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 makes up the dorsal stream?
The dorsal stream, or where pathway, describes a hierarchy of areas that support visually-guided behaviors and localizing objects in space . It involves two main groups of areas, which receive separate, strong projections from V1. The lateral group in the dorsal stream consists of areas MT, MTc, MST, and FST.
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 ...
What is dorsal language stream?
C: The dorsal language stream (SLF and AF) is the most superficial long association fiber tract in the cerebrum . ... The middle fiber pathway in the suprasylvian area is the SLF II, which connects the angular gyrus or middle portion of the occipital lobe to the middle frontal gyrus.
Where is the dorsal visual pathway?
Dorsal visual pathway: this pathway extends from the primary visual cortex (V1) in the occipital lobe to the parietal lobe . The dorsal pathway is subdivided by the intraparietal sulcus (IPS) into several main sectors including the superior parietal lobule, inferior parietal lobule, and the supramarginal gyrus.
What does damage to dorsal stream do?
If either the dorsal or ventral stream is damaged, this leads to dissociable behavioural deficits . For example, patients with optic ataxia have lesions in parietal areas, which are part of the dorsal stream. They have deficits in reaching and grasping objects, but are able to visually discriminate different objects.
What is the role of the dorsal stream?
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 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 the difference between the ventral and dorsal pathways?
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 dorsal vision?
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.
Is Wernicke’s area only on the left?
Structure. Wernicke’s area is traditionally viewed as being located in the posterior section of the superior temporal gyrus (STG), usually in the left cerebral hemisphere.
What happens when 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 does dorsal and ventral mean in anatomy?
On a human body, dorsal (i.e., posterior) refers to the back portion of the body , whereas ventral (i.e., anterior) refers to the front part of the body. ... For example, the stomach is ventral to the spinal cord, which means that the stomach is located in front of the spinal cord.
What are the two visual streams do?
The ventral stream, passing from primary visual cortex (V1) through to inferior parts of the temporal lobe, is considered to mediate the transformation of the contents of the visual signal into the mental furniture that guides memory, recognition and conscious perception .
What is the visual pathway?
The visual pathway consists of the retina, optic nerves, optic chiasm, optic tracts, lateral geniculate bodies, optic radiations, and visual cortex . The pathway is, effectively, part of the central nervous system because the retinae have their embryological origins in extensions of the diencephalon.
How does the ventral stream work?
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.
