Wednesday, September 30, 2009
Bye bye modular, hello cognit!
Termed by Fuster in 2006, the construct was created to solve the problematic yet popular view that the human brain is made up of discrete cortical domains dedicated exclusively to visual discrimination, language, spatial attention, face recognition, motor programming, memory retrieval, and working memory.
Although the modular modeling of the brain has utterly failed due to a lack of conclusive evidence, many neuroscientists continue to maintain this antiquated view... but why? Put quite simply, there was nothing better. However, thanks to Fuster, a new paradigm is emerging...
Introducing the cognit network model. It postulates that memory and knowledge are represented by interactive, distributed, and overlapping networks of neurons in association cortices.
The posterior-post-rolandic association cortex contains perceptual cognits and the frontal association cortex contains executive cognits. The prefrontal and posterior association cortices are linked by complex cognits in a hierarchical order. The parasensory and premotor cortex, found at the bottom of the hierarchy, contain relatively simple and small cognits which represent motor acts or simple percepts. At the top of the hierarchy is the temporo–parietal and prefrontal cortex containing larger cognits representing complex and abstract information of perception and executive control. The long reciprocal cortico–cortical connections between the posterior and frontal networks support sequential behavior, speech, and reasoning.
What I find most fascinating about the whole thing is that it's possible for a single neuron to be involved in multiple memory networks thus playing a part in many memories and units of knowledge.
Fuster JM (2009). Cortex and memory: emergence of a new paradigm. Journal of cognitive neuroscience, 21 (11), 2047-72 PMID: 19485699
FUSTER, J. (2006). The cognit: A network model of cortical representation International Journal of Psychophysiology, 60 (2), 125-132 DOI: 10.1016/j.ijpsycho.2005.12.015