Brodmann area 8

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Brain: Brodmann area 8
Brodmann area 8.png
Image of brain with Brodmann area 8 shown in red
Brodmann Cytoarchitectonics 8.png
Image of brain with Brodmann area 8 shown in orange
Latin Area frontalis intermedia
NeuroNames ancil-45
NeuroLex ID birnlex_1739
Lateral surface of the brain with Brodmann's areas numbered. (8 is labeled in upper left.)

Brodmann area 8 is one of Brodmann's cytologically defined regions of the brain. It is involved in planning complex movements.

Human[edit]

Brodmann area 8, or BA8, is part of the frontal cortex in the human brain. Situated just anterior to the premotor cortex (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[edit]

The term Brodmann area 8 refers to a 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 homologous to the intermediate frontal area 8 of the human.

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 cells; the internal pyramidal layer (V) has larger ganglion cells densely distributed with some granule cells interspersed; the external granular layer (II) is denser and broader; cell layers are more distinct; the abundance of cells is somewhat greater.[1]

Functions[edit]

The area is involved in the management of uncertainty. A functional magnetic resonance imaging study demonstrated that brodmann area 8 activation occurs when test subjects experience uncertainty, and that with increasing uncertainty there is increasing activation.[2]

An alternative interpretation is that this activation in frontal cortex encodes hope, a higher-order expectation positively correlated with uncertainty.[3]

Image[edit]

See also[edit]

References[edit]

  1. ^  This article incorporates text from this source, which is licensed under CC-BY 3.0.
  2. ^ Volz KG, Schubotz RI, von Cramon DY (2005). "Variants of uncertainty in decision-making and their neural correlates". Brain Res. Bull. 67 (5): 403–12. doi:10.1016/j.brainresbull.2005.06.011. PMID 16216687. 
  3. ^ Chew and Ho, Hope: An Empirical Study of Attitude toward the Timing of Uncertainty Resolution, J Risk and Uncertainty 8(3):267-288. 1994