What a vast, terribly uncertain abyss perception is. It is through some flurry of processes, interacting in a lurid convection akin to the turbulence of a particularly belligerent sea, that we produce, in our mind’s eye, something coherent and meaningful. Objective physical sensations (a squiggly sound wave, a playful touch on the wrist) converge and pinch together into a holistic image, an abstraction which is then projected on to the screen stretched taut and pinned within the architecture of lobes and cortexes. It is this pictoral representation, shaded in with our singular experiences and memories, that we incline our heads toward in acknowledgment. Hundreds of editions of a hundred separate, independent textbooks carefully delineate the precise mechanics of impulse transmission in nerves… and yet…
And yet, in spite of our understanding of how the nervous system’s minute electrons, leaping haphazardly about to culminate in what we call, “chemical activity”, we seem to have run against some sticky impenetrable darkness if we yearn to look further onwards. That is to say, nobody knows (yet) how these alterations of chemical activity relate to psychological states. The entire procedure indeed occurs, but there’s a gaping, palpable absence of a bridge of sorts that elegantly arches to render a connection between the quantifiable ocean of ion channel openings to the wonder of consciousness — to the mystery of perception and of interpretation. And surely, when we engage with art, we perceive and interpret seamlessly, while the systematic processes that are unbeknownst to even ourselves murmurs quietly and opaquely on. Regardless of how introspective we feel, we cannot reveal to ourselves what fantastical things are happening behind this black curtain.
Cognitive psychologists try to work this out, to sketch to their best ability a sort of crude functional bridge, by assessing at how automatic processes we take for granted operate and sometimes “malfunction”, producing what we know to be optical illusions. Psychologists call the “real world out there” the distal stimulus (a horizon), while the image projected upside-down on our retinas is termed as the proximal stimulus (a tiny, two-dimensional, rotated by 180° image of a horizon). The percept is that coalescence of the rather impersonal sensations (proximal stimulus) with the quiet whirrings of our cognitions, drawing in recollections and logical procedures to capture the most sense we can of this little upside-down universe, this universe beyond our seemingly disembodied mind.
What’s noteworthy is the observation that we are mostly ineffective, in recollection or in recreation, in seizing the entirety of what we perceive. Something, or rather, a dazzling cavalcade of things occur between the step of the proximal stimulus and the percept. We sometimes recognize what is actually absent while other times don’t see certain things that are there — things that are mightily exerting their existence in the corporeal world.
Automatically, like doting parents, our minds assign depth to the two-dimensional, maintain size constancy, and fill in blind spots with a surreptitious flourish. The mind does this by means of monocular and binocular cues, like relative size and linear perspective (artists have exploited these methods) to transform that image, pricking our retinas, to a more faithful description of the three-dimensional world outside. It is when these “cues” are mixed and used contradictorily, that we see optical illusions.
And this is simply visual perception. What about the embarrassing gaps of other perceptive mediums? What about more complex abstractions like thought and emotion?
Interesting musings, no?
Perhaps, as time trudges onwards, we’ll understand better. For now, the battalion of psychologists and neuroscientists continue to work in their labs, trying to answer smaller questions in hopes that one day, these collective little advances give rise to a fuller view on this front of knowledge.
Sue majors in Neuroscience & English and tends to lurk in bookstores.