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“You would be amazed at how much of the current experimental neuroscience literature is dominated by ‘top down-bottom up thinking’, which goes back to the 19th Century, especially in neurology,” – Professor Swanson, University of Southern California in Los Angeles
While neurology has always held the view that signals go to and from certain regions of the brain, this new research sheds light on how loops are formed between differing regions. These then feed back to, directly linking brain regions that were not known to communicate with one another. This further vindicates the fact that the brain is not a hierarchal network, like a company, but works more like the internet, which is a vast nodal network.
Incidentally, Robert Burton, writer of On Being Certain, brings together cutting edge neuroscience, anecdote and facts to further illustrate the complexity of this hierarchy-less network.
Our human brain has a unique ability to convert low-level functions to higher level behaviours. For example, even with our visual system, a host of visual modules are playing in unision to enable us interpret and perceive images. Our eyes are merely viewing devices. Stimulus from what we see (with our eyes) is processed in the sub-cortical regions of the brain, where several visual modules are processing the image with a ton of inputs from non-visual circuitry (anything relevant that your brain has seen earlier). These form visual associations, and a combination of these outputs becomes our perception, allowing us to recognise shapes, objects, people and things.
The complexity of neural networks can also be illustrated with the work of Dr. LeDoux, which greatly clarifies the role of the amygdala in evoking fear responses without the need for any conscious awareness and recognition of the stimulus.
This stripped down model of brain hierarchy means that the individual neurons, which contain no imagery and operate outside of awareness, flow into progressively higher-order networks until a picture emerges.
This allows the brain to strengthen episodic memory (remembrance of specific relevant episodes strung together by a narrative), which further non-consciously influences our behaviour.
Contribution to literature on neural networks is still limited, and what we know about the brain is yet very little. Nevertheless, understanding it from a more fundamental aspect is the key to decoding hidden patterns and explaining behaviour.