User:Tyler Chappel/sandbox/Neuroconstructivism
In Neuroconstructivism, gene/gene interaction, gene/environment interaction and, crucially, ontogeny are all considered to play a vital role in how the brain progressively sculpts itself and how it gradually becomes specialized over developmental time.
Neuroplasticity is considered an essential part of development.
Supporters of neuroconstructivism, such as Annette Karmiloff-Smith, argue against innate modularity of the mind. Instead, emphasis is put on innate domain relevant biases. These biases are understood as aiding learning and directing attention. Module-like structures are therefore the product of both experience and these innate biases. Neuroconstructivism can therefore be seen as a bridge between Jerry Fodor's Psychological nativism and Jean Piaget's Theory of cognitive development.
Development vs. Innate Modularity
[edit]Neuroconstructivism has arisen as a direct rebuttal from psychologists who argue for an innate modularity of the brain. [1] [2] Modularity of the brain would require a prespecified pattern of synaptic connectivity within the cortical microcircuitry of a specific neural system [3] Instead, Annette Karmiloff-Smith has suggested that the microconnectivity emerges from the gradual process of ontogenetic development. [3][4][5] Proponents of the modular theory might have been misled by test results for individuals who possess a learning disability. 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 do not measure underlying causes, instead only showing the end-product. 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.[3] Such compensation could only have resulted from developmental plasticity and the interaction between environment and brain functioning.
Differences arise in the brain] instead through development. Instead of having prespecified patterns of connectivity, neuroconstructivism suggests that there are tiny regional differences in type, density, and orientation of neurons, in neurotransmitters, in firing thresholds, in rate of myelination, lamination, ratio of gray matter to white matter, etc. that lead to differing capabilities of neurons to handle specific functions.[6][7] For example, the ventral and dorsal streams only arise because of innate differences in processing speed, not an innate desire to be either ventral or dorsal by the respective neurons.[6] Such a differentiation has been entitled a domain-relevant approach to development. [6][7] This contrasts the previous domain-general and domain-specific approaches in which differences in cognitive functioning were attributed to either over-arching inherent differences in the neurons or specific differences within the genes, respectively.
Context Dependence
[edit]Neuroconstructivism, by viewing development as an emerging process, uses context to demonstrate the possible changes to the brain's neural connections. Starting with genes and gradually incorporating more context clearly demonstrates the constraints involved in development. Instead of viewing the brain as independent of its current or previous environment, neuroconstructivism shows how context gradually interacts with the brain to eventually form the specialized, adult brain.
Genes
[edit]Previous theories have supposed that genes are static, unchanging code for specific developmental outcomes. However, new research suggests that genes may be triggered by both environmental and behavioral influences.[8] This probabilistic epigenesis view of development,[9] offers that genes, instead of following a predetermined path to expression, instead 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.
Encellment
[edit]Cells do not develop in isolation. Even from a young age, neurons are influenced by the surrounding environment (e.g., other neurons). [10] Over time, neurons interact either spontaneously or in response to some sensory experience to form neural networks.[8] Competition between neurons plays a key role in establishing the exact pattern of connections.[11] As a result, only certain 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 manipulation of current neuronal structures by someone's experience.[8]
While neurons are embedded within networks, these networks are further embedded within the brain as a whole. Neural networks do not work in isolation, such as in the modularity of mind perspective. Instead, different regions interact through feedback processes and top-down interactions[13], constraining and specifying the development of each region. For example, the primary visual cortex in blind individuals has been shown to process tactile information.[14] The function of cortical areas emerges as a result of this sensory input and competition for cortical space.[15] This interactive specialization view implies that cortical regions might initially be non-specific in their response but gradually sharpen their responses as their functional specialization restricts them to a narrower set of circumstances.[8]
Enbodiment
[edit]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.[8] However, the brain may also interact with the environment through manipulation of the body (e.g., movement, changes in attention, etc.), thus manipulating the environment or information received. Pro-activity while exploring the environment leads to altered experiences, and consequently altered cognitive development.[8]
Ensocialment
[edit]While a person may manipulate the environment, the specific environment in which the person develops has highly constraining effects on the possible neural representations through restriction of possible experiences, both physically and socially.[8] For example, if a child is raised with no mother, s/he cannot change his/her responses or actions to generate a mother. S/he may only work within the specified constraints of the environment in which s/he is born.
See Also
[edit]References
[edit]- ^ Fodor, J. (1983). The modularity of mind. Cambridge, MA: MIT Press.
- ^ Pinker, S. (1994). The language instinct. London: Penguin.
- ^ a b c Karmiloff-Smith, A. (2006). The tortuous route from genes to behavior: A neuroconstructivist approach. Cognitive Affective & Behavioral Neuroscience, 6(1), 9-17.
- ^ Karmiloff-Smith, A. (1992). Beyond modularity: A developmental perspective on cognitive science. Cambridge, MA: MIT Press, Bradford Books.
- ^ Karmiloff-Smith, A., Plunkett, K., Johnson, M., Elman, J. L., & Bates, E. (1998). What does it mean to claim that something is "innate"? Mind & Language, 13, 588-597.
- ^ a b c Karmiloff-Smith, A. (2009). Preaching to the converted? from constructivism to neuroconstructivism. Child Development Perspectives, 3(2), 99-102.
- ^ a b Karmiloff-Smith, A. (2012). Challenging the use of adult neuropsychological models for explaining neurodevelopmental disorders: Developed versus developing brains. The Quarterly Journal of Experimental Psychology, 66(1), 1-14.
- ^ a b c d e f g Westermann, G., Mareschal, D., Johnson, M. H., Sirois, S., Spratling, M. W., & Thomas, M. S. C. (2007). Neuroconstructivism. Developmental Science,10(1), 75-83.
- ^ Gottlieb, G. (1992). Individual development and evolution. Oxford: Oxford University Press.
- ^ Jessell, T.M., & Sanes, J.R. (2000). The induction and patterning of the nervous system. In E.R. Kandel, J.H. Schwartz, & T.M. Jessell (Eds.), Principles of neural science (4th edn., pp. 1019-1040). New York and London: McGraw-Hill.
- ^ Stryker, M.P., & Strickland, S.L. (1984). Physiological segregation of ocular dominance columns depends on the pattern of afferent electrical activity. Ophthalmological Visual Science (Suppl)."", 25(6), 727-788.
- ^ Johnson, M.H. (2005). Developmental cognitive neuroscience (2nd edn.). Oxford: Blackwell.
- ^ Friston, K.J., & Price, C.J. (2001). Dynamic representations and generative models of brain function. Brain Research Bulletin, 15(1), 94-100.
- ^ Sadato, N., Pascual-Leone, A., Grafman, J., Ibanez, V., Deiber, M.-P., Dold, G., & Gallett, M. (1996). Activation of the primary visual cortex by braille reading in blind subjects. Nature, 380, 526-528.
- ^ Johnson, M.H. (2000). Functional brain development in infants: elements of an interactive specialization framework. Child Development, 71(1), 75-81.
Further Reading
[edit]- Karmiloff-Smith, A. (1992). Beyond modularity: A developmental perspective on cognitive science. Cambridge, MA: MIT Press, Bradford Books.
- Mareschal D, Johnson M, Sirois S, Spratling M, Thomas M, Westermann G (2007). Neuroconstructivism - I: How the Brain Constructs Cognition. Oxford University Press. ISBN 0-19-852990-2.
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