The folding of the brain, and the resulting gyri and sulci, increases its surface area and enables more cerebral cortex matter to fit inside the skull. The frontal lobe is separated from the parietal lobe by a space called the central sulcus , and from the temporal lobe by the lateral sulcus.
The frontal lobe is generally where higher executive functions including emotional regulation, planning, reasoning and problem solving occur. This is why in frontotemporal dementia , personality changes are often the first signs of the disease. The most famous case of frontal lobe dysfunction is the story of railway worker Phineas Gage.
In , Gage was using a tamping iron to pack in gunpowder for blasting a tunnel through rock. While his head was slightly turned, a mistaken strike sparked an explosion that forced the rod upwards into his left eye and out through his skull. Miraculously, Gage survived, blinded in his left eye and sustaining damage to much of his left frontal lobe.
The frontal lobe also contains the primary motor cortex, the major region responsible for voluntary movement. Image: In , Phineas Gage survived an explosion that drove a tamping iron through his left frontal lobe. The parietal lobe is behind the frontal lobe, separated by the central sulcus. The sensory information that is received gets processed into meaningful units such as speech and words. As well as being able to do this, the signals can be transmitted back to the ears and can be interconnected with other parts of the cerebral cortex.
This area of the temporal lobes is therefore responsible for processing auditory information, especially important in processing the semantics in language and vision. The auditory cortex is also important for performing basic and higher functions in regard to hearing, as well as being essential for the ability to switch languages.
The temporal lobe is a significant part of the limbic system. The limbic system is a group of structures deep within the brain involved in processing and regulating emotions, memory and motivation. One of the substructures, the hippocampus, is a seahorse shaped area, essential in the formation of new memories. The hippocampus is important for early storage of long-term memories and is involved in the transition of long-term memory to an even more permanent memory.
Another substructure of the limbic system, the amygdala, is known as the emotional center of the brain. The amygdala is involved in processing emotions, fear and reward as well as playing a big role in the fight-or-flight response. As the amygdala is close to the hippocampus, it is involved in the modulation of memory strengthening, especially emotional memories. In essence, the stronger the emotional arousal of a memory, the more likely it will be retained.
It takes its name from Carl Wernicke, who worked with patients who had language impairments, in order to distinguish separate regions for language comprehension and production. In order to diagnosis damage to the temporal lobes, a thorough history of the symptoms being experienced need to be investigated.
This assessment can be accompanied by someone who knows the patient well and has witnessed the problems at hand. A common cause of temporal lobe damage is epilepsy, so a discussion of previous seizure activity can be discussed. A referral to a neuropsychologist may be necessary to enable an understanding of the precise nature of the problem and to help with managing the condition.
There are also some common tests which are used to test for temporal lobe function. There is the Rey-Complex Figure which is a test for visual memory.
The Wechsler Memory Scale- Revised is also a common test used to assess the verbal memory of an individual. Further tests including using magnetic resonance imaging MRI or functional MRI fMRI can also be used to identify underlying causes by viewing the temporal lobes themselves.
In terms of treatment for temporal lobe damage, especially when it comes to temporal lobe seizures, medication is a good option to control seizure activity. A doctor may prescribe one or more drugs and different dosages over a period of months to find the best approach for the patient.
There is also the option of electrical brain stimulators for controlling temporal lobe seizures if medication has proved to not be effective.
A vagus nerve stimulator, is implanted under the skin of the chest and attached to the vagus nerve in the neck to deliver brief intermittent electrical bursts to the brain to reduce seizure activity. The posterior cerebral artery, as it ascends through the tentorial notch, and its first branch, the posterior communicating artery, are also close to the medial surface of the temporal lobe, lying between the uncus and the oculomotor nerve.
The oculomotor nerve, which arises from the medial surface of the cerebral peduncle, passes through the subarachnoid space, just below the uncus, on its way to the cavernous sinus and superior orbital fissure.
The temporal lobe receives blood from both the carotid and the vertebrobasilar systems. The anterior choroidal artery, which is the preterminal branch of the internal carotid, runs alongside the optic tract and then along the choroid fissure, which at this level indents the medial surface of the temporal lobe, separating the fimbria of the hippocampus from the stria terminalis and tail of the caudate nucleus Figure 4.
Structures in the temporal lobe supplied by the anterior choroidal artery are the anterior end of the parahippocampal gyrus, the uncus, the amygdala, and the choroid plexus in the temporal horn of the lateral ventricle.
The middle cerebral artery, a terminal branch of the internal carotid, crosses the insula in the floor of the lateral sulcus, giving off branches that supply the cortex of the superior and middle temporal gyri and the temporal pole. The posterior cerebral artery gives off two to four temporal branches, before it divides into the calcarine and parieto-occipital arteries, which supply the occipital lobe. The temporal branches of the posterior cerebral artery supply the inferior surface of most of the temporal lobe, but not the temporal pole.
The arteries supplying the temporal lobe are illustrated in Figure Detailed anatomical accounts with photographs of serial slices of injected specimens are available [ 4 , 61 ], and neuroradiology textbooks and atlases identify the vessels as they appear in angiograms. Blood from interior of the lobe, including the amygdala, hippocampus, and fornix, flows into the posterior choroidal vein.
