The importance of early intervention

Early intervention is a term that describes the need to begin habilitation services as soon as disability is confirmed. It is the course of action taken to achieve the proper steps to obtain the services needed by the child (Northern & Downs, 2002).

During the past decade, research has gained new insights in regard to the development of the brain and the nervous system. Technologies such as brain mapping and brain scan have helped to understand the developing brain in greater details than ever before. One very important conclusion is that the brain development that takes place in the first 12 months of life is more rapid and extensive than previously realized. It is known that the brain is not a rigid structure but a “plastic”

organ, which can reorganize itself based on sensory and motor input. This phenomenon is known as neuroplasticity.

During the first three years of our life, the neurons in the cortex achieve maturation. Sensory activity stimulates the neuronal connections from the brain stem to the appropriate areas of the cortex. Then, the brain’s general organization does not change significantly. All this accumulative knowledge requires that more attention be focused on the importance of early childhood intervention (Nelson, 2000; Northern &

Downs, 2002).

Scientists have shown that the developing brain is much more vulnerable to environmental influence than previously suspected. It is capable of being modified by both deleterious (stressors) and beneficial (enriched environments) experiences (Nelson, 2000). For example, malnutrition before birth and during the first years of life can seriously interfere with brain development and can cause neurological and behavioral disorders, including learning disabilities and mental retardation (Carnegie Corporation, 1994). Other environmental factors such as drug use and stress may also affect prenatal and early postnatal brain development (Nelson, 2000).

The phenomenon of auditory system plasticity is supported in animal experiments (Sininger, Doyle, & Moore, 1999). There is evidence that the developing nerve, brainstem nuclei, and auditory cortex have the capacity to change during normal development and during times of interrupted sensory input. Experimental

evidence showed also that reintroduction of sensory input after auditory deprivation induces further plastic changes, and deleterious effects may be reversed only during early developmental stages. Research evidence obtained in animal anatomic studies supports the view that a critical period may exist for intervention to ameliorate the experimentally created deficits. This means that during that window of time, the experience a person is exposed to, will have its peak effect on the development. After that period, the same experience will result in a reduced effect or sometimes even in no effect at all. The human brain growth spurts begin to slow down around 10 years of age. These physiologic findings, confirmed by modern neuroscience, show the importance of early intervention. Although the adult nervous system continues to lay down new synaptic connections as one learns new ideas and skills, never again will the brain be able to assimilate and master new information so readily as during the first three years of life (Northern & Downs, 2002).

A report of the Carnegie Corporation (1994) summarizes five key findings that should inform the efforts to provide children at the earliest possible age with a healthy start:

1. The brain development that takes place during the prenatal period and in the first year of life is more rapid and extensive than was previously realized.

2. Brain development is much more vulnerable to environmental influence than was ever suspected.

3. The influence of early environment on brain development is long lasting.

4. The environment affects not only the number of brain cells and number of connections among them, but also the way these connections are "wired."

5. There is new scientific evidence for the negative impact of early stress on brain function.

Nelson (2000) refers to two key cognitive systems that are likely to be central to the success of early intervention that target intellectual development (p. 211):

• The ability to remember and recall events (i.e., explicit or declarative memory);

• The ability to engage in planning strategic activities (executive functions).

Sharma, Dorman, and Spahr (2002) emphasize the fact that in the absence of normal stimulation, there is a sensitive period of about 3.5 years during which the human central auditory system remains maximally plastic. They write that plasticity remains in some, but not all children until approximately age seven and after this age, plasticity is greatly reduced. They recommend taking these relevant data into consideration when dealing with the issue of when best to place a cochlear implant in a congenitally deaf child. This has recently been validated in the growing body of research on the topic. For example, Kirk et al. (2002) examined the effects of age at implantation on the development of communication abilities in 73 children with early implantation. The children who underwent implantation before three years of age had significantly faster rates of language development than did the children with later implantation (which was before five years of age). In another study of 47 implanted children ranging in age from 9 to 48 months at implantation, Hammes et al. (2002) found that the best outcomes occurred in children who underwent implantation at or before 18 months of age. Several of these infants even demonstrated age-appropriate spoken language skills (see also Huston et al., 2003; McConkey et al., 2004)

Nelson (2000) hopes that the understanding of the principles and methods of developmental neurobiology will ultimately facilitate the design of more effective intervention strategies and more thorough evaluations of their impacts.

With regards to the beneficial experience that can modify the brain, parent-child relationship is both a context and a mediator of optimal child development. Prizant, Wetherby, and Roberts (2000) indicate that as communication enhancement approaches have become more focused on interactional and relationship variables rather than child variables alone, a primary intervention goal is to work closely with caregivers, who have become primary intervention agents. Clinicians are trying to discover interactive styles and strategies that will best support a child’s communicative development and socio-emotional competence (see Prizant, Wetherby, & Roberts, 2000, p. 293, for reviews). As Mashie et al. (2005) write: ”It cannot be stressed enough that subsequent delays in one or more areas of development may result from failure to facilitate age-appropriate development of communication skills” (p. 4).

The increased acknowledgment in the value of music therapy has resulted in its incorporation into many health and educational settings as part of early intervention programs in medical, social, psychological, and/or cognitive areas due to its positive

outcomes. Some examples of these may be found in Humpal, 1990; Plahl, 2004;

Standley, 1991; Standley & Hughes, 1996.