Visuomotor function coordinates movements of the body and extremities with signals from human vision. The undisturbed interaction between the eyes and the motor system is a fundamental prerequisite for almost any sequence of actions. For example, when a sighted person reaches for an object, his hands are controlled by the visual sense in the brain. This coordination of visual perception on the one hand and the actions of the locomotor system on the other hand is a component of sensorimotor function, which encompasses the interlocking of all sensory and motor performance in humans. Crucial to visuomotor function is eye-hand coordination.
What is visuomotor function?
Through visuomotor function, movements of the body and extremities are coordinated with signals from human vision. In the development of children’s perceptual abilities, visuomotor performance is of great importance. In this process, numerous possible disorders can occur, which often only become apparent when children start school and make learning more or less difficult. These children have difficulty coordinating their daily movements, can process various sensory stimuli inadequately, and often reveal excessive anxiety, aggressiveness, or passivity toward other people and the immediate environment. Children can train their visual motor skills, for example, by improving their abilities in the so-called figure basic perception. This involves recognizing hidden and intersecting figures and being able to differentiate them from their respective backgrounds. It is also important to develop the children’s so-called perceptual constancy. This means, for example, being able to recognize specific properties of any object unchanged under changing viewing angles, even though the sensory impressions in the eyes shift depending on the perspective. This ability is crucial for the perception of geometric shapes regardless of color, size and position. Later, the child will also be able to recognize letters in this way, even if they appear in different words or in different fonts or handwriting. Furthermore, the perception of spatial position is very important for a normally developed child. From a purely spatial point of view, he sees himself as the center of his world and begins to classify all objects according to their respective position in relation to himself. Closely related to this is the perception of the spatial relationships of two or more objects to each other and to the child’s own person. In practice, the child needs this ability, for example, when stringing beads. It is required to perceive and constantly redefine the position of a bead in relation to the string and of both elements in relation to itself. Apart from this, the child will develop his eye-hand coordination in a direct way here.
Function and task
In the complex body coordination of a child, the sensory organs, the brain and the entire musculature work together. By nature, children want to practice these coordinated skills by playing, climbing, playing sports, etc. Irregularities in this coordination ability or even reluctance to move are the absolute exceptions and can usually be treated very creatively therapeutically. Many improvements can be achieved in a playful way. The dexterity of the hands and especially the writing movement (graphomotor function) are among the most demanding movement sequences that humans can master. In childhood this dynamic process (especially of the visuomotoric) can be observed very vividly; from the grasping of the baby to the pen guidance of the schoolchild. This development is primarily based on visual perception, the core organ of which is the eye. It recognizes visual stimuli and makes the decisive differentiations by being able to distinguish between near and far, depths and colors. Its versatile muscles always keep the eye in the right position and ensure its permanent mobility as well as the necessary correction of the visual perspective. In the brain, a concrete image is formed from the visual impressions of the two eyes. This depends on other sensory systems whose information is processed in the brain. The visuomotor system equips humans with the ability to plan and combine movements.Whether catching a ball, reaching for a glass, or perfecting complicated technical sequences of athletic disciplines, these movements always follow the same pattern. At the same time, visual and motor impulses produce different influences on the learning of movements. Likewise, they influence this learning process at different times. Movement learning through visual stimuli occurs largely independent of motor mechanisms and idiosyncrasies. In this context, motor learning begins later and also only increases in importance over time. Target-oriented movements do not consist of single partial movements, but of manifold sequences. Each movement is an ordered sequence, for example of several steps in walking. This becomes particularly clear in sporting movements. They are complexly composed of their mechanical execution and simultaneously optical perceptions. The sprinter must not leave the track if he wants to win. Being as fast as possible is not enough for him.
Diseases and ailments
Research has shown that the cerebellum is particularly important for functioning visuomotor function. If damage occurs in the cerebellum, for example as a result of a stroke, visuomotor activity becomes noticeably more difficult. What has already been learned can only be recalled with difficulty. It is not so much the execution of the movement sequences that is disturbed, but rather the processing of the sensory stimuli. This effect is comparable to the state of drunkenness. Alcohol primarily affects the cerebellum, which is why a drunk person has difficulty staying on his or her feet.