Are all conscious experiences stored as memories? There are people with supermemories, called highly superior autobiographical memory (HSAM), i.e., the detailed recollection of events that occurred in the distant past. Although the recollection of, say the weather on this day 15 years ago may not be entirely accurate (errors occur) and may contain gaps (maybe an hour of sunshine on a predominantly rainy day is not recollected), their memories are clearly superior nonetheless. 

I have heard these statements that all memories are stored in the brain and that the reason why we forget is because those memories are simply not accessible anymore. This would metaphorically be like the workings of a hard drive, where deletion of a file removes the flag, but the information is physically still stored, it is just invisible to the user and difficult to access. Following this reasoning, everyone would have HSAM in a way, barred that normally the memories can't readily be accessed. 

Hypnosis seems to be capable of enhancing the recollection of memories in people without HSAM, and hence hypnosis is said to improve memory, indirectly indicating that memory storage indeed may generally be higher than apparent in everyday life, but that the brain needs a hand in retrieving those memories.

My question is:


Are all conscious1 memories stored, but access is permitted only when its regularly accessed, or enhanced through hypnosis or other means? In other words, does everyone have super memory like HSAM, but do people without HSAM simply lack an efficient way to access those distant memories? 


1 With all conscious memories I mean memories of life events that were experienced while being awake and vigilant. For the sake of question focus, I suggest disregarding life events occurring during sleep, coma, anesthesia or other periods of reduced consciousness.
This question can be addressed in many ways. One approach that we have taken is to test memory for what has just recently happened a few seconds ago.  In these experiments we ask people to find a target in a simple visual search, and report its location.  For example we might show them 3 numbers and one letter and ask them to report the location of the letter.  After several minutes of doing this task, we give them a surprise question in which we ask them to tell us the actual letter that they had just located in the most recent trial (which they saw just a few seconds ago).  What we find is that it is easy to find situations in which our participants have very little memory of that letter. What is interesting about this is that they had just located the letter by virtue of the fact that it was a letter.  We presume, therefore, that the letter had briefly entered their awareness.  This can be debated, if one assumes that one can search for letters without actually experiencing the letters.  However we also found the same result with digit-parity tasks (i.e. find the odd number among evens or vice versa). 

We called this effect attribute amnesia, since people seem to have amnesia for a specific attribute of a stimulus they had just selected.  

So while there are lots of ways to interpret this finding, the clearest result seems to be that performing a mental operation that selects a piece of visual information can leave a memory trace so weak that it cannot be remembered just a few seconds later.  Our interpretation is that the memory was never created in the first place.  We believe that the brain has filters on memory encoding that allow us to process information without remembering it.  It is also possible that it was encoded into memory and immediately forgotten but we do not favor this view as it seems less parsimonious than the filter that prevents encoding in the first place.  

Here are some articles on this phenomenon:
Chen, H., &amp; Wyble, B. (2015). Amnesia for object attributes: Failure to report attended information that had just reached conscious awareness. Psychological science, 26(2), 203-210.

Chen, H., Swan, G., &amp; Wyble, B. (2016). Prolonged focal attention without binding: Tracking a ball for half a minute without remembering its color. Cognition, 147, 144-148.

Chen, H., &amp; Wyble, B. (2016). Attribute amnesia reflects a lack of memory consolidation for attended information. Journal of Experimental Psychology: Human Perception and Performance, 42(2), 225.

Here are some freely-available pre-prints of related articles if you cannot access the ones above:
https://psyarxiv.com/gbdcr/
https://psyarxiv.com/87yg2/

I apologize that not all of our work is available on preprint servers yet.  I'd be happy to email copies of published articles if you email me at bwyble@gmail.com