Few concepts are as central to understanding the modern world as borders, and the now-thriving field of border studies has already produced a substantial literature analyzing their legal, ideological, geographical, and historical aspects. Such studies have hardly exhausted the subject’s conceptual fertility, however, as this pioneering collection on the aesthetics of borders demonstrates. Organized around six key ideas—ecology, imaginary, in/visibility, palimpsest, sovereignty and waiting—the interlocking essays collected here provide theoretical starting points for an aesthetic understanding of borders, developed in detail through interdisciplinary analyses of literature, audio-visual borderscapes, historical and contemporary ecologies, political culture, and migration.

Precise isolation of individual chromatic mechanisms is useful for investigations of vision. One technique for isolating chromatic pathways is "silent substitution" (modulating colors along specific color directions). The minimally distinct border (MDB) technique can be further used to determine the specific color direction that isolates the S-cones (tritan axis). However, macular pigment distribution may render a foveally-measured tritan line imprecise when stimuli are large or peripheral. We had subjects make MDB judgments at five retinal eccentricities, and compared the results to a model of macular distribution. The model predicted the direction of chromatic rotation but the predicted magnitude was less than observed. We hypothesized that the neural properties that underlie MDB judgments in the fovea may not be valid for the periphery. For example a decrease in L-M sensitivity across the visual field may result in minimum border detection shifted near the L-M axis. We investigated this issue by using a suprathreshold contrast matching task to examine the perceptual scaling of chromatic and luminance as a function of eccentricity. Subjects made contrast matches between Gabor patches across the visual field, comparing chromatic and achromatic stimuli to a foveal achromatic stimulus. Our results show a falloff in L-M and luminance sensitivity, relative to S-cone sensitivity with increasing eccentricity. Our suprathreshold results mirror those of threshold measures for chromatic pathways but not for luminance, consistent with known physiology of magno and parvo luminance pathways. Our results indicate that MDB may not be a valid peripheral indicator of the tritan axis.