Sex and Handedness in Development of Visuomotor Skills

Development of visuomotor skills in 420 left-handed and 420 right-handed school children were investigated using the Rey-Osterrieth Complex Figure. Analysis indicate that the visuomotor skills involved in copying a complex figure improve with age until the mean age of 10.5 yr., in both sex and handedness groups. Further analysis showed that girls performed significantly better than boys at certain developmental stages and right-handers performed better than left-handers in various age groups. Some possible differences in performance could be attributed to different rates of maturation of the cerebral hemispheres, to different neuropsychological strategies, or to functional differences between the sex groups and between right- and left-handed children.

Development of graphic formulas for the depiction of familiar objects

We investigated the nature of graphic formulas in 5-, 7-, and 9-year-old children when they were asked to draw a house and a television in a free condition, and then to draw from photographs of these objects. Assuming that the frequency of occurrence of a feature in children's drawings reflects its semantic weight, we studied the relations between occurrence and order of production of features to assess the extent to which a core-to-periphery progression principle (van Sommers, 1984) applies to the graphic formulas. The results showed that this principle was essentially present in the free drawing context. Under copying conditions, the order of production of the features was under the influence of perceptual and geometric factors, which elicited the production of subsystems of features at the depends of the application of the core-to-periphery progression principle. In the free condition, the core-to-periphery principle was mostly relevant in accounting for graphic formulas of the house in the young children (5 and 7 years), and of the television at ages 7 and 9. We suggest that the development of a graphic formula is partially related to the development of the object as a category in the child's conceptual system.

Writing and Drawing Performance of School Age Children

The aim of our study was to investigate possible relationships between writing and drawing performance of school-aged children, in order to compare the two skills at the within-individual level. The sample consisted of 182 right- and left-handed children, aged 8 to 12 years. Children were examined by the Greek adaptation of the Luria-Nebraska neuropsychological battery in spontaneous writing, copying and writing to dictation and they were asked to complete four different drawing tasks. The results produced significant correlations between drawing scores and scores in all three writing tasks. Significant differences in drawing performance among proficient and poor hand writers were also found. On the other hand, there were no significant differences between right- and left-handers’ performance on the above tasks, despite the overrepresentation of left-handed amongst between poor writers. Our findings create a fruitful ground for the further study of early drawing as a means to predict later handwriting problems.

Drawing the line: drawing and construction strategies for simple and complex figures in Williams syndrome and typical development

In the typical population, a series of drawing strategies have been outlined, which progressively emerge during childhood. Individuals with Williams syndrome (WS), a rare genetic disorder, produce drawings that lack cohesion, yet drawing strategies in this group have hitherto not been investigated. In this study, WS and typically developing (TD) groups drew and constructed (from pre-drawn lines and shapes) a series of intersecting and embedded figures. Participants with WS made use of the same strategies as the TD group for simple intersecting figures, though were less likely to use a typical strategy for more complex figures that contained many spatial relations. When replicating embedded shapes, the WS group used typical drawing strategies less frequently than the TD group, despite attempting to initiate a strategy that is observed in TD children. Results suggested that individuals with WS show a particular difficulty with replicating figures that include multiple spatial relations. The impact of figure complexity and task demands on performance are discussed.

The use of graphic rules in grade one to help identify children at risk of handwriting difficulties

Previous researches on elementary grade handwriting revealed that pupils employ certain strategy when writing or drawing. The relationship between this strategy and the use of graphic rules has been documented but very little research has been devoted to the connection between the use of graphic rules and handwriting proficiency. Thus, this study was conducted to investigate the relative contribution of the use of graphic rules to the writing ability. A sample of 105 first graders who were average printers and 65 first graders who might experience handwriting difficulty, as judged by their teachers, of a normal primary school were individually tested on their use of graphic rules. It has been found that pupils who are below average printers use more non-analytic strategy than average printers to reproduce the figures. The results also reveal that below average printers do not acquire the graphic principles that foster an analytic approach to production skills. Although the findings are not sufficient to allow definitive conclusions about handwriting ability, it can be considered as one of the screening measures in identifying pupils who are at risk of handwriting difficulties.

Persons with and without Down syndrome use similar strategies when using visual instructions for bimanual drumming

BACKGROUND

Previous research suggested that persons with Down syndrome (DS) used a different strategy to drum than typical adults.

METHODS

The present study examined continuous bimanual drumming strategies in response to different instructions in 10 persons with DS, 10 mental age-matched and 10 chronological age-matched groups. The drumming task required participants to hit two drums with the drumsticks at the same time following verbal (e.g. 'up' and 'down'), visual (e.g. video of both drumsticks moving up and down together) or auditory (e.g. sound of both drums being hit, then cymbal being hit) instructions for 10 s. Sensors placed on the wrists of each participant and the end of each drumstick provided data that allowed the assessment of individual drumming strategies.

