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 the ventral stream responsible for?
a pathway that carries visual information from the primary visual cortex to the temporal lobe . According to one widely-accepted hypothesis, the ventral stream (so named because of the path it takes along the ventral side of the brain) carries information related to object form and recognition.
What information does the dorsal stream process?
Dorsal stream processes compute information about the absolute size of objects and the properties of objects in egocentric space .
What does damage to the dorsal stream cause?
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.
Where does the dorsal stream terminate?
The dorsal stream (or, “how pathway”) terminates in the parietal lobe and is involved with processing the object’s spatial location relevant to the viewer, in order to program behaviour.
What happens if the ventral stream is damaged?
Patients with damage to the ventral stream are typically unable to perceive the size, shape, and orientation of objects . Remarkably, however, some of these patients continue to show normal preshaping and rotation of the hand when they reach out to grasp the very objects whose forms they fail to see.
What are the function of ventral and dorsal stream?
The ventral stream is likely not contributing toward object vision alone but is involved in the processing of a number of visual features; the ventral stream is not solely responsible for object recognition; the dorsal stream is responsible for spatial vision as well as for spatial attention , and is responsible for ...
Where is the dorsal stream located?
Dorsal stream
Also known as the parietal stream, the “where” stream, or the “how” stream, this pathway stretches from the primary visual cortex (V1) in the occipital lobe forward into the parietal lobe .
What is the difference between ventral and dorsal stream?
The ventral stream (or “vision-for-perception” pathway) is believed to mainly subserve recognition and discrimination of visual shapes and objects, whereas the dorsal stream (or “vision-for-action” pathway) has been primarily associated with visually guided reaching and grasping based on the moment-to-moment analysis ...
What is form agnosia?
Visual form agnosia is a severe disorder of visual recognition resulting from extrastriate lesions in occipital and temporal cortex . Despite preserved visual acuity and minor visual field defects, patients with visual form agnosia are severely impaired in shape and form discrimination.
What is an example of a patient’s experience of agnosia?
This condition can also be described by only seeing one object at a time. An example is having two cups in your visual field and only being able to see one at a time . Impaired ability to recognize or identify objects by touch alone.
What is visual agnosia in dementia?
General Discussion. Primary visual agnosia is a rare neurological disorder characterized by the total or partial loss of the ability to recognize and identify familiar objects and/or people by sight . This occurs without loss of the ability to actually see the object or person.
What is Balint’s syndrome?
Balint syndrome sometimes referred to as Balint-Holmes syndrome, is described as a triad of optic ataxia, oculomotor apraxia, and simultagnosia. It is a rare and disabling condition usually seen with bilateral parietal lobe lesions .
What is dorsal pathway?
Definition. The dorsal visual pathway is a functional stream originating in primary visual cortex and terminating in the superior parietal lobule that is responsible for the localization of objects in space and for action-oriented behaviors that depend on the perception of space.
What is dorsal and ventral side?
In general, ventral refers to the front of the body, and dorsal refers to the back . These terms are also known as anterior and posterior, respectively. ... Similarly, for the feet, the dorsal side is the top of the foot, or the area facing upwards when standing upright.
What is the dorsomedial stream?
The dorsomedial stream uses visual motion information to continuously monitor the spatial location of objects while we are looking and/or moving around, to allow skilled reaching for and grasping of the objects in structured, dynamically changing environments.
