Cerebral hemisphere

The cerebral hemisphere refers to each of the two structures that make up the largest part of the brain. They are inverse of each other, but not inversely symmetrical: they are asymmetrical, like the two sides of the individual's face. A deep sagittal fissure in the midline (the interhemispheric or longitudinal cerebral fissure) divides them into the right and left hemispheres. This fissure contains a fold of the dura mater and the anterior cerebral arteries. In the deepest part of the fissure, the corpus callosum (a commissure formed by a conglomeration of white nerve fibers), connects both hemispheres by crossing the midline and transferring information from one side to the other.

Ways

The white matter of the cerebral hemispheres is found below the cortex and is made up of myelinated axons. The nerve fibers that form the white matter of the cerebral hemisphere are classified as:

1. Comisural fibersthey connect and transmit nervous impulses from one hemisphere to the other; they cross the middle line, forming a thick, compact structure (silent body).
2. Association fibres, they operate in the circles of the same hemisphere: they communicate neurons from a part of the bark of a hemisphere with those from another part of the same hemisphere.
3. Projection fibersthey transmit the impulses from the brain to the spinal cord (and vice versa); they leave the bark to lower centers; they leave almost all areas of the cortex and converge towards the inner capsule. This sheet of white substance separates the basal nuclei from the thalamus.

Functions

Front lobe Temporary lobe Parietal lobe Occipital lobe
Side vision of the cerebral lobes.

Functional differences between hemispheres are minimal and differences in function have only been found in a few areas and these are not found in all people. The part of the difference in competences between the two cerebral hemispheres seems to be exclusive to the human being. It has been said that our brains have become specialized in this way, because language and logic require more orderly and sophisticated thought processes than spatial orientation, for example.

The two halves of the brain are complementary; in most adults, the speech centers are located on the left side. However, around 15% of left-handers and 2% of right-handed users have speech centers in both parts of the brain.

Some left-handers develop speech in the left hemisphere only; less than half have it on the right side. Even though the right side of the brain primarily controls the left side of the body, and the left side of the brain largely controls the right side of the body, being ambidextrous indicates that the two halves of the brain have not come to be in harmony. fully specialized as they are in right-handed individuals.

In young children, each side of the brain has the potential for speech and language. A lesion on the left side in the first years of life results in the development of the language faculty in the right side of the brain. Mastery of speech and probably of other faculties as well is firmly established in one hemisphere by the age of ten and cannot be transferred to the other hemisphere thereafter.

The brain processes sensory information, controls and coordinates movement, behavior, and homeostatic bodily functions such as heartbeat, blood pressure, fluid balance, and body temperature.

The brain is responsible for cognition, emotions, creativity, memory, and learning.

The processing and storage capacity of a standard human brain surpasses even the best computers today.

Until not many years ago, it was thought that the brain had exclusive areas of operation until, through imaging, it was possible to determine that when a function is performed, the brain acts in a similar way to a symphony orchestra, interacting several areas with each other.. In addition, it was possible to establish that when a non-specialized brain area is damaged, another area can perform a partial replacement of its functions.

There are many theories about how each hemisphere affects how a person thinks. One divides thinkers into two camps: visual simultaneous and linear sequential.

According to this hypothesis, most right-handed people (who use their left hemisphere more) process information in a linear sequential manner in which a schema must complete its processing before it can be processed. I can start with the next one.

On the other hand, says the hypothesis, individuals whose right hemisphere is dominant process information with visual simultaneity, a way in which various schemes are processed simultaneously.

• An example to understand it is to imagine that there are a thousand popcorn, one of which is pink. An individual linear sequential You will look one by one the pieces until you find the pink color, while an individual visual simultaneity It will extend all, visually look at the popcorn set and see that one is pink.

A side effect of these modes of processing information is that left-brained individuals need to complete one task before beginning the next. Right-sided individuals, by contrast, take comfort in multitasking, for which they are more adept. This makes them appear to the majority, left cerebral side, as if they did not finish anything. Alternatively, visual simultaneity individuals have excellent multitasking skills, which may be at the root of anecdotes suggesting they are more creative.

Most people process information using analysis, which is the method of solving a problem by breaking it down into pieces and analyzing them one by one. In contrast, visual simultaneity individuals process information using "synthesis", where a problem is solved as a whole, attempting to use a relational method to solve the problem.

