Is the Filter Theory committing the ad hoc fallacy and is it unfalsifiable?

To my thinking, the brain acts perhaps as something closer to a "limiter", in that it restricts the memories and experiences that the mind may have access to. Like the "filter" analogy, it is imperfect and incomplete, because it does not and cannot really explain entirely how the brain functions. But it explains some aspects.

I agree that this is the type of thing that one would expect to observe if the brain is just a device that transmits information to the soul.

I keep using the illustration of my grandmother, who had had a stroke, forgetting that I had come to visit her. The filter theory says her eyes and ears sensed my presence and transmitted data to her brain. The brain somehow manipulated that into information that the soul could understand. Had the brain been functioning normally, the essence of the message could be described as:

Brain to soul: There is a guy here that looks like your grandson. He says, "Hi, how are you doing." Over.

If the filter theory is true, then one might expect grandma's soul to hear something like:

Brain to soul: [static] a guy [static] that looks like someb...[static] er uh [static] Hi are [static] doing [static]

And grandma, that is, her soul, would still be grandma, still alert, and would be trying to figure out the garbled messages coming from the brain. All of that is consistent with the filter theory.

But what actually happens could be illustrated as:

Brain to soul: There is a guy here that looks like your grandson. He says, "Hi, how are you doing." This message will self-destruct in 30 seconds.....[pffft!].

That is the part that makes no sense from the filter theory. Altering the message that got to grandma would be expected. But adding in that self-destructing aspect of the message, that simply makes no sense.

If we say that a damaged brain can indeed generate such a message, that is indeed an ad hoc fallacy. It is simply making up that brains can make their messages to the soul become self destructing. There is no way dualism or idealism predicts this. It is simply an ad hoc explanation thrown in there to explain what is observed.