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The Hemispheres Conceptual Model (HCM) of practice puts forward theories to explain the key elements which underpin both the Hemispheres Neurological Assessment (HNA) and the Hemispheres Treatment Programme (HTP). It provides explanations for problems which arise in association with developmental delay, learning difficulties, general delays in skills acquisition and neurodevelopmental disorders. This conceptual model illustrates the complex and dynamic relationships that are present in a theory concerned with the holistic assessment and treatment of an individual.

The Hemispheres Conceptual Model (HCM) shows the multifaceted and dynamic relationship between:

1. the child,
2. the evolution of the neurological system which predominantly underpins the development of functional skill development, cognitive and academic success, play, social and communication skills, and physical development.

All of these occur whilst the child openly interacts with their environment, and is influenced by their familial and social culture.

The Components of the Child

The child being assessed is viewed as an open system. This system is comprised of interrelated subsystems. These subsystems interact with each other. They influence emotional and behavioural responses as well as the production of functional skills.

Subsystems:

1. The cognitive-brain-body subsystem.
2. The routine subsystem.
3. The motivational subsystem.

The cognitive-brain-body subsystem is responsible for ‘what we have to do it with’.  This subsystem provides the structures that support a child in developing and learning new skills. 

These structures include (a) musculoskeletal, the joints and muscles which constitute the physical ability to move; (b) neurological, including the central and peripheral nervous systems; (c) cardiac and respiratory systems, and (d) cognitive or intellectual processes.

Hemispheres emphasises the role of the neurological system in the development of both musculoskeletal and cognitive processes. Hemispheres asserts that these systems are dependent on the correct ‘wiring’ of the neurological system for them to evolve and mature.

Children who have neurological impairment at birth can equally be understood within the context of this model, as they will present with a different pattern of responses and behaviours in their social, play and communication, physical, functional and cognitive development.

The routine subsystem organises the ‘what we do’ and ‘when we do it’. In young children there is a strong interaction between this subsystem and that of the child’s environment. This subsystem evolves as the child learns to influence their environment. It also impacts on their behaviour and emotional responses.

The motivational subsystem determines ‘why we do what we do’ and relates to the choices children make in their play, interactions, interests and activities. Children with a neurodevelopmental delay often show limited motivation and choice in their interactions and play. This system provides a link between physical development and the other quadrants of the model.

Within the theoretical framework of the Hemispheres Model we view the child as an open system that interacts with the environment and produces output in the form of skills. The developmental skills a child learns are perceived as ‘prescribed’ sequences of actions which are relevant to their culture and chronological age.

Evolution of the Neurological System

Hemispheres Hierarchical Level of Neurodevelopment, Motor Control and Integration

As stated, Hemispheres emphasise the role of the neurological system in the development of both musculoskeletal and cognitive processes. We assert that these systems are dependent on the correct ‘wiring’ of the neurological system in order for them to evolve and mature. Let us now consider, therefore, the primary importance of this system and how the primitive and postural reflexes are intrinsically woven in its evolution and influence.

The neurological system is a dynamic and highly interactive system which comprises of many structures with specialised function. It is  unique in the area of human development because it matures across three decades, and is hugely influenced by the environment in which the child is exposed.

In considering this crucial system we will look at:

1. Foetal Development
2. Neuromaturation
3. Cortical Control

Foetal development is essentially directed by the development of the structures and immature neural connections within the central nervous system. This process is part of ‘nature’ and is predetermined by evolution. The primitive reflexes are woven into the central nervous system at this stage.

At birth there is a predictive pattern of involuntary responses a baby is expected to display. These responses guide and influence the interactions the child has with their environment. The primitive reflexes create these vital involuntary responses and aid survival of the newborn.

Neuromaturation is the process which stimulates the CNS from the spinal cord up to the cortex. Stimulation generates the maturation of the different levels of the CNS. This coincides with the development of the postural reflexes and functional motor, sensory, interaction skills of an infant under 12 months of age.

By 3 years of age, it is expected that the cortex has developed a degree of influence and control on the child’s body with the presence of more dynamic motor skills, speech, play, cognition and functional skills which will be present as a result.

Neuromaturation facilitates the natural emergence and curiosity in children in four quadrants of development:

• Physical skills
• Play, Social and Communication skills
• Functional Skills
• Cognitive and Academic Skills

Cortical control, being the ultimate level of organisation within the CNS, implies the full and complete integration of the primitive and postural reflexes. Expected by the age of 4 years, it prepares the child for their entry into education. Cortical control continues to mature over the next 20 years.

