Visuo-motor coordination in 8-year-old children born pre-term before and after 28 weeks of gestation.

Purpose: This study compared the visuo-motor abilities between pre-term and full-term children.

Methods: Twenty-three 8-year-old children participated, five being born under 28 weeks gestational age (wGA) referred to as Preterms1 (mean=8 years 5 months [SD 0.3]), nine Preterms2 of 28-35 wGA (mean=7 years 9 months [SD 0.

Age-related differences in the reaching and grasping coordination in children: unimanual and bimanual tasks.

This study examined age-related differences in the coordinative mechanism of the reach-to-grasp movement in three groups of children aged 6, 8, and 11 year, and in healthy adults. Three prehension conditions were manipulated: an unimanual and a bimanual self-driven tasks in which the reaching and grasping of the object were performed by participants, and a bimanual externally-driven task, in which the experimenter brought the object into the vicinity of the participant which grasped it. Classical kinematics data-peak velocities of the reaching and the grasping, the time to onset grip opening, maximum grip opening and grip closure-were calculated.

Updating of an internal model without proprioception: a deafferentation study.

This study sought to determine whether intact proprioception is required to adapt to a novel kinematic environment. We compared adaptation with a rotated visual feedback between a deafferented patient and healthy participants. They performed reaching movements towards visible targets while vision of the cursor was rotated by 30 degrees with respect to hand position.

Role of proprioceptive information in movement programming and control in 5 to 11-year old children.

The role of proprioceptive inputs in the control of goal-directed movements was examined, by means of the tendon vibration technique, in 5 to 11-year old children performing a serial pointing task. Children pointed, with movements of various amplitudes and at various positions, by alternating wrist flexions and extensions. Tendon vibration was applied to both agonist and antagonist muscles to perturb relevant muscular proprioceptive inputs during the static or dynamic phase of the task, i.

Acquisition of visuomanual skills and improvement of information processing capacities in 6- to 10-year-old children performing a 2D pointing task.

The aim of this study was to investigate motor performance and visuomanual control through the analysis of Fitts' law in 6-, 8-, and 10-year-old children and adults performing a constrained two-dimensional pointing task. Participants were required to point and click on targets appearing on a laptop computer screen with a standard computer mouse. Three sizes of targets were used to create different indexes of difficulty.

Contribution of the cerebellum to self-initiated synchronized movements: a PET study.

Positron emission tomography (PET) was used to examine the neural substrate underlying self-initiated versus externally triggered synchronized movements. Seven healthy subjects performed synchronized right index finger and foot movements in two conditions: either by setting them going at their own pace (self-initiated condition) or by reacting to randomly dispensed auditory signals (externally triggered condition). In addition, subjects either self-initiated or performed in reaction to an audible tone a sequence of finger and foot movements.

Age-related differences in the visual processes implied in perception and action: distance and location parameters.

The aim of the two present experiments was to examine the ontogenetic development of the dissociation between perception and action in children using the Duncker illusion. In this illusion, a moving background alters the perceived direction of target motion. Targets were held stationary while appearing to move in an induced displacement.

Aged-related differences in the attentional cost of pointing movements.

The aim of the present study was to analyze, in children aged 6, 8 and 11, the developmental trend of the attentional cost related to the programming and execution of pointing movements, using a dual-task paradigm. Our results showed that the attentional cost associated to the programming and the first phase of the pointing movement decreased non linearly with age, in particular a plateau between 8 and 11 was observed. This confirmed that the developmental trend of the control of pointing movements is characterized by a no monotonic evolution in which feedforward processes were predominantly used in the younger children, feedback processes were predominantly used in older children (since age 8), and one-line over feedforward processes were used in adults.

Visuomanual coordination in childhood: adaptation to visual distortion.

The aim of the experiment was to study the adaptive capacities of children to perform drawing movements while being visually perturbed. Children aged 5-11 years and a group of adults drew diamonds via information provided through a computer screen. The screen display was either upright or rotated 180 degrees.