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18374Self-Awareness Activates Particular Brain Centers

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  • medit8ionsociety
    Aug 3, 2012
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      Self-Awareness Activates Particular Brain Centers
      31 Jul 2012

      Scientists in Germany have found which centers of
      the brain become active when we are aware of ourselves,
      the so-called state of "metaconsciousness". Their
      study, which appears online in the July issue of
      SLEEP, is the first to show visible evidence of the
      neural networks that underpin the human conscious state.

      They identified them by comparing brain scans of a
      volunteer during "lucid dream" episodes, to brain
      scans taken during normal dream states.

      The areas they pinpointed as the seat of meta-consciousness
      belong to a network in the outer layer (cortical) of
      the brain that includes the right dorsolateral prefrontal
      cortex, the frontopolar regions and the precuneus.

      Some people can have episodes of self-awareness while
      they sleep and dream. These "lucid dreamers" are aware
      that they are dreaming, and are also able to control
      their dreams. During lucid dreaming episodes they can
      access their memories, perform actions and are aware of
      themselves, even though they are unmistakeably in a dream
      state and not awake.

      First author Martin Dresler, from the Max Planck Institute of Psychiatry in Munich, explains:

      "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 state."

      The human capacity for self-perception, self-reflection and consciousness are some of the biggest unsolved mysteries of neuroscience.

      It is not easy to measure which parts of the brain help
      us do these things. When we are awake, we are self-aware,
      conscious of what we think and feel. But we can't do this
      when we are asleep - unless we are lucid dreamers.

      One way could be to compare the brains of people asleep
      with the brains of people awake, or to monitor brain
      activity while people moved from sleep to wakefulness.

      But it is difficult to pick out from these comparisons
      those precise areas of activity that relate to self-awareness, because, for instance, as people move from sleep to wakefulness
      there are too many other changes going on in the brain at
      the same time.

      So Dresler and colleagues decided on a different approach:
      compare brain scans taken during periods of lucid activity
      with brain scans taking during the normal dreaming that
      precedes these episodes.

      For their study, they recruited four experienced lucid
      dreamers and invited them to spend the night in a sleep
      lab while scientists monitored their brain activity using
      parallel functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) recordings of their night sleep.

      Of the four volunteers, one had two episodes of "verified
      lucid REM sleep" that were long enough to be analyzed by
      fMRI, said the researchers, who note in their paper that:

      "During lucid dreaming the bilateral precuneus, cuneus,
      parietal lobules, and prefrontal and occipito-temporal
      cortices activated strongly as compared with non-lucid
      REM sleep."

      Senior author Michael Czisch, head of a research group
      at the Max Planck Institute of Psychiatry, said:

      "The general basic activity of the brain is similar in
      a normal dream and in a lucid dream."

      "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 self-perception."

      Although the results are based on scans from one person,
      the authors suggest, by making them visible for the first
      time, their findings show the neural networks of the human
      conscious state, and confirm suggestions made in other studies.

      Written by Catharine Paddock PhD
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