What is the dorsal stream responsible 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 does the dorsal stream process?
The dorsal stream (or, “where pathway”) leads to the parietal lobe, which is involved with processing the object’s spatial location relative to the viewer and with speech repetition.
How do the two visual streams interact with each other?
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 are M and P cells?
M cells respond transiently to the presentation of visual stimuli, while P cells respond in a sustained fashion. Moreover, P ganglion cells can transmit information about color, whereas M cells cannot. M and P ganglion cells terminate in different layers of the lateral geniculate nucleus (Figure 12.14B).
What does paraventricular nucleus produce?
The hypothalamic paraventricular nucleus (PVN) is the major region in the brain of CRF-containing cell bodies and through axonal projections to the capillaries of the median eminence can secrete CRF directly into the portal system where it acts at the pituitary to regulate ACTH secretion into the circulation.
What are blobs and Interblobs?
Blobs are sections of the visual cortex where groups of neurons that are sensitive to color assemble in cylindrical shapes. Interblobs are areas between blobs which receive the same input, but are sensitive to orientation instead of color.
What is a Hypercolumn?
A cortical column, also called hypercolumn, macrocolumn, functional column or sometimes cortical module, is a group of neurons in the cortex of the brain that can be successively penetrated by a probe inserted perpendicularly to the cortical surface, and which have nearly identical receptive fields.
What is the meaning of blobs?
noun. a globule of liquid; bubble. a small lump, drop, splotch, or daub: A blob of paint marred the surface. an object, especially a large one, having no distinct shape or definition: a blob on the horizon.
What is the striate cortex?
The striate cortex is the part of the visual cortex that is involved in processing visual information. The striate cortex is the first cortical visual area that receives input from the lateral geniculate nucleus in the thalamus.
Where is V4 in the brain?
V4 is the third cortical area in the ventral stream, receiving strong feedforward input from V2 and sending strong connections to the PIT. It also receives direct input from V1, especially for central space. In addition, it has weaker connections to V5 and dorsal prelunate gyrus (DP).
Why is it called the striate cortex?
The primary visual cortex is sometimes also called the striate cortex due to the presence of a large band of myelinated axons that runs along the eges of the calcarine sulcus.
What is Inferotemporal cortex?
cortex covering the inferior side of the temporal lobe, the inferior temporal cortex is thought to be especially important to visual processing and visual object recognition.
Where is the fusiform face area?
temporal lobe
What does the middle temporal gyrus do?
The middle temporal gyrus and inferior temporal gyrus are involved in a number of cognitive processes, including semantic memory processing, language processes (middle temporal gyrus), visual perception (inferior temporal gyrus), and integrating information from different senses.
What does the inferior temporal lobe do?
The inferior temporal (IT) cortex plays a critically important role for the visual recognition of objects. The visual recognition system in the IT cortex is distributed in multiple areas, including area TE and the rhinal cortex.
Where is Wernicke’s area?
The Wernicke area is located in the posterior third of the upper temporal convolution of the left hemisphere of the brain.
Where is Broca’s area?
frontal cortex
What is the visual area?
Introduction. The visual cortex is the primary cortical region of the brain that receives, integrates, and processes visual information relayed from the retinas. It is in the occipital lobe of the primary cerebral cortex, which is in the most posterior region of the brain.
Which brain area is the smallest?
The midbrain is, in human beings, the smallest part of the brain. It connects the hindbrain to the forebrain, and contains several pathways important to hearing and vision.
Is visual processing disorder dyslexia?
Individuals with dyslexia struggle to connect letters to sounds; those with visual processing disorder struggle to understand visual information, whether letters, shapes, or objects.
What happens if the visual association area is damaged?
Damage to posterior association areas also sometimes including parts of the unimodal association areas can result in agnosia, a Greek word meaning “not knowing.” Lesions of the visual posterior association area can result in the inability to recognize familiar faces or learn new faces while at the same time leave other …
What is the function of association area?
The association areas integrate information from different receptors or sensory areas and relate the information to past experiences. Then the brain makes a decision and sends nerve impulses to the motor areas to elicit responses.
What is the purpose of association areas?
parts of the cerebral cortex that receive inputs from multiple areas; association areas integrate incoming sensory information, and also form connections between sensory and motor areas.
What happens if the primary visual cortex is damaged?
In a nutshell: Even if the primary visual cortex is damaged — causing blindness — the pathway that transmits visual information from the retina is not completely destroyed. If the V1 is damaged, conscious vision is lost in the area of the visual field that corresponds to the damage.