective for training behavioral interviewing skills, with all students reaching a level of 90%-100% correct responding. Finally, a group of experts in behavior analysis rated each interviewing skill as relevant to the conduct of an assessment interview and a group of behavioral clinicians socially validated the outcomes of the two procedures.