Finally, it's not all or nothing. The processing style operates as a continuum where at times and for some tasks people are more visually simultaneous but for others they are more linear sequential, and this can change as time goes on. over time according to the mood and adaptation of the individual.

This can best be explained by computing. A computer processor can only process one piece of information at a time, regardless of how many tasks it is performing. But a computer with multiple processors doing the same thing at the same speed is faster, which represents the case of the right-lateral hemisphere-dominant individual.

Left hemisphere

The left hemisphere is the motor part capable of recognizing groups of letters forming words, and groups of words forming sentences, both in terms of speaking, writing, the number system, mathematics and logic, as well as to the faculties necessary to transform a set of information into words, gestures and thoughts. John Hughlings Jackson, a British neurologist, already in 1878 described the left hemisphere as the center of the faculty of expression. Depending on its severity, an embolism affecting this structure can cause functional loss, functional loss of speech, and affect motor skills on the right side of the body.

According to psycholinguistic theory, the process of building a sentence is governed by a certain number of interrelated ideas, but the mechanism that allows the mind to group words to form grammatical sentences is not fully deciphered. The hemisphere stores concepts that it later translates into words (amor, amour, amore, love, liebe) better than a textual memory. The brain understands ideas, concepts and stores them in a non-verbal language, which it then translates into a language or language learned by the individual through culture.

Intelligence tests that investigate vocabulary, verbal comprehension, memory, and mental arithmetic calculation detect the origin of activity in the left hemisphere.

The left hemisphere specializes in articulated language, motor control of the fundus articulator apparatus, logical information handling, proportional thinking, one-on-one series of information processing, mathematical information handling, verbal memory, grammatical logical aspects of language, syntax organization, phonetic discrimination, focused attention, time control, planning, execution, decision-making and long-term memory.

IQ tests mainly measure the activity of this hemisphere. Many of the activities attributed to the conscious are its own. It governs mainly the right part of the body. It processes information using analysis, which is the method of solving a problem by breaking it down into pieces and examining them one by one.

Right hemisphere

The right hemisphere governs as many specialized functions as the left hemisphere. Its way of preparing and processing information is different from the left hemisphere. It does not use the conventional mechanisms for the analysis of thoughts that the left hemisphere uses. It is an integrating hemisphere, within the non-verbal visuo-spatial faculties, specialized in sensations, feelings, prosody and special abilities such as visual and sound, for example artistic and musical abilities.

Conceives situations and thinking strategies in a total way. It integrates various types of information (sounds, images, smells, sensations) and transmits them as a whole. The elaboration method used by the right hemisphere is adjusted to the type of immediate response that is required in visual processes and spatial orientation. The right frontal lobe and the right temporal lobe seem to be in charge of exercising the specialized non-verbal activities of the right hemisphere. This corresponds, in many ways, to the speech control functions of the frontal lobe and temporal lobe of the left hemisphere. The other two lobes of the right hemisphere, the parietal and the occipital lobes, seem to have fewer functions.

However, as a result of the study of patients with split brains (sectioned), or with patients suffering from lesions in the left hemisphere, a small degree of speech comprehension has been detected in the right parietal lobe, which has the ability to to understand a selection of simple nouns and verbs. And conversely, the left parietal lobe appears to have certain limited spatial functions. Therefore, although the right hemisphere is undoubtedly specialized in non-verbal functions, specifically visuospatial ones, it is not easy to discern the differences between the two hemispheres.

The right hemisphere is considered, as the receptor and identifier of spatial orientation, responsible for our perception of the world in terms of color, shape and place.

John Huglings Jackson reported that a patient with a tumor on the right side of the brain could not recognize objects, places, or people. Using his faculties we are able to situate ourselves and orient ourselves; we can know which street we are walking on simply by looking at the architecture of the buildings on either side of it, that is, the shape and appearance of the facades, roofs, and entrance doors. If we are walking down the street and we recognize a face, the identification of said face is also carried out by the visual memory of the right hemisphere. The name that corresponds to the person who has said known face is provided, instead, by the left hemisphere.

Many of the activities attributed to the unconscious are its own. It processes the information mainly using the synthesis method, composing or forming the information from its elements, to a set.

It also controls the left side of the human body. In this case, an embolism can cause functional loss or affect motor skills on the left side of the body. It can also cause disturbance of normal attention to the left side of the body and its surroundings even with the other.