Hebbian plasticity induction (associative pairing)

The deliberate use of a BCI to satisfy Hebb's postulate — making an upstream (presynaptic) event reliably precede and help cause a downstream (postsynaptic) one, so their connection strengthens. In practice this is associative pairing: repeatedly co-activating two sites, or a descending command and its afferent feedback, with the correct order and lag, aiming to induce a long-term-potentiation-like change in the pathway between them. It is the mechanistic core shared by spike-triggered stimulation, paired associative stimulation, and contingent-feedback rehabilitation BCIs.

Honesty: inducing an LTP-like change in a controlled experiment is well demonstrated; guaranteeing that it maps onto a specific, lasting, behaviorally-useful gain in an injured human is much harder. Induction is sensitive to timing (on the order of milliseconds to tens of milliseconds), to the states of both sites, and to homeostatic limits, so a protocol that works in one subject or session may not transfer.