FOCUS ON EARLY CHILDHOOD

Critical Windows of Opportunity for Learning

The brain research of the past two decades has provided solid scientific evidence of the neuroplasticity (the remarkable capacity to change and adapt to environmental conditions) of the human brain. The neurological research has shown that the brain is not a static, fixed entity from birth and that there are few preset limits to an individual’s learning potential. Through the use of sophisticated brain imaging techniques, scientists have been able to document the energy levels in different areas of the developing brain (the developing brain is nearly twice as active as the brain of an adult). The results of this research has led to the notion of critical windows or periods for brain development (when synapse density and metabolic activity in specific parts of the brain are very high) in which the brain is particularly efficient at specific types of learning.

The theory of critical windows for learning is best illustrated by a Nobel prize winning study by David Hubel and Torsten Wiesel. In this study, Hubel and Weisel showed that sewing one eye shut on a healthy kitten resulted in permanent vision loss in the animal. The study concluded that the lack of visual stimulation during the critical period for vision development prevented the formation of the necessary neurological connections between the eye and the visual cortex of the kitten’s brain. Once the critical window for vision development was closed, it was impossible to establish the neurological connections for vision (Markezich, 1997).

The idea of critical windows for learning has important implications for educators, parents and child care providers. It is now well documented that appropriate environmental stimuli is crucial for the brain to develop to its fullest potential. Timing the presentation of that stimuli is also critical. Several of the critical windows of opportunity are discussed below.

Vision skills have a window of opportunity from birth to 6 months of age. The permanent neural connections are formed by visual stimuli. If the developing child was deprived of light and a visually stimulating environment during this window, sight would not develop.

The critical window for the development of speech and language skills is birth to 3 years with the first two years being the most important. The vocabulary of an adult is determined to a great extent by the speech they heard during their first three years of life. The brain concentrates on the phonemes that make up syllables and words in the child’s native language and builds connections that allow us to recognize those sounds and attach meaning to them as words. If the child is not exposed to language during this time, either due to a hearing impairment or lack of adequate auditory stimuli, speech will not develop properly.

The critical period of development for emotional skills occurs from birth to 18 months of age. During this time, a child’s genetic heritage interacts with the environment to influence personality traits. A nurturing environment can help to build connections that foster emotional stability. In contrast, negative experiences, such as neglect or abuse, can result in a child who is anxious, fearful and unable to form healthy attachments to others.

Math and logic skills have a critical window of opportunity from age 1 to age 4. Exposure to quantitative concepts such as few and many, heavy and light, little and big, and thin and thick help to develop critical thinking skills in the developing brain. Sorting tasks, counting games and music also enhance the development of math and logic skills.

These critical periods of brain development illustrate the importance of a stimulating, enriched environment and age appropriate activities for the developing child. When critical windows of opportunity for learning are missed, it doesn’t mean that a child will never be able to learn a specific skill. It just means that it will take more effort to learn that particular skill.

Early childhood educators need to be aware of these critical periods for learning. Early experiences have decisive and long lasting effects on the developing child. The results of this new research provide evidence that young children who are exposed to positive, stimulating environments can overcome a wide range of developmental problems and actually increase their lifelong learning potentials.

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