McIntosh A R, Kovacevic N, Lippe S, Garrett D, Grady C, Jirsa V
Rotman Research Institute of Baycrest Centre, University of Toronto, Ontario, Canada.
Arch Ital Biol. 2010 Sep;148(3):323-37.
Early in life, brain development carries with it a large number of structural changes that impact the functional interactions of distributed neuronal networks. Such changes enhance information processing capacity, moving the brain from a deterministic system to one that is more stochastic. The evidence from empirical studies with EEG and functional MRI suggests that this stochastic property is a result of an increased number of possible functional network configurations for a given situation. This is captured in the variability of endogenous and evoked responses or "brain noise ". In empirical data from infants and children, brain noise increases with maturation and correlates positively with stable behavior and accuracy. The noise increase is best explained through increased noise from network level interactions with a concomitant decrease of local noise. In old adults, brain noise continues to change, although the pattern of changes is not as global as in early development. The relation between high brain noise and stable behavior is maintained, but the relationships differ by region, suggesting changes in local dynamics that then impact potential network configurations. These data, when considered in concert with our extant modeling work, suggest that maturational changes in brain noise represent the enhancement offunctional network potential--the brain's dynamic repertoire.
在生命早期，大脑发育伴随着大量的结构变化，这些变化会影响分布式神经网络的功能相互作用。此类变化增强了信息处理能力，使大脑从一个确定性系统转变为一个更具随机性的系统。脑电图（EEG）和功能磁共振成像（fMRI）的实证研究证据表明，这种随机特性是给定情况下功能网络配置可能性增加的结果。这体现在内源性和诱发性反应的变异性或“脑噪声”中。在婴幼儿和儿童的实证数据中，脑噪声随着成熟而增加，并且与稳定行为和准确性呈正相关。噪声增加最好通过网络层面相互作用产生的噪声增加以及局部噪声的相应减少来解释。在老年人中，脑噪声持续变化，尽管变化模式不像早期发育那样全面。高脑噪声与稳定行为之间的关系依然存在，但这种关系因区域而异，这表明局部动态变化进而影响了潜在的网络配置。当将这些数据与我们现有的建模工作结合起来考虑时，表明脑噪声的成熟变化代表了功能网络潜力的增强——大脑的动态功能组合。
