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Christian Kaul, Bahador Bahrami, Geraint Rees; Multivoxel fMRI analysis reveals the representation of spatial frequency information in human primary visual cortex. Journal of Vision 2009;9(8):766. doi: 10.1167/9.8.766.
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© ARVO (1962-2015); The Authors (2016-present)
Previous research in macaque and cat primary visual cortex revealed columnar organisation of spatial frequency representations . However, previous results from functional magnetic resonance imaging (fMRI) in humans failed to produce evidence for selectivity of spatial frequency in human primary visual cortex .
Here, we measured BOLD contrast activity in human primary cortex with high spatial resolution (1.5mm voxels) fMRI during a simple dimming task at fixation, simultaneously presenting humans with a grating with one of two spatial frequencies in the periphery. The spatial frequency of the peripheral grating was either low (1.5 cycles/ degree) or high (4.5c/d). Replicating previous results , univariate analysis did not reveal any significant differences between the conditions. However, multivariate pattern decoding (MVPD) from voxels in early visual area V1 reliably distinguished high from low spatial frequency gratings. These results demonstrate that spatial frequency information is represented in the pattern of V1 BOLD responses and MVPD techniques are able to probe this representation. Therefore it extends the reliabily and suitability of the MVPD approach as complementary to univariate fMRI analysis.
1. Tootell, R. B., Silverman, M. S., & De Valois, R. L. (1981). Spatial frequency columns in primary visual cortex. Science, 214, 813–815.
Singh, K. D., Smith, A. T., & Greenlee, M. W. (2000). Spatiotemporal frequency and direction sensitivities of human visual areas measured using fMRI. Neuroimage, 12, 550–564.
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