Newman J
Colorado Neurological Institute, Denver 80218, USA.
Conscious Cogn. 1995 Jun;4(2):172-93. doi: 10.1006/ccog.1995.1024.
A tacit assumption since the 19th Century has been that the neocortex serves as the "seat of consciousness." An unexpected challenge to that assumption arose in 1949 with the discovery that high-frequency EEG activation associated with an alert state requires the intactness of the brainstem reticular formation. This discovery became the impetus for nearly three decades of research on what came to be known as the reticular activating system. By the 1970s, however, methodological and philosophical controversies led to the general abandonment of subcortical theories of attention and consciousness, with a return to an almost exclusive focus upon the cortex. With recent advances in the neurosciences the focus is shifting once more, this time to the unique contributions of cortical, thalamic, and brainstem structures in mediating selective attention and perceptual awareness. This paper offers a nontechnical review of the history of these developments up to contemporary interest in the putative role of oscillatory EEG patterns in the integration of perceptual features of experience. It puts forward the thesis that a key to understanding attention and consciousness is an appreciation of the contributions of the thalamus to these cognitive processes.
自19世纪以来一直存在的一个默认假设是，新皮层是“意识的所在”。1949年，这一假设受到了意想不到的挑战，当时发现与警觉状态相关的高频脑电图激活需要脑干网状结构的完整性。这一发现成为了近三十年对后来被称为网状激活系统研究的推动力。然而，到了20世纪70年代，方法学和哲学上的争议导致了对注意力和意识的皮层下理论的普遍摒弃，几乎再次完全回归到对皮层的关注。随着神经科学的最新进展，关注点再次发生转移，这次转向了皮层、丘脑和脑干结构在介导选择性注意力和感知意识方面的独特贡献。本文对这些发展历程进行了非技术性的回顾，直至当代对振荡脑电图模式在整合经验感知特征中假定作用的兴趣。它提出了一个论点，即理解注意力和意识的关键在于认识丘脑对这些认知过程的贡献。
