July 30, 2012
Identifying the areas of the brain that
help us to perceive our world in a self-reflective manner is
difficult to measure.
During wakefulness, we are always
conscious of ourselves. In sleep, however, we are not. But there are
people, known as
lucid dreamers, who can become
aware of dreaming during sleep.
These dreamers are giving insight into
the neural basis of human consciousness.
Dreams have fascinated philosophers for
thousands of years, but only recently have dreams been subjected to
empirical research and concentrated scientific study.
Chances are that you’ve often found
yourself puzzling over the mysterious content of a dream, or perhaps
you’ve wondered why you dream at all.
Although anecdotal reports of people awakening inside a dream have
been around for centuries and over 50 per cent of people report
having at least one such experience in their lifetime, the first
rigorous study of the phenomenon was only conducted in the last
Studies employing magnetic resonance tomography (MRT) have
now been able to demonstrate that a specific cortical network
consisting of the right dorsolateral prefrontal cortex, the
frontopolar regions and the precuneus is activated when this lucid
consciousness is attained.
All of these regions are associated with
The human capacity of self-perception, self-reflection and
consciousness development are among the unsolved mysteries of
neuroscience. Despite modern imaging techniques, it is still
impossible to fully visualize what goes on in the brain when people
move to consciousness from an unconscious state. The problem lies in
the fact that it is difficult to watch our brain during this
Although this process is the same, every
time a person awakens from sleep, the basic activity of our brain is
usually greatly reduced during deep sleep.
This makes it impossible to clearly
delineate the specific brain activity underlying the regained
self-perception and consciousness during the transition to
wakefulness from the global changes in brain activity that takes
place at the same time.
Scientists from the Max Planck Institutes of Psychiatry in
Munich and for Human Cognitive and Brain Sciences in Leipzig
and from Charite in Berlin have now studied people who are
aware that they are dreaming while being in a dream state, and are
also able to deliberately control their dreams.
Those so-called lucid dreamers have
access to their memories during
lucid dreaming, can perform actions
and are aware of themselves - although remaining unmistakably in a
dream state and not waking up.
As author Martin Dresler
“In a normal dream, we have a very
basal consciousness, we experience perceptions and emotions but
we are not aware that we are only dreaming. It’s only in a lucid
dream that the dreamer gets a meta-insight into his or her
By comparing the activity of the brain
during one of these lucid periods with the activity measured
immediately before in a normal dream, the scientists were able to
identify the characteristic brain activities of lucid awareness.
“The general basic activity of the
brain is similar in a normal dream and in a lucid dream,” says
Michael Czisch, head of a research group at the Max Planck
Institute of Psychiatry.
“In a lucid state, however, the
activity in certain areas of the cerebral cortex increases
markedly within seconds. The involved areas of the cerebral
cortex are the right dorsolateral prefrontal cortex, to which
commonly the function of self-assessment is attributed, and the
frontopolar regions, which are responsible for evaluating our
own thoughts and feelings. The precuneus is also especially
active, a part of the brain that has long been linked with
The findings confirm earlier studies and
have made the neural networks of a conscious mental state visible
for the first time.