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An ongoing, consciousness
raising exercise
by Tim Lougheed
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| Kenneth
Campbell |
DURING THE 1966 FILM FANTASTIC VOYAGE, THE CREW OF A MINIATURIZED
submarine travels through a man’s brain, witnessing the exchange
of electrical impulses between the cells around them. This dramatic
scene prompts one of these explorers to suggest that they are looking
at human thoughts.
Such comments contain a host of assumptions about the nature of the
mind, assumptions that have taunted philosophers and scientists for
centuries. Not long after the movie appeared, Kenneth Campbell found
himself taunted in much the same way. As an undergraduate at the University
of New Brunswick, he encountered some of the more radical perspectives
of the 1960s, delivered personally by lecturers steeped in such ideas,
including the celebrated beat poet Allen Ginsberg.
The experience cultivated in Campbell a lifelong fascination with
the questions surrounding human behavior. He pursued the field of
psychology to the doctoral level, and has been a member of the University’s
School of Psychology for more than 25 years. Now a professor,
he remains intrigued by the notion of consciousness, an everyday expression
for something that has proven to be scientifically elusive.
“If I want to know whether you’re awake or asleep, conscious
or unconscious, I can just look at the EEG,” he says, referring
to the electroencephalograph, recordings of the electrical waves generated
when an array of detectors is mounted on top of an individual’s
head. “We can teach first-year students to do this. As you lose
consciousness, there are changes, and they’re very subtle. But
when you’re definitely not conscious, that’s no longer
subtle.”
The EEG is a centrepiece of Campbell’s work, which examines
the frequency and size of the various waves generated by the brain’s
activities. Often measured in millionths of a volt, these weak electrical
exchanges enable us to analyse when and where information is processed
in the brain. The real challenge, he explains, is relating these findings
to specific mental states.
“One of the problems we encounter is that few of us can agree
on just how to define ‘consciousness’ or ‘unconsciousness’,”
says Campbell. “It’s beyond just looking at sleep. It’s
a question of how the brain processes information when I’m more
or less conscious of what I’m processing.”
The EEG reveals, for example, that the brain responds to images and
sounds even when a subject is ignoring these stimuli. Ever faster
computer systems, combined with scanning technology such as positron
emission tomography (PET) and magnetic resonance imaging (MRI), now
make it possible to map the physical locations in the brain where
these responses occur.
Such results have made a vital contribution to our understanding of
how various parts of the brain work, and why they sometimes do not
work well. Campbell and his colleagues still have plenty of questions,
however.
For one thing, they want to know how we avoid being overwhelmed by
the wide variety of sensations that are constantly available to us.
Our ability to discriminate among these sensations is a key part of
the ongoing debate about the nature of human consciousness.
“We’re talking about the essence of humanity, how
my consciousness is different from animal consciousness, and how my
experience of the world is different from yours,” Campbell concludes.
“Those are the hard questions. And I’m not sure scientists
will ever be able to answer those, no matter how many electrodes we
put on the brain or how many MRIs we have.” |
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