Evidence against independent processing of black and white pattern features

Cavanagh, Patrick; Brussell, Edward M.; Stober, Stephen R.

doi:10.3758/bf03207355

Cited by 6 publications

(2 citation statements)

References 10 publications

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“…Our data are in accord with the view that stimulus components of opposite polarity are jointly processed (Cavanagh, Brussell, & Stober, 1981). However, for stimuli which are spatially complex or changing in time, 'light' and 'dark' are not synonymous with signals along the ON and OFF pathways, respectively.…”

Section: Relation To Pre6ious Psychophysical Studiessupporting

confidence: 88%

Short-range vernier acuity: interactions of temporal frequency, temporal phase, and stimulus polarity

Victor

Conte

1999

Vision Research

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We examined how vernier thresholds for flickering bars depend on the temporal frequency and relative temporal phase of the bars. The largest effect of relative phase (up to a fivefold increase in displacement thresholds) was seen at 2 Hz, and for most subjects, relative phase had little effect at 16 Hz and above. The effect of relative phase was essentially independent of contrast and trial duration. Thresholds were elevated by the greatest amount when bars were presented in antiphase, but at 1 and 4 Hz, quadrature phase offsets also led to substantial elevations in displacement thresholds. An experiment designed to examine the interaction of the vernier judgment with apparent motion failed to identify a role for mechanisms sensitive to apparent motion in threshold elevation. Another experiment in which the bars were modulated with sawtooth waveforms indicated that temporal correlation between the bars, rather than the ON versus OFF distinction, underlies the phase sensitivity. A simple dynamical model that posits partial rectification prior to a cross-correlation-like interaction accounts for the observed results.

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Section: Relation To Pre6ious Psychophysical Studiessupporting

confidence: 88%

Short-range vernier acuity: interactions of temporal frequency, temporal phase, and stimulus polarity

Victor

Conte

1999

Vision Research

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“…la. The finding may bear some relation to the general difficulty encountered by the visual system when processing edges along which the sign of contrast reverses (Cavanagh et al, 1981;Fig. lb).…”

Section: Introductionmentioning

confidence: 81%

Responses of neurons in cat striate cortex to vernier offsets in reverse contrast stimuli

Swindale

1995

Vis Neurosci

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This paper examines how the responses of cells in area 17 of the cat vary as a function of the vernier offset between a bright and a dark bar. The study was prompted by the finding that human vernier acuity is reduced for bars or edges of opposite contrast sign (Mather & Morgan, 1986; O'Shea & Mitchell, 1990). Both simple and complex cells showed V-shaped tuning curves for reverse contrast stimuli: i.e. response was minimum at alignment, and increased with increasing vernier offset. For vernier bars with the same contrast sign, γ-shaped tuning curves were found, as reported earlier (Swindale & Cynader, 1986). Sensitivity to offset was inversely correlated in the two paradigms. However, complex cells with high sensitivity to offsets in a normal vernier stimulus were significantly less sensitive to offsets in reverse contrast stimuli. A cell's response to a vernier stimulus in which both bars are bright can be predicted by the shape of its orientation tuning curve, if the vernier stimulus is approximated by a single bar with an orientation equal to that of a line joining the midpoints of the two component bars (Swindale & Cynader, 1986). This approximation did not hold for the reverse contrast condition: orientation tuning curves for compound barswere broad and shallow, rather than bimodal, with peaks up to 40 deg from the preferred orientation. Results from simple cells were compared with predictions made by a linear model of the receptive field. The model predicted the V-shaped tuning curves found for reverse contrast stimuli. It also predicted that absolute values of tuning slopes for vernier offsets in reverse contrast stimuli might sometimes be higher than with normal stimuli. This was observed in some simple cells. The model was unable to explain the shape of orientation tuning curves for compound bars, nor could it explain the breakdown of the equivalent orientation approximation.

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A comparison of varieties of “second-order” motion

Petersik

1995

Vision Research

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Bistable apparent-movement displays were created using four different kinds of "second-order" stimuli in which figures were defined by binocular disparity, spatial phase shifts of periodic luminance distributions, relative motion, and texture-element orientation differences. For each display, characteristics of the local structure of the figures, backgrounds, or both were varied. For each experimental condition, the type of apparent movement seen as a function of interstimulus interval was measured, and it was found that the relationship between perceived apparent movement and interstimulus interval differed across the types of displays viewed. The results suggest that the transformations between first-order stimulus properties and second-order motion may be too complex to imply a single uniform class of second-order motion detectors. Alternative physiological accounts of the results are discussed.

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Evidence against independent processing of black and white pattern features

Cited by 6 publications

References 10 publications

Short-range vernier acuity: interactions of temporal frequency, temporal phase, and stimulus polarity

Short-range vernier acuity: interactions of temporal frequency, temporal phase, and stimulus polarity

Responses of neurons in cat striate cortex to vernier offsets in reverse contrast stimuli

A comparison of varieties of “second-order” motion

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