The acquisition of movement skills: practice enhances the dynamic stability of bimanual coordination.

During bimanual movements, two relatively stable "inherent" patterns of coordination (in-phase and anti-phase) are displayed (e.g., Kelso, Am. J. Physiol. 246 (1984) R1000). Recent research has shown that new patterns of coordination can be learned. For example, following practice a 90 degrees out-of-phase pattern can emerge as an additional, relatively stable, state (e.g., Zanone & Kelso, J. Exp. Psychol.: Human Performance and Perception 18 (1992) 403). On this basis, it has been concluded that practice leads to the evolution and stabilisation of the newly learned pattern and that this process of learning changes the entire attractor layout of the dynamic system. A general feature of such research has been to observe the changes of the targeted pattern's stability characteristics during training at a single movement frequency. The present study was designed to examine how practice affects the maintenance of a coordinated pattern as the movement frequency is scaled. Eleven volunteers were asked to perform a bimanual forearm pronation-supination task. Time to transition onset was used as an index of the subjects' ability to maintain two symmetrically opposite coordinated patterns (target task - 90 degrees out-of-phase - transfer task - 270 degrees out-of-phase). Their ability to maintain the target task and the transfer task were examined again after five practice sessions each consisting of 15 trials of only the 90 degrees out-of-phase pattern. Concurrent performance feedback (a Lissajous figure) was available to the participants during each practice trial. A comparison of the time to transition onset showed that the target task was more stable after practice (p=0.025). These changes were still observed one week (p=0.05) and two months (p=0.075) after the practice period. Changes in the stability of the transfer task were not observed until two months after practice (p=0.025). Notably, following practice, transitions from the 90 degrees pattern were generally to the anti-phase (180 degrees ) pattern, whereas, transitions from the 270 degrees pattern were to the 90 degrees pattern. These results suggest that practice does improve the stability of a 90 degrees pattern, and that such improvements are transferable to the performance of the unpractised 270 degrees pattern. In addition, the anti-phase pattern remained more stable than the practised 90 degrees pattern throughout.     

The Timing of Intralimb Coordination

The authors examined the manner in which self-selected movement frequencies are impacted upon by repeated engagement in an intralimb coordination task and by alterations in the inertial characteristics of the limb. Twelve healthy adult volunteers rhythmically flexed and extended their elbow and wrist joints at a comfortable self-established frequency in 1 of 2 modes of coordination (in-phase and antiphase), while grasping 1 of 3 weighted dowels (no-weight condition [0.03 kg], light weight condition [0.5 kg], heavy weight condition [1.0 kg]). The movement frequencies adopted by subjects on the 3rd of 3 weekly sessions, following more than 120 experimental trials, were appreciably higher than those obtained during an initial session. The addition of mass to the system had an inconsistent influence upon the preferred frequency of movement. When subjects' limbs were loaded with what was deemed to be a light weight (0.5 kg), the movement frequencies that were adopted were indistinguishable from those selected when there was no (0.03 kg) loading of the limbs. In contrast, when subjects' limbs were loaded with a relatively heavy weight (1 kg), the resulting self-selected movement frequencies were reliably lower than when there was no loading of the limbs. The adopted frequency of movement was also influenced in a reliable fashion by the mode of coordination in which the movements were prepared. Those results are discussed with reference to mechanical and neuromuscular constraints on coordination dynamics.     

