Tag: Signal processing

• Non-rigid deformation for calcium imaging frame alignment

  Following my PhD at McGill, I moved to LA to work in Dr. Dario Ringach’s lab at UCLA. We’ve been doing calcium imaging – GCamp6 – in mice via a custom-built microscope – you can read more about the microscope over at the Scanbox blog. If you’re used to working with single electrodes or multi-unit…

  August 2, 2014

• Whiten images in Matlab

  Previously, I showed how to whiten a matrix in Matlab. This involves finding the inverse square root of the covariance matrix of a set of observations, which is prohibitively expensive when the observations are high-dimensional – for instance, high-resolution natural images. Thankfully, it’s possible to whiten a set of natural images approximately by multiplying the…

  April 30, 2013

• Spikes trigger LFP waves – not so fast

  There’s been a lot of buzz at recent conferences around a controversial new paper in J. Neurosci. from Ray and Maunsell on LFP traveling waves. It’s a pretty direct, and rather convincing rebuttal of an influential Nature Neuroscience paper by Nauhaus et al. published a couple of years ago. Initial findings Nauhaus found what seemed…

  September 14, 2011