Parietal lobe 465886 219974837 2008-06-17T18:37:01Z Gail 7214503 Reverted edits by [[Special:Contributions/168.169.88.218|168.169.88.218]] to last version by Gail (using [[WP:HG|Huggle]]) {{Infobox Brain| Name = {{PAGENAME}} | Latin = lobus parietalis | GraySubject = 189 | GrayPage = 822 | Map = Cerebrum map| MapPos = | MapCaption = Principal fissures and lobes of the [[cerebrum]] viewed laterally. (Parietal Lobe is shown in yellow) | Image2 = Gray726.png | Caption2 = Lateral surface of left cerebral hemisphere, viewed from the side. (Parietal Lobe is in upper right.) | IsPartOf = [[Cerebrum]]| Components = | Artery = [[Anterior cerebral artery|Anterior cerebral]] <br/> [[Middle cerebral artery|Middle cerebral]]| Vein = [[Superior sagittal sinus]]| BrainInfoType = hier | BrainInfoNumber = 77 | MeshName = Parietal+Lobe | MeshNumber = A08.186.211.730.885.213.670 | }} The '''parietal lobe''' is a lobe in the [[brain]]. It is positioned above (superior to) the [[occipital lobe]] and behind (posterior to) the [[frontal lobe]]. The parietal lobe integrates [[sensory]] information from different [[sensory modality|modalities]], particularly determining spatial sense and navigation. For example, it comprises [[somatosensory cortex]] and the [[dorsal stream]] of the [[visual system]]. This enables regions of the parietal cortex to map objects perceived visually into body coordinate positions. ==Anatomy== The parietal lobe is defined by four anatomical boundaries: the [[central sulcus]] separates the parietal lobe from the [[frontal lobe]]; the [[parieto-occipital sulcus]] separates the parietal and [[occipital lobe]]s; the [[lateral sulcus]] (sylvian fissure) is the most lateral boundary separating it from the [[temporal lobe]]; and the [[medial longitudinal fissure]] divides the two hemispheres. Immediately posterior to the central sulcus, and the most anterior part of the parietal lobe, is the [[postcentral gyrus]] ([[Brodmann area]] 3), the primary [[somatosensory cortex|somatosensory cortical area]]. Dividing this and the [[posterior parietal cortex]] is the [[postcentral sulcus]]. The posterior parietal cortex can be subdivided into the [[superior parietal lobule]] (Brodmann areas [[Brodmann area 5|5]] + [[Brodmann area 7|7]]) and the [[inferior parietal lobule]] ([[Brodmann area 39|39]] + [[Brodmann area 40|40]]), separated by the [[intraparietal sulcus]] (IP). The intraparietal sulcus and adjacent [[gyrus|gyri]] are essential in guidance of limb and [[saccade|eye movement]], and based on cytoarchitectural and functional differences is further divided into medial (MIP), lateral (LIP), ventral (VIP), and anterior (AIP) areas. ==Function== The parietal lobe plays important roles in integrating sensory information from various parts of the body, knowledge of numbers and their relations<ref>Blakemore & Frith (2005). ''The Learning Brain''. Blackwell Publishing. ISBN 1-4051-2401-6</ref>, and in the manipulation of objects. Portions of the parietal lobe are involved with visuospatial processing. Much less is known about this lobe than the other three in the cerebrum. Various studies in the 1990s found that different regions of the parietal cortex in [[Macaque]]s represent different parts of space. *The lateral intraparietal (LIP) contains a 2-dimensional topographic map of retinotopically-coded space representing the saliency of spatial locations. It can be used by the oculomotor system for targeting eye movements, when appropriate. *The ventral intraparietal (VIP) area receives input from a number of senses (visual, [[somatosensory]], auditory, and [[Vestibular system|vestibular]]<ref name="avillac2005">Avillac M, Deneve S, Olivier E, Pouget A, Duhamel JR. (2005) Reference frames for representing visual and tactile locations in parietal cortex. Nat Neurosci. 8(7):941-9.</ref>). Neurons with [[tactile]] receptive fields represented space in a head-centered reference frame<ref name="avillac2005"/>. The cells with visual receptive fields also fire with head-centered reference frames<ref name="zhang2004">Zhang T, Heuer HW, Britten KH. (2004) Parietal area VIP neuronal responses to heading stimuli are encoded in head-centered coordinates. Neuron 42(6):993-1001.</ref> but possibly also with eye-centered coordinates<ref name="avillac2005"/> *The medial intraparietal (MIP) area neurons encode the location of a reach target in eye-centered coordinates.<ref name="pesaran2006">Pesaran B, Nelson MJ, Andersen RA. (2006) Dorsal premotor neurons encode the relative position of the hand, eye, and goal during reach planning. Neuron 51(1):125-34.</ref> *The anterior intraparietal (AIP) area contains neurons responsive to shape, size, and orientation of objects to be grasped<ref name="murata2000">Murata A, Gallese V, Luppino G, Kaseda M, Sakata H. (2000) Selectivity for the shape, size, and orientation of objects for grasping in neurons of monkey parietal area AIP. J Neurophysiol 83(5):2580. PMID 10805659</ref> as well as for manipulation of hands themselves, both to viewed<ref name="murata2000"/> and remembered stimuli. <ref name="murata1996">Murata A, Gallese V, Kaseda M, Sakata H. (1996) Parietal neurons related to memory-guided hand manipulation. J Neurophysiol 75(5):2180-6. PMID 8734616</ref> ==Pathology== [[Gerstmann's syndrome]] is associated with lesion to the dominant (usually left) parietal lobe. [[Balint's syndrome]] is associated with bilateral lesions. The syndrome of [[hemispatial neglect]] is usually associated with large deficits of attention of the non-dominant hemisphere. <!--I don't know what this means:--> <!--Dysgraphia/agraphia, Dyscalculia/acalculia, Finger agnosia, and Left-right disorientation. --> ==Additional images== <gallery> Image:Illu cerebrum lobes.jpg|Lobes Image:Gray1197.png|Drawing to illustrate the relations of the brain to the skull. </gallery> ==References== {{reflist}} == See also == [[Lobes of the brain]] {{Prosencephalon}} [[Category:Cerebrum]] [[de:Parietallappen]] [[el:Βρεγματικός λοβός]] [[es:Lóbulo parietal]] [[fa:لوب آهیانه‌ای]] [[fr:Lobe pariétal]] [[nl:Pariëtale kwab]] [[ja:頭頂葉]] [[no:Isselapp]] [[pl:Płat ciemieniowy]] [[fi:Päälakilohko]] [[sv:Parietallob]] [[th:กลีบข้างขม่อม]] [[zh:顶叶]]