Cognitive psychology

Eating Disorders (ED) are notoriously difficult to treat due, in part, to commonly observed inefficiencies in cognitive flexibility and central coherence, which are believed to maintain disordered cognitions and behaviours and negatively impact prognosis. Cognitive remediation therapy (CRT) has recently been used effectively with adults with ED; however, evidence among adolescents is limited. The present study explored change in flexibility and central coherence in a group of 23 adolescent ED inpatients (M = 16 years, SD = 0.95). All participants received a comparable dose of ED treatment. Participants were split into two groups for comparison: the CRT group (n = 15) received CRT in addition to TAU; and a TAU group for control (TAU; n = 8). Improvements in flexibility and central coherence were superior in the CRT group, suggesting that CRT is a potentially useful treatment for adolescents with AN as part of an overall psychosocial rehabilitation program.

Author Keywords: anorexia nervosa, central coherence, cognitive flexibility, cognitive remediation, eating disorders, set shifting

Aging is associated with a multitude of changes, including changes in the motor system. One such change that has been documented is increased levels of inherent movement variability (the inability to consistently replicate movements over time) with increasing age. Previous research has had controversial findings regarding the effect that movement variability has on motor learning and motor adaptation. Some research suggests that movement variability is beneficial to motor learning, while other research indicates that movement variability is the by-product of a noisy motor system and is a detriment to learning new skills. How do changes in movement variability associated with aging affect the ability to adapt to a mass perturbation? We tested younger and older individuals on a mass adaptation task (applying mass to the lateral side of the arm to perturb inertial forces of the limb during reaches). We analyzed baseline levels of movement variability, learning during the adaptation block and how baseline levels of movement variability explained differences in learning. We focused on measures of accuracy, speed and precision. We found that younger individuals displayed greater levels of movement variability throughout the experiment and that they also learned to adapt to the mass perturbation more successfully than their older counterparts. Multi-joint movements displayed greater degrees of learning in comparison to single-joint movements, likely due to the difference in difficulty when completing the two movements. Taken together, our results suggest that purposeful movement variability may be beneficial to motor adaptation.

Author Keywords: aging, mass adaptation, motor adaptation, motor learning, movement variability

Three experiments examined whether semantics is activated automatically by testing whether Arabic digits (e.g., 4), number words (e.g., four), and non-number words (e.g., rat) activate semantics in the absence of central attention within the Psychological Refractory Period (PRP) paradigm. In all three experiments, subjects performed colour discriminations as Task 1. In Task 2, subjects performed magnitude comparisons on digits (Experiment 1) and number words (Experiment 2) and size comparisons on animal words (Experiment 3). Task overlap was controlled by varying stimulus onset asynchrony (SOA). A distance effect arose in Task 2 and yielded underadditive effects with decreasing SOA for both digits and number words, consistent with these notations activating semantics in the absence of central attention, or automatically. A distance effect also arose for animal words, but it was additive with SOA, inconsistent with non-number words activating semantics automatically.

Author Keywords: Automaticity, Central attention, Dual-task, Numerical cognition, Semantics, Word recognition

Evidence suggests that visuomotor system behaviour may be more sensitive to the prolonged effects of mild brain injuries than neuropsychological tests. We evaluated whether participants with a mild closed head injury (CHI) would show lingering visuomotor deficits, but not cognitive deficits, up to three years post-injury compared to participants with an orthopaedic injury and healthy controls. All three groups completed a tablet-based visuomotor assessment tool and a brief neuropsychological test battery. The CHI participants scored comparable to the control groups on the neuropsychological tests, but when assessed for visuomotor function requiring adjustment to a changing stimulus, CHI participants showed poorer performance than the control groups. Combined, these findings add to the evidence that CHI can lead to persistent visuomotor deficits that extend beyond those of neuropsychological tests. Therefore, visuomotor assessment should be included in brain injury and recovery evaluation, and this can be accomplished easily using tablet-based tasks.

Author Keywords: closed head injury, neuropsychological assessment, recovery, tablet, traumatic brain injury, visuomotor