Measuring Anhedonia in Adolescents: A Psychometric Analysis

Anhedonia—the reduced capacity to experience pleasure—is a trait implicated in mental and physical health. Yet, psychometric data on anhedonia measures in adolescents are absent. We conducted an in-depth psychometric analysis of the Snaith–Hamilton Pleasure Scale (SHAPS; Snaith et al., 1995 Snaith, R. P., Hamilton, M., Morley, S., Humayan, A., Hargreaves, D., & Trigwell, P. (1995). A scale for the assessment of hedonic tone: The Snaith–Hamilton Pleasure Scale. British Journal of Psychiatry, 167, 99–103. doi:10.1192/bjp.167.1.99[Crossref], [PubMed], [Web of Science ®] , [Google Scholar])—a self-report measure of anticipated pleasure response to 14 pleasant experiences—in adolescents. Adolescents (N = 585, M age = 14.5) completed the SHAPS and other paper-and-pencil surveys. Item response theory models were used to evaluate the psychometric performance of each SHAPS item. Correlations of the SHAPS with other personality and psychopathology measures were calculated to evaluate construct validity. Results showed that (a) certain items (e.g., reported pleasure from basic experiences like “seeing smiling faces” or “smelling flowers”) provided more information about latent anhedonia than others; and (b) SHAPS scales exhibited construct-consistent convergent and discriminant validity (i.e., stronger correlations with low positive affect constructs, weaker correlations with negative affect). Reporting diminished pleasure from basic pleasant experiences accurately indicates adolescent anhedonia, which is important for future scale development and understanding the phenomenology of anhedonia in teens. These data support using the SHAPS for assessing anhedonia in epidemiological research and school-based universal prevention programming in general adolescent populations.     

Asymmetries in the Regulation of Visually Guided Aiming

An experiment was conducted to examine the contribution of sensory information to asymmetries in manual aiming. Movements were performed in four vision conditions. In the full-vision condition (FV), subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off condition (AO), the room lights were extinguished at movement initiation, preventing vision of the moving limb. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. In a no-vision (NV) condition, ambient illumination was removed and the target was extinguished upon initiation of the response movement. Results indicated that accuracy was superior in the full-vision and target-off conditions and when movements were made by the right hand. Movements made by the right hand were also of shorter mean duration. The magnitudes of performance asymmetries were uninfluenced by vision condition. Analyses of movement kinematics revealed that movements made in conditions in which there was vision of the limb exhibited a greater number of discrete modifications of the movement trajectory. On an individual-trial basis, no relationship existed between accuracy and the occurrence of discrete modifications. These data suggest that although vision greatly enhances accuracy, discrete modifications subserved by vision reflect the imposition of nonfunctional zero-order control processes upon continuous higher-order control regimes.     

Assessment: What Role the Assessor?

The advent of automated assessment contains the seeds of both threat and promise for professional assessors. Placing the problem in the historical and sociological contexts, this article examines computer-based test interpretation (CBTI) and the frequently misunderstood role of actuarial data in relation to it. I argue that sound clinicianship is central not only to the development of adequate CBTI systems, but also to the systems' appropriate and skillful use in practice. When properly utilized by otherwise well-qualified clinicians, CBTI can substantially enhance practice.     

Child Sexual Abuse in India: Current Issues and Research

Child sexual abuse (CSA) is a serious and widespread problem in India as it is in many parts of the world today. The trauma associated with sexual abuse can contribute to arrested development, as well as a host of psychological and emotional disorders, that some children and adolescents may never overcome. When sexual abuse goes unreported and children are not given the protective and therapeutic assistance they need, they are left to suffer in silence. This article discusses the nature and incidence of the sexual abuse of minors in India and presents an overview of research findings to date. Socio-cultural and familial risk factors involved in CSA are discussed. Common symptoms and disorders associated with sexual abuse are outlined. Finally, some implications for counselors working with children in India who have been sexually abused are highlighted.     

Dialogue in Therapy's "Borderzone"

This article explores some implications of practicing therapy from a discourse perspective. In particular, the dialogues of therapy are portrayed as a context in which client and therapist practice culture. Therapy, from this perspective, can optimally take place in an imaginary dialogic meeting place--a "borderzone"--wherein the discussions of therapy can occur in respectful ways. Discursive therapists are encouraged to see the differends, or potential stuck times of therapy, as times to turn to alternative discourses to keep the dialogue resourceful and collaborative.     

Conceptually Downstream: Revisiting Old Tributaries of Thought for “New” Constructivist Ideas and Practices

Contemporary constructivism occurs at the confluence of three tributaries of thought and practice: hermeneutics, phenomenology, and linguistic philosophy. Selectively tracing the contributions of each tributary, or tradition of thought, a case is made for integrating cultural meanings and customs, lived experience, and people's uses of language in a generative and socially grounded approach to constructivism.