Fusion and Fission of Cognitive Functions in the Human Parietal Cortex

Abstract

How is higher cognitive function organized in the human parietal cortex? A century of neuropsychology and 30 years of functional neuroimaging has implicated the parietal lobe in many different verbal and nonverbal cognitive domains. There is little clarity, however, on how these functions are organized, that is, where do these functions coalesce (implying a shared, underpinning neurocomputation) and where do they divide (indicating different underlying neural functions). Until now, there has been no multi-domain synthesis in order to reveal where there is fusion or fission of functions in the parietal cortex. This aim was achieved through a large-scale activation likelihood estimation (ALE) analysis of 386 studies (3952 activation peaks) covering 8 cognitive domains. A tripartite, domain-general neuroanatomical division and 5 principles of cognitive organization were established, and these are discussed with respect to a unified theory of parietal functional organization.

Establishing task- and modality-dependent dissociations between the semantic and default mode networks

“…but (ii) is positively engaged by a variety of different domains (episodic retrieval, numerical tasks, sentence-level tasks, etc.) (24). Thus, it appears that the AG serves a more domain-general function and is not specialized for semantic processing.…”

“…Thus, it appears that the AG serves a more domain-general function and is not specialized for semantic processing. One possibility is that the parietal cortex acts as a multimodal online buffer of incoming internal or external information (24). Within this system, the dorsal and ventral parietal cortex serve counterpointed roles; the ventral system automatically buffers input, whereas the dorsal system is involved in top-down executive processing of buffered information.…”

“…Secondly, the AG has been implicated in numerous cognitive domains outside of the field of semantic cognition, suggesting a more domain-general cognitive function (attention, episodic memory, numerical processing, and syntax; ref. 24). Indeed, one possibility is that the AG forms part of a domain-general processing network that is involved in "automatic" or "stimulus-driven" taskprocesses and is anticorrelated with the "executive" dorsal parietal cortex (IPS) (24)(25)(26).…”

“…24). Indeed, one possibility is that the AG forms part of a domain-general processing network that is involved in "automatic" or "stimulus-driven" taskprocesses and is anticorrelated with the "executive" dorsal parietal cortex (IPS) (24)(25)(26). Together, these inconsistencies in both the current SN and DMN literatures make establishing the relationship between the two networks difficult.…”

Knowing what from where: Hippocampal connectivity with temporoparietal cortex at rest is linked to individual differences in semantic and topographic memory

“…Left temporoparietal cortex is linked to many different forms of memory retrieval: Angular gyrus (within the default mode network) supports autobiographical memory (Spreng, Mar, & Kim, 2008;Cabeza, Ciaramelli, Olson, & Moscovitch, 2008;Bonnici, Richter, Yazar, & Simons, 2016) and more automatic aspects of semantic retrieval (Binder et al, 2009;Humphreys & Lambon Ralph, 2014, Seghier, 2012. Inhibitory TMS to the left angular gyrus region disrupts the retrieval of detailed conceptual knowledge (Davey et al, 2015b).…”