Hostname: page-component-7c8c6479df-ws8qp Total loading time: 0 Render date: 2024-03-19T08:47:22.986Z Has data issue: false hasContentIssue false

Multifocal visual evoked potential responses to pattern-reversal, pattern-onset, pattern-offset, and sparse pulse stimuli

Published online by Cambridge University Press:  01 March 2009

BRAD FORTUNE*
Affiliation:
Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health System, Portland, Oregon
SHABAN DEMIREL
Affiliation:
Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health System, Portland, Oregon
BANG V. BUI
Affiliation:
Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Victoria, Australia
*
*Address correspondence and reprint requests to: Brad Fortune, Discoveries in Sight Research Laboratories, Devers Eye Institute, 1225 NE Second Avenue, Portland, OR 97232. E-mail: bfortune@deverseye.org

Abstract

The purpose of the present study was to compare standard multifocal visual evoked potential (mfVEP) pattern-reversal responses with those produced by pattern-onset, pattern-offset, and pulsed pattern stimuli. mfVEP recordings were obtained from five normal subjects using VERIS and a 4-electrode array. The standard reversal stimulus had 215 m-sequence steps (7.5-min duration). Pattern-onset and -offset responses were evaluated using sequences that all had 32 frames per m-step and 210 total steps (7.5 min); but the duration of the contrast step varied so that it was 1, 2, 4, 8, 12, or 16 of the 32 frames. The same series was also inverted so that adapting contrast was high and the stimulus step began with a contrast decrement. The effect of temporal sparseness was studied with positive contrast pulses (two-frame duration) within 16, 20, 24, 28, or 32 frames per m-step (all had 211 total steps). Four stimulus locations were isolated to study the effect of spatial sparseness. Standard mfVEP reversal responses were virtually identical to onset responses throughout the field, but ~3.5 times smaller. Responses to pattern onset were about twice as large as those for offset, especially in the lower hemifield, irrespective of adapting contrast level. Offset responses exhibited a different waveform compared with reversal, onset, or brief pulse responses. Though temporally sparse pattern-pulse responses were ~3.5 times larger than standard reversal responses, there was no improvement in signal-to-noise ratio (SNR). However, spatial isolation increased SNR by 22% for reversal responses and by 62% for temporally sparse pulses. Temporally sparse pattern-pulse stimuli do not improve mfVEP SNR unless they are also spatially sparse, suggesting that lateral inhibitory mechanisms have a greater impact than temporal contrast gain control mechanisms. The mfVEP response depends on the polarity of a contrast step, irrespective of the state of contrast adaptation.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baseler, H.A., Sutter, E.E., Klein, S.A. & Carney, T. (1994). The topography of visual evoked response properties across the visual field. Electroencephalography and Clinical Neurophysiology 90, 6581.Google Scholar
Brigell, M.G. (2001). The visual evoked potential. In Electrophysiological Testing in Disorders of the Retina, Optic Nerve, and Visual Pathway, ed. Fishman, G.A., Birch, D.G., Holder, G.E. & Brigell, M.G., pp. 237279. San Francisco, CA: American Academy of Ophthalmology.Google Scholar
Fortune, B., Demirel, S., Zhang, X., Hood, D.C. & Johnson, C.A. (2006). Repeatability of normal multifocal VEP: Implications for detecting progression. Journal of Glaucoma 15, 131141.Google Scholar
Fortune, B., Demirel, S., Zhang, X., Hood, D.C., Patterson, E., Jamil, A., Mansberger, S.L., Cioffi, G.A. & Johnson, C.A. (2007). Comparing multifocal VEP and standard automated perimetry in high-risk ocular hypertension and early glaucoma. Investigative Ophthalmology and Visual Science 48, 11731180.Google Scholar
Fortune, B. & Hood, D.C. (2003). Conventional pattern-reversal VEPs are not equivalent to summed multifocal VEPs. Investigative Ophthalmology and Visual Science 44, 13641375.Google Scholar
Fortune, B., Zhang, X., Hood, D.C., Demirel, S. & Johnson, C.A. (2004). Normative ranges and specificity of the multifocal VEP. Documenta Ophthalmologica. Advances in Ophthalmology 109, 87100.Google Scholar
Fortune, B., Zhang, X., Hood, D.C., Demirel, S., Patterson, E., Jamil, A., Mansberger, S.L., Cioffi, G.A. & Johnson, C.A. (2008). Effect of recording duration on the diagnostic performance of multifocal visual-evoked potentials in high-risk ocular hypertension and early glaucoma. Journal of Glaucoma 17, 175182.Google Scholar
Fraser, C.L., Klistorner, A., Graham, S.L., Garrick, R., Billson, F.A. & Grigg, J.R. (2006). Multifocal visual evoked potential analysis of inflammatory or demyelinating optic neuritis. Ophthalmology 113, e321e323.Google Scholar
