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Occipital lobe: anatomy and function

Occipital lobe: anatomy and function

The two occipital lobes are the smallest of four lobes paired in the human cerebral cortex. Located in the most posterior part of the skull, the occipital lobes are part of the anterior brain.

The occipital lobes rest on the cerebellum store, the dura separates the brain from the cerebellum. Both lobes are structurally isolated in their respective cerebral hemispheres by the separation of the cerebral fissure. On the front edge there are several occipital lateral convolutions, which are separated by the lateral occipital groove.

Occipital lobe functions

One of the most important parts of this lobe is the primary visual cortex, a region of the brain that receives images from the eye's retina. This is where the mind interprets color and other important aspects of vision.

The occipital lobe contains different areas related to visual communication. In one of the areas it is where the visual images of the language are received (the zone of visual reception) and in the other it is where it is interpreted (area of ​​visual association). It is of critical importance for reading and reading comprehension. For example, words from another language can be seen, but if the language is not understood, only the visual reception area will be used.

Initially the researchers thought that the occipital lobe controlled only visual functions. But in recent years it has been discovered that some parts of this lobe receive contributions from other regions of the brain. Specifically, a region of the brain called the dorsomedial current It receives input from both brain regions related to vision, and from other areas that are not related to visual processing. This suggests that the occipital lobe can perform additional functions, or that researchers have not identified all regions of the brain associated with visual processing.

Although it is known that the occipital lobe is dedicated to vision, this process is very complex, and includes a number of separate functions. They include:

  • General visual mapping, which helps both spatial reasoning and visual memory. Most visual processes involve some type of memory, since the exploration of the visual field requires that you remember what was seen a second ago.
  • The determination of the properties of the colors of the objects in the visual field.
  • The evaluation of distance, size and depth.
  • The identification of visual stimuli, particularly faces and familiar objects.
  • The transmission of visual information to other regions of the brain, so that the brain lobes can encode memories, assign meaning, linguistic responses and thus continuously respond to information from the world around us.
  • Receive primary visual data from the perception sensors in the retina of the eyes.

Occipital Lobe Injuries

The occipital lobes are the center of our visual perception system. These lobes are not particularly vulnerable to injury due to their location in the back of the brain, although any significant brain trauma could cause subtle changes in our perceptual-visual system, such as visual field defects and scotomas (a zone of partial, temporary or permanent blindness in the eye).

The occipital lobe is also involved in visuospatial processing and movement discrimination. Damage to one side of the right occipital lobe causes loss of vision in exactly the same "cut field" in both eyes.

Occipital lobe disorders can cause visual hallucinations and illusions. Visual hallucinations (visual images without external stimuli) can be caused by lesions in the occipital region or convulsions of the temporal lobe. Visual illusions (distorted perception) can take the form of objects that appear larger or smaller than they really are, objects that lack color or have an abnormal coloration.

Finally, lesions in the area of ​​parietal-temporal-occipite associationl They can cause word blindness with writing problems.

References

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