Page 175 - Mind Games The Aging Brain and How to Keep it Healthy

Regain an Agile Brain • 159

memories. Light reaches the retina of the eye, travels via the
optic nerve to the brain, and resets the SCN.
The resulting change in the SCN produces cycles, affects
the nervous system, and sends signals to the pineal gland,
which in turn affects hormonal levels. Recent studies indi-
cate that the SCN can be reset using exposure to light on
other areas of the body, such as the back of the knees, where
blood vessels are close to the surface of the skin.
Your body temperature, blood pressure, hormonal lev-
els, sleep/wake cycle, and many other functions are con-
trolled by your particular circadian rhythm. Although your
rhythms may be similar to someone else’s in many respects,
they will not be an exact match. Scientists have performed
experiments that demonstrate how much control the SCN
has over a body. In animals, if the SCN of one animal is re-
placed with the SCN from a second animal, the first animal
will take on the biological rhythms of the second animal.
We intentionally or unintentionally interfere with the
functioning of our internal clocks in many ways. When Day-
light Savings Time (DST) goes into effect in the spring, the
clocks in your house may be easily reset, but the clocks in
your body are a little more difficult to reset. For several