Markowitsch H J, Tulving E
University of Bielfeld, Germany.
Neuroreport. 1995 Feb 15;6(3):413-8. doi: 10.1097/00001756-199502000-00002.
Human brain evolution has resulted in a large increase in cortical folding as a result of which 60% of the cerebral cortical mantle is buried within sulci. Cortical regions within the sulci, and especially in the fundal zones (fundi) at the bottom of sulci, differ from the rest of the cortex in a number of ways with respect to anatomical and histological morphology. Although physiological implications of the fundal morphology have been discussed from time to time, and although scattered evidence hints at a special functional role for fundi, until recently there have been few empirical facts to guide the inquiry into a possibly special physiological function of fundal zones. In this article we review findings yielded by positron emission tomography studies showing that the peaks of changes in neuronal activity are frequently observed in and near fundi. We discuss, but do not accept, the possibility that these findings reflect either the partial volume effect or the course of cerebral blood vessels. Instead, because of a coarse correlation observed between fundal fraction (the proportion of fundally related activity peaks) and the apparent cognitive complexity of the tasks probed, and in light of the anatomical evidence reviewed, we propose the hypothesis that cortical sulcal and fundal regions play a distinctive role in higher cognitive processing.
人类大脑的进化导致皮质褶皱大幅增加，结果60%的大脑皮质被埋在脑沟内。脑沟内的皮质区域，尤其是脑沟底部的基底部区域，在解剖学和组织学形态方面与皮质的其他部分在许多方面存在差异。尽管人们不时讨论基底部形态的生理意义，尽管零散的证据暗示了脑沟底部的特殊功能作用，但直到最近，几乎没有实证事实来指导对脑沟底部区域可能的特殊生理功能的探究。在本文中，我们回顾了正电子发射断层扫描研究的结果，这些研究表明，在脑沟底部及其附近经常观察到神经元活动变化的峰值。我们讨论了这些发现反映部分容积效应或脑血管走向的可能性，但并不认同。相反，由于观察到脑沟底部比例（与脑沟底部相关的活动峰值比例）与所探究任务的明显认知复杂性之间存在粗略的相关性，并且鉴于所回顾的解剖学证据，我们提出一个假设，即皮质脑沟和脑沟底部区域在更高层次的认知加工中发挥独特作用。
