The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance ...on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20-89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation.
Background. Recent studies have shown that focal injuries can have remote effects on network function that affect behavior, but these network-wide repercussions are poorly understood. Objective. This ...study tested the hypothesis that lesions specifically to the outflow tract of a distributed network can result in upstream dysfunction in structurally intact portions of the network. In the somatomotor system, this upstream dysfunction hypothesis predicted that lesions of the corticospinal tract might be associated with functional disruption within the system. Motor impairment might then reflect the dual contribution of corticospinal damage and altered network functional connectivity. Methods. A total of 23 subacute stroke patients and 13 healthy controls participated in the study. Corticospinal tract damage was quantified using a template of the tract generated from diffusion tensor imaging in healthy controls. Somatomotor network functional integrity was determined by resting state functional connectivity magnetic resonance imaging. Results. The extent of corticospinal damage was negatively correlated with interhemispheric resting functional connectivity, in particular with connectivity between the left and right central sulcus. Although corticospinal damage accounted for much of the variance in motor performance, the behavioral impact of resting connectivity was greater in subjects with mild or moderate corticospinal damage and less in those with severe corticospinal damage. Conclusions. Our results demonstrated that dysfunction of cortical functional connectivity can occur after interruption of corticospinal outflow tracts and can contribute to impaired motor performance. Recognition of these secondary effects from a focal lesion is essential for understanding brain–behavior relationships after injury, and they may have important implications for neurorehabilitation.
Previous research has not sufficiently addressed factors that define and moderate racial categorization judgments. This study independently manipulated skin color and facial physiognomy to determine ...their relative weighting in racial categorization. Participants (N=250) judged faces varying on 10 levels of facial physiognomy (from Afrocentric to Eurocentric) and 10 levels of skin color (from dark to light) under either no time constraints, a modest time constraint, and under a stringent time constraint. Skin color was a powerful predictor of racial typicality ratings at all levels of facial physiognomy, but participants relied upon facial physiognomy more when rating faces of light than dark skin color. Skin color was a more important cue than facial physiognomy under no time constraints, but as time constraints became more severe, skin color's importance decreased, yet it remained a more important cue at extreme physiognomy levels. The relationship between skin color and racial typicality ratings was stronger for those with more negative implicit racial attitudes. These findings suggest the primary role of skin color in racial categorization and underscore the importance of implicit attitudes in explicit categorization judgments.
► We study the effects of skin color and facial features in racial categorization. ► Skin color has a primary role in racial categorization. ► People rely on facial features more when rating light than dark faces. ► Skin color was a more important cue under time constraints. ► Those with a greater implicit racial bias are more likely to rely on skin color.
To determine the effects of weight-bearing (WB) versus nonweight-bearing (NWB) exercise for persons with diabetes mellitus (DM) and peripheral neuropathy (PN).
Randomized controlled trial with ...evaluations at baseline and after intervention.
University-based physical therapy research clinic.
Participants with DM and PN (N=29) (mean age ± SD, 64.5±12.5y; mean body mass index kg/m(2) ± SD, 35.5±7.3) were randomly assigned to WB (n=15) and NWB (n=14) exercise groups. All participants (100%) completed the intervention and follow-up evaluations.
Group-specific progressive balance, flexibility, strengthening, and aerobic exercise conducted sitting or lying (NWB) or standing and walking (WB) occurred 3 times a week for 12 weeks.
Measures included the 6-minute walk distance (6MWD) and daily step counts. Secondary outcome measures represented domains across the International Classification of Functioning, Disability and Health.
The WB group showed greater gains than the NWB group over time on the 6MWD and average daily step count (P<.05). The mean and 95% confidence intervals (CIs) between-group difference over time was 29m (95% CI, 6-51) for the 6MWD and 1178 (95% CI, 150-2205) steps for the average daily step count. The NWB group showed greater improvements than the WB group over time in hemoglobin A1c values (P<.05).
The results of this study indicate the ability of this population with chronic disease to increase 6MWD and daily step count with a WB exercise program compared with an NWB exercise program.
Background. Upper limb (UL) performance, or use, in daily life is complex and likely influenced by many factors. While the recovery trajectory of UL impairment poststroke is well documented, little ...is known about the recovery trajectory of sensor-measured UL performance in daily life early after stroke and the potential moderating role of psychosocial factors. Objective. To examine the recovery trajectory of UL performance within the first 12 weeks poststroke and characterize the potential moderating role of belief, confidence, and motivation on UL performance. Methods. This was a longitudinal, prospective cohort study quantifying UL performance and related psychosocial factors early after stroke. UL performance was quantified via bilateral, wrist-worn accelerometers over 5 assessment sessions for 24 hours. Belief, confidence, and motivation to use the paretic UL, and self-perceived barriers to UL recovery were quantified via survey. Change in 4 accelerometer variables and the moderating role of psychosocial factors was tested using hierarchical linear modeling. The relationship between self-perceived barriers and UL performance was tested via Spearman rank-order correlation analysis. Results. UL performance improved over the first 12 weeks after stroke. Belief, confidence, and motivation did not moderate UL performance over time. There was a negative relationship between UL performance and self-perceived barriers to UL recovery at week 2, which declined over time. Conclusions. Sensor-measured UL performance can improve early after stroke. Early after stroke, rehabilitation interventions may not need to directly target belief, confidence, and motivation but may instead focus on reducing self-perceived barriers to UL recovery.
The current natural gas and oil boom in North America requires new pipelines, which pose environmental risks from wellheads to their destinations. The environmental justice literature suggests that ...ethno‐racial minorities, populations with low socioeconomic status, and rural communities are disproportionally exposed to risks associated with potentially harmful land uses. Using data from the American Community Survey's 2015 five‐year estimates and data on the route of proposed pipelines compiled by The FracTracker Alliance, this study tests whether the above assumptions are true for proposed FERC‐permitted natural gas transmission pipelines in the United States for which planned routes have been made available. The results of logistic regression models provide only limited, and in some cases contradictory, support for these hypotheses. Although an increased share of highly educated residents significantly decreases the likelihood of a pipeline proposal in a census tract, a higher poverty rate also significantly lowers this probability. Likewise, the share of Black and Hispanic residents is significantly and negatively associated with pipeline proposals. However, reliable routing data are needed to test whether this holds true for built pipelines, but these data are considered confidential and thus inaccessible in the United States.
We describe a new laryngeal mask airway (LMA) that incorporates a second tube placed lateral to the airway tube and ending at the tip of the mask. The second tube is intended to separate the ...alimentary and respiratory tracts. It should permit access to or escape of fluids from the stomach and reduce the risks of gastric insufflation and pulmonary aspiration. It can also determine the correct positioning of the mask. A second posterior cuff is fitted to improve the seal. A preliminary crossover comparison with the standard mask in 30 adult female patients showed no differences in insertion, trauma or quality of airway. At 60 cm H2O intracuff pressure, the new LMA gave twice the seal pressure of the standard device (P<0.0001) and permitted blind insertion of a gastric tube in all cases. It is concluded that the new device merits further study.
To what extent are personality traits and sexual strategies linked? The literature does not provide a clear answer, as it is based on the Sociosexuality model, a one-dimensional model that fails to ...measure long-term mating (LTM). An improved two-dimensional model separately assesses long-term and short-term mating (STM; Jackson and Kirkpatrick, 2007). In this paper, we link this two-dimensional model to an array of personality traits (Big 5, Dark Triad, and Schizoid Personality). We collected data from different sources (targets and peers; Study 1), and from different nations (United States, Study 1; India, Study 2). We demonstrate for the first time that, above and beyond STM, LTM captures variation in personality.
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