Purchase this article with an account.
Patrick T. Goodbourn, Jenny M. Bosten, Ruth E. Hogg, Gary Bargary, Adam J. Lawrance-Owen, J. D. Mollon; Poor Correlation between Different Putative Measures of Magnocellular Function. Invest. Ophthalmol. Vis. Sci. 2011;52(14):1878.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Deficits of rapid temporal processing have frequently been associated with certain cognitive disorders, particularly developmental dyslexia, autism and schizophrenia. Several theorists have proposed that these findings reflect a generalised deficit affecting the visual magnocellular system as well as its auditory homologue. However, it is unclear whether performance on the various psychophysical tasks intended to probe magnocellular function is actually supported by a common substrate. To investigate this question, we asked whether different putative tests of magnocellular function correlate across participants.
As part of the PERGENIC project, 1064 participants completed four putative tests of magnocellular function: detection of Gabors of low spatial and high temporal frequency (GS); detection of pulsed gratings on a steady luminance pedestal (SP); detection of coherent motion (CM); and discrimination of auditory temporal order (TO). We calculated correlations between these measures within our sample, as well as test-retest reliabilities based on a randomly selected subsample of 105 participants.
All measures showed good test-retest reliability, ranging from ρ = .52 (SP) to .77 (TO). However, only the correlation between the two most similar tasks (GS-SP) was of notable magnitude (ρ = .38). Most intercorrelations between other measures were significant, but effect sizes were poor to modest, ranging from .06 (FD-TO) to .20 (SP-TO).
Our results suggest that—with the exception of GS and SP—very little of the variance in performance on each of the tests is mediated by a common substrate. We discuss the implications of our findings for magnocellular theories of cognitive disorder.
This PDF is available to Subscribers Only