Drawing insight from pictures: The development of concepts of false drawing and false belief in children with deafness, normal hearing, and autism

Theory-of-mind concepts in children with deafness, autism, and normal development (N = 154) were examined in three experiments using a set of standard inferential false-belief tasks and matched sets of tasks involving false drawings. Results of all three experiments replicated previously published findings by showing that primary school children with deafness or autism, aged 6 to 13 years, scored significantly lower than normal-developing 4-year-old preschoolers on standard misleading-container and unseen-change tests of false-belief understanding. Furthermore, deaf and autistic children generally scored higher on drawing-based tests than on corresponding standard tests and, on the most challenging of the false-drawing tests in Experiment 2, they significantly outperformed the normal-developing preschoolers by clearly understanding their own false intentions and another person's false beliefs about an actively misleading drawing. In Experiment 3, preschoolers; outperformed older deaf and autistic children on standard tasks, but did less well on a task that required the drawing of a false belief. Methodological factors could not fully explain the findings, but early social and conversational experiences in the family were deemed likely contributors.

Applications of motion study in developmental disabilities: A review

Motion study is an engineering technology that analyzes human body motions. During the past decade (1990-1999) a series of studies investigated the role of motion study in developmental disabilities. This article reviews the literature on the applications of motion study in the field. A historical and conceptual review of motion study leading to the current status of studies is presented followed by a review of the research literature. Two main eras of research focus were identified. The first era (1990-1995) of studies established the superior effectiveness and efficiency of tasks designed with motion study or motion study-related principles over traditional site-based task designs. The second era (1995-1999) of studies examined the interaction between motion study-based task designs and other variables such as choice, preference, and functionally equivalent and competing task designs and communicative alternatives. Our review found that applying motion study principles as an antecedent guide and practice to eliminating or reducing ineffective motions and simplifying effective motions resulted in positive task outcomes with most of the participants.

Postural control and movement performance during upper limb tasks in children with developmental co-ordination disorder (DCD)

At least 6% of primary school aged children present with DCD, where co-ordination is substantially below the normal range for the child’s age and intelligence. Motor skill difficulties negatively affect academic achievement, recreation and activities of daily living. Poor upper-limb co-ordination is a common difficulty for children with DCD. A possible cause of this problem is deviant muscle timing in proximal muscle groups, which results in poor postural and movement control. While studies have been published investigating postural control in response to external perturbations, detail about postural muscle activity during voluntary movement is limited even in children with normal motor development. No studies have investigated the relationship between muscle timing, resultant arm motion and upper-limb coordination deficits. Objectives: To investigate the relationship between functional difficulties with upper-limb motor skills and neuromuscular components of postural stability and coordination. Specifically, to investigate onset-timing of muscle activity, timing of arm movement, and resultant three-dimensional (3D) arm co-ordination during rapid, voluntary arm movement and to analyse differences arising due to the presence of DCD. This study is part of a larger research program investigating postural stability and control of upper limb movement in children. Design: A controlled, cross-sectional study of differences between children with and without DCD. Methods: This study included 50 children aged eight to 10 years (25 with DCD and 25 without DCD). Children participated in assessment of motor skills according to the Movement ABC Test and a laboratory study of rapid, voluntary arm movements. Parameters investigated included muscle activation timing of shoulder and trunk muscles (surface electromyography), arm movement timing (light sensor) and resultant 3D arm motion (Fastrak). Results: A MANOVA is being used to analyse between-group differences. Preliminary results indicate children with DCD demonstrate altered muscle timing during a rapid arm raise when compared with the control group of children. Conclusion: Differences in proximal muscle timing in children with DCD support the hypothesis that altered proximal muscle activity may contribute to poor proximal stability and consequently poor arm movement control. This has implications for clinical physiotherapy.

Developmental changes in the cone visual pigments of black bream Acanthopagrus butcheri

The spectral absorption characteristics of the visual pigments in the photoreceptors of the black bream Acanthopagrus butcheri Munro (Sparidae, Teleostei), were measured using microspectrophotometry. A single cohort of fish aged 5-172 days post-hatch (dph), aquarium-reared adults and wild-caught juveniles were investigated. During the larval stage and in juveniles younger than 100 dph, two classes of visual pigment were found, with wavelengths of maximum absorbance (lambda(max)) at approximately 425 nm and 535 nm. Following double cone formation, from 40 dph onwards, the short wavelength-sensitive pigment was recorded in single cones and the longer wavelength-sensitive pigment in double cones. From 100 dph, a gradual shift in the lambda(max) towards longer wavelengths was observed in both cone types. By 160 dph, and in adults, all single cones had a lambda(max) at approximately 475 nm while the lambda(max) in double cones ranged from 545 to 575 nm. The relationships between the lambda(max) and the ratio of bandwidth:lambda(max), for changes in either chromophore or opsin, were modelled mathematically for the long-wavelength-sensitive visual pigments. Comparing our data with the models indicated that changes in lambda(max) were not mediated by a switch from an A(1) to A(2) chromophore, rather a change in opsin expression was most likely. The shifts in the lambda(max) of the visual pigments occur at a stage when the juvenile fish begin feeding in deeper, tannin-stained estuarine waters, which transmit predominantly longer wavelengths, so the spectral sensitivity changes may represent an adaptation by the fish to the changing light environment.

