Development is a broad term that encompasses a great number of progressive achievements and abilities. For a child to develop normally they must attain physical milestones like sitting and walking. They must acquire the expression and the comprehension of language. They must be able to retain old knowledge and use it as the foundation for new knowledge. They must learn to relate effectively to the people and the environment around them. Development is a global process where no domain exists in isolation of another. It is rare to find a task that relies solely on one skill which is why if one area is lagging or dysfunctional, the entire process of development is compromised. When these areas of cognition or function are delayed, an individual may be said to be experiencing a developmental delay.
What is Developmental delay?
Developmental delay refers to a pervasive problem that affects one or more areas of a child’s development. It usually takes time to make a clear diagnosis to be sure that the delay is not temporary or due to a treatable condition. Development in children is measured against the usual timeline for certain skills and abilities to appear; these benchmarks are known as developmental milestones and are achieved within a period of time defined as normal. It cannot be expected that every child will progress at the same rate, but there needs to be an age-range that allows parents or professionals to differentiate between children who are slightly behind and those who require attention and intervention.
Because children do not acquire language immediately and cannot be tested for cognitive ability, developmental milestones can be recognized as physical accomplishments such as crawling, sitting without support and standing unassisted. Also, there are speech and language milestones such as monosyllabic and polysyllabic babbling, recognizing common words and combining words and gestures. If these milestones are achieved only slightly later than reasonably expected, the child may catch up eventually and suffer no academic consequences. However, late development and ongoing problems may also indicate a more severe form of developmental delay which can have a limited or overall effect on a child’s life.
Global delay is used to describe the condition of a child who suffers impairments in all developmental domains. Motor delay may be characterized by clumsiness, poor balance and coordination, inability to manipulate objects and poor gross and fine motor skills. Language disorders may be evident through the child’s inability to use and deliver language signals at the expected age, and this may progress into poor reading and language comprehension and limited vocabulary.
Children with developmental delay commonly display unusually extreme reactions to neutral stimuli (e.g.. withdrawing from soft touch) or unusually unresponsive reactions to painful stimuli (e.g.. not reacting to a very loud noise). This reflects a problem with sensory integration, the way sensory information is interpreted by the brain. Any neurological problem such as developmental delay can impact the acquisition of language and the ability to communicate effectively, and learning difficulties may become apparent when the child begins to attend school.
Children with developmental delay do not fail to develop – they just develop at a slower rate than most children of the same age. The progressions still occur and milestones can be eventually reached. Development ceases for all people at a certain stage but the end point for developmentally delayed adults tends to arrive before they have acquired enough skills to allow them to function without impairment. The prognosis for children with developmental delay depends entirely on the severity of their symptoms and has no conclusive or single cause. Some types of developmental problems are inherited and can be predicted or tested such as in the case of Down’s syndrome or dyslexia. Most developmental problems are suspected or found to occur in the critical period of a child’s growth before, during, or soon after birth, either because of infection, nutritional issues, exposure to toxins or a variety of other disruptions or abnormalities.
The physiology of developmental delay
Although a child’s development can be observed, its foundation is neurological. This means that although developmental milestones may not be reached, such shortcomings are not related to the child’s intelligence or physical ability but the way their brain is processing information. Speech and language develop in synchrony with the growing brain. So do motor skills, balance, coordination and sensory integration. If any part of this process is disturbed or abnormal it is highly likely that the resulting problems will not be restricted to only one developmental domain. The only way to understand this is to appreciate how normal development takes place.
When a child is in the womb, the ear is the first organ to mature and become functional and after 16 weeks the child can hear sounds in the uterine environment and the mother’s voice. There are two organs in the inner ear that are responsible for perceiving sound. The cochlea attends to all sounds in the auditory spectrum while the vestibule responds to bone-conducted sound (sound waves hitting the body and the head). The vestibule has the equally important task of regulating the position of the body. It uses knowledge of gravity and where the head is to maintain physical balance and equilibrium and also enables smooth and controlled coordination.
