TY - JOUR
T1 - Flicker-defined form stimuli are minimally affected by centre-surround lateral contrast interactions
AU - Denniss, Jonathan
AU - McKendrick, Allison M
N1 - © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - PURPOSE: Flicker-defined form (FDF) stimuli have recently been adopted for visual field testing. A key difference between FDF and traditional perimetric stimuli is that the entire display background contains flickering dots. The purpose of this study was to determine whether the perception of FDF stimuli is influenced by lateral interactions involving regions beyond the stimulus border in young healthy observers.METHODS: Experiment 1 measured the effect of surround size and retinal eccentricity on the detection of the FDF contour. Psychometric functions were collected for surround diameters of 20°, 30° and 40°, and with stimuli centred at eccentricities of 0°, 10° and 20°. Experiment 2 measured the effect of target-surround temporal phase difference on apparent temporal contrast (flicker strength) of the target for both the FDF stimulus and a solid-field stimulus. Psychometric functions were collected for target-surround phase differences of 0°, 45°, 90°, 135° and 180°.RESULTS: Our results show a mild surround-suppression effect for FDF stimuli that is independent of surround size. Magnitudes of FDF surround suppression were consistent with the reduced temporal contrast energy of the stimulus compared to solid-field stimuli.CONCLUSION: FDF stimuli necessarily have both flickering target and background. Our results suggest that visual field defects outside the target are unlikely to markedly influence the detection and perception of the FDF stimulus. Nevertheless, mild surround suppression of contrast arises for FDF stimuli, hence interactions between the background and the target area may influence FDF results in conditions that alter centre-surround perceptual effects.
AB - PURPOSE: Flicker-defined form (FDF) stimuli have recently been adopted for visual field testing. A key difference between FDF and traditional perimetric stimuli is that the entire display background contains flickering dots. The purpose of this study was to determine whether the perception of FDF stimuli is influenced by lateral interactions involving regions beyond the stimulus border in young healthy observers.METHODS: Experiment 1 measured the effect of surround size and retinal eccentricity on the detection of the FDF contour. Psychometric functions were collected for surround diameters of 20°, 30° and 40°, and with stimuli centred at eccentricities of 0°, 10° and 20°. Experiment 2 measured the effect of target-surround temporal phase difference on apparent temporal contrast (flicker strength) of the target for both the FDF stimulus and a solid-field stimulus. Psychometric functions were collected for target-surround phase differences of 0°, 45°, 90°, 135° and 180°.RESULTS: Our results show a mild surround-suppression effect for FDF stimuli that is independent of surround size. Magnitudes of FDF surround suppression were consistent with the reduced temporal contrast energy of the stimulus compared to solid-field stimuli.CONCLUSION: FDF stimuli necessarily have both flickering target and background. Our results suggest that visual field defects outside the target are unlikely to markedly influence the detection and perception of the FDF stimulus. Nevertheless, mild surround suppression of contrast arises for FDF stimuli, hence interactions between the background and the target area may influence FDF results in conditions that alter centre-surround perceptual effects.
KW - Adult
KW - Analysis of Variance
KW - Contrast Sensitivity/physiology
KW - Female
KW - Flicker Fusion/physiology
KW - Form Perception/physiology
KW - Humans
KW - Male
KW - Pattern Recognition, Visual/physiology
KW - Photic Stimulation/methods
KW - Psychometrics
KW - Sensory Thresholds/physiology
KW - Visual Fields/physiology
KW - Young Adult
UR - http://www.scopus.com/inward/record.url?scp=84959507779&partnerID=8YFLogxK
U2 - 10.1111/opo.12268
DO - 10.1111/opo.12268
M3 - Article
C2 - 26743018
SN - 0275-5408
VL - 36
SP - 174
EP - 182
JO - Ophthalmic and Physiological Optics
JF - Ophthalmic and Physiological Optics
IS - 2
ER -