Neuroscience

Neuroscience is the study of the nervous system and its components. Neuroscientists may examine the nervous systems of humans and higher animals as well as simple multicellular nervous systems, or investigate nervous phenomenon at the cellular, organelle, or molecular level.

In the twentieth century, neuroscience was greatly advanced by Wilder Penfield, who stimulated nerves in the brains of conscious patients to obtain a rudimentary functional map of the brain.

In the 1970s, it became possible to probe brain nerve function without the need for surgery. Sophisticated brain imaging techniques such as Positron emission tomography (PET) revolutionized neuroscience by allowing scientists to produce pictures of a working brain. Since then, scientists and engineers have come up with even better brain imaging systems, such as functional magnetic resonance imaging (fMRI). Using fMRI, neuroscientists can detect increases in blood oxygenation during brain function, and this shows which areas of the brain are most active. Brain activity occurs very quickly—neurons can respond to stimulus within 10 milliseconds—and very sophisticated equipment is needed to capture such fleeting movements. Using neuroimaging, the flux of sodium ions within the brain can be measured, giving a direct record of neural activity. As well, the scattering of light by brain tissues can be measured with fiber-optics. Both these techniques hope to give a more precise picture of which areas of the brain become active when a person thinks.