[From Bruce Nevin (980121.1040)]
Bill Powers (980121.0250 MST)--
The imagination connection simply ties output signals
to perceptions. Higher systems don't know where perceptual signals come
from; as far as they're concerned, a perception is a perception.
Hm. When I'm imagining something on purpose, I can tell the difference
between imagination and reality. Subjectively, I think this is because the
inputs are not so rich and diverse at lower levels when I'm imagining.
Instructions on creative visualization emphasize a need to include this
richness and diversity of lower-level perceptions. Without it, they say,
the visualization is not as effective. Setting aside the opportunity to
discuss the effectiveness of creative visualization (an exercise for the
student this suggests that my experience of imagining things is
commonplace; for if imagining were commonly replete with lower-level
perceptions, this instruction would not be necessary.
Subjectively, it seems easier to imagine a scene than to imagine a light
intensity, the pressure of a door handle in the hand, its temperature
against the palm. Maybe just lack of practice. We don't notice the extent
to which we ignore the immediacies of low-level perceptions. "I know that
street like the palm of my hand" means we go through it ho hum without
paying attention, relying on its predictability. When was the last time you
*studied* the palm of your hand? Seems maybe we substitute habitual
imaginings for lower-level perceptions. Living in a universe of categories
would be an example. And without clear attention there can be no clear
memories as a basis for imagining.
Conversely, it appears to be possible to fill in the lower levels in
hallucination, hypnotic acquiescence, dreaming, and so on.
But in ordinary states, one attending to perceptions (whatever attention
is) can tell the difference between imagination and reality. As you say, a
higher-level perception can't tell the difference--by definition, that is,
by construction of the model. Its input function can, but there's no way in
the model for that to make a difference.
The key to our knowing reality from imagination, then, seems to be
awareness of more than one level at once, or possibly awareness associated
somehow with the input function, or its inputs. Does this give us any clues
about how to model attention and awareness?
Bruce