Visual Information and the Control of Reaching in Children: A Comparison Between Children With and Without Developmental Coordination Disorder

Three experiments were performed on reach and grasp in 9- to 10-year-old children (8 controls and 8 with developmental coordination disorder [DCD]). In normal reaching, children in the DCD group were less responsive to the accuracy demands of the task in controlling the transport component of prehension and spent less time in the deceleration phase of hand transport. When vision was removed as movement began, children in the control group spent more time decelerating and reached peak aperture earlier. Children in the DCD group did not do that, although, like the control group, they did increase grip aperture in the dark. When depth cues were reduced and only the target or only the target and hand were visible, children in the control group used target information to maintain the same grip aperture in all conditions, but DCD children behaved as if the target was not visible. Throughout the studies, the control group of 9- to 10-year-olds did not produce adult-like adaptations to reduced vision, suggesting that they had not yet attained adult-like integration of sensory input. Compared with control children, children with DCD did not exhibit increased dependence on vision but showed less recognition of accuracy demands, less adaptation to the removal of vision, and less use of minimal visual information when it was available.     

On the Hand Transport Component of Prehensile Movements

Jeannerod (1981) proposed that prehensile movements involve two independent visuomotor channels that are responsible for hand transport and hand aperture. In many studies, the movement of a marker placed on the wrist has been used as an index of hand transport because wrist movement is unaffected by the movements of the digits responsible for hand aperture. In the present study, the spatial paths of the wrist, index finger, and thumb of 5 adults, each performing 50 reaching movements, were measured with a WATSMART movement tracking system, and their variability was analyzed. The measures of movement variability suggest that the motor system is more concerned with thumb position than with wrist position during hand transport. Although the wrist is a technically convenient index of hand transport, the thumb may be a more appropriate index from the point of view of motor control.     

Immediate Effect of Training at the Onset of Reaching in Preterm Infants: Randomized Clinical Trial

The authors' aim was to investigate the immediate effect of a single specific training session (serial varied practice), of short duration on the kinematic parameters of reaching, in the period of the emergence of the skill in preterm and low birth weight infants. The study included 16 infants of both sexes, born at a mean gestational age of 32.13 (±1.36) weeks and mean birth weight of 1720.94 (±358.46) g. The infants were randomly divided into 2 groups: experimental and control. The experimental group was given a 5-min training session in reaching, while the control group received no training. The results showed significant differences in peak velocity in the intra (Z = –2.10, p = .036) and intergroup (U = 9.00, p = .016) evaluations, which decreased in the experimental group after training. Cohen's d test for clinical relevance suggested that the specific, short duration training proved effective in promoting slower reaches, with greater adjustment and lower number of units of movement. These results are positive for preterm infants given that these parameters more closely resemble the typical development of mature reaching behaviors in term infants, which suggests that this protocol of reaching training (serial varied practice) could be used as an evidence-based intervention strategy.     

Why the brain needs language in order to be self-conscious

It has been argued that natural language, in the form of inner speech, plays a central role in self-consciousness. However, it is not quite clear why. In this paper, we present a novel answer to the why question. According to the thesis presented in this paper, the brain as a physical system is limited in observing itself and relies on the mediation of natural language for the reconstruction of its phase space trajectory. Drawing on knowledge gathered on the measurement of dynamical systems, we detail the unique properties of natural language that may support this reconstruction.     

Social cognitive model of adjustment to engineering majors: Longitudinal test across gender and race/ethnicity

We conducted a longitudinal test of a social cognitive model of academic adjustment in a sample of 732 engineering students. The model, designed to explain students' satisfaction with and intentions to persist in their majors, integrated features of social cognitive career theory's (SCCT) segmental models of satisfaction, interest, choice, and performance (Lent & Brown, 2006; Lent, Brown, & Hackett, 1994). Students completed measures of academic support, self-efficacy, outcome expectations, interests, satisfaction, positive affect, and intended persistence at three time points (at the end of their second, third, and fourth semesters in engineering). A bidirectional version of the model offered good fit to the data, both in the larger sample and across gender and racial/ethnic groups. Self-efficacy was the most reliable direct predictor of academic satisfaction and intended persistence across the third and fourth semesters, though other social cognitive variables also contributed, either directly or indirectly, to predictions at one time point or the other. We consider implications of the findings for further research and practice on academic adjustment and persistence in STEM fields.     