Goldberg, I., Graham, S.L. & Klistorner, A.I. (2002). Multifocal objective perimetry in the detection of glaucomatous field loss. American Journal of Ophthalmology 133, 2939.Google Scholar
Graham, S.L., Klistorner, A.I. & Goldberg, I. (2005). Clinical application of objective perimetry using multifocal visual evoked potentials in glaucoma practice. Archives of Ophthalmology 123, 729739.Google Scholar
Graham, S.L., Klistorner, A.I., Grigg, J.R. & Billson, F.A. (2000). Objective VEP perimetry in glaucoma: Asymmetry analysis to identify early deficits. Journal of Glaucoma 9, 1019.Google Scholar
Hoffmann, M.B., Straube, S. & Bach, B. (2003). Pattern-onset stimulation boosts central multifocal VEP responses. Journal of Vision 3, 432439.Google Scholar
Hood, D.C. & Greenstein, V.C. (2003). Multifocal VEP and ganglion cell damage: Applications and limitations for the study of glaucoma. Progress in Retinal and Eye Research 22, 201251.Google Scholar
Hood, D.C., Odel, J.G. & Zhang, X. (2000 a). Tracking the recovery of local optic nerve function after optic neuritis: A multifocal VEP study. Investigative Ophthalmology and Visual Science 41, 40324038.Google Scholar
Hood, D.C., Thienprasiddhi, P., Greenstein, V.C., Winn, B.J., Ohri, N., Liebmann, J.M. & Ritch, R. (2004). Detecting early to mild glaucomatous damage: A comparison of the multifocal VEP and automated perimetry. Investigative Ophthalmology and Visual Science 45, 492498.Google Scholar
Hood, D.C., Zhang, X., Greenstein, V.C., Kangovi, S., Odel, J.G., Liebmann, J.M. & Ritch, R. (2000 b). An interocular comparison of the multifocal VEP: A possible technique for detecting local damage to the optic nerve. Investigative Ophthalmology and Visual Science 41, 15801587.Google Scholar
Hood, D.C., Zhang, X., Hong, J.E. & Chen, C.S. (2002). Quantifying the benefits of additional channels of multifocal VEP recording. Documenta Ophthalmologica. Advances in Ophthalmology 104, 303320.Google Scholar
Hood, D.C., Zhang, X. & Winn, B.J. (2003). Detecting glaucomatous damage with multifocal visual evoked potentials: How can a monocular test work? Journal of Glaucoma 12, 315.Google Scholar
James, A.C. (2003). The pattern-pulse multifocal visual evoked potential. Investigative Ophthalmology and Visual Science 44, 879890.Google Scholar
James, A.C., Maddess, T., Goh, X.L. & Winkles, N. (2005 a). Spatially sparse pattern–pulse stimulation enhances multifocal visual evoked potential analysis. Investigative Ophthalmology and Visual Science 46, E-Abstract 3602.Google Scholar
James, A.C., Ruseckaite, R. & Maddess, T. (2005 b). Effect of temporal sparseness and dichoptic presentation on multifocal visual evoked potentials. Visual Neuroscience 22, 4554.Google Scholar
Klistorner, A. & Graham, S.L. (2000). Objective perimetry in glaucoma. Ophthalmology 107, 22832299.Google Scholar
Klistorner, A.I. & Graham, S.L. (2001). Electroencephalogram-based scaling of multifocal visual evoked potentials: Effect on intersubject amplitude variability. Investigative Ophthalmology and Visual Science 42, 21452152.Google Scholar
Klistorner, A.I., Graham, S.L., Grigg, J.R. & Billson, F.A. (1998). Multifocal topographic visual evoked potential: Improving objective detection of local visual field defects. Investigative Ophthalmology and Visual Science 39, 937950.Google Scholar
Maddess, T., James, A.C. & Bowman, E.A. (2005). Contrast response of temporally sparse dichoptic multifocal visual evoked potentials. Visual Neuroscience 22, 153162.Google Scholar
Maddess, T., James, A.C., Ruseckaite, R. & Bowman, E.A. (2006). Hierarchical decomposition of dichoptic multifocal visual evoked potentials. Visual Neuroscience 23, 703712.Google Scholar
Regan, D. (1989). Human Brain Electrophysiology: Evoked Potentials and Evoked Magnetic Fields in Science and Medicine. New York: Elsevier.Google Scholar
Ruseckaite, R., Maddess, T., Danta, G., Lueck, C.J. & James, A.C. (2005). Sparse multifocal stimuli for the detection of multiple sclerosis. Annals of Neurology 57, 904913.Google Scholar
Sutter, E.E. (1991). The fast m-transform: Fast computation of cross-correlations with binary m-sequences. SIAM Journal on Computing 20, 686694.Google Scholar
Sutter, E.E. & Tran, D. (1992). The field topography of ERG components in man–I. The photopic luminance response. Vision Research 32, 433446.Google Scholar
Zhang, X. & Hood, D.C. (2004 a). Increasing the sensitivity of the multifocal visual evoked potential (mfVEP) technique: Incorporating information from higher order kernels using a principal component analysis method. Documenta Ophthalmologica. Advances in Ophthalmology 108, 211222.Google Scholar
Zhang, X. & Hood, D.C. (2004 b). A principal component analysis of multifocal pattern reversal VEP. Journal of Vision 4, 3243.Google Scholar
Zhang, X., Hood, D.C., Chen, C.S. & Hong, J.E. (2002). A signal-to-noise analysis of multifocal VEP responses: An objective definition for poor records. Documenta Ophthalmologica. Advances in Ophthalmology 104, 287302.Google Scholar