Maladaptive plasticity

Plasticity is not intrinsically restorative; the same activity-dependent mechanisms can entrench unhelpful patterns. Examples include learned non-use (the paretic limb is used less, so its cortical representation shrinks, worsening disability in a vicious cycle), maladaptive cortical remapping underlying phantom-limb pain, focal hand dystonia from excessive co-activation, and spasticity-related circuit changes. For a plasticity-driven BCI this is the central risk: a poorly-timed or wrongly-targeted pairing can strengthen compensation or the wrong connection rather than recovery.

Honesty: distinguishing adaptive from maladaptive plasticity in an individual is often only possible retrospectively, by outcome, which complicates real-time dosing. Therapies such as constraint-induced movement therapy are explicitly designed to reverse learned non-use, illustrating that the goal is to steer plasticity, not merely to maximize it.