The effect of dividing attention between walking and auxiliary tasks in people with Parkinson's disease

This controlled study examined the effects of dividing attention between walking and the performance of a secondary cognitive task in people with mild to moderate Parkinson's disease (Hoehn and Yahr stages 2-3.5). Participants in the training group (n=6) received 30 min divided attention training in taking big steps while simultaneously performing serial three subtractions. Participants in the control group (n=6) received no training. Stride length, gait velocity and accurate enumeration rate were measured at baseline, immediate after training and 30 min after training under single-task (walk only or subtract only) and dual-task (walk and subtract) conditions. Data were also collected at training in the training group. Immediate improvement in stride length and gait velocity was found when instruction was given to participants to pay equal attention to gait and subtractions (p=0.001, p=0.05) compared to baseline. Short-term improvement in the gait variables was also found after training when compared to the controls (p=0.001, p=0.001). Nevertheless, there was no significant difference in the accurate enumeration rate. Based on the findings, we conclude that divided attention can be used as a strategy to improve slow and short-stepped gait under dual-task conditions. Divided attention can also be used in gait training for short term stride length and gait velocity improvement.     

Arm adductor with arm abduction in rotator cuff tear patients vs. healthy--design of a new measuring instrument

The incidence of (a)symptomatic rotator cuff tears is high, but etiologic mechanisms are unclear and treatment outcomes vary. A practical tool providing objective outcome measures and insight into etiology and potential patient subgroups is desirable. Symptomatic cuff tears coincide with humerus cranialization. Adductor co-activation during active arm abduction has been reported to reduce subacromial narrowing and pain in cuff patients. We present an easy-to-use method to evaluate adductor co-activation. Twenty healthy controls and twenty full-thickness cuff tear patients exerted EMG-recorded isometric arm abduction and adduction tasks. Ab- and adductor EMG's were expressed using the "Activation Ratio (AR)" (-1 ≤ AR ≤ 1), where lower values express more co-activation. Mean control AR's ranged from .7 to .9 with moderate to good test-retest reliability (ICC: .60-.74). Patients showed significantly more adductor co-activation during abduction, with adductor AR's ranging between .3 (teres major) and .5 (latissimus dorsi). In conclusion, the introduced method discriminates symptomatic cuff tear patients from healthy controls, quantifies adductor co-activation in an interpretable measure, and provides the opportunity to study correlations between muscle activation and humerus cranialization in a straightforward manner. It has potential as an objective outcome measure, for distinguishing symptomatic from asymptomatic cuff tears and as a tool for surgical or therapeutic decision-making.     

Positive Traits Linked to Less Pain through Lower Pain Catastrophizing

The present study examined the association between positive traits, pain catastrophizing, and pain perceptions. We hypothesized that pain catastrophizing would mediate the relationship between positive traits and pain. First, participants (n = 114) completed the Trait Hope Scale, the Life Orientation Test-Revised, and the Pain Catastrophizing Scale. Participants then completed the experimental pain stimulus, a cold pressor task, by submerging their hand in a circulating water bath (0 °C) for as long as tolerable. Immediately following the task, participants completed the Short-Form McGill Pain Questionnaire (MPQ-SF). Pearson correlation found associations between hope and pain catastrophizing (r = −.41, p < .01) and MPQ-SF scores (r = −.20, p < .05). Optimism was significantly associated with pain catastrophizing (r = −.44, p < .01) and MPQ-SF scores (r = −.19, p < .05). Bootstrapping, a non-parametric resampling procedure, tested for mediation and supported our hypothesis that pain catastrophizing mediated the relationship between positive traits and MPQ-SF pain report. To our knowledge, this investigation is the first to establish that the protective link between positive traits and experimental pain operates through lower pain catastrophizing.     

Influence of perceived social support and functioning on the quality of life of patients with schizophrenia and their caregivers

Perception of social support and functioning of patients with schizophrenia and their primary caregivers and its relationship to quality of life are described. Forty-five patients and their 45 relatives, treated at the Mental Health Services in Arica, Chile, participated. Both patients and caregivers in the study have a poor perception of social support with regard to extra-family people, as well as a low social integration. However, patients showed adequate capacity to function within their immediate family. Unlike what was found in developed countries, these patients showed moderate levels of quality of life, with a strong relationship with perceptions of the social support they receive from family and significant others and the ability to establish and maintain social contacts. Quality of life of primary caregivers is linked to patients' ability to establish and maintain social contacts within the family group, as in other social instances, such as keeping a job. The results of the study suggest the need to consider the design and application of programs of support for these patients and their caregivers, with the central aim of the social functioning of the above-mentioned patients and their familiar and community integration.     

