Monocular and Binocular Steady-state Flicker VEPs: Frequency-response Functions to Sinusoidal and Square-wave Luminance Modulation

Overview

Journal Doc Ophthalmol

Specialty Ophthalmology

Date 2011 Feb 1

PMID 21279419

Authors

David S Nicol

Ruth Hamilton

Uma Shahani

Daphne L McCulloch

Affiliations

Soon will be listed here.

Abstract

Steady-state VEPs to full-field flicker (FFF) using sinusoidally modulated light were compared with those elicited by square-wave modulated light across a wide range of stimulus frequencies with monocular and binocular FFF stimulation. Binocular and monocular VEPs were elicited in 12 adult volunteers to FFF with two modes of temporal modulation: sinusoidal or square-wave (abrupt onset and offset, 50% duty cycle) at ten temporal frequencies ranging from 2.83 to 58.8 Hz. All stimuli had a mean luminance of 100 cd/m(2) with an 80% modulation depth (20-180 cd/m(2)). Response magnitudes at the stimulus frequency (F1) and at the double and triple harmonics (F2 and F3) were compared. For both sinusoidal and square-wave flicker, the FFF-VEP magnitudes at F1 were maximal for 7.52 Hz flicker. F2 was maximal for 5.29 Hz flicker, and F3 magnitudes are largest for flicker stimulation from 3.75 to 7.52 Hz. Square-wave flicker produced significantly larger F1 and F2 magnitudes for slow flicker rates (up to 5.29 Hz for F1; at 2.83 and 3.75 Hz for F2). The F3 magnitudes were larger overall for square-wave flicker. Binocular FFF-VEP magnitudes are larger than those of monocular FFF-VEPs, and the amount of this binocular enhancement is not dependant on the mode of flicker stimulation (mean binocular: monocular ratio 1.41, 95% CI: 1.2-1.6). Binocular enhancement of F1 for 21.3 Hz flicker was increased to a factor of 2.5 (95% CI: 1.8-3.5). In the healthy adult visual system, FFF-VEP magnitudes can be characterized by the frequency-response functions of F1, F2 and F3. Low-frequency roll-off in the FFF-VEP magnitudes is greater for sinusoidal flicker than for square-wave flicker for rates ≤ 5.29 Hz; magnitudes for higher-frequency flicker are similar for the two types of flicker. Binocular FFF-VEPs are larger overall than those recorded monocularly, and this binocular summation is enhanced at 21.3 Hz in the mid-frequency range.

References

Regan D . A high frequency mechanism which underlies visual evoked potentials. Electroencephalogr Clin Neurophysiol. 1968; 25(3):231-7. DOI: 10.1016/0013-4694(68)90020-5. View

Eizenman M, Westall C, Geer I, Smith K, Chatterjee S, Panton C . Electrophysiological evidence of cortical fusion in children with early-onset esotropia. Invest Ophthalmol Vis Sci. 1999; 40(2):354-62. View

CIGANEK L . Binocular addition of the visually evoked response with different stimulus intensities in man. Vision Res. 1970; 10(6):479-87. DOI: 10.1016/0042-6989(70)90004-0. View

Norcia A, Tyler C . Spatial frequency sweep VEP: visual acuity during the first year of life. Vision Res. 1985; 25(10):1399-408. DOI: 10.1016/0042-6989(85)90217-2. View

Leguire L, Rogers G, Bremer D . Visual-evoked response binocular summation in normal and strabismic infants. Defining the critical period. Invest Ophthalmol Vis Sci. 1991; 32(1):126-33. View

Zemon V, Hartmann E, Gordon J . An electrophysiological technique for assessment of the development of spatial vision. Optom Vis Sci. 1997; 74(9):708-16. DOI: 10.1097/00006324-199709000-00018. View

Spekreijse H, VAN DER TWELL L, Zuidema T . Contrast evoked responses in man. Vision Res. 1973; 13(8):1577-601. DOI: 10.1016/0042-6989(73)90016-3. View

Adachi-Usami E, Lehmann D . Monocular and binocular evoked average potential field topography: upper and lower hemiretinal stimuli. Exp Brain Res. 1983; 50(2-3):341-6. DOI: 10.1007/BF00239198. View

Mackay A, Hamilton R, Bradnam M . Faster and more sensitive VEP recording in children. Doc Ophthalmol. 2004; 107(3):251-9. DOI: 10.1023/b:doop.0000005334.70304.c7. View

10.

Joost W, Bach M . Variability of the steady-state visually evoked potential: interindividual variance and intraindividual reproducibility of spatial frequency tuning. Doc Ophthalmol. 1990; 75(1):59-66. DOI: 10.1007/BF00142594. View

11.

Shea S, Aslin R, McCulloch D . Binocular VEP summation in infants and adults with abnormal binocular histories. Invest Ophthalmol Vis Sci. 1987; 28(2):356-65. View

12.

Johansson B, Jakobsson P . Fourier-analysed steady-state VEPs in pre-school children with and without normal binocularity. Doc Ophthalmol. 2006; 112(1):13-22. DOI: 10.1007/s10633-005-5889-4. View

13.

Mizota A, Hoshino A, Adachi-Usami E, Fujimoto N . Binocular summation in visual evoked cortical potential in patients who have significantly different P100 peak latencies in their two eyes. Graefes Arch Clin Exp Ophthalmol. 2004; 242(9):762-6. DOI: 10.1007/s00417-004-0899-6. View

14.

Bach M, Meigen T . Do's and don'ts in Fourier analysis of steady-state potentials. Doc Ophthalmol. 2000; 99(1):69-82. DOI: 10.1023/a:1002648202420. View

15.

Fiorentini A, Maffei L . Electrophysiological evidence for binocular disparity detectors in human visual system. Science. 1970; 169(3941):208-9. DOI: 10.1126/science.169.3941.208. View

16.

Odom J, Bach M, Brigell M, Holder G, McCulloch D, Tormene A . ISCEV standard for clinical visual evoked potentials (2009 update). Doc Ophthalmol. 2009; 120(1):111-9. DOI: 10.1007/s10633-009-9195-4. View

17.

Regan D . Speedy assessment of visual acuity in amblyopia by the evoked potential method. Ophthalmologica. 1977; 175(3):159-64. DOI: 10.1159/000308649. View

18.

Norcia A, Tyler C . Infant VEP acuity measurements: analysis of individual differences and measurement error. Electroencephalogr Clin Neurophysiol. 1985; 61(5):359-69. DOI: 10.1016/0013-4694(85)91026-0. View

19.

Regan D . Assessment of visual acuity by evoked potential recording: ambiguity caused by temporal dependence of spatial frequency selectivity. Vision Res. 1978; 18(4):439-43. DOI: 10.1016/0042-6989(78)90054-8. View

20.

Parry N, Murray I, Hadjizenonos C . Spatio-temporal tuning of VEPs: effect of mode of stimulation. Vision Res. 2000; 39(21):3491-7. DOI: 10.1016/s0042-6989(99)00098-x. View