The Developing Brain
This chapter considers the structural development of the brain, both prenatally and postnatally. It also considers the nature of developmental change, including evidence for critical/sensitive periods and innate knowledge. One common idea is that the genetic code provides a blueprint for the structure of the brain. At some gross level, this must be true: all human brains are similar to each other, but differ from the brains of other species. However, a blueprint can’t specify brain structure at a fine level (and the brains of “identical” twins are not identical). Brain imaging studies reveal that both age of acquisition and level of proficiency determine the neural substrates of second language processing in adults. Heritability estimates can also be applied to structural and functional brain differences as well as to cognitive and behavioral traits. However, genetic influences (measured by heritability) and environmental ones will typically work in combination. For example, gene X environment interactions occur when susceptibility to a trait depends on a particular combination of a gene and environment.
Multiple Choice Questions
Flashcards
The extent to which cognition and behavior can be attributed to genes or environment
A process of interaction between environment and brain-based constraints that leads to the mature cognitive system emerging out of transformations of earlier ones (but does not assume discrete stages)
The embryo’s precursor to the central nervous system, consisting of a set of cells arranged in a hollow cylinder
Support cells that guide neurons from the neural tube to final destination
Strengthening of a synapse that occurs when the presynaptic and postsynaptic neurons are active at the same time (" what wires together, fires together" )
An increase in the fatty sheath that surrounds axons and increases the speed of information transmission
The brain’s ability to change as a result of experience
The idea that that the earlier that brain damage is sustained, the better the functional outcome
The process by which a young animal comes to recognize the parent
A time window in which appropriate environmental input is essential for learning to take place
A time window in which appropriate environmental input is particularly important (but not necessarily essential) for learning to take place
In philosophy, the view that the newborn mind is a blank slate
In philosophy, the view that at least some forms of knowledge are innate
A behavior that is a product of natural selection
The theory that common phobias are biologically determined from evolutionary pressures
An organized package of DNA bound up with proteins; each chromosome contains many genes
Different versions of the same gene
A field concerned with studying the inheritance of behavior and cognition
Genetically identical twins caused when a fertilized egg splits in two
Twins who share half of their genes, caused when two eggs are fertilized by two different sperm
The proportion of variance in a trait, in a given population, that can be accounted for by genetic differences among individuals
The proportion of variance in a trait, in a given population, that can be accounted for by events that happen to one twin but not the other, or events that affect them in different ways
The proportion of variance in a trait, in a given population, that can be accounted for by events that happen to both twins, affecting them in the same way
An analysis approach in which different phenotypes are used to explore genetic differences
an analysis approach in which different genotypes (e.g. different alleles) are used to explore for phenotypic variation
A phenotype-first approach in which the presence/absence, or continuous variation, in a trait is linked to variations at many different sites in the genetic code
genome-wide association study (GWAS)
Genetic influences in people’s exposure to different environments
Gene–environment correlations
Susceptibility to a trait depends on a particular combination of a gene and environment
Gene X–environment interactions
An impaired ability to perform the coordinated movements that are required for speech
