Occipital lobe
Occipital lobe | |
---|---|
Details | |
Part of | Cerebrum |
Artery | Posterior cerebral artery |
Identifiers | |
Latin | lobus occipitalis |
MeSH | D009778 |
NeuroNames | 140 |
NeuroLex ID | birnlex_1136 |
TA98 | A14.1.09.132 |
TA2 | 5480 |
FMA | 67325 |
Anatomical terms of neuroanatomy |
The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin ob, 'behind', and caput, 'head'.
The occipital lobe is the
Structure
The two occipital lobes are the smallest of four paired lobes in the human brain. Located in the rearmost portion of the skull, the occipital lobes are part of the posterior cerebrum. The lobes of the brain are named from the overlying bone and the occipital bone overlies the occipital lobes.
The lobes rest on the
The occipital aspects along the inside face of each hemisphere are divided by the calcarine sulcus. Above the medial, Y-shaped sulcus lies the cuneus, and the area below the sulcus is the lingual gyrus.
Damage to the primary visual areas of the occipital lobe can cause partial or complete blindness.[2]
Function
The occipital lobe is divided into several functional visual areas. Each visual area contains a full map of the visual world. Although there are no anatomical markers distinguishing these areas (except for the prominent striations in the
The first functional area is the
The ventral stream is known for processing the "what" in vision, while the dorsal stream handles the "where/how". This is because the ventral stream provides important information for the identification of stimuli that are stored in memory. With this information in memory, the dorsal stream is able to focus on motor actions in response to the outside stimuli.
Although numerous studies have shown that the two systems are independent and structured separately from another, there is also evidence that both are essential for successful perception, especially as the stimuli take on more complex forms. For example, a case study using fMRI was done on shape and location. The first procedure consisted of location tasks. The second procedure was in a lit-room where participants were shown stimuli on a screen for 600 ms. They found that the two pathways play a role in shape perception even though location processing continues to lie within the dorsal stream.[3]
The dorsomedial (DM) is not as thoroughly studied. However, there is some evidence that suggests that this stream interacts with other visual areas. A case study on monkeys revealed that information from V1 and V2 areas make up half the inputs in the DM. The remaining inputs are from multiple sources that have to do with any sort of visual processing [4]
A significant functional aspect of the occipital lobe is that it contains the primary visual cortex.[citation needed]
Clinical significance
If one occipital lobe is damaged, the result can be
Epilepsy
Recent studies have shown that specific neurological findings have affected idiopathic occipital lobe
Additional images
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Base of brain.
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Drawing to illustrate the relations of the brain to the skull.
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Occipital lobe in blue
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Occipital lobe
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Occipital lobe
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Ventricles of brain and basal ganglia. Superior view. Horizontal section. Deep dissection
See also
- Alpha wave
- Lobes of the brain
- List of regions in the human brain
- Lunate sulcus
- Visual evoked potential
- Vertical occipital fasciculus
- Visual snow syndrome
References
- ^ "SparkNotes: Brain Anatomy: Parietal and Occipital Lobes". Archived from the original on 31 December 2007. Retrieved 27 February 2008.
- ^ Schacter, D. L., Gilbert, D. L. & Wegner, D. M. (2009). Psychology. (2nd ed.). New York: Worth Publishers.
- ^ Valyear, Culham, Sharif, Westwood, & Goodale, 2006.
- ^ Valyear et al., 2006.
- ISBN 978-0-205-64524-4.
- S2CID 23702191.
- PMID 10986003.
- ^ PMID 23027097.