What part of the brain is damaged in optic ataxia?

What part of the brain is damaged in optic ataxia?

Optic ataxia is a neuropsychological disorder that affects the ability to interact with objects presented in the visual modality following either unilateral or bilateral lesions of the posterior parietal cortex (PPC).

What happens when the dorsal visual stream is damaged?

Dorsal damage can cause: Trouble with spatial perception and perception of complex movement. Trouble with spatial orientation and navigation. Impaired spatial guidance of motor activities (saccadic and pursuit eye movements; reaching, grasping and pointing; walking over steps; navigating crowds and obstacles)

What causes optic ataxia?

Optic ataxia is thought to be related to a lesion in the superior parietal lobule and around the intraparietal sulcus. Isolated optic ataxia is associated with lesions in Brodmann’s areas 5, 7 , 19, 39, 37.

What happens optic ataxia?

Optic ataxia is broadly characterized by an inaccuracy of visually guided arm movements. In reaching for an object, a person with severe optic ataxia may seem to grope in the dark, extending a flattened hand hesitantly until chance contact allows the object to be retrieved by touch.

What is the dorsal stream used for?

According to one widely-accepted hypothesis, the dorsal stream (so named because of the path it takes along the dorsal side of the brain) carries information related to movement and spatial relationships between objects in the visual field. It is sometimes called the “where” pathway. See also: ventral stream.

What is ocular ataxia?

Ataxia with oculomotor apraxia is a condition characterized by problems with movement that worsen over time. The hallmark of this condition is poor coordination and balance (ataxia), which is often the first symptom.

What is dorsal stream dysfunction?

Dorsal stream dysfunction results from posterior parietal damage and is associated with cerebral palsy, periventricular white matter injury, premature birth, hydrocephalus and Williams syndrome, and similar visual difficulties are becoming apparent in children with autistic spectrum disorder.

What is a main function of the dorsal stream for perception?

They argued that the ventral stream is involved in the perception of information about objects (vision for perception) and the dorsal stream processes information to guide actions (vision for action).

What is optic apraxia?

Ocular motor apraxia (OMA) is a neurological disorder that causes problems with voluntary horizontal eye movement. Children with this condition have difficulty moving their eyes in a desired direction. In other words, their saccades (the quick, simultaneous movement of both eyes in the same direction) are abnormal.

What is meant by ataxia?

Ataxia describes poor muscle control that causes clumsy voluntary movements. It may cause difficulty with walking and balance, hand coordination, speech and swallowing, and eye movements. Ataxia usually results from damage to the part of the brain that controls muscle coordination (cerebellum) or its connections.

Which visual features are processed by the dorsal stream?

From their model, the ventral stream processes visual information for the purpose of visual perception (“vision for perception”), while the dorsal stream processes visual information for the purpose of executing movements (“vision for action”).

What causes ocular apraxia?

Causes. Cogan type ocular motor apraxia is a genetic condition for which the inheritance pattern has not been well established. It is not clear if it is inherited as an autosomal recessive genetic trait or an autosomal dominant genetic trait.