Separating value from selection frequency in rapid reaching biases to visual targets

Stimuli associated with positive rewards in one task often receive preferential processing in a subsequent task, even when those associations are no longer relevant. Here we use a rapid reaching task to investigate these biases. In Experiment 1 we first replicated the learning procedure of Raymond and O'Brien (2009), for a set of arbitrary shapes that varied in value (positive, negative) and probability (20%, 80%). In a subsequent task, participants rapidly reached toward one of two shapes, except now the previously learned associations were irrelevant. As in the previous studies, we found significant reach biases toward shapes previously associated with a high probable, positive outcome. Unexpectedly, we also found a bias toward shapes previously associated with a low probable, negative outcome. Closer inspection of the learning task revealed a potential second factor that might account for these results; since a low probable negative shape was always paired with a high probable negative shape, it was selected with disproportionate frequency. To assess how selection frequency and reward value might both contribute to reaching biases we performed a second experiment. The results of this experiment at a group level replicated the reach-bias toward positively rewarding stimuli, but also revealed a separate bias toward stimuli that had been more frequently selected. At the level of individual participants, we observed a variety of preference profiles, with some participants biased primarily by reward value, others by frequency, and a few actually biased away from both highly rewarding and high frequency targets. These findings highlight that: (1) rapid reaching provides a sensitive readout of preferential processing; (2) target reward value and target selection frequency are separate sources of bias; and (3) group-level analyses in complex decision-making tasks can obscure important and varied individual differences in preference profiles.     

A constructive replication of client change during psychodynamic treatment in an outpatient setting

We responded to the need for replication in psychotherapy research by extending a prior naturalistic study documenting the effectiveness of long-term psychodynamic treatment. We employed three novel analytic strategies and evaluated their influence on substantive interpretations offered in the prior study. The sample consisted of clients (N = 387; M_age = 31.61; SD = 11.13; 58.9% female; 79.1% Caucasian/White) receiving outpatient treatment at a psychodynamic training clinic. Results replicated the original two-class solutions for social functioning, depression and life satisfaction. Novel to the replication analyses, each trajectory for social functioning and depression exhibited nonlinear change and results advanced research on a theorised mechanism of effective psychodynamic treatment. Results showed that change in experiential avoidance was a possible mechanism between early-treatment change in social functioning and later-treatment changes in depression symptoms and life satisfaction. Clinical implications focus on the influence that initial levels of symptoms and well-being may have on early and later phases of treatment, monitoring progress throughout treatment, and how to promote symptom and well-being improvement.     

Help or hinder? When recommendation signage expands consideration sets and heightens decision difficulty

This research examines whether recommendation signage helps or hinders the consumer when faced with choosing from large product assortments. In spite of frequent usage and retailer intuition suggesting that providing recommendation signs (e.g., “Best Seller,” “Award Winner”) should help consumers in the choice process, we propose that signs can hinder choice for consumers with more developed preferences by adding to the complexity and difficulty of the decision process. In three experiments using horizontally differentiated products in multiple categories, we provide evidence that recommendation signs create preference conflict for consumers with more developed preferences, leading these consumers to form larger consideration sets and ultimately experience more difficulty from the decision-making process. In addition, we show that these effects are mitigated for consumers with less developed preferences and when the choice is from a small assortment. The results suggest that recommendation signage may not be an effective tool for aiding choice from large assortments; instead signage can exacerbate the difficulties associated with having too many choices, with implications on purchase quantity.