This Thursday (May 27th), David Crewther will give a project proposal talk at 4 pm in YNiC open plan entitled "Nonlinearities in Multi-focal Magnetoencephalography" Abstract Multi-focal visual evoked potentials have become a standard tool in the diagnosis of glaucoma and retinal vascular disease. However, the randomization techniques employed to de-correlate sequences for stimulation of patches of visual field also offer the opportunity for analysis of non-linearities in evoked responses. These have been used to derive separate magnocellular and parvocellular contributions to the cortical VEP. Here we propose to develop similar m-sequence based pseudo-random stimulation techniques to MEG with the purpose of localizing the time-course of activation of the M and P pathways as they extend into dorsal and ventral cortical streams. A beam-former approach to this question will be followed, answering questions regarding the role of the “magnocellular advantage” in object recognition. An initial 13 patch cortically scaled m-sequence multi-focal stimulus has been developed. Extensions to higher resolution cortical imaging are proposed. However multi-focal fMRI imaging indicates eye-movement control is vital. Hence a gaze-contingent system using retinally-stabilized presentation is being developed that will allow an estimate of the optimal high resolution MEG mapping of visual cortex. All welcome YNIC 5th Birthday drinks will be held immediately after the seminar -- Gary Green York Neuroimaging Centre The Biocentre York Science Park Innovation Way Heslington York YO10 5DG http://www.ynic.york.ac.uk https://www.ynic.york.ac.uk/about-us/people/ggrg tel. +44 (0) 1904 435349 PA (Claire Fox) +44 (0) 1904 435329 fax +44 (0) 1904 435356 mobile +44 (0) 788 191 3004