TEMPORAL LOBE: CHARACTERISTICS, ANATOMY AND FUNCTIONS - NEUROPSYCHOLOGY

The temporal lobe is a region of the brain that is part of the cerebral cortex, being the second largest structure of this, behind the frontal lobe. It is located in front of the occipital lobe, that is, approximately behind the temples. It is a brain region that plays an important role in the development of complex visual tasks, such as face recognition.

Scientifically it is interpreted as the primary cortex of hearing. Likewise, this structure performs many other functions such as the development of language, the execution of auditory memory or the processing of audio information.

Temporal lobe

It is characterized by processing information from the ears and plays an especially relevant role in establishing body balance. On the other hand, certain studies suggest that the temporal lobe could also participate in the regulation of emotions and other psychological processes such as motivation, anxiety, pleasure or anger.

Temporal lobe characteristics

Lateral view of the temporal lobe

The temporal lobe is a large brain structure that is located on the lower side of the brain. That is, in the region of the skull closest to the ears.

When speaking of the temporal lobe, it is more appropriate to do so in the plural, since there are two temporal lobes in each human brain. One of them corresponds to the right hemisphere of the brain (located in the area of the right ear) and the other to the left hemisphere (located in the area of the left ear).

The temporal lobe limits its superior region with the parietal lobe, another structure of the cerebral cortex. The division between both lobes of the brain is effected by the Silvio fissure.

On the other hand, it is in contact with the occipital lobe through its posterior region and borders the frontal lobe through its anterior region.

Frontal lobe (orange), parietal lobe (pink), occipital lobe (purple), temporal lobe (green).

One of its main characteristics is that it includes the medial temporal lobe, which presents a system of anatomically related structures that are key when developing declarative memory (the conscious recall of events and experiences).

In this sense, it constitutes a large brain structure that includes the hippocampal region, the adjacent perirrinal, entorhinal and parahippocampal cortex.

Likewise, the temporal lobe is characterized by being the lobe of the cerebral cortex that establishes a greater connection with the limbic system, which is why different psychological variables are related to this part of the brain.

Structure and functions

Lower view of the temporal lobe

The temporal lobe is a structure that makes up about a quarter of the entire cerebral cortex. In this sense, it is one of the main regions of the cerebral cortex of human beings.

Functionally, this region of the cortex is characterized by not presenting a single activity, but is involved and performs a large number of functions.

In general, the temporal lobe has three main main regions. One of them is related to the processing of auditory input, another is specialized in object recognition and the third is related to long-term storage.

Other important regions of the temporal lobe include the angular gyrus, supramarginal gyrus, Wernicke's area, the parieto-temporo-occipital association area, and the limbic system association area.

Each of these structures of the temporal lobe is characterized by carrying out certain brain activities.

Auditory cortex

Brodmann's areas 41 and 42 in the human brain. Source: Jimhutchins

The auditory cortex is located in the transverse temporal gyri of Heschl, which are buried in the floor of the Silvio fissure, that is, areas 41 and 42 of the cerebral cortex.

The area 41 of the cortex is in the anterior gyrus and extends slightly through an adjacent part of the posterior gyrus. Continuously to area 41 is area 42 and, adjacent to this, is located the part of the auditory association area (area 22).

Secondary auditory area of association

The secondary auditory and association area is in the superior temporal gyrus. This region includes Wernicke's area, a vital structure that allows the auditory decoding of language, that is, that leads to understanding.

Lesions in these secondary auditory areas cause problems in the ability to select or recognize auditory elements.

Specifically, lesions in the left association cortex can cause impaired recognition and lead to extreme deafness for words. Lesions originating in Wernicke's area, on the other hand, originate a pathology known as Wernicke's aphasia, which causes a notable reduction in the meaning of language.

Visual cortex

The visual cortex is a region of the temporal lobe that encompasses areas 20, 21, 37, and 38 of the cerebral cortex. This structure is involved in object recognition and gives rise to a process that requires a categorization of visual stimuli.

Lesions originating in this region cause difficulty in the identification and / or categorization of visual stimuli, a fact that directly affects the memory process.

The cortex of the superior temporal sulcus is often involved in the association between visual and auditory information. For example, this region allows an adequate understanding of visual and auditory stimuli that are presented simultaneously.

Medial temporal lobe

The medial temporal lobe is a broad region of the temporal lobe that includes structures such as the hippocampus, perirrinal cortex, entorhinal cortex, or parahippocampal cortex.

These brain regions and their connection with the cerebral cortex allow the development of memory in people. In other words, without the medial temporal lobe and the association of this structure with other regions of the cortex, people would have no memory.

Lesions in the left hemisphere of the medial temporal lobe are associated with difficulties in remembering verbal information, since this region of the temporal lobe is in charge of developing such memory activities.

In contrast, lesions originating in the right hemisphere of the medial temporal lobe often lead to difficulties in remembering patterns of non-verbal information.

