Following Korbinian Brodmann it has traditionally been considered a homogeneous structure and with limited distinction between it and the neighboring posterior cingulate area.

This occurs around the precuneal sulcus (  green in figure) and is connected with the inferior parietal lobule particularly the angular gyrus and prefrontal areas 10, 46 and 8.

[1][3] The mental imagery concerning the self has been located in the forward part of the precuneus with posterior areas being involved with episodic memory.

[11] The precuneus is involved in memory tasks, such as when people look at images and try to respond based on what they have remembered in regard to verbal questions about their spatial details.

[15] In the recollection of memories, it has been postulated that the precuneus discerns whether contextual information exists that can be useful for involving the aid of the hippocampus.

[16] The precuneus has been suggested to be involved in directing attention in space both when an individual makes movements and when imaging or preparing them.

[20] Together with the superior frontal gyrus and orbitofrontal cortex, the precuneus is activated when people make judgments that require understanding whether to act out of empathy and forgiveness.

[26] Olaf Sporns and Ed Bullmore have proposed that its functions link to its role as a central and well connected "small-world network" hub between parietal and prefrontal regions.

These clusters or modules are interlinked by specialized hub regions, ensuring that overall path lengths across the network are short.

Most studies identified [such] hubs among parietal and prefrontal regions, providing a potential explanation for their well-documented activation by many cognitive functions.

Particularly notable is the prominent structural role of the precuneus, a region that is homologous to the highly connected posteromedial cortex in the macaque.

An intriguing hypothesis suggests that these functional aspects can be explained on the basis of its high centrality in the cortical network.

[1] It has been noted that "the precuneus is more highly developed (i.e. comprises a larger portion of the brain volume) in human beings than in non-human primates or other animals, has the most complex columnar cortical organization and is among the last regions to myelinate".