What is the lateral geniculate nucleus responsible for?
The lateral geniculate nucleus (LGN) belongs to the category of sensory projection nuclei of the thalamus and plays an essential role in normal visual processing.
What is the purpose of the visual processing in the dorsal lateral geniculate nucleus of the thalamus?
In the visual system, the lateral geniculate nucleus (LGN) of the dorsal thalamus is the gateway through which visual information reaches the cerebral cortex.
What is the possible effect of lesions of the visual pathway?
Lesions involving the whole optic nerve cause complete blindness on the affected side, that means damage at the right optic nerve causes complete loss of vision in the right eye. Optic neuritis involving external fibers of the optic nerve causes tunnel vision.
What effect would a lesion have in the right optic nerve?
A lesion of the right optic nerve causes a total loss of vision in the right eye; it also produces a right afferent pupil deficit.
What is the function of intralaminar nuclei?
In summary, the intralaminar nuclei, through their connections with the SC and basal ganglia, provide the striatum with short-latency access to salient stimuli important for behavioral learning and selection.
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.
What lobe of the brain is responsible for visual processing?
the occipital lobe
The paired occipital lobes are separated from each other by a cerebral fissure. The posteriormost part of the occipital lobe is known as the occipital pole. The occipital lobe is primarily responsible for visual processing. It contains the primary and association visual cortex.
What causes a simple cell to fire?
Simple cell RFs are characterized by nonoverlapping, spatially restricted subregions in which visual stimuli can either increase or decrease the firing rate of the cell, depending on contrast. Inhibition is believed to be triggered exclusively from visual stimulation of individual RF subregions.
What happens when there is a lesion in optic nerve?
What is the effect of a lesion in the left optic tract?
A lesion in one optic tract, interrupting all fibers carrying information from the contralateral visual fields, may cause homonymous hemianopia. When an injury to the left optic tract occurs, the patient will have visual difficulties (visual field cuts) in the right eye’s inner field, but in the left eye’s outer field.
What are the functions of caudate nucleus?
These deep brain structures together largely control voluntary skeletal movement. The caudate nucleus functions not only in planning the execution of movement, but also in learning, memory, reward, motivation, emotion, and romantic interaction.
What happens if your dorsal 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 are the two theories regarding the functions of the dorsal and ventral streams?
Two proposals theorize that the pathways are segregated in function: The ventral stream processes information about object identity, whereas the dorsal stream, according to one model, processes information about either object location, and according to another, is responsible in executing movements under visual control …
Which part of the brain is essential to the maintenance of attention?
The front of the brain behind the forehead is the frontal lobe. The frontal lobe is the part of the brain that helps people to organize, plan, pay attention, and make decisions.