Self-amplification mechanisms of aging.
This article uses the term "memory overexpression", or "MO", which is explained on the Introduction page. Briefly, memory overexpression refers to the slight memory overactivity that results from the continuously ongoing intrinsic activity of the CNS and from damages to a certain kind of memory system, the so-called "extinction memory". The function of this memory system is to inhibit aversive memories. Damage to this memory system (referred to as "extinction memory damage", or "EMD") leads therefore to a permanent overactivity of aversive memories, which has a permanent detrimental, aging-inducing effect on the body.
The most important self-amplification mechanism of aging originates from a quite surprising and peculiar source. Actually, the overexpression of an aversive memory does not only enforce aging onto the body as explained in the Introduction. Additionally, it influences the state of mind by slightly activating the emotional quality of the overexpressed memory. This effect acts analogously to memory recall. For instance, remembering a sad event makes sad. Thus, the activation of a memory induces the associated emotion. And as the overexpression of a memory is equivalent to a slight activation of the memory, this implies that the overexpression of a memory slightly induces the associated emotion. Thus, the overexpression (e.g. due to EMDs) of a memory of a sad event also induces the associated emotion and therefore makes slightly sad.
The effect is extremely weak for a single overexpressed memory and not noticeable. But consider that already after some years of life a quite high amount of memories has accumulated and that many of these memories are slightly overexpressed due to naturally occurring EMDs or due to intrinsic neuronal network activity and therefore slightly induce the associated emotions. Due to these induced emotions, this kind of natural memory overexpression has already a significant (but still very weak) changing effect on one's state of mind. However, also this effect is usually not noticed because its magnitude increases so slowly during the life that one does not notice the significant change in mental state that develops in this way over the years. We just get very slowly used to no longer to feel as vital as before and believe that this is the normal consequence of "wear and tear aging", whilst it is actually our memory that permanently and actively induces this changed mental state.
But most importantly, this changed mental state, which was shifted towards aversiveness by overexpressed memories, is continuously re-memorized as a kind of baseline emotion along with the continuously occurring, usually quite neutral autobiographical events. That means, even though most autobiographical events are emotionally neutral, their memorization permanently adds the aversiveness originating from memory overexpression to the amount of already accumulated aversive memories. In short, memory overexpression, by exerting a slight negative effect on one's mental/emotional state, which in turn is re-memorized, continually increases the amount of weak aversive memories that are overexpressed and in this way drives the aging process.
Importantly, approximately every eye movement engenders a new basic autobiographical event that demands a new emotional assessment and therefore creates an emotional memory. As a consequence, the described self-amplification mechanism of aging creates new memories in the quite high velocity of the frequency of eye movements, i.e. about one memory per second. Theoretically, this may lead to about a billion (!) of weak aversive memories (or rather the respective silent engrams) in a person of 80 years. The permanent anti-homeostatic effect that arises from the slight overexpression of this enormous amount of very weak aversive memories is, in my opinion, the primary driving force of aging (for a discussion of possible alleviating influences of memory decay see chapter 5.4 of emdscientific.pdf). In a similar way, the described mechanism drives aging in all organisms with a nervous system.
One might object to the idea of the continuous formation of weakly aversive memories because it appears counterintuitive in the first place. Why should the very weak overexpression of memories induce an "aversive" mental/emotional state, whilst nobody actually feels this aversiveness and complains about it? This is actually a problem of naming. To better understand this point, it is important to appreciate the following detail: the anti-homeostatic effect of an overexpressed memory actually depends not on its aversiveness but rather on its deviation from positivity. In other words, only the memory of a positive emotional state, like the quite blissful emotional state of a healthy and happy baby, has no anti-homeostatic effect. However, memories produced later in life by the described self-amplification mechanism of aging deviate more and more from this optimal positivity and therefore exert a slight anti-homeostatic effect - even though such memories cannot really be called "aversive". And the cumulative anti-homeostatic effect of the massive amount of such slightly "non-positive" memories finally causes aging.
This article describes the self-amplification of aging in more detail.
Chapter 3.2 of emdscientific.pdf presents two further mechanisms that lead to self-amplification of aging. Briefly, i) cytokine release provoked by MO induces 'sickness behavior', the emotional component of which is continuously memorized and in this way continuously increases the number of memories that are overexpressed, and ii) neuronal inflammation induced by MO causes EMDs which in turn increase MO. (As i developed the EMD hypothesis focusing on disease mechanisms, and not on aging, i overlooked the self-amplification mechanism described on this page because it is only relevant for the process of aging. It is actually very similar to the mechanism described under point i). Please consider it to be part of emdscientific.pdf).