RESULTS

In general, when persons with DS were following the visual instructions their drumming movements were shorter, straighter and less variable as compared with their movements in the auditory and verbal conditions.

CONCLUSIONS

Whether movement paths were straight or curved, the strategy was to move the drumstick and wrist together as one unit.

Organizing principle in 4- to 8-year-old children's drawings of embedded geometric shapes

This study looks at the way children aged 4 to 8 organize the execution of three drawings composed of simple geometric shapes (a circle, a rectangle or square, a triangle, and a diamond). In the first two experiments, we analyze the execution process used to copy and draw from memory, and we attempt to determine how this process evolves with age. The results showed that the “centripetal” execution order, where subjects drew the shapes in the outside-to-inside direction, was already prevalent in 4-year-olds. The third experiment was aimed at assessing the frequency and stability of this drawing process. We superimposed transparencies of simple geometric shapes in front of the subject's eyes. The results showed that the order in which the shapes were presented had an effect on the drawing process and how it evolved with age. They also showed that the centripetal execution principle had stabilized by the age of 8. The centripetal execution principle appears to act like the syntactic rules in the action grammar that governs elementary figure drawing.

Exploitation of elasticity as a biomechanical property in the production of graphic stroke sequences

In the present study we report several findings which indicate that subjects exploit elasticity of muscles and tendons as a biomechanical property of the motor system in the execution of graphic stroke sequences. The drawing movements of 15 right-handed subjects were analyzed, who copied a geometrical pattern consisting of four line segments. Three of these segments were connected by an acute and an obtuse angle. A first analysis concerning stroke-direction preferences shows that subjects tended to produce final strokes in preferred movement directions and obeyed an end-state stability constraint. Subsequently, we analyzed the copying movements with respect to (1) pauses at acute and obtuse angles, (2) local deviations in angle size, and (3) size variations of the strokes surrounding the angles. The results reveal a higher incidence of pauses at obtuse than at acute angles. Furthermore, a local sharpening of angles was found which was most pronounced at obtuse angles. Finally, systematic size variations of the strokes surrounding the angles were found. The results are considered to reflect the functional use of elasticity during task performance. It is concluded that biomechanical properties of the motor system significantly influence higher-order preparatory processes involved in multi-trajectory control.

Visuomotor organization in the child: a neuropsychological approach

The ability of children to copy a complex figure was investigated by means of the Rey-Osterrieth complex figure and the corresponding methodology. The sample consisted of 420 children (boys and girls) aged 5 1/2 to 12 1/2 years. Responses indicate that the visuomotor ability involved in copying a complex figure increases with increasing age and that girls show significantly better performance than boys during the ages 8 1/2 to 12 1/2 years. The differences in performance can be attributed to differential neuropsychological strategies or functional differences that require further investigation.

Constraints on representational change: evidence from children's drawing

This paper uses children's drawing as clues to general constraints on internal representational change and flexibility. Fifty-four children between 4 and 11 years of age each produced six drawings. They were first asked to draw a house, and then to draw a house that does not exist. The same procedure was used for man and animal. The technique forced children into operating on their normal, efficient drawing procedures, and allowed the researcher to ascertain the types of constraint that obtain on representational change and flexibility. Striking developmental differences emerged between the 4- to 6-year-old age group and the 8- to 10-year-old age group. Changes introduced by the younger children involved deletions and changes in size and shape, whereas older children changed position and orientation of elements and added elements from other conceptual categories, resulting in ever-increasing inter-representational flexibility. Development is accounted for in terms of reiterated cycles of change from internal representations specified as a sequentially fixed list, embodying a constraint that was inherent in the earlier procedural representations, to internal representations specified as a structured, yet flexibly ordered set of manipulable features. The constraints are considered to be general and are compared with work on seriation and number in children, and on phonological awareness and musical ability in adults. The results are integrated into a general model of developmental change which is compatible both with initial modularity and with subsequent domain-general constraints.

Visual control of movement patterns and the grammar of action

In this experiment adult subjects copied three types of material (letters, reversed letters and geometric shapes) with and without sight of the hand and the writing trace. Without vision the number of movement segments decreased and the sequence and direction of movements were altered. This means that subjects did not use a fixed stored representation to produce items nor did they obey the rules of Goodnow and Levine's (1973) grammar of action. When spatial location is made more difficult by the removal of vision, movement production is simplified to reduce the number of relocations required. The use of consistent directions of movement depends on the ability to use visual control of spatial location.