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| Non-linear Visual Evoked Potentials and the neural basis of luminance,colour and form |
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| 作者：David Ph… 文章来源：1Brain Sciences Institute, Swinburne University of Technology Melbourne, Australia 2School of psych 点击数1331 更新时间：2005/6/30 17:43:00 文章录入：aya610 责任编辑：毛进 |
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| Purpose - The 1990s saw a rapid expansion of knowledge of the neuroscience of the magnocellular and parvocellular pathways and their roles in perception of colour, motion and form in primate. Despite the advent of brain imaging techniques with high spatial resolution, the extension of primate findings into human has been hampered by the lack of techniques that relate directly to the neural types contributing function. Non-linear analysis of the visual evoked potential provides one such means.
Methods: The VERIS system (EDI, Ca) was used to stimulate and record visually evoked potentials (recorded between Oz and Fz with ear ground). Signals were amplified with gain of 100000 and filtered in a band pass fashion between 1 Hz and 300Hz, with a sampling frequency of 1 kHz. Achromatic unpatterned binary stimuli ranging in contrast from 5% to 96% and chromatic diffuse and patterned stimuli varying in hue and saturation were employed.
Results: Achromatic flash VEP develops non-linear signals that have contrast response functions that resemble those recorded from primate magnocellular and parvocellular neurons. Luminance and chromatic signals can be separated for diffuse but not for patterned chromatic VEP.
Conclusions: The ability to dissect the achromatic and chromatic structure of the visual evoked potential has significance for clinical diagnosis as the signals can be related to the functional anatomy of striate and extrastriate visual cortex.
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