Loss of memory and decline in overall mental faculties afflicts many people as they grow older, with devastating consequences to the individual and loved ones. But what happens to the real person, the inner human, during this process? Does the soul Memory also decline?
In such cases the issues are physical and therefore based in the brain, so the soul remains basically unchanged, although the interfaces between brain and soul are diminished. These issues result from diseases, syndromes, and also trauma, so all are not equal. Recall we discussed previously how the interface between brain and soul is like a wireless connectivity, because the brain is physical and the soul is immaterial. So the connection starts out as electrical in the brain and is converted into immaterial in a system only God could design, which is why science cannot understand or locate it. The soul relies on the brain to take in and transmit sensory data so it can understand and communicate with the outside world. These dysfunctions affect the brain side of the equation but not the soul side. But why is the person confused about functions inside the soul, such as memories related to humanity? If they are still there, why can't they be used internally to the soul even if they cannot get out through the brain?
The answer is that the soul is not designed to function isolated from a body, either during the natural lifetime or during eternity. If the brain is damaged or diminished as with Alzheimer's, Dementia, or trauma the soul may not be as capable of communicating with itself about self-awareness status and internal functions such as memories. The soul can only operate correctly from inside a support structure which is working as required, meaning a physical body while living on earth, or in an eternal body later. The soul is not a closed loop system, meaning it cannot send or receive finalized information inside of itself without outward communication capability outside of itself. Which means that without support from the brain, or a new body during eternity, the soul cannot express itself. And when the brain is diminished, the overall process of brain to soul and back to brain information flow is diminished.
Therefore the person who has diminished mental functions has reduced ability to develop new thoughts internal to the soul. The level to which this occurs depends on the degree of impairment, so it is not all or nothing. But if the brain is fully unconscious, the individual involved cannot communicate at all to self regarding the internal status of the soul, even though the soul has remained unchanged. So to the extent the soul intake through the brain has been diminished, that soul has a reduced ability to form new information internally beyond the capabilities of what the brain can accommodate. Because these types of diseases and syndromes shut off the soul to some degree, the soul becomes increasingly isolated, but otherwise the same person is inside even if they act differently.
The point here is that although the brain is diminished, the soul status will remain generally static until death, when the soul departs and is placed into a new body, first into a temporary one until their resurrection occurs, and later into a final body at the resurrection. For Church Age believers, the final resurrection is called the Rapture of the Church. Therefore, after death the believer's soul and human spirit are taken to Heaven where they are placed into a temporary body, and soul functions and memories become available again at that moment. However, the memories stop at the point new information could no longer effectively be taken into the soul while still alive. For unbelievers, there is also a new body after death, and it is designed for their eternal state, which is much different. They will also have memories, but will only serve to feed their regrets of failure to do the one thing required of them to be saved.
The important issue to understand is that the soul of the loved one who is a believer remains fully functional and unchanged inside the body and will be set free at the point of death and placement into a new body, with memories intact. It should therefore be comforting to know that this condition is only temporary, that the soul of the person remains unchanged, and after death will be the same person with soul memories intact. Then all involved can pick up where they left off.
In a similar way, those who are born with issues which restrict mental development may not be able to fully develop the soul due to limitations in brain capabilities. In such instances, the brain cannot provide the soul with certain types of high level data in the required format to develop soul capabilities to think in more complex ways, whether in limited areas or broad-based. In other instances the soul can become more fully developed, but the brain cannot export the results to the outside world due to limitations on the outbound part of the brain. The person is forced to live a more sensory life, and more out of the brain with less soul involvement, which means less soul control over their actions. This may result in the Emotion exerting more control than the logical soul components so that logical thought may be difficult. Often the brain and soul fight each other due to mismatches in capabilities, and when the person sees others around them demonstrate far superior capabilities, frustration can result. There are many variations, so this is just to explain that brain to soul, and soul back to brain interface issues can cause soul isolation or inability to perform in some areas.
If the impact is severe enough so that the soul cannot make informed decisions about God, He does not require them to believe in Christ as Savior for salvation, and it is automatically provided by a gracious, merciful, and fair God. And since the soul itself is not limited, it will be set free during eternity.