Psyfield

    简 繁

    Topics

    All terms About

    Sensitive periods

    敏感期

    Concept
    Also called
    Sensitive periods in brain development

    A sensitive period is a limited time in development when experience has an unusually strong effect on a neural circuit. When that experience is essential for normal development and its effects cannot be reversed, the period is called a critical period, a special case of sensitive period.[1]

    Select a row for details. The first three rows come from studies of children born with cataracts; the dashed line marks the often-quoted age of three.
    Three sensitive periods for human visual acuity, from studies of children treated for congenital cataracts. Bar ends are approximate ages and the fades mark a gradual end, not measured curves; the adult row is schematic. Point at or tap parts of the figure for details
    Three sensitive periods for human visual acuity, from studies of children treated for congenital cataracts. Bar ends are approximate ages and the fades mark a gradual end, not measured curves; the adult row is schematic. Save as image (PNG)

    Key points

    • Different circuits have their sensitive periods at different ages: those for basic sensory analysis end early, those for language or reading facial expressions much later.[2]
    • Human visual acuity alone has at least three: normal development runs to about 5–7 years, vulnerability to damage to about 10, and the capacity to recover to about 5–9.[3]
    • “The critical period for language” is too simple: circuits for phonetic analysis pass through sensitive periods, while those for word meaning stay plastic throughout life.[1]
    • In animals, maturing inhibitory neurons open critical periods and “brakes” such as perineuronal nets and myelin close them; lifting the brakes restores some plasticity in adults.[4]

    An example

    Jay started Japanese at 30. Years later his vocabulary and grammar are solid, yet colleagues in Japan can tell at once that he is not a native speaker. His six-year-old daughter, after a year at a Tokyo school, already sounds like her classmates. This fits findings that speech-sound circuits have sensitive periods while word learning stays plastic.

    Misreadings and limits

    The most common misreading is that once a window closes, learning becomes impossible. The National Scientific Council on the Developing Child calls claims that it closes at age three unfounded; for most functions it stays open well beyond. Many circuits remain substantially plastic after their sensitive period, though change is harder.[1][2]

    Sources

    1. 1 Knudsen, E. I. (2004). Sensitive periods in the development of the brain and behavior. Journal of Cognitive Neuroscience, 16(8), 1412–1425. doi:10.1162/0898929042304796
    2. 2 National Scientific Council on the Developing Child (2007). The timing and quality of early experiences combine to shape brain architecture (Working Paper No. 5). Center on the Developing Child, Harvard University. View source
    3. 3 Maurer, D., & Lewis, T. L. (2013). Sensitive periods in visual development. In P. D. Zelazo (Ed.), The Oxford handbook of developmental psychology, Vol. 1: Body and mind. Oxford University Press. doi:10.1093/oxfordhb/9780199958450.013.0008
    4. 4 Hensch, T. K., & Bilimoria, P. M. (2012). Re-opening windows: Manipulating critical periods for brain development. Cerebrum: The Dana Forum on Brain Science, 2012, 11. View source

    Last checked against sources: October 26, 2026