The human visual system is able to extract an object from its surrounding using a number of cues. These include foreground/background gradients in disparity, motion, texture, colour, and luminance. We have investigated normal subjects' ability to detect objects defined by either motion, texture, or luminance gradients. The effects of manipulating cue density and cue foreground/background gradient on both detection and recognition accuracy were also investigated. The results demonstrate a simple additive relationship between cue density and cue gradient across forms defined by motion, luminance, and texture. The results are interpreted as evidence for the notion that form parsing is achieved via a similar algorithm across anatomically distinct processing streams.
Get full access to this article
View all access options for this article.
References
1.
BantonTLeviD M, 1990“Vernier localisation in the motion system”Investigative Ophthalmology & Visual Science31Supplement, 443
2.
BraddickO J, 1974“A short range process in apparent motion”Vision Research14519–527
3.
CornsweetT N, 1962“The staircase method in psychophysics”American Journal of Psychology75485–491
4.
GiaschiDReganDKotheAHongX HSharpeJ A, 1992“Motion-defined letter detection and recognition in patients with multiple sclerosis”Annals of Neurology31621–628
5.
GilbertC DHirschJ AWeiselT N, 1990“Lateral interactions in visual cortex”Cold Spring Harbor Symposia on Quantitative Biology55663–667
6.
GrayRReganD, 1998“Spatial frequency discrimination and detection characteristics for gratings defined by orientation texture”Vision Research382601–2617
7.
GrossbergS, 1994“3-D vision and figure – ground separation by visual cortex”Perception & Psychophysics5548–120
8.
HamstraSReganD, 1991“Dot lifetime and presentation duration have little effect on orientation discrimination for equally-detectable motion-defined and contrast defined bars”Investigative Ophthalmology & Visual Science32Supplement, 1270
9.
JuleszB, 1971Foundations of Cyclopean Perception (Chicago, IL: University of Chicago Press)
10.
NakayamaKTylerC W, 1981“Psychophysical isolation of movement sensitivity by removal of familiar positional cues”Vision Research21427–433
11.
NothdurftH C, 1985a“Orientation sensitivity and texture segmentation in patterns with different line orientations”Vision Research25551–560
12.
NothdurftH C, 1985b“Sensitivity for structure gradient in texture discrimination tasks”Vision Research251957–1968
13.
NothdurftH C, 1990“Texton segregation by associated differences in global and local luminance distribution”Proceedings of the Royal Society of London, Series B239295–320
14.
NothdurftH C, 1991“Texture segmentation and pop-out from orientation contrast”Vision Research311073–1078
15.
ParkJ YKurzL, 1996“Unsupervised segmentation of textured images”Information Sciences92(1–4) 255–276
16.
ReganD, 1986a“Form from motion parallax and form from luminance contrast: vernier discrimination”Spatial Vision1305–318
17.
ReganD, 1986b“Visual processing of four kinds of relative motion”Vision Research26127–145
18.
ReganD, 1989“Orientation discrimination for objects defined by relative motion and objects defined by luminance contrast”Vision Research291389–1400
19.
ReganD, 1995“Orientation discrimination for bars defined by orientation texture”Perception241131–1138
20.
ReganDBeverleyK I, 1984“Figure–ground segregation by motion contrast and by luminance contrast”Journal of the Optical Society of America A1433–442
21.
ReganDGiaschiDSharpeJ AHongX H, 1992“Visual processing of motion-defined form: Selective failure in patients with parietotemporal lesions”Journal of Neuroscience122198–2210
22.
ReganDHamstraS J, 1991“Shape discrimination for motion-defined and contrast-defined form: squareness is special”Perception20315–336
23.
ReganDHamstraS J, 1992“Dissociation of orientation discrimination from form detection for motion-defined bars and luminance-defined bars: Effects of dot lifetime and presentation duration”Vision Research321655–1666
24.
ReganDHongX H, 1990“Visual acuity for optotypes made visible by relative motion”Optometry and Vision Science6749–55
25.
ReganDHongX H, 1994“Recognition and detection of texture-defined letters”Vision Research342403–2407
26.
ReganDHongX H, 1995“Two models of the recognition and detection of texture-defined letters compared”Biological Cybernetics72389–396
27.
ReganDKotheA CSharpeJ A, 1991“Recognition of motion-defined shapes in patients with multiple sclerosis and optic neuritis”Brain1141129–1155
28.
ReganDSimpsonT L, 1995“Multiple sclerosis can cause visual processing deficits specific to texture-defined form”Neurology45809–815
29.
RichardsW, 1971“Motion detection in man and other animals”Brain Behavior and Evolution4162–181
30.
StevensK A (Ed.), 1987Visual Object Perception from a Computational Perspective. Visual Object Processing (Hove, Sussex: Lawrence Erlbaum Associates)
31.
VainaL M, 1994“Functional segregation of color and motion processing in the human visual cortex–clinical evidence”Cerebral Cortex4555–572
32.
Van EssenD CFellemanD JDeYoeE AOlavarriaJKnierimJ, 1990“Modular and hierarchical organization of extrastriate visual cortex in the macaque monkey”Cold Spring Harbor Symposia on Quantitative Biology55679–696
33.
YenS CFinkelY H, 1998“Extraction of perceptually salient contours by striate cortical networks”Vision Research38719–741
34.
ZekiS, 1990a“A century of cerebral achromatatopsia”Brain1131721–1777
35.
ZekiS, 1990b“Parallelism and functional specialization in human visual cortex”Cold Spring Harbor Symposia on Quantitative Biology55651–661
36.
ZekiS, 1991“Cerebral akinetopsia (visual motion blindness). A review”Brain114811–824
37.
ZekiSWatsonJ D GLueckC JFristonK JKennardCFrackowiakR S J, 1991“A direct demonstration of functional specialization in human visual cortex”Journal of Neuroscience11641–649
