Brodmann area 8 524221 222731716 2008-06-30T20:57:50Z Tkgd2007 2934677 svg brain {{Infobox Brain| Name = {{PAGENAME}} | Latin = | GraySubject = | GrayPage = | Image = Ba8.png | Caption = Image of brain with Brodmann area 8 shown in red | Image2 = Gray726-Brodman.svg | Caption2 = Lateral surface of the brain with Brodmann's areas numbered. (8 is labeled in upper left.) | IsPartOf = | Components = | Artery = | Vein = | BrainInfoType = ancil | BrainInfoNumber = 45 | MeshName = | MeshNumber = | DorlandsPre = | DorlandsSuf = | }} '''Brodmann area 8''' is one of [[Brodmann]]'s [[cytological]]ly defined regions of the brain. It is involved in planning complex movements. ==Human== '''Brodmann area 8''', or BA8, is part of the [[frontal lobe|frontal]] [[cerebral cortex | cortex]] in the [[human brain]]. Situated just anterior to the premotor cortex ([[Brodmann area 6|BA6]]), it includes the [[frontal eye fields]] (so-named because they are believed to play an important role in the control of eye movements). Damage to this area, by stroke, trauma or infection, causes tonic deviation of the eyes towards the side of the injury. This finding occurs during the first few hours of an acute event such as cerebrovascular infarct (stroke) or hemorrhage (bleeding). ==Guenon== The term '''Brodmann area 8''' refers to a [[cytoarchitecture|cytoarchitecturally]] defined portion of the frontal lobe of the [[guenon]]. Located rostral to the [[arcuate sulcus]], it was not considered by Brodmann-1909 to be topographically [[homology (biology)|homologous]] to the intermediate frontal area 8 of the human. <ref>{{BrainInfo|ancil|1045}}</ref> ==Distinctive features== Distinctive features (Brodmann-1905): compared to [[Brodmann area 6]]-1909, area 8 has a diffuse but clearly present internal [[granular layer]] (IV); sublayer 3b of the external [[pyramidal layer]] (III) has densely distributed medium sized [[pyramidal cell]]s; the internal pyramidal layer (V) has larger [[ganglion cell]]s densely distributed with some [[granule cell]]s interspersed; the external granular layer (II) is denser and broader; cell layers are more distinct; the abundance of cells is somewhat greater. ==Functions== The area is involved in the management of uncertainty. A functional magnetic resonance imaging study demonstrated that that brodmann area 8 activation occurs when test subjects experience uncertainty, and that with increasing uncertainty there is increasing activation.<ref>{{cite journal |author=Volz KG, Schubotz RI, von Cramon DY |title=Variants of uncertainty in decision-making and their neural correlates |journal=Brain Res. Bull. |volume=67 |issue=5 |pages=403–12 |year=2005 |pmid=16216687 |doi=10.1016/j.brainresbull.2005.06.011}}</ref> An alternative interpretation is that this activation in frontal cortex encodes hope, a higher-order expectation positively correlated with uncertainty.<ref>Chew and Ho, ''[http://ideas.repec.org/a/kap/jrisku/v8y1994i3p267-88.html Hope: An Empirical Study of Attitude toward the Timing of Uncertainty Resolution]'', J Risk and Uncertainty 8(3):267-288. 1994</ref> ==References== <references/> ==See also== * [[Brodmann area]] * [[List of regions in the human brain]] {{neuroanatomy-stub}} {{Prosencephalon}} [[Category:Brodmann areas|08]] [[nl:Brodmann gebied 8]]