Neural control of the heart: developmental changes in ionic conductances in mammalian intrinsic cardiac neurons

The expression and properties of ionic channels were investigated in dissociated neurons from neonatal and adult rat intracardiac ganglia. Changes in the hyperpolarization-activated and ATP-sensitive K+ conductances during postnatal development and their role in neuronal excitability were examined. The hyperpolarization-activated nonselective cation current, I-h, was observed in all neurons studied and displayed slow time-dependent rectification. An inwardly rectifying K+ current, I-K(I), was present in a population of neurons from adult but not neonatal rats and was sensitive to block by extracellular Ba2+. Using the perforated-patch recording configuration, an ATP-sensitive K+ (K-ATP) conductance was identified in greater than or equal to 50% of intracardiac neurons from adult rats. Levcromakalim evoked membrane hyperpolarization, which was inhibited by the sulphonylurea drugs. glibenclamide and tolbutamide. Exposure to hypoxic conditions also activated a membrane current similar to that induced by levcromakalim and was inhibited by glibenclamide. Changes in the complement of ion channels during postnatal development may underlie observed differences in the function of intracardiac ganglion neurons during maturation. Furthermore, activation of hyperpolarization-activated and KATP channels in mammalian intracardiac neurons may play a role in neural regulation of the mature heart and cardiac function during ischaemia-reperfusion. (C) 2002 Elsevier Science B.V All rights reserved.

Social rules for managing attempted interpersonal domination in the workplace: Influence of status and gender.

The present study utilized a social rules approach to investigate the relative influence of gender and status on managers' self-evaluations of their effectiveness in handling a dominating subordinate. In the first study 84 White middle-class participants identified the prescriptive and proscriptive rules for socially appropriate responding to a stimulus situation involving a pushy subordinate. Four rule sets were identified for female and male managers and subordinates, respectively. Rule-sets shared a number of common rules and showed some variation according to gender roles. In the second study, 91 White middle-class participants rated the individual rules for importance and also rated their personal and managerial effectiveness when responding to the stimulus situation using gender- and status-consistent and gender-and status-inconsistent response strategies. Both men and women rated the female gender and status- consistent strategy as most effective, and rated the status-inconsistent strategy as less effective than a gender-inconsistent response. Results were interpreted as providing more support for a situational gender-related theory of workplace behavior, rather than a traditional gender role perspective.

Morphology, ultrastructure, and implied function of ciliated sensory structures on the developmental stages of Merizocotyle icopae (Monogenea : Monocotylidae)

Experimental infections were used to track the fate of the dorsal sensilla of Merizocotyle icopae (Monogenea: Monocotylidae) from nasal tissue of the shovelnose ray, Rhinobatos typus (Rhinobatidae). Scanning and transmission electron microscopy revealed that 3 types of uniciliate dorsal sensilla exist at different times in the development of the monogenean. Type 1 sensilla have little or no invagination where the cilium exits the distal end of the dendrite and possess a ring of epidermis surrounding the cilium distal to the invagination. Type 2 sensilla have a deep invagination where the cilium exits the dendrite. Type 3 sensilla can be distinguished from the other types by the shape of the dendrite. The larvae have predominantly Type I dorsal sensilla, most of which are lost approximately 24 h after infection and a few Type 2 sensilla, which are retained. Additional Type 2 sensilla (termed Adult Type 2 sensilla), which are slightly different morphologically from the Type 2 sensilla of the larvae, form in later stages of development. Numerous Type 3 sensilla are unique to the dorsal surface of adults. Loss of all Type I sensilla upon attachment to the host, R. typus, suggests that these may be chemo- or mechanoreceptors responsible for host location by the swimming infective larvae. Type 2 sensilla appear to be important in the larvae, juveniles, and adults whereas the modality mediated by Type 3 is specific to adults. (C) 2003 Wiley-Liss, Inc.

Lateral epicondylalgia: a musculoskeletal physiotherapy perspective

Tennis elbow or lateral epicondylalgia (LE) is a challenging musculoskeletal condition to treat. This is largely due to the lack of research-based evidence of the clinical efficacy of the myriad of treatment approaches espoused in the literature. In view of this, successful rehabilitation of LE is based on choosing treatments that address the physical impairments found during clinical examination. The primary physical impairment in LE is a deficit in grip strength predominately due to pain and its consequences on motor function. Hence the mainstay of successful management of this condition is therapeutic exercise, providing it is not pain provocative. Adjunctive procedures such as manipulative therapy and sports taping techniques have recently been shown to provide substantial initial pain relief. Early relief of pain in the rehabilitation program helps accelerate recovery and most importantly motivates the client to persist with the therapeutic exercise program. The manipulative therapy and taping treatments presented in this masterclass warrant consideration in the clinical best practice management of LE, and serve as a model for other similar musculoskeletal conditions. (C) 2003 Elsevier Science Ltd. All rights reserved.