168 Self and the Phenomenon of Life
b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”water, but what is below can become visible by lowering the water level.
A case of heightened consciousness happens when your name is suddenly
announced in the public address system, or when you unexpectedly spot
your loved one in a crowd.
It is interesting that only 5% of our daily activities are in the
conscious realm; the rest, including such semi-conscious vital functions
as breathing, are carried out automatically.^13 Subliminal stimulation is
one that is short enough (a few milliseconds) not to arouse awareness
but long enough to affect subsequent behavior of the subject, as used in
commercial advertisement.
Every object of awareness carries a graded emotional value, marked
as good, bad or neutral. Without emotion, consciousness is a barren
landscape; without consciousness, emotion is a blind impulse. From the
evolutionary standpoint, consciousness combined with emotion provides
great survival advantage.
8.3 Electrical Correlates of Consciousness
The physical correlate of consciousness was first demonstrated in 1924
when Hans Berger recorded electrical signals from the human scalp and
related them to the state of wakefulness. The electrical recordings are
called electro-encephalograms (EEG), commonly known as brain waves
(Fig. 8.2). When a person is awake and looking out, the EEG pattern is
that of a series of very rapid, desynchronized waves, corresponding to a
state of alertness. With eyes closed, the EEG pattern of an awake but
resting brain is that of synchronized waves of 8 to 12 hertz (cycles per
second), called alpha rhythm. When a person becomes drowsy, the waves
slow down with increase in amplitude, and the rhythm is less regular.
As a person goes deeper and deeper into sleep, the waves further slow,
the amplitude further increases, and the rhythm tends to disappear. But
when a person starts to dream, the electrical activity is energized again
(high frequency, low amplitude, irregular rhythm), simulating the state
of alert wakefulness, hence the name “paradoxical sleep.” This stage is