The Hippocampal Simulation Theory

 

"I?" began in 2012, as a collaboration between filmmaker Matt Faw and his consciousness researcher dad, Dr. Bill Faw.  Along the journey of interviews and research, Matt was shocked to find that the state of the art of consciousness studies was entirely missing any coherent anatomical models for explaining Subjective Experience and the other mysteries of consciousness. 

 

In 2013, during a discussion between father and son, we stumbled across an elegant idea: there is already a well-known experience generator in the brain, but for some reason, it was being overlooked as a target site.  This experience generator is the hippocampal formation.  It creates episodic memories and serves as the 'mind's eye' for the brain's 'Intrinsic Network' (DMN).  What if 'consciousness' was a lot less mysterious than it seemed?  What if 'Subjective Experience' was really just a brand new episodic memory, still vivid and full of detail? 

 

The more we looked at recent research about the hippocampus, the more plausible the hypothesis became.  The many mysteries and pathologies of consciousness, even the 'Hard Problem', seemed to finally make sense, in context of this theory.

 

The model that we were developing needed to be heard, skeptically discussed, and thoroughly tested, before we could claim it as science, so we set about writing a theory paper that hopefully would start such a discussion.

 

After 3 years and 70 drafts, we found a respected peer-reviewed publisher for our theory paper.  World-renowned hippocampus expert Dr. Lynn Nadel saw the potential in the theory, and invited us to submit our paper to WIREs Cognitive Science, a Wiley publication.  Now we're hoping to continue that conversation with all of you. 

The above video is a short explainer about the theory.  Below is the abstract from the published paper, and below that, links to the published paper on the journal's site, as well as a downloadable link.  There is also a link to a shorter, more colloquial version of the paper we wrote for the Brains Blog, with a pretty involved conversation, already underway.  Or please join us on the forum of this site, to ask us anything, or converse with others who are interested in the theory.

Abstract:  

We propose that the phenomenon known as ‘Subjective Experience’ is best understood as: the brain’s first activation by a brand new episodic memory, still vivid and full of detail.  In the formation of a new memory, the Hippocampal Complex (HC) receives reports from widely distributed structures around the brain.  The HC organizes and binds those reports together into a brand new episodic memory, which we can describe as a virtual-reality movie-like, unified, contextualized, but vastly simplified summation of what just happened).  This memory pattern is then reported back back to structures across the brain, (via bidirectional pathways to and from the HC) for error correction, to expedite predictive processing, and to inform sites in both extrinsic and intrinsic networks of one unified history.  It is the cortical activation by the new episodic memory engram that gives rise to the event of experiencing.   Because episodic memory is the only unified and contextualized representation of self-in-the-world in the brain, and because it informs most of the major cortices about ‘what just happened’, it is subjectively misinterpreted as the actual interaction of the body/mind with its environment.  This misinterpretation offers insight into many of the distinct and mysterious features of Subjective Experience and pathologies of consciousness.

Précis of the Theory and Discussion on the Brains Blog