Popular models of how “memory” works makes as much sense to me as most theodicies. Even with constructs like engrams, where we assume that certain configuration of electrical pulses get magically integrated into something coherent somewhere else in the network is really incoherent in the face of the evidence.
“Memory” is a consistent and necessary component of life. Without some type of “memory”, an organism cannot carry out the functions necessary to life. Thus, the model of how “memory” works must be consistent throughout all biological life, unless we are asserting that there are divergent biological approaches to “memory”. I’ve yet to see any evidence which supports this concept, even among something like a “plant vs animal” split.
If we view DNA as a “memory” machine, the greatest divergence among organisms appears to be how flexibly they can store and reproduce the “memory” within DNA.
Let’s just get to the candy everybody wants.
All memory in human brains is physical and internal to the person.
We create memories by physically recording them via actin dynamics/rna expression in astrocytes.
The primary mechanic of astrocytes in human brains is to create levels of differentiation from stimuli. Each level of differentiation is assigned a specific peptide tag which represents that stimulus level. Not all astrocytes are capable of the same level of differentiation. All astrocytes are capable of working against multiple types of stimuli, and it is the overlay of these differentiations of stimuli which produces unique peptide combinations, or a “micro-engram”.
These “micro-engrams” are recorded in the branches of astrocytes, and via rna expression are recorded into the branches of local neurons as well. When a neuron fires due to accumulated stimuli, it fires along the these branches, and if the stimuli combination is similar enough to a recorded micro-engram, it fires a peptide combination, which is received by an astrocyte, which fires an organizing chemical signal (calcium waves).
More simply, an astrocyte “learns” the differences between levels of stimuli, programs local neurons to fire a chemical alert when that particular configuration of stimuli is found, at which point it coordinates with other astrocytes to combine constructs or reprogram local neuron groups to modify the response signal and ultimately produce behavior.
Neurotransmitters are chemical signalers of stimuli region/class. They do not store any information in and of themselves and are not interpreted as anything other than a general regionality or destination of stimuli (from the nervous system’s perspective). They are the general channels that astrocytes use in the differentiation process, and allows varying response to similar stimuli based on interaction with other systems. Think of a combination of neurotransmitters as a type of addressing mechanism, rather than a data transfer mechanism.
The actual data is encoded in specific branches when enough similarity between a combination of signals is encountered, which triggers a specific combination of peptides, which triggers astrocytes to remodel the local environment in response. All cognitive processes are ultimately abstractions of how efficiently an astrocyte can remodel it’s local environment in response to stimuli.
This metabolic remodeling in response to external stimuli is again, a requirement of life as currently defined.
Because the signalling system is physical and based on peptides, it’s consistent with many of the artifacts we see in current evidence. For example, neuro-stimulation seems to be completely agnostic to type for the most part (albeit some showing larger effect than others). We can invoke stimulation via electricity, vibration, light, heat, and even the every popular chemical means. The commonality among all of these is that a relaying neuron is popping it’s signal load, which is configured to a specific peptide configuration stored into the neuron, resulting in the astrocyte responding as if that particular stored combination of stimuli has been encountered and it remodeling the local environment and firing a chemical response accordingly.
Stepping through an interaction: Eyes receive stimuli, the stimuli is mapped onto millions of discrete sensors, which are integrated down stream and monitored by astrocytes for particular combinations of data. These types of streams are isolated and managed by astrocytes (myelin, nodes of ranvier, etc) where the stream is monitored for particular types of information. When an astrocyte encounters information it’s experienced, it remodels the local neurons to send a specific signal representing it’s “learned” information forward. This remodeling is literally astrocytic mito rna expression->actin manipulation->neuron remodeling->neuronal mito replication of peptide signallers.
The astrocyte receives feedback through a couple of mechanisms, the first being whether or not the other end of the neuron was able to successfully carry the peptide signal. The second are modifying signals from other astrocytes, which usually come in the form of neurotransmitter level signalling. These signals give a general “positive/negative” response from areas up/down stream of the particular astrocyte, and provide guidance on how to adjust it’s remodeling of the local signal.
Lol, I guess this isn’t all that clear to anyone not really familiar with the mechanics, I need to pick at this a bit before I post it.