While checking a road atlas, today, to see if I could make it to
another performance of "the voice filled with Genius" [Martina
McBride - if you get a chance to attend a performance of hers, don't
miss-out - her performances are spectacularly-good, and you won't be
sorry for having experienced her] I was reminded of a a
rather-well-delineated depth-perception phenomenon that happens when
I look at road maps.
The red routes appear 'at-depth' with respect to other map features.
The phenomenon occurs on;y binocularly [close one eye, and it
disappears].
I first observed the phenomenon when I was preparing the maps to be
included with invitations to my Father's 90th Birthday celebration
~four years ago.
It's 'curious' because, "of course", the maps are strictly 2-D
stuff - yet there's this binocular experience of there being 'depth'.
Since I first experienced it, I've 'wondered' why I've never read
about this phenomenon.
'Wonder' if it's a 'quirk' of my nervous system, or if other folks
can see it, too.
Anyway, if it's a 'universal' phenomenon, it presents a very-nice
opportunity to study at least a bit of the neural dynamics that
underpin binocular depth-perception. [If anyone 'wonders', I stand on
what's in AoK, Ap6 with respect to monocular depth-perception.]
Anyway, have subject-volunteers who preceive the reds 'at-depth' go
in a scanner and alternate between binocular and monocular viewing of
atlas pages [I have experienced analogous phenomena when viewing
CRTs, but, with CRTs is's more whimsical [probably because of the way
the screen is refreshed via progressive scanning, which doesn't allow
the visual apparatus to 'settle-in' to an overall relatively-TD
E/I-minimized 'state' [there's another experiment, waiting to be
done - paper vs. CRT visual TD E/I-minimization - will surely expose
'the costs' of prolonged CRT-viewing].
The neural topology will be differentially-activated in the monocular
and binocular cases, of course, mostly because of the drastic
alteration of total-input, but that can be
mathematically-separated-out, leaving a, probably-small, differential
that corresponds to this viewing-at-depth phenomenon.
And, because the phenomenon is with respect to red feature, the
investigation is likely to shed some new light upon color perception,
too.
If I was in an academic institution that had an appropriate scanner,
I'd not hesitate to do this analysis, as a
'spare-'time'-side-project'. It's the sort of thing that tends,
strongly, to yield new insights in abundance, and, so, it's a
worthwhile thing to pursue.
K. P. Collins
