There is no Chief Executive Officer neuron in a brain. In brains, the most general decision-making processes (top of the executive hierarchy) and the broadest and most abstract representations (top of the perceptual hierarchy) are physically instantiated in the broadest networks of neurons. That’s rather different from the structure of a company in which the Chief Executive Officer is considered to be the highest decision-maker and the best representative of the company.
Joaquín Fuster, a leading neuroscientist, described this contrast:
The cortical structure and dynamics of the executive hierarchy, like those of the perceptual hierarchy, differ radically from the structure of social hierarchies. In social hierarchies, such as those of industrial and military organizations, representation — like power — is concentrated at the top; in cortical hierarchies, it is distributed at the top. Because both perceptual and executive hierarchies are formed largely by divergent connections, representations at the top are much more broadly based, in neural terms, than those at the bottom….
The Neurocritic provides conceptual and anatomical diagrams from one of Fuster’s earlier papers.
Note that this difference involves neither an absence of hierarchy nor a contrast between bottom-up and top-down control. The brain’s executive and perceptual hierarchies are built upon anatomical gradients of memory formation:
Because the three gradients of memory formation — phylogeny, ontogeny, and connectivity — largely coincide temporally and spatially, we can trace them by focusing on any one of them, such as the ontogenetic gradient, as portrayed by the myelogenetic map of the cortex. The numeration of the map refers to the order of myelination of the various cortical areas in perinatal periods.
Moreover, both top-down and bottom-up control are important aspects of brain functioning, each with somewhat different communications technologies.
The Internet is like a global brain. That global brain, like the one in your head, includes hierarchies and forms of top-down control. At the same time, the most general decisions about the goals of the Internet are a product of the relations of many active participants. Relations among persons, not one corporate person, represents what the Internet is.
 Joaquín Fuster (2006), “The cognit: A network model of cortical representation,” International Journal of Psychophysiology 60, p. 130.
 Id. p. 127, reference to figure omitted.