Development of the Brain
Effects and Affects
The human brain is a marvelously simple and complex organ. Simple because at the highest levels, it has but one function – survival. The brain acts to sense, process, perceive, store and act on information to promote your survival. It does this by using two main parts of the brain. Survival functions are mediated by the “lower” parts of the brain while the most complex functions like abstract thinking happen in its most complex cortical structures.
Brain development is characterized by sequential development and “sensitivity” from the brainstem to cortex.
Use dependent development and the resulting organization of the brain are stored reflections of the collective experiences of the developing child. Use-Dependent Organization means that the brain develops capabilities suited for the environment in which it is growing. Children reflect the world in which they are raised. These various brain areas develop, organize and become fully functional at different stages during childhood. Birth- brainstem capabilities: cortical function absent. Any brain area or system, once organized, is less sensitive to experience – less likely to change – less plastic.
The mature organization and functional capabilities of each of the hundreds of systems and areas of the brain reflect some aspect of the quantity, quality, and pattern of sensory experience present during the critical organizational periods of development.
Structural organization and functional capabilities of the mature brain develop throughout life, with the vast majority of the critical structural organization taking place in childhood.
It is of critical importance that we understand that, by age 3, the vast majority of the brain has been organized. 3 year old brain is 90% adult size, body is 15% adult size. The vast majority of brain development takes place in the first few years of life.
By birth the final number of cells is roughly the same as in the mature brain Over the three years following birth the process of maturation of cells takes place. Each neuron’s unique structure, biochemical and functional character is a function of its unique environmental history – the specific pattern, timing, and quality of these microenvironmental cues.
Catacholamine (NE, Da) cues during development are important in determining critical functional properties of mature brain cells. Alterations in the pattern, timing, and quantity of these cues will result in altered development of the functions mediated by these systems.
The earlier and more pervasive the trauma, the more neurodevelopment will be disrupted.Prenatal or maternal stress has significant impact on neurodevelopmentAlterations in brain development which persist into adolescence and adult-hood, impact all aspects of emotional, cognitive and behavioral functioning.
Children are “resilient”, they bounce back from whatever is going on.
Children are NOT resilient, they are MALLEABLE The functional capabilities of the central nervous system mediating stress in the adult are determined by the nature of the stress experiences during the development of these systems, i.e., in utero, during infancy, and during childhood.
Exposure to unpredictable, inconsistent stress resulted in deficits in the systems
Exposure to predictable stress resulted in improved or superior behavior – resiliency.
Elements of predictability and some element of control make stress less destructive.
What we know
Early parental loss (a trauma), accompanied by the lack of a supportive relationship subsequent to the loss, is related to the development of adult psychopathology. Developmental stress may be the primary etiological factor in the development of borderline personality disorders, depressive disorders, disassociative disorders and others (ADHD ie).
The degree of brain plasticity is related to two main factors – stage of development and area or system of the brain. Once an area is organized, it is less responsive to the environment, less plastic. You can “change your mind” but you can’t — Once the brain has organized, the lower (survival portion) system is less likely to change.
Brain’s Response to Threat
Prime directive of brain is to promote survival and procreation. Cognitive, emotional, social, behavioral and physiological residue of a trauma may impact an individual for a lifetime. In order for any experience, traumatic or not, to become part of memory, it must be “sensed”, perceived by the individual.
The five senses transform forms of energy from the external world (light, sound etc) into patterned activity of sensory neurons. The first “stop” of this input is the lower, survival oriented brainstem and midbrain. This input is matched against previously stored patterns and, if unknown, or if associated with previous trauma, begins an alarm response.
A cascade of activity is initiated in these primitive areas which moves “up” for review in other areas. This allows the individual to act in a near- reflexive fashion to survive well before the information is interpreted by the cortex. A complex pattern of sensory brain cell activity associated with a specific visual image, or specific smell or sound make connections with networks in these levels of the brain.
So, What is Produced?
Neuronal systems alter themselves in a “use-dependent” way in response to repetitive activation in this diverse set of brain systems – resulting in a set of patterns of neuronal networks solidly in place. We call these solid patterns of input MEMORIES.
SURVIVALThese “state” memories, memories of previous patterns of sensory input which were connected with bad experience – produce an automatic response for survival. For example: Sight – Sound – Smell of something that “reminds” the brain of previous threat will elicit an immediate fight of flight response, without thinking.
In persons exposed to chronic abuse or neglect or trauma early in life, they will have little insight of how the anxiety, impulsivity, social and emotional distress they suffer are related to the brain’s creation of ‘memories’ during previous traumatic experiences.
Somatosensory pattern of developing brainstem and maternal heartbeat. Oropharangeal motor patterns: Eye contact, touch, cooing, social intimacy, calm, safety Disruptions of this ‘bath’ can result in abnormal eating patterns and difficult relationship formation.
WHAT ABOUT GENETICS?
We inherit half our genes from Mom and half from Dad, we don’t get a choice. The genes decide the levels of chemistries. If our parents were under prolonged or extreme stress then via their DNA – We can inherit deficiencies of chemistry necessary to feel calm, feel complete, sense pleasure, be stable, etc. We begin life with what we are given and the environment alters that.
The brain’s primary function is to keep you alive. Early childhood experience formats the brain for adolescence and adulthood. Behaviors described as “ADHD” may be present because the brain is hypervigilent and focused on survival cues. Many anxiety syndromes may represent a maladaptive generalized activation of alarm response, with symptoms representing exaggerations of originally adaptive and appropriate functions. These “sensitized” networks communicate with feeling and thinking areas for perception and interpretation and result in altered perception and interpretation due to stored sensitized configuration. Children with these altered and sensitized systems tell us they “were just defending themselves” when aggressive. They have a persisting state of fear. Frequently (mis)diagnosed ADD/HD Frequently mislabeled learning disordered, tend to focus on non-verbal cues and are consumed by hyper-vigilance.