The third function of the vestibule is as a sensory integrator. Because the ear is the first fully matured organ, the vestibule is the primary receptor of information from every sensory system in the body. That is, the vestibule receives all sensory input and relays the information to the appropriate part of the brain. The multitude of problems experienced by children with developmental delay starts to become clearer when the role of the inner ear is explored in detail. Because the cochlea and the vestibule share some of the same anatomical components it is not uncommon for language (cochlea), motor and sensory ability (vestibule) to demonstrate parallel strengths or weaknesses.
Children with all types of developmental delay tend to demonstrate abnormal listening patterns. This is not to say that they have problems with their hearing – the problem exists in how the received sound is transmitted to the brain and interpreted for its meaning. Good listening involves the ability to analyze, perceive, inhibit and differentiate sounds, a system referred to as auditory processing. Listening is essential not only for learning and language acquisition but for communication and self-awareness. The multitude of problems experienced by children with developmental delay can be explained with reference to the inner ear, their pathways and the brain, making these areas important focal points for intervention.
Plasticity describes how sensory stimulation can strengthen old neural pathways and establish new ones. Permanent change in the synaptic organization of the brain can only occur when the exposure to stimulation is intense, sustained and frequent, thus retraining the brain to function at a more efficient level. Earlier work suggested that plasticity was only present in younger children and that the brain became fixed once adulthood was reached but research demonstrates that this is not the case – having said this, the plasticity of children’s brains is certainly greater than that of adults which is why early detection and treatment is so vital. Auditory processing interventions such as the Auditory Integration Listening Program have been designed to optimize a child’s capabilities by making use of the brain’s remarkable ability to be shaped.
Treatment of developmental delay
It is vital that a child with developmental delay is identified early. Although there is no cure or infallible treatment for the condition many types of interventions have been shown to be of assistance if implemented early in the child’s life. There are countless numbers of specific programs and specialists that attend to the symptoms of the disorder. The Auditory Training Program works at ear-to-brain level, stimulating many aspects of basic neurological processes that are functioning poorly. Other therapies that may be used instead or in conjunction with Auditory Training Program include Developmental Movement Therapy, Neurofeedback and other brain training programs.
Combining the Auditory Training Program with Developmental Movement Exercises
Our senses are only useful when the connections from the organ to the brain are operating normally, but children who experience early neurological problems often demonstrate sensory hyposensitivity (under-sensitivity) or hypersensitivity (over-sensitivity). This reflects a weakness in the way sensory information from various parts of the body is integrated and transmitted to the brain. Because the vestibule is where initial sensory integration takes place, the Auditory Integration Listening Program is often combined with a program of Developmental Movement Exercises so that the vestibule is stimulated through both sound and sensory input. This combination assists not only motor coordination and balance, greater physical awareness and better posture, but also improved receptive and expressive language and as a consequence greater confidence and self-esteem may be observed.
When children are born, they emerge from the womb with primitive reflexes: physical responses initiated without conscious thought or intention. These reflexes allow the child to cope with the influx of new sensory information from the post-utero environment, but should soon be overtaken and inhibited by voluntary actions – these are referred to as postural reflexes or postural control. It has been found that problems with neurosensory integration may be attributed to partially uninhibited primitive reflexes. It is through movement that a child develops postural control as every movement stimulates specific neural connections but this is made difficult if the vestibule is not operating normally.
The rationale behind Developmental Movement Exercises (DME) is that sensory systems and reflexes are indivisible and that any existing partially retained primitive reflex can be actively inhibited by exercising the postural equivalent. Postural reflexes have the effect of maintaining and controlling posture, physical actions and equilibrium. Movements can be made because the brain sends messages to the area requiring action. The more often certain movements are performed, the better developed these neural pathways become. Developmental Movement Therapy involves a program of movements designed to retrace motor development as it ideally should have been experienced and it complements the auditory input of the Auditory Training Program, by providing the vestibule with additional stimulation, leading to accelerated improvements in motor control and coordination.
Developmental Movement Therapy and the Auditory Training Program both work at brain level, and they attempt to normalize many aspects of basic neurological processes that may be functioning poorly. This facilitates improvements in many areas and directly assists any subsequent interventions that address the manifestations of developmental delay.
In order to recommend the most appropriate intervention it is necessary to attend an assessment at the centre.