There is evidence that signal coordination between regions depends more on the total number of possible communication routes between them than on the existence of direct connections between points A and B.

Brain regions dynamically affiliate with multiple networks in a context-dependent manner, forming coalitions that assemble and disassemble based on current demands. This interactional complexity means that functions aren’t localised to discrete modules but emerge from decentralised coordination across multiregion assemblies. The properties that... See more

An important one is that signals from different sites exhibit synchronised neuronal activity. This is notable because groups of neurons that fire in a coherent fashion indicate that they are functionally interrelated, and potentially part of a common process. Different types of signal coordination are believed to reflect processes such as attention... See more

Modularity here refers to the idea that the brain consists of specialised, relatively independent components or modules that each handle specific mental functions, much like distinct parts in a machine that work together but perform separate operations.

we also observe functional relationships between neuronal signals from locations that are situated much farther apart and, critically, between brain parts that are not directly anatomically connected – there is no direct axonal connection between them.

The brain’s massive combinatorial connectivity and highly distributed functional coordination defy clean compartmentalisation. The extensive bidirectional pathways spanning the entire brain create crisscrossing connectional systems that dissolve potential boundaries between traditional mental domains (cognition, emotion, etc).

The dense nexus of pathways allows for remarkable flexibility in how the brain processes information and controls behaviour. Signals of all types can be exchanged and integrated in multiple ways. All this potential mixing strongly challenges how we traditionally think of the mind and brain in terms of simplistic labels such as ‘perception’,... See more

fMRI studies in humans have shown that the brain is organised in terms of large-scale networks that stretch across the cortex as well as subcortical territories. For example, the so-called ‘salience network’ (suggested to be engaged when significant events are encountered) spans brain regions in the frontal and parietal lobes, among others, and can... See more

If the mapping between structure and function is not one-to-one, then what kind of system is the brain? This is the question the entangled brain concept sets out to tackle. It’s useful to consider two types of information: anatomical and functional.