Methods for averaging alpha coefficients in reliability generalization studies

The reliability generalization (RG) approach is a kind of meta-analysis that aims to statistically integrate a set of independent reliability coefficients obtained in several applications of a test, with the purpose of characterizing the measurement error and determining which factors related to the studies and samples can explain its variability. Diverse procedures have been proposed in the literature for averaging a set of independent alpha coefficients, and there is no consensus about which methods are best. Here, we present the results of a Monte Carlo simulation study, comparing the performance of twelve procedures proposed in Feldt and Charter, in terms of bias and mean square error. These procedures differ from each other in the transformation (or not) of the coefficients, and in the application or not of a weighting scheme based on sample size. Our results recommend using weighted methods in contrast to unweighted ones, and transforming the coefficients by the Hakstian and Whalen's proposal or by the proposal based on the square root of the inverse alpha coefficient. Lastly, we discuss the relations between the diverse procedures for averaging alpha coefficients with fixed-effects, random-effects, and varying coefficients models.     

Assessing acute stress with the Implicit Association Test

Assessments of acute stress using self-report questionnaires can be biased by various factors, including social desirability. The present study used a bias-free method, the Implicit Association Test (IAT), to assess stress. Unlike a previous study (Schmukle & Egloff, 2004) in which acute stress was not detected with the IAT, this study manipulated stress by generating test anxiety and threatening self-esteem. The results revealed that the IAT effect was greater in the high-stress group than in the low-stress group. Participants in the high-stress group associated their concept of self with the concept of anxiety more strongly than did those in the low-stress group. This result suggests that the IAT is a sensitive measure for detecting group differences in acute stress.     

Mighty metaphors: behavioral and ERP evidence that power shifts attention on a vertical dimension

Thinking about the abstract concept power may automatically activate the spatial up-down image schema (powerful up; powerless down) and consequently direct spatial attention to the image schema-congruent location. Participants indicated whether a word represented a powerful or powerless person (e.g. ‘king’ or ‘servant’). Following each decision, they identified a target at the top or bottom of the visual field. In Experiment 1 participants identified the target faster when their spatial position was congruent with the perceived power of the preceding word than when it was incongruent. In Experiment 2 ERPs showed a higher N1 amplitude for congruent spatial positions. These results support the view that attention is driven to the image schema congruent location of a power word. Thus, power is partially understood in terms of vertical space, which demonstrates that abstract concepts are grounded in sensory-motor processing.     

Dampening of positive affect prospectively predicts depressive symptoms in non-clinical samples

Past research has convincingly shown that a ruminative response style to negative affect (NA) predicts concurrent and prospective levels of depressive symptoms. Recent findings suggest that how people respond to positive affect (PA) might also be involved in the development of depressive symptoms, although this has heretofore not been tested prospectively. Participants from two non-clinical samples (total N=487) completed measures of depressive symptoms, response styles to NA (negative rumination) and response styles to PA (positive rumination and mood dampening) at two assessments separated by a 3-month (Sample 1) and 5-month period (Sample 2). Results in both samples showed that increased dampening responses to PA predict depressive symptoms at follow-up, even when taking into account baseline depressive symptoms and ruminative responses to NA. The results suggest that (dampening) responses to PA add useful information above and beyond (ruminative) responses to NA in predicting depression symptoms prospectively.     

Cumulative estrogen exposure and prospective memory in older women

This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to influence estrogen levels across the life span, and performance on prospective and retrospective memory measures in a group of 50 postmenopausal women (mean age=69.3years) who, if they were current or former users of estrogen therapy, had started therapy within 5years of menopause. The ICEE was found to be a significant predictor of performance on the Prospective Memory task (F(1)=4.21, p=.046, η(p)(2)=.084). No significant relationship was noted between the ICEE and performance on measures of retrospective memory. The results suggest that the level of cumulative lifetime exposure to estrogen a woman has influences her prospective memory performance later in life and that the influence of reproductive and biological markers of endogenous estrogen exposure are relevant factors to consider when studying the effect of estrogen therapy on cognitive functioning in postmenopausal women. In addition, the finding that performance on a measure of prospective memory, but not performance on measures of retrospective memory, was associated with the ICEE adds further support to the theory that the frontal cortex may be especially sensitive to estrogen.