Definition
Critical periods are windows of heightened plasticity for specific developmental processes (e.g., vision, language, attachment). They are more open in early life but not universally closed thereafter.
Why it matters
The line between "critical" and "sensitive" periods matters for reasonable expectations about intervention timing.
The Science
Some systems (e.g., vision in ocular dominance columns) have relatively strict critical periods; others (language, motor skills) show substantial adult plasticity. Molecular mechanisms of critical-period closure are increasingly understood.
The NSI Perspective
NSI treats critical periods as biological windows to respect — without turning them into verdicts on late intervention.
Clinical Implications
Early intervention has strong evidence; later intervention is often still meaningful.
Practical Application
If timing was not ideal, that is not a life sentence. Adult plasticity is real — slower, but real.
References
- 1.Hensch TK. Critical period plasticity in local cortical circuits. Nat Rev Neurosci. 2005;6(11):877–888.