Home' Technology Review : July August 2007 Contents 68 ESSAY
TECHNOLOGY REVIEW /
ing? Dream thought is di erent from drifting or
free-associating pre-sleep thought, which is di er-
ent from "ordinary" thought. We know that children
tend to think more concretely than adults. Studies
have also suggested that children are better at invent-
ing metaphors. And the keenest of all obser vers of
human thought, the English Romantic poets, sug-
gest that dreaming and waking consciousness are less
sharply distinguished for children than for adults.
Of his childhood, Wordsworth writes (in one of the
most famous short poems in English), "There was a
time when meadow, grove, and stream, / The earth,
and every common sight, / To me did seem / Appar-
elled in celestial light, / The glory and the freshness
of a dream."
Today s cognitive science and philosophy can t
explain any of these mysteries.
The philosophy and science of mind has other
striking blind spots, too. AI researchers have been
working for years on common sense. Nonetheless,
as Fodor writes in The Mind Doesn t Work That Way,
"the failure of arti cial intelligence to produce suc-
cessful simulations of routine commonsense cognitive
competences is notorious, not to say scandalous." But
the scandal is wider than Fodor reports. AI has been
working in recent years on emotion, too, but has yet
to understand its integral role in thought.
In short, there are many mysteries to explain---and
many "cognitive competences" to understand. AI---and
software in general---can pro t from progress on these
problems even if it can t build a conscious computer.
These observations lead me to believe that the "cog-
nitive continuum" (or, equally, the consciousness con-
tinuum) is the most important and exciting research
topic in cognitive science and philosophy today.
What is the "cognitive continuum"? And why care
about it? Before I address these questions, let me note
that the cognitive continuum is not even a scienti c
theory. It is a "prescienti c theory"---like "the earth
Anyone might have surmised that the earth is round,
on the basis of everyday obser vations---especially the
way distant ships sink gradually below (or rise above)
the horizon. No special tools or training were required.
That the earth is round leaves many basic phenomena
unexplained: the tides, the seasons, climate, and so on.
But unless we know that the earth is round, it s hard
to progress on any of these problems.
The cognitive continuum is the same kind of the-
ory. I don t claim that it s a millionth as important as
the earth s being round. But for me as a student of
human thought, it s at least as exciting.
What is this "continuum"? It s a spectr um (the
"cognitive spectr um") with in nitely many interme-
diate points between two endpoints.
When you think, the mind assembles thought
trains---sequences of distinct thoughts or memories.
(Sometimes one blends into the next, and sometimes
our minds go blank. But usually we can describe the
train that has just passed.) Sometimes our thought
trains are assembled---so it seems---under our conscious,
deliberate control. Other times our thoughts wander,
and the trains seem to assemble themselves. If we start
with these obser vations and add a few simple facts
about "cognitive behavior," a comprehensive picture
of thought emerges almost by itself.
Obviously, you must be alert to think analytically.
To solve a set of mathematical equations or follow a
proof, you need to focus your attention. Your concen-
tration declines as you grow tired over the day.
And your mind is in a strange state just before you
fall asleep: a free-associative state in which, rather than
following from another logically, one thought "sug-
gests" the next. In this state, you cannot focus: if you
decide to think about one thing, you soon nd yourself
thinking about something else (which was "suggested"
by thing one), and then something else, and so on. In
fact, cognitive psychologists have discovered that we
start to dream before we fall asleep. So the mental state
right before sleep is the state of dreaming.
Since we start the day in one state (focused) and
nish in another (free-associating, unfocused), the
two must be connected. Over the day, focus declines---
perhaps steadily, perhaps in a series of oscillations.
Which suggests that there is a continuum of mental
states between highest focus and lowest. Your "focus
level" is a large factor in determining your mode of
thought (or of consciousness) at any moment. This
spectrum must stretch from highest-focus thought
(best for reasoning or analysis) downward into modes
based more on experience or common sense than
on abstract reasoning; down further to the relaxed,
drifting thought that might accompany gazing out a
window; down further to the uncontrolled free asso-
ciation that leads to dreaming and sleep---where the
spectrum bottoms out.
Low focus means that your tendency (not necessarily
your ability) to free-associate increases. A wide-awake
person can free-associate if he tries; an exhausted per-
son has to try hard not to free-associate. At the high
end, you concentrate unless you try not to. At the low
end, you free-associate unless you try not to.
Notice that the role of associative recollection---in
which one thought or memory causes you to recall
Links Archive May June 2007 September October 2007 Navigation Previous Page Next Page