5.9

Question 1

Positron emission tomography (PET)

Answer 1

A functional imaging method that
reveals the localization of a radioactive
tracer in a living brain.

Question 2

Functional MRI

Answer 2

A functional
imaging method; a modification of the
MRI procedure that permits the measurement of regional metabolism in the brain,
usually by detecting changes in blood
oxygen level.

Question 3

Transcranial magnetic stimulation (TMS)

Answer 3

Stimulation of the cerebral cortex
by means of magnetic fields produced by
passing pulses of electricity through a coil
of wire placed next to the skull; interferes
with the functions of the brain region that
is stimulated.

Question 4

Optogenetic method

Answer 4

The use of a
genetically modified virus to insert lightsensitive ion channels into the membrane of
particular neurons in the brain; can depolarize or hyperpolarize the neurons when light
of the appropriate wavelength is applied.