Where Are "You"?

A new scientific study conducted on people suffering from epilepsy may have just supplied scientists with the answer to one of the most difficult questions about the human brain, namely where does consciousness come from? Is it based in certain areas of the brain, or is it generated by the organ functioning as a whole? The new research seems to favor the second option, as the scenarists in charge of the investigation say that consciousness arises from the coordinated activity of the entire brain, and not from certain portions of the cortex. _Softpedia

Are you a conscious being? If you are conscious, then your consciousness is "you". Where are "you"? The ancients believed that consciousness, "the soul", was in the heart. The heart was obviously doing something, whereas the brain just sat there taking up space. Now we know that the activity of the brain determines consciousness, but where in the brain? Do we have a homunculus -- a little man -- inside our brains watching through our eyes, hearing with our ears, smelling and tasting and feeling with our sense organs?

Scientists in and near Paris have used intracranial EEG electrodes to monitor consciousness and unconscious (masked) evaluation of visual word images. By comparing conscious and unconscious brain activity when evaluating words, the French neuroscientists were able to determine what parts of the brain were active exclusively during the conscious evaluation of the visual word stimulus.

We compared conscious and nonconscious processing of briefly flashed words using a visual masking procedure while recording intracranial electroencephalogram (iEEG) in ten patients. Nonconscious processing of masked words was observed in multiple cortical areas, mostly within an early time window (<300 ms), accompanied by induced gamma-band activity, but without coherent long-distance neural activity, suggesting a quickly dissipating feedforward wave. In contrast, conscious processing of unmasked words was characterized by the convergence of four distinct neurophysiological markers: sustained voltage changes, particularly in prefrontal cortex, large increases in spectral power in the gamma band, increases in long-distance phase synchrony in the beta range, and increases in long-range Granger causality. We argue that all of those measures provide distinct windows into the same distributed state of conscious processing. These results have a direct impact on current theoretical discussions concerning the neural correlates of conscious access. _PLOS_via_Eurekalert

Not many neuroscientists are able to use large arrays of intracranial electrodes to study human brain function. In this study, the electrodes were placed to facilitate epilepsy treatment. The researchers were able to take advantage of the medical opportunity to collect data for analysis.

The short answer to the question "where are 'you'?" is everywhere and nowhere. "Everywhere", because consciousness is an active process that takes place across the different lobes of the cerebrum and in subcortical structures. "Nowhere", because consciousness is such an ephemeral activity, flitting on and off, here and there over time.

When the mind examines thought images, different parts of the brain activate simultaneously and in close sequence, in order to "flesh out" the components of the image. Different parts of the brain that are in "synchrony" oscillate in the same frequency bands -- either lower frequency beta bands (roughly 13 to 30 Hz) or higher frequency gamma bands (centered around 40 Hz but up to 100 Hz). This synchrony of separated brain regions with each other allows the brain to construct more complex thought images. The added complexity of sequential synchronies and overlapping synchronies provides for ever more intricate and presumably ever more exquisite conscious experience.

Basic physics and neurochemistry set limits to consciousness, of course, but most humans come nowhere near those limits.

The study linked above is worth reading, even if you need several reference books handy to check terminology and technique. The concepts underlying human consciousness are basic to who we are and why. There are already too many zombies roaming the halls of government, media, academia, and industry. It is time to begin an anti-zombie movement. Up with consciousness.

More commentary on this research here