This vessel lies alongside the choroid plexus of the lateral ventricle, passing upward and then forward, joining the thalamostriate vein immediately behind the interventricular foramen to form the internal cerebral vein. The left and right internal cerebral veins run posteriorly in the transverse fissure between the crura of the fornix and below the splenium of the corpus callosum, where they are joined by the basal veins and unite to form the great cerebral vein, a midline structure that continues into the straight sinus.
The basal vein vein of Rosenthal , which carries blood from the cortex and the interior of the frontal lobe, traverses the subarachnoid space in the cisterna ambiens, medial to the temporal lobe. This is an open access article distributed under the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Article of the Year Award: Outstanding research contributions of , as selected by our Chief Editors. Read the winning articles. Special Issues. Academic Editor: Seyed M. Received 06 Oct Accepted 03 Dec Published 29 Mar Introduction In this paper, I attempt to explain the positions of the parts of the normal human temporal lobe in relation to one another and to nearby structures.
Surface Features and Delimitation Like the other lobes of the cerebral hemisphere, the temporal lobe is delineated by cortical landmarks. Figure 1. Boundaries of the temporal lobe and positions of major sulci and gyri and other anatomical landmarks of the lateral and medial surfaces of the left cerebral hemisphere. Figure 2. Anatomical landmarks of the cortex of the left temporal lobe.
Photographs are of the lateral a , inferior b , and superior c surfaces. The superior surface, along with the insula, was exposed by removal of parts of the frontal and parietal lobes above the lateral sulcus. Figure 3. The hippocampus, dentate gyrus and fimbria as they appear after removal of the roof of the temporal horn of the lateral ventricle and of the choroid plexus modified from Piersol, [ 27 ].
The photograph on the right courtesy of Dr. Laszlo Seriss, University of Pecs, Hungary shows a dissected hippocampal formation, including the reflexed intrauncal component, with a sea-horse alongside. Figure 4. A transverse section through the body of the hippocampus and dentate gyrus, choroid fissure, and inferior horn of the lateral ventricle. The dentate gyrus and CA sectors of the hippocampus are outlined in red modified from Edinger, [ 33 ].
Figure 5. Drawing of a coronal section through the temporal lobe and adjacent structures, at a level anterior to the hippocampal head. The amygdala is coloured green, with the positions of its three nuclear groups indicated: corticomedial CM , basolateral BL , and central Ce. Selected bodies of white matter are coloured blue. Figure 6. Colour scheme used in Figures 7 , 8 , and 9.
Figure 7. Anatomical relations of the temporal lobe, as seen in a schematic coronal section passing through the temporal pole, anterior to the amygdala, hippocampus, and temporal horn. Figure 8. Anatomical relations of the temporal lobe, as seen in a schematic coronal section passing through the amygdala and the head of the hippocampus. This section is in a plane anterior to that shown in Figure 4. Figure 9. Anatomical relations of the temporal lobe, shown in a schematic horizontal section in the plane of the pituitary gland.
Figure Arteries supplying the temporal lobe. The colour scheme is explained in Figure 6. The posterior cerebral artery is shown, with anterior and posterior temporal branches to the inferior temporal gyrus, and calcarine and other branches supplying the occipital lobe.
Central branches to the midbrain and thalamus are represented by two small upwardly directed vessels. The medial temporal structures, supplied by the anterior choroidal artery, are hidden from view by the optic chiasma, hypothalamus and midbrain.
The larger superficial cerebral veins, including those draining the cortex of the temporal lobe. References J. Sarnat and M. Mai, G. Paxinos, and T. Penfield and T.
Rasmussen, The Cerebral Cortex of Man. View at: Google Scholar R. View at: Google Scholar M. Jones-Gotman, R. Zatorre, F. Cendes et al. View at: Google Scholar K. Baloh and K. Kluver and P. View at: Google Scholar H. Lilly, J. Cummings, F. Benson, and M. Ozawa, M. As part of this process, the temporal lobe is responsible for selective hearing in humans. Selective hearing helps filter out the unnecessary frequencies so that a person can focus on the important sounds from the environment. There is a visual aspect to the temporal lobe as well.
The temporal lobe helps establish object recognition, including complex objects, such as faces. Lastly, the temporal lobe plays a role in understanding and giving meaning to language.
This makes language distinguishable and understandable. The temporal lobe is a significant part of the limbic system. The limbic system is involved with motivation, emotion, learning, and memory. While the limbic system interacts with other areas of the brain, it works directly with the temporal lobe to influence the components of the limbic system.
The limbic system itself contains important structures, including the amygdala and hippocampus. These structures are responsible for key processes in the brain, such as memory, learning, and attention. The temporal lobe interacting with these structures also plays a role in memory, helping to form conscious long-term memory.
Because of the connection to the limbic system, the temporal lobe contributes to a number of automatic states and bodily functions. This includes states of sexual arousal, anxiety levels, and appetite, among others.
It is responsible for processing and giving meaning to speech and the written word. The temporal lobe plays a role in numerous functions in the brain. As such, damage in the temporal lobe may produce a wide variety of symptoms.
Damage in the temporal lobe may lead to one or more presenting symptoms. A person with damage in the temporal lobe may experience issues, including:.
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