He Left cerebral hemisphere Is the left brain region. Anatomically it is identical to the right hemisphere, but it keeps a number of differences in both its functioning and in the activities it performs.
The left hemisphere is characterized by a much more analytical, detailed and arithmetical functioning than the right hemisphere . At the same time, there is now a high consensus in naming the left hemisphere as the linguistic hemisphere of the brain.
The term Cerebral hemisphere Designates each of the two structures that make up the largest region of the brain.
He brain Can be divided into two large regions: the left hemisphere and the right hemisphere. Both structures are connected and work together to provide an integral functioning of the brain.
Anatomical properties of the left hemisphere
The left hemisphere constitutes the left region of the Encephalon . It is an inverse portion of the right hemisphere, but not inversely symmetric. As with the rest of the body, the left side of the brain is asymmetrical with respect to the right side.
The left hemisphere is separated from the right hemisphere by a deep sagittal fissure located in the midline of the brain. This fissure known as interhemispheric or longitudinal cerebral cleft allows the establishment of anatomical differentiation between the two hemispheres of the brain.
The interhemispheric fissure contains a fold of the dura and the anterior cerebral arteries. In the deepest region of the fissure is the hard body , A commissure formed by a conglomerate of white nerve fibers.
The function of the corpus callosum is to connect both hemispheres across the midline and transfer information from one side to the other. In this way, the left hemisphere works together with the right hemisphere, thus providing an integral and joint brain activity.
Like the right hemisphere, the left hemisphere can be divided into four large Brain lobes : he Frontal lobe Located on the front of the skull, the occipital lobe Which is in the posterior region (above the nape of the neck), the Parietal lobe Which is located in the upper region of the brain, and the temporal lobe that lies in the medial region.
characteristics
The two cerebral hemispheres are characterized by being very similar to each other. Anatomically they are not symmetrical but very similar.
In fact, each of the hemispheres comprises a proportional part of the structures of the brain. For example, the frontal lobe divides into two parallel regions (one is located in the right hemisphere and another in the left hemisphere).
Thus, when referring to cerebral hemispheres, no reference is made to distinct brain structures, each of which encompasses a portion of the same regions of the brain.
Nevertheless, the left hemisphere is characterized by presenting a series of unique attributes. That is, it presents a series of characteristics different from those of the right hemisphere.
In this sense, the left hemisphere is interpreted as the linguistic cerebral hemisphere, since it is the portion of the brain that plays a more important role in the development of this type of activities.
The main characteristics of the left cerebral hemisphere are:
1- Verbal
The left hemisphere uses words to name, describe, and define the inner and outer elements.
Unlike Right cerebral hemisphere , The left hemisphere adopts a leading role in the performance of activities related to language and verbal memory.
2- Symbolic
The left hemisphere uses, apart from language, symbols for the representation of external objects.
For example, the + sign represents the addition process and the symbol - the subtraction process. The association between these symbols and their meanings are activities performed by the left cerebral hemisphere.
3- Analytical
The left cerebral hemisphere presents an analytical functioning of things. Study the elements step by step and part by piece. It uses rational inductive methods, and allows the development of analytical and descriptive thinking of people.
4 - Retailer
The left hemisphere also plays a leading role in the detailed and objective analysis of the elements. It allows specific observations and develops concrete thinking.
5- Abstract
The operation of the left hemisphere is characterized by taking a small piece of information and using it to represent the whole.
As it is represented in the other characteristics, it adopts an analytical character that allows to go from the most concrete to the most general.
6- Temporal
The left hemisphere is responsible for following the passage of time. He arranges things into temporal and situational sequences. It analyzes the elements beginning at the beginning and adopts an organized and sequential operation.
7- Rational
First and foremost, the left cerebral hemisphere is characterized by a rational thought about things. It allows to abstract conclusions based on the reason and the data specifically examined.
8- Digital
The left hemisphere also uses the numbers. For example, it takes an active role in counting.
9- Logical
The conclusions drawn by the left hemisphere are always based on logic: one thing follows another in a logical order.
For example, mathematical problems or reasoned arguments are activities that define well the functioning of this cerebral hemisphere.
10- Linear
Finally, the left cerebral hemisphere is characterized by thinking in terms of chained ideas. The elaboration of one thought follows another, so it usually leads to convergent conclusions.
Functions
The left cerebral hemisphere forms the motor region that is able to recognize groups of letters forming words, as well as groups of words forming phrases.
In this way, it performs activities related to speech, writing, numeracy, mathematics and logic, which is why it is named as the verbal hemisphere.
On the other hand, it is responsible for developing the necessary powers to transform a set of information into words, gestures and thoughts. In this regard, the neurologist Hughlins Jackson described the left hemisphere as the center of the faculty of expression.
The left hemisphere is responsible for storing concepts that are later translated into words. That is, the left hemisphere does not function as a textual memory, since it allows to bring meaning to the elements of expression.
The left hemisphere understands ideas and concepts, stores them in a non-verbal language, and then translates those elements into a given language or language.
More specifically, the left hemisphere specializes in articulate language, motor control of articulating fund apparatus, management of logical information, proportional thinking, serial information processing, and mathematical information management.
Likewise, it plays a major role in verbal memory, grammatical aspects of language, organization of syntax, phonetic discrimination, focused attention, planning, decision making, time control, execution and memory Long term, among others.
Evaluation of the left hemisphere
Nervous system and brain
The functioning of the left cerebral hemisphere is evaluated by intelligence tests.
In fact, intellectual performance tests primarily evaluate the functioning of this hemisphere and less examine the performance of the right hemisphere.
Specifically, intelligence tests that investigate vocabulary, verbal comprehension, memory, and mental arithmetic allow us to examine the performance of the left cerebral hemisphere.
Relationship to right hemisphere
Although the left cerebral hemisphere has a number of specific functions, this does not mean that such activities are performed by this part of the brain alone.
In fact, both hemispheres of the brain can participate together in the performance of all brain activities. However, in some the left hemisphere becomes more prominent and in others the right hemisphere.
In this sense, the functional differences between hemispheres are minimal, and it is only in certain brain areas that we have been able to connote distinctions about functioning.
The differences between hemispheres seem to be an exclusive faculty of human beings. Several authors have pointed out that such differentiation exists since language and logic (left hemisphere) require more orderly and sophisticated thought processes than for example spatial orientation (right hemisphere).
The two hemispheres of the brain are complementary in most people. Speech is an activity mainly regulated by the left hemisphere, however, about 15% of left-handed individuals and 2% of those who preferentially use the right hand, have speech centers in both parts of the brain.
Also, during the first years of life people have the potential to develop the center of speech in both hemispheres. In this way, a lesion in the left hemisphere in young people results in the development of the language faculty in the right hemisphere.
Finally, emotional processes and the generation of emotions are activities that are performed equally in both cerebral hemispheres, since they are produced by the limbic system of the brain.
References
- Anderson, B.; Rutledge, V. (1996). "Age and hemisphere effects on dendritic structure". 119: 1983-1990 .
- Boller, and Grafman, J (2000). Handbook of Neuropsychology. Ed. Elsevier.
- Goldberg, E (2002). The executive brain: frontal lobes and civilized mind Critical, cop. 2002.
- Jódar, M (Ed) et al (2013). Neuropsychology. Barcelona, UOC Editorial.
- Snell, Richard S. (2009). Clinical Neuroanatomy (Clinical Neuroanatomy for Medical Students (Snell)). Hagerstwon, MD: Lippincott Williams & Wilkins. P. 262.