The brain structure is preordained so the missing sensory input still indirectly affects perception. The lost sensation remains implied in the interpretation of the redirected information because the nervous system is hard-wired. Thus a touch near the insensitive scar is interpreted as coming from a region of the skin that includes the scar implying the skin is intact.
In effect the redirection of sensory input from the active sensory areas toward the deactivated area is a substitution of the missing sensory input with that of the intact somatosensory pathways. The reactivated sensory area delivers atypical information to the parts of the brain involved in the interpretation of sensory perception.
The lost sensory input cannot be regained. It can only be substituted. The regions of the brain that normally receive the information of the lost receptors become engaged in interpreting that of the existing ones. They do not know that the input they receive is aberrant. So the redirected sensory input is unconsciously associated with the quality of the missing one in the perception. The lost sensitivity mixes with and tints the existing sensitivities. Its quality infiltrates them. The lost sensory input creates gaps in perception and reduces the accurateness of discrimination while its substitution falsifies it.
The cortical reorganization ensuing from the loss of receptors develops abstract reasoning that re-creates the idea of the missing sensation and tends to integrate it into the existing ones.This type of associative reasoning that blends virtual and actual sensations relates to ideasthesia,[ii] a phenomenon in which concepts evoke perception-like sensations. With regard to their effect on perception the ideasthesia is conductive to confabulation[iii] and paramnesia, which are psychiatric terms referring to genuine falsifications of memory.
Both synaesthesia and ideasthesia are ordinary cognitive phenomena and only their highest forms are rare. The same must be valid for confabulation and paramnesia. For instance, it is not so rare an occasion that one begins to believe that he really took part in some story that he only observed or even only heard of especially after he repeatedly narrated it. The fabricated memories alter the perception of the present and shape the future in the same way as mythology does.
The cortical reorganization ensuing the loss of sensation fosters the abstract and associative reasoning. The former simulates the missing sensitivity by replacing it with a concept while the latter incorporates it in perception. The cortical reorganization modifies the actual sensations by imprinting them with a brain-generated feeling.
The associative reasoning ensuing the loss of receptors tends to falsify reality in perception much the same way as cortical reorganization substitutes for the missing sensitivity. Whatever is the psychological term that best describes this, one thing is certain: the loss of receptors favours the forming of new associations and relates the missing sensation to them.
The associative reasoning fostered by the loss of receptors embeds a virtual sensation in the existing ones. The implanted sensation is more autonomous, subjective, uncontrolled and capricious than the ordinary associative reasoning because it is disconnected from its origin and lacks informational feedback.
With the advance of the cortical reorganization the lost sensitivity gradually distributes among and merges in a greater number of brain activities which authenticates the implanted sensation. The gap in perception is filled in a trustworthy manner so the sufferer is unaware or at least unsure of its existence.
- Paramnesia (Psychiatry) – a distortion of memory in which fact and fantasy are confused. [Webster’s Dictionary]; A disorder of the memory or the faculty of recognition in which dreams may be confused with reality [World English Dictionary]; A distortion of memory in which fantasy and objective experience are confused. [Medical Dictionary] → Back