Dear Users Today Suresh Muthukumaraswamy from the Cardiff University Brain Research Imaging Centre (CUBRIC) will be giving a talk on "Gamma oscillations in human visual cortex: Function, physiology and relationship to BOLD" from 4-5 pm in YNiC open plan. Everyone is welcome to attend. Best wishes Rebecca Here is Suresh's web page: http://www.cardiff.ac.uk/psych/contactsandpeople/researchstaff/muthukumaras… and here is the abstract for his talk: "I review a number of studies conducted at CUBRIC using magnetoencephalography to investigate gamma oscillations (> 30 Hz) in human visual cortex. Firstly we demonstrate that gamma band responses are sensitive to a number of bottom-up stimulus parameters including spatial and temporal frequency, colour, contrast, motion and stimulus type. Studies comparing both BOLD and gamma are then considered. These data demonstrate that while BOLD and gamma responses demonstrate considerable spatial coincidence they are markedly different in their response across parametrically varied stimulus dimensions. This functional decoupling implies that gamma band oscillations as recorded by MEG are not sufficient to generate a BOLD response and that MEG can be sensitive to certain stimulus parameters that BOLD is not. Gamma band responses in individuals can be shown to be quite variable in terms of frequency and amplitude across individuals but that these effects are highly repeatable across recording sessions. Our data also demonstrate how this variability in gamma band responses and BOLD can be accounted for by measuring GABA concentration with magnetic resonance spectroscopy." -- ************************************************************************ Dr. Rebecca E. Millman Science Liaison Officer York Neuroimaging Centre The Biocentre York Science Park Heslington YO10 5DG Tel: +44 (0) 1904 567614 Fax: +44 (0) 1904 435356