Category: Journal club
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Decoding fMRI activity evoked by natural movies
The Gallant lab have just published a new paper in Current Biology about decoding visual activity in fMRI evoked through natural movies. TryNerdy has a very high level overview of the paper. Here I’m more interested in the nitty gritty computational/statistical details. The idea is to train an encoding model using fMRI responses during natural…
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Video super-resolution coming to consumer software
Video super-resolution is a technique to increase the resolution of a movie by exploiting the redundancy between frames. It’s easiest to understand the technique by first thinking of the corresponding technology in images. It’s possible to increase the effective resolution of an image by taking multiple pictures, each offset by a fraction of a pixel,…
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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…
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Temporal precision in the LGN
There’s a new paper just out in J Neurosci by Dan Butts et al. (2011) that offers some key insights into temporal precision in the lateral geniculate nucleus (LGN). The spike trains of LGN cells are remarkably regular; while a Poisson train has Fano factor (variance to mean ratio) of 1, and cortical neurons in…
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Hexagonal orientation maps in V1
Interesting paper from Se-Bum Paik and Dario Ringach in this month’s issue of Nature Neuroscience on the origins of the orientation map in V1. Dr. Ringach has been developing a model of V1 orientation selectivity for a number of years now, the statistical connectivity hypothesis, based on the idea that the retinotopic map in V1…
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The far-reaching influence of sparse coding in V1
Introduction Olshausen and Field (1996) made a big splash in visual neurophysiology and machine learning by offering an answer to a provocative question: Why are simple cell receptive fields (RFs) organized the way they are? After all, they could just as well be shaped like elongated sine waves, as in Fourier analysis, or they could…
xcorr: AI & neuro 