Now the concept of critical and sensitive periods provides insight into what might be happening during the phases of acceleration and regression of the child's sport performance. Contemporary child development theory suggests that neural circuits controlling critical organ systems, such as breathing and heart rate and reflexes are prewired. However, other neural circuits are rudimentary, and their formation depends on the child's environment. If neural connections are not activated or are only weakly activated they will be pruned and the well used neurons become integrated into the circuitry of the brain. It is this existence of the rudimentary pathways that are of particular interest to us in terms of developing athletic potential. All your athletes will have been exposed to different movement experiences and therefore their rudimentary circuits will be wired and mature in slightly different ways. Even identical twins are wired differently because their movement experiences are not identical. Two streams of research help us understand how rudimentary circuits become fully wire and integrated into brain functioning. In one stream of research relates to the effects of exposure the child has to enriched environments. And the other, relates to the timing of this exposure to these environments. And this is where the notion of critical and sensitive periods become important. Most of our knowledge about the environmental effects of rudimentary nervous system pathways come from studies comparing the brain structures of animal raised in two different environments. One was at deprived environment and the other was in enriched environment. Animals in the enriched environments are given the opportunity to interact with toys and treadmills and obstacle courses. Now animals placed in the enriched environments had larger brains with more synaptic connections than animals raised in the deprived environments, where there were no toys. And this research illustrates the importance of the environmental stimulation on overall brain development. Extrapolation of this research to the sports setting suggests that exposure to various forms of movement will have an impact on the development of the athlete's brain. And possibly affect their sports potential. Animal research also instigates that there are critical periods and sensitive periods for exposure to the enriched environments. Now, the two critical period, refers to stages in the child's movement development with certain type of movement exposures appear compulsory for optimal development of a particular sport skill later on. Lack of exposure during the critical periods could permanently affect the child's ability to perform that skill effectively later on in life. The cortical areas allocated for a particular skill do not adapt in the correct way. And no amount of remediation can completely make up for this lack of adaptation. The research on vision and lack of exposure to language has consistently shown the importance of early exposure for optimal development of both vision and language. And the notion of the existence of critical periods in a growing child's life is the driving force behind intervention programs, such as the government sponsored Head Start programs. However, the research does become a wee bit fuzzy when we start examining the development of motor behaviors. While missing the appropriate stimulus during a critical period can negatively affect future abilities, missing a sensitive period merely delays the development of that ability. In the case of motor abilities missing a sensitive period makes it more difficult for the child to learn the skill and learning can take much, much longer. However, the skill can still be learned to a fairly proficient level. Now from the perspective of maximizing sport performance, what impact does this animal research on enriched environments, the critical and sensitive periods have all now understanding of motor skill development for sport. Does this really suggest that a child's ability to reach their genetic ceiling for a sport will be permanently impaired? And these remain largely unanswered questions and still are very, very highly debated. The long term development of the athlete in many countries though is founded on the notion of enriched environments in conjunction with the existence of these critical and sensitive periods. Although the distinction between critical and sensitive periods becomes rather muddled. Long-term athlete development researchers talk more in terms of optimizing the individual motor development and tend not to discuss the possibility that missing a critical or sensitive period leads to permanent damage. Instead the belief is for now anyway that the hypothetical windows of opportunity narrow but do not completely close. So with this background we will now discuss the windows for motor ability development. And will only refer to sensitive periods and ignore the possibility that critical periods exist. If we just focus on sensitive periods, we're assuming that the window of opportunity can narrow or even possibly, close. But the skill can still be learned, albeit at a much slower and more difficult rate.