Hemispheres asserts that the development of the neurological system and the proper emergence and inhibition of the primitive and postural reflexes within it:

• Follows a predetermined path.
• Is central to the evolution of the diverse skills children develop most noticeably in the first 10 years of life.
• Is fundamental to the overall process of development.
• Influences the emergence of other skills over time through the interaction of the cognitive-brain-body subsystem and the environment

The HCM conceptualises the neurological system, and the reflexes within it, as the driving force of the child’s development. If this system shows errors or becomes disrupted there will be a knock-on effect to one, some or all of the other areas of development.  

Hemispheres asserts that the process of neuromaturation is key to understanding the development of normal sensory, motor, emotional, behavioural, language, play and academic skills. However, foetal development underpins the success of neuromaturation.   Both stages, therefore, determine the overall level of cortical control and development.

Assumptions Underpinning the HCM   

As discussed above, the HCM is underpinned by the following assumptions regarding the development of the neurological system:

• The neurological system develops cephalocaudally.
• Reflexes form the basis of neural development.
• Reflexes predict neural maturation.
• Neural maturation predicts functional ability.
• Reflexes are the foundation for motor, sensory, emotional, functional and cognitive development.
• Reflexes work together in a sequence to achieve a common goal.
• Different structures in the CNS levels are able to act upon other structures and other levels.
• All children need to follow the same sequence of development, regardless of gender, culture, injury, disease or trauma.
•  The reflexes contribute to the CNS’s ability to process internal and external sensory stimuli.
• Certain infant reflexes group together to produce spatial, temporal, emotional and functional behaviours.
• Higher centres of the CNS can exert control over the lower centres of the CNS as a means of compensating for ‘atypical’ patterns of development.
• Persistence or presence of reflex activity within any system can contribute to ‘atypical’ development of the Cerebral Cortex.
• Treating the reflexes can produce functional and academic improvement in the ‘typically developing’ child.
• The reflexes influence learning through the level of integration of different CNS structures

Definition of the Four Quadrants of Development within the HCM.

The four quadrants defined within the HCM encapsulate the type of skills a child is expected to develop if they are to meet developmental milestones. Assessment of these four category groups determines if a child is meeting expected targets for their chronological age. If a child is at risk of developmental delay, then the quadrants are used to determine diagnostic categories. Ultimately, delays in the acquisition of these skills can indicate neurological immaturity. Assessment using the Hemispheres Neurological Assessment can pinpoint where these delays are likely occurring within the neurological system itself.

The Four Quadrants of Development:

1. Physical
2. Play, Social and Communication
3. Cognitive and Academic
4. Functional.

Hemispheres assert that skill acquisition in the Four Quadrants of Development is directly related to hierarchically ordered and correlating structures within the brain, and to their full and proper development, interconnectivity and maturation. This occurs in a cephalocaudal direction. Each level requires consolidation and is a foundation and stepping stone to the next. As connectivity and maturation occurs at each level skills are acquired in a step wise and commensurate manner.

Level 1:             Lower Brain Stem: Medulla,

Level 2:             Brain Stem: Cerebellum, Pons,

Level 3:             Mid Brain:  Limbic System, Hippocampus and Basal Ganglia

Level 4:             Cortex:  Thalamus, Hypothalamus, Right and Left Hemispheres and Corpus Callosum

Physical Development

Physical development is simply the physical manifestation of the connection and control the brain has with the body and how it initiates, processes and controls the behavioural responses the body makes. This offers a concrete and active way of interacting with the environment, facilitating learning and development of play, communication and functional growth.

Hemispheres asserts that the physical movements a child makes form the first level of communication that they have with their environment. This level of interaction forges more determined pathways of communication within the cognitive-brain-body subsystem. If physical skills are restricted in early life due to ill health, hospitalisation, injury or disability then a child’s ability to learn and develop will be affected.

The child’s observable physical skills are a behavioural manifestation of neurological connections. They reflect the evolution of the reflexes, their emergence, development and inhibition. This quadrant is influenced by the functioning and interaction of all the levels of the neurological framework and the connections to the body.

Physical skills are the primary observational tool in the assessment of the neurological system

Play, Social and Communication Development

Hemispheres asserts that this is a manifestation of the neurological skills linked to Level Two to Level Four in the neurological hierarchy of the brain, depending on the complexity of the play and language displayed. Speech and interaction is dependent on attention and arousal systems. These stimulate the motivational drive to interact with both the people and activities present within the environment. Children’s play and language development are secondary to physical development, and form part of the sequence of chronological skill development. Children who have a less aroused nervous system are often observed to be under focused in their play, preferring activities which are self-directed, typically physical in nature, that do not rely on shared attention and interaction. Hemispheres perceives that an underdevelopment of language and social interaction is the outcome of an immature neurological system which is inhibiting the arousal and motivational systems. Equally, a potential physical immaturity in oral motor skills can contribute.

