I’ve been reading a bit from Edmund Rolls and others on auto associative memory. Perhaps the most well known structure to perform autoassociation is CA3 in the hippocampus. The recurrent connections between the pyramidal neurons allow for all associated parts of cortex to associate together to form episodic memory. When parts of that memory are triggered the whole memory is recovered and the original parts of cortex are reactivated - essentially reliving the cortical activity.
As the cortex evolved from the hippocampus it seems safe to assume that autoassociation will carry on over into the cortex (in a more local fashion). Apparently it does.
Perhaps the most interesting thing I have learned is that layers 2/3 are recurrently connected - forming autoassociative memory. From the sparse inputs from layer 4, layers 2/3 can recover the whole pattern from noisy or incomplete patterns. This is an easy task due to the sparse nature of SDRs. HTM theory suggests that dendritic segments act to perform pattern completion. However, recurrent networks complete patterns that come from other parts of the cortex (like the entorhinal/hippocampus relationship, but via the thalamus) but which the patterns maybe very sub-sampled - to which the pattern has to be progressively recovered over n cycles.
I’ve also read that layers 5/6 are also recurrently connected. Possibly the cortical paramore to sensory feedforward input - motor output.
As there is a lot of neuroscience out there claim autoassociation is globally central to memory (in HTM that means both spatial and temporal). It could even be the case that associative memory is dimension-agnostic - in that there is no specific mechanism for spatial or temporal memory (or any higher dimension for that matter).
Last time I asked about auto-association the replies seemed to suggest that temporal memory essentially performs temporal autocompletion - which it does. However I feel organic/general autoassociation provides global functionality that gives arise to many useful properties that applied across all dimensions.
So my question - there is a lot in neuroscience about autoassociation, why is it not apart of HTM theory? Given that HTM is meant to be based upon biologically plausible cortical principles.