RIGHT CEREBRAL HEMISPHERE: CHARACTERISTICS AND FUNCTIONS - NEUROPSYCHOLOGY - 2024

The right cerebral hemisphere is one of the two structures that makes up the largest region of the brain. Specifically, as its name suggests, it encompasses the right portion of the brain.

The right cerebral hemisphere encompasses a large number of cerebral structures referring to the cerebral cortex, and is correctly delimited from the left cerebral hemisphere through an interhemispheric fissure.

Thus, the right hemisphere encompasses a very broad brain structure that is easily identifiable through neuroimaging. It is characterized by having a series of properties in its functioning that distinguish it from the left cerebral hemisphere.

Multiple studies coincide in defining the right cerebral hemisphere as an integrating hemisphere that is the neural center of the non-verbal visuospatial faculties.

Likewise, it seems that the right hemisphere also plays a major role in the elaboration of sensations, feelings and spatial, visual and sound abilities. For this reason it is conceived by many authors as the artistic and creative hemisphere of the brain.

Anatomy

The right cerebral hemisphere constitutes the right and superior region of the brain. That is, it encompasses the right portion of the cerebral cortex.

It is an inverse structure to the left cerebral hemisphere, although as with the rest of the body, the right portion of the brain is not inversely symmetrical to the left portion, although it is very similar.

-Structure of the right hemisphere

Anatomically, it is characterized by covering half of the five large lobes of the cerebral cortex. These are:

1. Frontal lobe: located in the frontal portion of the brain (on the forehead).
2. Parietal lobe: located in the upper portion of the brain.
3. Occipital lobe: located in the posterior portion of the brain (at the nape).
4. Temporal lobe: located in the medial portion of the brain.
5. Insula: small region located below the temporal lobe.

These lobes are characterized by completely covering the entire cortex of the brain. For this reason, they are not unique structures of the right hemisphere, since they are also located in the left hemisphere.

Each of the lobes are symmetrically distributed between both cerebral hemispheres, so that half of the frontal, parietal, occipital, temporal and insula lobes are in the right hemisphere and the other half in the left hemisphere.

-Division of hemispheres

The right hemisphere is correctly separated from its left analog, that is, from the left hemisphere. This division is carried out through a deep sagittal fissure in the medial line of the cortex, which is called the interhemispheric or longitudinal cerebral fissure. In the following image you can see this division, the left hemisphere being lilac or purple:

The interhemispheric fissure contains a fold of dura mater and anterior cerebral arteries. In the deepest region of the fissure the corpus callosum is located, a commissure formed by white nerve fibers that is responsible for connecting both hemispheres.

Despite encompassing a different brain structure, the right cerebral hemisphere is connected both anatomically and functionally with the left cerebral hemisphere.

The exchange of information between hemispheres is constant and both participate jointly in the performance of the vast majority of brain activities.

-Meninges

As is the case in all brain regions, the right hemisphere is characterized by being surrounded by three envelopes: the dura mater, the pia mater, and the arachnoid membrane:

-Dura mater: it is the outermost membrane of the right hemisphere, that is, the one that is closest to the skull. This layer is attached to the bony structures that are part of the skull to properly support the brain.

- Arachnoid membrane: this membrane is located on the inner side of the dura mater and acts as a bridge between the dura mater itself and the cortical regions of the hemisphere.

-Pia mater: it is the innermost membrane of the right cerebral hemisphere. This membrane is contiguous with brain matter and is attached to other lower brain structures.

characteristics

Although the brain regions encompassed by the right hemisphere are the same as those contained by the left hemisphere, both hemispheres have different functional characteristics and properties.

It is as if each structure of the cortex adopts a different function depending on the hemisphere in which it is located.

At the functional level, the right cerebral hemisphere opposes the characteristics of the left cerebral hemisphere.

While the left hemisphere is considered a verbal, analytical, arithmetic and detailed hemisphere, the right hemisphere is considered a non-verbal, musical, synthetic and holistic hemisphere.

The main characteristics of the right cerebral hemisphere are:

Non verbal

The right cerebral hemisphere (normally) does not participate in the performance of verbal activities such as speaking, language, reading or writing.

This hemisphere is considered a visuospatial structure, where the main functions performed are related to the analysis and reasoning about visual and spatial elements.

Musical

The right brain hemisphere takes a leading role in the development of activities related to music. Learning to play an instrument, for example, takes place mainly in this brain hemisphere.

Likewise, elements such as melody, rhythm or harmony are processed by the right brain hemisphere.

Synthetic

Unlike the left cerebral hemisphere, the right hemisphere does not present an analytical function, but adopts a synthetic activity.

The right hemisphere allows hypotheses and ideas to be posited in order for them to be contrasted, and the generation of thoughts does not have to always be subject to detailed analysis or truthfulness tests.

Holistic

The functioning of the right cerebral hemisphere adopts a methodological position that analyzes the elements through integrated and global methods.

The thoughts generated in the right hemisphere are not limited to the analysis of the parts that make up the elements, but allow us to adopt a broader and more generalized vision.

For this reason, the right cerebral hemisphere is a highly involved structure in artistic, creative and innovative thought processes.

Geometric-spatial

The cognitive ability that stands out most in the right hemisphere has to do with spatial and geometric abilities. The ordering of space, the generation of mental images or the geometric construction are activities carried out by this cerebral hemisphere.

Features

The right hemisphere is capable of conceiving situations and thinking strategies in an integrated way. It encompasses different types of information (images, sounds, smells, etc.) and transmits them as a whole.

Specifically, the frontal lobe and the temporal lobe of the right hemisphere are responsible for specialized non-verbal activities. In contrast, the other two lobes (the parietal and the occipital) appear to have fewer functions in the right hemisphere.

Stimulus processing

In the first place, the right hemisphere is in charge of elaborating and processing the stimuli captured by the left hemi-body of the organism. For example, the information captured by the left eye is processed by the right hemisphere, while the stimuli captured by the right eye are processed by the left hemisphere.

Visual-spatial, sound and feeling-elaboration skills

It is the center of the non-verbal visuospatial faculties, and plays an especially relevant role in the elaboration of feelings, prosody and special abilities such as visual or sound.

Regarding its functioning, the right hemisphere does not use conventional mechanisms for the analysis of thoughts, but rather acts as an integrating hemisphere.

Spatial Orientation

The right hemisphere is considered as the receiver and identifier of spatial orientation, and it is the brain structure that allows developing the perception of the world in terms of color, shape and place.

Thanks to the functions of the right hemisphere, people are able to carry out activities such as positioning themselves, orienting themselves, identifying familiar objects or structures or recognizing faces of familiar people, among many others.

Right hemisphere syndrome

Right hemisphere syndrome is a condition characterized by an alteration in the white matter of this hemisphere, or in the pathways that allow connection with the dominant hemisphere.

This alteration is called right hemisphere syndrome but it can also develop in the left hemisphere. It always occurs in the non-dominant (non-verbal) hemisphere, which is usually the right hemisphere.

In the right hemisphere syndrome there is an alteration in the hemispheric connection pathways, which constitute the commissural fibers. It can affect different cortical areas that constitute the association fibers and the projection fibers.

The specific function of the non-dominant hemisphere (usually the right) is non-verbal communication. In this way, this syndrome usually generates non-verbal communication problems, including difficulties in interpreting gestural language, facial expression and postural variations.

Children with right hemisphere syndrome usually present a picture characterized by non-verbal disabilities in learning: visual-spatial, graph-motor, and organizational difficulties in the sequencing of activities.

References

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