critical period

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crit·i·cal pe·ri·od

1. in the first hours after birth, the period of maximum imprintability; the period before and after which imprinting is difficult or impossible;
2. in animals, a period following birth when the processes underlying the capacity for socialization are activated or stamped in;
3. Synonym(s): amblyogenic period

critical period

Paranormal
A point in a biological rhythm (biorhythm) that occurs when an individual crosses the middle of a cycle, either from a high to a low or a low to a high; during critical periods, the person is believed to be more accident- and illness-prone.

period, critical 

A time after birth during which neural connections can still be modified by interference with normal visual experience or lesion of the visual pathway. If a person has an anomaly (e.g. amblyopia), the treatment is most likely to be effective during the earliest part of the critical period. In man it lasts up to about seven to eight years of age. If neural connections are impaired permanently during this period it will usually be impossible to repair later and the younger the child the more damaging it is. Example: binocularly sensitive cortical cells (stimulated by normal binocular vision) may never develop in uncorrected strabismus, or prolonged occlusion occurring during the critical period, especially before the age of three, and therefore the patient will not have binocular vision. Syn. plastic period. (However, this term relates more specifically to the time course during which the visual system is still responsive to treatment. This may differ from the critical period of development); sensitive period. See form-deprivation myopia; occlusion treatment.

Patient discussion about critical period

Q. what is the most critical period of pregnancy where i should be more aware? to the environment , diet ... and things like that...

A. The most critical, is unfortunately, the period with the highest chances of the pregnancy not to be noticed - the first weeks of the pregnancy. During the first eight weeks of pregnancy the various organs of the body develop most substantially, also called organogenesis. This is considered the most sensitive period. However, the fetus may be sensitive to insults during the whole pregnancy, so other periods are not "safe".

you may read more here (www.nlm.nih.gov/medlineplus/birthdefects.html)

More discussions about critical period
References in periodicals archive ?
A critical period is a developmental stage during which the nervous system is especially sensitive to environmental stimuli.
ETSO identifies the most critical period as December and January, albeit excluding the holiday period.
Developmental effects of chlorpyrifos extend beyond neurotoxicity: critical periods for immediate and delayed-onset effects on cardiac and hepatic cell signaling.
Bruer's three myths are that learning is limited to "windows of opportunity," or critical periods; that these windows of opportunity occur only as long as there is a significant growth of connections, or synapses, between brain cells; and that children require enriched environments for optimal learning to take place during these windows of opportunity.
"Everybody's favorite example of critical periods is Henry Kissinger," Bruer adds.
The three strands of this Myth & early synapse formation, critical periods, and enriched environments & are all derived, Bruer points out, from developmental neurobiology.
"A baby's intelligence depends as much on the levels of thyroid hormone reaching the brain during critical periods of development as on inheriting smart genes," write the authors of Our Stolen Future, a groundbreaking book that made the connection between pollution and reproductive abnormalities.
Topics discussed include different paths to bilingualism; emphasis on the whole child; observing the child's behavior in natural communicative settings; cognitive academic language proficiency; the importance of high expectations; speech skills; a cost-benefit perspective; residual hearing; critical periods and spoken language; critical periods and sign language; and the importance of natural language.
In critical periods like the present, the emphasis should be on monthly monitoring, perhaps even weekly monitoring in the case of critical situations.
By studying the relationship between maternal iron intake and fetal iron levels through a diet study, the team was able to pin down the critical periods of gestation when the developing central nervous system was most vulnerable.
Serotonergic systems targeted by developmental exposure to chlorpyrifes: effects during different critical periods. Environ Health Perspect 111:1736-1743.