The medial temporal lobe is one of the most affected regions in patients with dementia and / or neurodegenerative diseases. Memory loss, in general, is related to a dysfunction of this region of the temporal lobe.

Angular twist

Angular turn. Source: Gray, vectorized by Mysid, colourd by was_a_bee. / Public domain

The angular gyrus is an especially relevant area of the temporal lobe. This region allows reading-writing, since it carries out the association of visual and auditory information.

The angular gyrus is part of the auditory cortex of the temporal lobe and its function is to allow each grapheme to be assigned its corresponding phoneme.

Supramarginal gyrus

Supramarginal gyrus. Source: Gray, vectorized by Mysid, colourd by was_a_bee. / Public domain

The supramarginal gyrus is a small structure that is part of the tertiary sensory area, which is located in the temporal lobe.

This turn actively participates in the recognition of tactile stimuli. Likewise, it seems to play an important role in language development.

Parieto-temporo-occipital association area

The parietal-temporal-occipital association area is located at the junction point between the three large lobes of the cerebral cortex. That is, it is a region that unifies the parietal lobe, the temporal lobe, and the occipital lobe.

This area is basic to relate the information of the visual, auditory and somatosensory systems (of the primary and secondary areas), as well as to send the integrated information to many other areas of the brain, such as, for example, the prefrontal cortex or the limbic system.

This area of association has been related to many complex functions, such as spatial perception, directed attention, visual-motor integration, one's own body situation in space, or the relationship of auditory or visual information.

Likewise, certain studies suggest that the parieto-temporo-occipital association area could play an important role in verbal and memory aspects.

Lesions in this area of the temporal lobe often cause problems in the functioning of all these complex cognitive activities. One of the best known conditions is prosopagnosia, an alteration that generates a deficit of recognition of the faces of relatives.

Limbic system association area

Finally, the limbic association area is a region of the temporal lobe that is in charge of integrating information from the primary and secondary areas with affective and memory experiences.

That is, this region makes it possible to relate the captured stimuli with the elements that the person has in their memory and with specific emotional responses. This area would constitute a key brain region for the control of behavior and the development of motivation.

The limbic association area allows adding an affective component to all the elements that are captured through the senses, a fact that allows interacting with the world in an active way and favoring the survival of the individual.

The limbic association area is also involved in the regulation of emotions, sexual behavior and learning processes.

Lesions suffered in this region of the temporal lobe can cause alterations in the regulation of affect and severe changes in personality traits. Likewise, they can motivate the appearance of sexual alterations and the reduction of motivation.

Associated diseases

The great variety of functions that the temporal lobe performs means that lesions in this region of the cerebral cortex can motivate the appearance of very diverse pathologies.

In fact, the temporal lobe is one of the regions of the cerebral cortex that is associated with more pathologies. The main ones are: cortical deafness, hemiacusis, propasognosia, heminegligence and aphasia.

Cortical deafness

Cortical deafness is a pathology that causes a total loss of hearing. The main characteristic of this condition is that the sensory organs of hearing function properly, however, a lesion in the temporal lobe prevents the performance of auditory activities.

This means that in this pathology, auditory information correctly reaches the perceptual organs, but it is not processed by the brain. As a final result, a total loss of auditory perception is obtained.

This alteration is usually generated by the destruction of the primary and secondary auditory cortices of both cerebral hemispheres, or the nerve pathways that access them.

Hemiacusis

Hemiacusis is a condition that causes a total loss of hearing in one of the two ears.

This alteration is caused by the destruction of the primary and secondary auditory cortex of one of the two cerebral hemispheres. Hearing loss is experienced in the contralateral ear of the damaged hemisphere.

Propasognosia

Propasognosia is a disease that causes an inability to recognize the faces of any person. This condition is caused by a bilateral lesion in the temporoccipital area.

Hemineglect

Hemineglect is a serious disease that makes it difficult to orient oneself, act or respond to stimuli that occur on the opposite side of the injured hemisphere. In fact, in some cases people with hemi-intelligence are not able to recognize one of their hemibodies.

This alteration is caused by a condition in the parieto-temporo-occipital association area of one of the two cerebral hemispheres, and it usually appears in conjunction with anosognosia, that is, a lack of awareness about the disease.

Aphasias

Finally, aphasias are language disorders that originate from brain injury. Currently there are different types of aphasias, which differ from each other depending on the area of the brain damaged.

For example, injury to Wernicke's area of the temporal lobe causes Wernicke's aphasia, which involves loss of verbal compression. In contrast, anomic aphasia causes difficulty in finding the name of things and is caused by a lesion in the associative temporo-parietal-occipital area.

References

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Lapuente, R. (2010). Neuropsychology. Madrid, Plaza edition.
Kolb B and Whishaw IQ (2006): Human Neuropsychology. Pan-American Medical.
Rubin M and Safdich JE (2008). Netter- Essential Neuroanatomy. Barcelona. Elsevier Masson.

TEMPORAL LOBE: CHARACTERISTICS, ANATOMY AND FUNCTIONS - NEUROPSYCHOLOGY - 2025