Old Habits Gone But Not Forgotten Old Habits Gone But Not
Forgotten Scientists have identified a small region of the rat
brain that seems to control whether certain habits will continue
or be replaced by new habits. The finding offers insights into
the brain pathways that help us shift between fixed and flexible
behaviors. Habits are a powerful force in our lives. Repeated
activities—like tooth brushing or driving the same route to
work—can become ingrained behaviors performed with little
conscious thought. Such automatic habits can be helpful. Others
can become harmful routines, such snacking on sweets, smoking,
or abusing drugs or alcohol. Scientists have long searched for
the brain circuitry that creates, controls and overwrites our
habits. Earlier research hinted that a specific brain area—known
as the infralimbic cortex in rats—plays an important role. To
learn more, Drs. Ann Graybiel and Kyle Smith of the
Massachusetts Institute of Technology and their colleagues used
a technique called optogenetics to