A new method of extrapolating the sweep pattern visual evoked potential acuity
Purpose In order to compare the amplitude-spatial frequency (A-SP) regression method with amplitude-logVA (A-logVA) regression methods in extrapolating the sweep pattern visual evoked potential (SPVEP) acuity. Methods We measured SPVEPs in 21 children and three adults using sinusoidally-modulated ho...
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Published in | Documenta ophthalmologica Vol. 117; no. 2; pp. 85 - 91 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer-Verlag
01.09.2008
Springer Springer Nature B.V |
Subjects | |
Online Access | Get full text |
ISSN | 0012-4486 1573-2622 |
DOI | 10.1007/s10633-007-9095-4 |
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Summary: | Purpose
In order to compare the amplitude-spatial frequency (A-SP) regression method with amplitude-logVA (A-logVA) regression methods in extrapolating the sweep pattern visual evoked potential (SPVEP) acuity.
Methods
We measured SPVEPs in 21 children and three adults using sinusoidally-modulated horizontal gratings as stimuli. The responses were averaged and displayed through discrete Fourier transformations. SPVER acuity was then estimated by using both the SPVEP amplitude- spatial frequency function (A-SP function regression method) and the SPVEP amplitude-log visual-angle function (A-logVA function regression method). Furthermore, the Bailey Lovie logMAR chart was employed to define visual acuity. Curve estimates were calculated to derive a correlation index (
R
) for each method.
Results
There are significant differences (
t
= 2.71,
P
< 0.05) between the correlation indices of curves obtained using the A-logVA function (logarithmic model, 0.95 ± 0.01) and that obtained by the A-SP function (inverse model, 0.92 ± 0.02). The overall correlation coefficient (
r
) between logMAR acuity and acuity calculated by the A-logVA regression method was 0.32 (
P
< 0.05). The overall correlation coefficient (
r
) between logMAR acuity and acuity calculated by the A-SP regression method was 0.41 (
P
< 0.05). Paired t-tests show that SPVEP acuity from the A-logVA function was not significantly different from acuities of the logMAR function (
t
= 1.77,
P
= 0.09). The difference in their mean values is 0.14 ± 0.08. However, SPVEP acuity calculated using the A-SP function regression method is significantly different from the acuity calculated from the logMAR function (
t
= 10.09,
P
< 0.01). The difference in their mean values is 0.41 ± 0.04.
Conclusions
The amplitude-logVA function regression method is more accurate in estimating SPVEP acuity in normal subjects with good visual acuity. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
ISSN: | 0012-4486 1573-2622 |
DOI: | 10.1007/s10633-007-9095-4 |