Academic / Cognitive Development

Delayed academic development is often the precipitant for referral to a clinician, especially when associated with functional delays in, for example, handwriting. Hemispheres perceives academic skills to be related to Level Four of the neurological hierarchy. They are a behavioural manifestation of a fully integrated neurological system, with efficient mind-brain-body connections. We assert that efficient functioning at Level Four, the Cerebral Hemispheres, is a product of the physical development which provides efficient communication networks (wiring of the brain and body) for stored learning to be located. This is then combined with new experiences and then re-stored in efficient and easily accessible ‘files’. The functional skills then form the tangible expression of these pathways; demonstrating the cognitive and academic understanding of a child through handwriting and other forms of expressed learning.

This level is dependent on the integration of the two sides of the brain: physically, emotionally and structurally.

Failure to connect all levels of the neurological system will result in increased effort, attention difficulties, behavioural difficulties and, in some incidences, failure to learn and express academic potential.

Functional Development

Functional development is the behavioural manifestation of a child’s occupational performance; a sequence of goal directed behaviours which enable a child to demonstrate mastery of age-appropriate skills and interaction with the environment.

It is universally accepted that children are expected to develop their physical, sensory, play, language, interaction and self-help skills within certain parameters. Concerns are often raised when a child’s functioning falls outside of these predetermined levels. In childhood, there is a surge of skill development between the ages of 0 and 7 years of age.  We assert that functional skills are the outcome of the interaction between the child’s neurological subsystems and the environment.

 Child’s Occupational Roles

In childhood, occupational roles are primarily associated with the child’s ability to participate in activities such as play, social interaction and self-care skills and to ultimately fulfil their potential as a learner at school.  The skill and competence a child has at participating in these roles helps form their personal identify and belief systems about themselves, based on their own experiences. Being competent within different roles, commensurate with their peer group, is important. This reflects their ability to fulfil their roles, maintain a routine and participate in a range of activities which provide them with a sense of purpose, of “fitting in” and of satisfaction and fulfilment. 

A child who can access these abilities and outcomes is more likely to pursue activities which will become part of their values, beliefs and desires to achieve. Children who have difficulty in one or more of their developmental modalities are restricted in their ability to engage and participate in a variety of activities, relationships and roles and their sense of purpose, satisfaction and fulfilment can be diminished as a result.

OTHER COMPONENT AND INFLUENCING PARTS OF THE HCM DEFINED

The environment and culture in which a child grows up is pervasive and can have a strong impact, interplay and influence on all the other quadrants and subsystems within the HCM.

The Environment

The environment provides social and physical opportunities, limitations, challenges and support. Children are exposed to different social and physical environments including school and home.

The Culture

Culture is all-encompassing and permeates all aspects of a child’s development. It structures the environment a child lives in, the routines, beliefs and values it lives by. Ultimately it can greatly dictate the experiences a child will have. Hemispheres recognises the role that culture has overall and of the importance of providing an assessment which can be administered to all children, regardless of culture. Assessment of neurological development and functional skills ensures an assessment based on universal principles that underpin global childhood development.

 Applying the Model to Clinical Reasoning:

It is important that the model is effective in guiding clinical reasoning. The assessment process needs to reflect the reasoning behind the model as well as guiding the choice of intervention and support.

Hemispheres Neurological Assessment

The Hemispheres Assessment was developed on the premise that accurate assessment of the primitive and postural reflexes will provide a comprehensive understanding of why a child is presenting with functional and learning difficulties; what these functional and learning difficulties are; and where in the child’s neurological development the cognitive-brain-body connection has been “blocked”. The reflexes are hierarchically ordered in their emergence and inhibition. This pattern correlates with the process of neuromaturation and the subsequent functional development of associated neural structures.  By understanding the levels of neuromaturation, the practitioner can accurately predict the functional, social, academic and physical difficulty a child is likely to be presenting with. 

By understanding the levels of neuromaturation, one is able to accurately predict with which functional, social, academic and physical difficulty a child is likely to be presenting. The model can be applied in two different ways:

1. Assessment of the reflexes can predict the likely difficulties a child is having.
2. Viewing the child’s presenting difficulties through the model can help predict which reflexes and associated neural structures are not fully functioning.