Eye-hand coordination (also known as hand-eye coordination ) is the coordinated control of eye movements with hand movements, and visual input processing to guide reach and grasping with the use of hand proprioception to guide the eye. Eye-hand coordination has been studied in diverse activities such as the movement of solid objects such as logs, archery, sports performances, reading music, computer games, copying-typing, and even making tea. This is part of the mechanism of doing everyday tasks; in its absence most people will not be able to do even the simplest of actions like taking a book off the table or playing a video game. Although this is acknowledged by the term "hand-eye coordination", with no exception of medical resources, and most psychological sources, see eye-hand coordination.
Video Eye-hand coordination
Perilaku dan kinematika
Neuroscientists have extensively examined the behavior of human gazes, with research noting that the use of gaze is very specific task, but humans usually exhibit proactive controls to guide their movements. Usually, the eyes are glued to the target before the hand is used to perform the movement, indicating that the eye provides spatial information for the hand. The duration that the eye appears to be locked to the destination for varied hand movements - sometimes the eyes remain fixed until the task is completed. At other times, the eyes appear to be lurking forward toward another interesting object before the hand even grasps and manipulates the object. Instead, humans are able to direct the saccade toward the hands without sight, using spatial information from hand proprioception.
Hand-guided hand gestures
When the eyes and hands are used for core exercises, the eye generally directs hand gestures to the target. Furthermore, the eye provides the initial information of the object, including its size, shape, and perhaps the sites used to determine which fingertip style needs to be used to perform the task.
For successive tasks, eye-gaze movements occur during important kinematic events such as changing the direction of movement or when passing through perceived landmarks. It is related to the nature of the task livelihood and its relation to the planning of the hand movement, and the error between the motor signal output and the consequences felt by the eye and other senses that can be used for corrective movement. The eye has a tendency to "fix" on the target to refresh its shape memory, or to update shape or geometry changes in drawing tasks involving visual input links and hand gestures to produce copies of what is felt. In high-accuracy tasks, when acting in larger quantities of visual stimuli, the time required to plan and execute movements increases linearly according to Fitts Law.
Hand-guided saccades
Humans have shown the ability to direct eye movement toward the hands without sight, using a sense of proprioception, with only minor faults associated with internal knowledge of the position of the limbs. Proven proprioception of limbs, both in active and passive movements, produces saccade eye overshoots when the hand is being used to guide eye movement. This overshoot results from saccade eye control rather than previous hand movements in the experiment. This implies that limb-based proprioception is capable of being converted into eye motor coordinates to guide the eye saccade, which allows for saccade guidance by hand and foot.
Maps Eye-hand coordination
Nervous mechanism
Nerve control of eye-hand coordination is complex because it involves every part of the central nervous system involved in vision: eye movement, touch, and hand control. These include the eye itself, the cerebral cortex, subcortical structures (such as cerebellum, basal ganglia, and brainstem), spinal cord, and peripheral nervous system. Other areas involved in the most intensely studied eye-hand coordination are the frontal and parietal cortex areas for control of eye saccade and hand coverage. These two areas are believed to play a key role in eye-hand coordination and movement planning during the task.
The more specific area, the parieto occipital junction, is believed to be involved in the transformation of peripheral visual input to reach by hand, as found through fMRI. This region in particular has subdivisions for reach, grasp, and saccade. In addition to the parieto-occipital junction, the posterior parietal cortex is believed to play an important role in linking proprioception and transformation of motor sensory inputs to plan and control movement related to visual input.
Many of these areas, in addition to controlling the saccade or range, also show the eye position signals required to convert visual signals into motor commands. In addition, some areas involved in the range, such as the medial intraparietal cortex, show remission-centered responses during eye movements in monkeys and humans. However, when a single neuron is recorded in this area, the coverage area often shows some responses related to saccade and the saccade area often shows some related responses. This can help hand-eye coordination or guidance on the ability of cells to wire together as they are more commonly used.
Clinical syndrome
Many disorders, diseases, and disorders have been found to result in hand-eye coordination disorders, due to damage to the brain itself, brain degeneration due to illness or aging, or inability to coordinate the senses completely.
Aging
Impaired hand-eye coordination has been shown in older adults, especially during high-speed and precise movements. This has been attributed to the general degeneration of the cortex, resulting in the loss of the ability to calculate visual input and relate it to hand movements. However, while older adults tend to take more time for these tasks, they can still be as accurate as adults, but only when extra time is taken.
BÃÆ'¡lint's syndrome
BÃÆ'¡lint syndrome is characterized by a lack of hand-eye coordination and has been shown to occur in isolation for optic ataxia. This is the rare infrequent psychological condition of bilateral damage to the superior parieto-occipital cortex. One of the most common causes is of a stroke, but tumors, trauma, and Alzheimer's disease can also cause damage. Balint syndrome patients can suffer from 3 major components: optic apraxia, optic ataxia, and simultaneous diagnosis. Simultanagnosia is when the patient has difficulty observing more than one object at a time. There are three different approaches to rehabilitation. The first approach is adaptive or functional approach. It involves functional tasks that use the strength and ability of the patient. The second approach is the remedial approach and involves restoration of the damaged central nervous system by practicing perceptual skills. The final approach is a multicontext approach and this approach involves putting into practice targeted strategies in various environments with various tasks and motion demands, along with self-awareness tasks.
Apraxia optics
Optical apraxia is a condition resulting from a person's total inability to coordinate eye and hand movements. Although similar to optical ataxia, the effect is more severe and does not always come from brain damage, but may arise from genetic defects or tissue degeneration.
Optical ataxia
Optical ataxia or visuomotor ataxia is a clinical problem associated with damage to the occipital-parietal cortex in humans, resulting in a lack of coordination between the eyes and hands. This can affect one or both hands and may be present in the visual field or the entire visual field. Optical ataxia is often regarded as a high-level hand-eye coordination disorder resulting from a cascade of failures in sensory and motor transformations in the posterior parietal cortex. Visual perception, naming, and reading are still possible, but visual information can not direct motor hand movement. Optical ataxia is often confused with Balint syndrome, but recent research has shown that optic ataxia can occur independently of Balint syndrome. Optic ataxia patients usually have problems to achieve visual objects on the world side opposite to the side of brain damage. Often this problem is relative to the direction of the current view, and appears to be mapped together with a change of direction of view. Some patients with damage to the parietal cortex show "magnetic range": a problem in which the range appears to be drawn in the direction of the gaze, even when it deviates from the desired object of the grasp.
Parkinson's disease
Adults with Parkinson's disease have been observed to show the same disorders as normal aging, only to a more extreme degree, in addition to loss of motor function control as per normal symptoms of the disease. This is a movement disorder and occurs when there is degeneration of dopaminergic neurons that connect the nigra substansia with the caudate nucleus. The main symptoms of the patient include muscle stiffness, movement slowness, resting tremor, and postural instability. The ability to plan and learn from experience has been shown to allow adults with Parkinson's to increase in time, but only in those conditions where they use drugs to combat the effects of Parkinson's. Some patients are given L-DOPA, which is a precursor to dopamine. It is able to cross the blood-brain barrier and then taken by dopaminergic neurons and then converted to dopamine.
See also
- Kinematics
- Motor control
- Neuroplasticity
- The human senses
- Compensation tracking tasks
- Cheiroscope
References
Further reading
Source of the article : Wikipedia
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