Temporal lobe
| Brain: Temporal lobe | ||
|---|---|---|
| Lobes of the human brain | ||
| Section of brain showing upper surface of temporal lobe. | ||
| Latin | lobus temporalis | |
| Gray's | subject #189 823 | |
| Part of | Brain | |
| Artery | Middle cerebral and Posterior cerebral |
|
| NeuroNames | hier-107 | |
| MeSH | Temporal+Lobe | |
| NeuroLex ID | birnlex_1160 | |
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain.[1]
The temporal lobe is involved in auditory perception and is home to the primary auditory cortex. It is also important for the processing of semantics in both speech and vision. The temporal lobe contains the hippocampus and plays a key role in the formation of long-term memory.
The superior temporal gyrus includes an area (within the Sylvian fissure) where auditory signals from the cochlea (relayed via several subcortical nuclei) first reach the cerebral cortex. This part of the cortex (primary auditory cortex) is involved in hearing. Adjacent areas in the superior, posterior and lateral parts of the temporal lobes are involved in high-level auditory processing. In humans this includes speech, for which the left temporal lobe in particular seems to be specialized. Wernicke's area, which spans the region between temporal and parietal lobes, plays a key role (in tandem with Broca's area, which is in the frontal lobe). The functions of the left temporal lobe are not limited to low-level perception but extend to comprehension, naming, verbal memory and other language functions.
The underside (ventral) part of the temporal cortices appear to be involved in high-level visual processing of complex stimuli such as faces (fusiform gyrus) and scenes (parahippocampal gyrus). Anterior parts of this ventral stream for visual processing are involved in object perception and recognition.
The medial temporal lobes (near the Sagittal plane that divides left and right cerebral hemispheres) are thought to be involved in episodic/declarative memory. Deep inside the medial temporal lobes lie the hippocampi, which are essential for memory function – particularly the transference from short to long term memory and control of spatial memory and behavior. Damage to this area typically results in anterograde amnesia.
[edit] Medial temporal lobe
The medial temporal lobe consists of structures that are vital for explicit memory. The link between the medial temporal lobe and memory was first hypothesized a century ago. Explicit or declarative memory is the conscious memory of facts and events. Explicit memory is further sub-divided into semantic memory and episodic memory. The structures contained within the medial temporal lobe include the hippocampal regions and the parahippocampal gyrus, which consists of the perirhinal, parahippocampal and entorhinal cortices. Though the hippocampus is critical for memory formation, the surrounding medial temporal cortex is also cited as playing a part in establishing memories. Research has shown that lesions in the hippocampus of monkeys results in limited impairment of function, whereas extensive lesions that include the hippocampus and the medial temporal cortex result in severe impairment. [2]
[edit] References
- ^ "Temporal Lobe". Langbrain. Rice University. http://www.ruf.rice.edu/~lngbrain/cglidden/temporal.html. Retrieved 2 January 2011.
- ^ "Squire , L. R., Stark, C. E. L., & Clark, R. E. (2004). The medial temporal lobe. Annu. Rev. Neurosci, 27, 279–306."
[edit] External links
| Wikimedia Commons has media related to: Temporal lobe |
- University of Idaho
- Temporal-lobe.com An interactive diagram of the rat parahippocampal-hippocampal region
- Planning for Hope: Living with Frontotemporal Disease documentary film on YouTube
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