Neuroconstructivism

Theory about how the brain sculpts itself and becomes specialized over time

Neuroconstructivism is a theory that states that phylogenetic developmental processes such as gene–gene interaction, gene–environment interaction Modularity of the brain would require a pre specified pattern of synaptic connectivity within the cortical microcircuitry of a specific neural system. Instead, Annette Karmiloff Smith has suggested that the microconnectivity of the brain emerges from the gradual process of ontogenetic development. Proponents of the modular theory might have been misled by the seemingly normal performances of individuals who exhibit a learning disability on tests. While it may appear that cognitive functioning may be impaired in only specified areas, this may be a functional flaw in the test. Many standardized tasks used to assess the extent of damage within the brain do not measure underlying causes, instead only showing the static end state of complex processes. An alternative explanation to account for these normal test scores would be the ability of the individual to compensate using other brain regions that are not normally used for such a task. For example, the ventral and dorsal streams only arise because of innate differences in processing speed of neurons, not an innate selection to be either ventral or dorsal by the respective neurons. This contrasts the previous domain general and domain specific approaches. In the domain general framework, differences in cognitive functioning are attributed to overarching differences in the neurons across the entire brain. The domain specific approach in contrast argues for inherent, specific differences within the genes which directly control a person's development. While it cannot rule out domain specificity, This leads to "restrictions of fate" in which later learning is more restricted than earlier learning. This probabilistic epigenesis view of development suggests that instead of following a predetermined path to expression, genes are modified by the behavior and environment of an organism. Furthermore, these modifications can then act on the environment, creating a causal circle in which genes influencing the environment are re influenced by these changes in the environment.

Cells do not develop in isolation. Even from a young age, neurons are influenced by the surrounding environment (e. g. other neurons). Over time, neurons interact either spontaneously or in response to some sensory stimulation to form neural networks. to an approximate 128 billion. This allows a vast neural network to be formed, and consequently a "storage capacity of the human brain." Competition between neurons plays a key role in establishing the exact pattern of connections. Through neuron neuron communication made possible by the neuron's synapses, axon, and dendrites, different neurons can influence each other and lead to changes in the neural network. This is important for processing information and learning new material. This is possible because of neuron interactions that occur between neurons. As a result, specific neural activation patterns may arise due to the underlying morphology and connection patterns within the specified neural structures. These may subsequently be modified by morphological change imposed by the current representations. Progressively more complex patterns may arise through the manipulation of current neuronal structures by an organism's experience. constraining and specifying the development of each region. For example, the primary visual cortex in blind individuals has been shown to process tactile information. The function of cortical areas emerges as a result of this sensory input and competition for cortical space. "This interactive specialization view implies that cortical regions might initially be non specific in their responses but gradually narrow their responses as their functional specialization restricts them to a narrower set of circumstances." Chronic stress causes long term changes in the structure and function of the brain. This form of stress can cause an increase in myelin producing cells and a decrease in neurons. Chronic stress reduces the amount of stem cells that grow into neurons, which may explain how it impacts learning and memory. Having said that, the neuronal network of a brain is continually changing due to plasticity. Chronic stress, as well as mindset and behaviour, are never resolved. The power of neuroplasticity allows to modify the shape and function of a brain throughout its lifespan.

The brain is further limited by its constraint within the body. The brain receives input from receptors on the body (e. g., somatosensory system, visual system, auditory system, etc.). These receptors provide the brain with a source of information. As a result, they manipulate the brain's neural activation patterns, and thus its structure, leading to constraining effects on the construction of representations in the mind. The sensory systems limit the possible information the brain can receive and therefore act as a filter. Alcohol diminishes the brain's capacity to form neural connections and suppresses specific activities and pathways of neurons. Alcohol attacks the frontal lobe, which is heightened in development in puberty and keeps growing till the age of 21. Research performed by neuroscientist Jay Giedd provides strong support for a second period of synaptic plasticity, and he did a case study on his own teenage kids. He reasons with poor decision making teenagers make due to their brains not being fully mature. Support for the idea that the brain has a capacity to rewire have been found in a research conducted by Takashi Ohnishi have been made on musicians and non musicians to test what parts of the brain are active during the playing of an Italian orchestra, and it had shown that non musicians' right temporal lobe and the secondary area of the auditory cortex was activated compared to musicians' brains whose activity was in the left temporal cortex and in the left prefrontal cortex.

All of the above constraints interact to form cognitive representations in the brain. The main principle is context dependence, as shaping occurs through competition and cooperation. Competition leads to the specialization of developing components which then forms new representations. Cooperation, on the other hand, leads to combinations of existing mental representations that allow existing knowledge to be reused. Construction of representations also depends on the exploration of the environment by the individual. However, the experiences derived from this pro activity constrain the range of possible adaptations within the mental representations. Such progressive specialization arises from the constraints of the past and current learning environment. To alter representations, the environment demands improvements through small additions to the current mental state. This leads to partial instead of fixed representations that are assumed to occur in adults. Neuroconstructivism argues such end products do not exist. The brain's plasticity leads to ever changing mental representations through individual proactivity and environmental interactions. Such a viewpoint implies that any current mental representations are the optimal outcome for a specified environment. For example, in developmental disorders like autism, atypical development arises because of adaptations to multiple interacting constraints, the same as normal development. However, the constraints differ and thus result in a different end product. This view directly contrasts previous theories which assumed that disorders arise from isolated failures of particular functional modules.