xcorr

Visit Blog Website

20 posts · 23,944 views

Discussions on computational neuroscience, journal club, hot software and hardware, resources, Matlab, Python and C code

Patrick Mineault
20 posts

Sort by: Latest Post, Most Popular

View by: Condensed, Full

  • March 1, 2014
  • 01:26 AM
  • 331 views

How real science labs work

by Patrick Mineault in xcorr

I was reading The Antidote – an excellent book on negative thinking, stoicism and the bankruptcy of self-help; via this post on the New Yorker – and I stumbled onto a paper by the psychologist Kevin Dunbar on how science is made. It’s an illuminating read. Dunbar followed 4 molecular biology lab for a year, […]... Read more »

Kevin Dunbar. (1995) How scientists really reason: Scientific reasoning in real-world laboratories. . The nature of insight, Sternberg, Robert J. (Ed); Davidson, Janet E. (Ed), 365-395. info:/

  • January 24, 2013
  • 06:00 PM
  • 534 views

Category representation in the brain

by Patrick Mineault in xcorr

You can solve most problems in life by buying more computers – or grad students, or microscopes, or lasers for that matter. Some of Jack Gallant’s lab recent efforts in fMRI analysis are a good example of this approach. They published an interesting paper in Neuron last month about the representation of categories in cortex.

Objects can be classified by humans in thousands of different categories. How are those categories represented in cortex? How would you even try to locate whe........ Read more »

  • May 30, 2012
  • 03:35 AM
  • 607 views

Modifying body representation through vision and vice versa

by Patrick Mineault in xcorr

There’s a few interesting multi-modal illusions involving vision and another sense. Proprioception, the ability to sense the position of one’s body parts, is one sense that gets a bad rep; it’s not even included in the classic 5 senses. Yet it’s certainly quite important, and people that lose proprioception have difficulty functioning at first, a [...]... Read more »

Carlson, T., Alvarez, G., Wu, D., & Verstraten, F. (2010) Rapid Assimilation of External Objects Into the Body Schema. Psychological Science, 21(7), 1000-1005. DOI: 10.1177/0956797610371962  

  • May 24, 2012
  • 05:36 PM
  • 1,013 views

Hearing radio frequencies

by Patrick Mineault in xcorr

I was reading the Wikipedia article on tinnitus, and came across this pearl of a sentence: A common and often misdiagnosed condition that mimics tinnitus is Radio Frequency (RF) Hearing in which subjects have been tested and found to hear high-pitched transmission frequencies that sound similar to tinnitus. Hmm, what? Yes, humans, under special circumstances, [...]... Read more »

  • May 15, 2012
  • 10:04 PM
  • 659 views

Modeling the Spatial Reach of LFP

by Patrick Mineault in xcorr

As regular readers will know, I’ve been intrigued by the nature of local field potential for some time. There’s a recent paper in Neuron by Lindén et al. that uses a modeling approach to explain the spatial reach of the LFP. This is a subject of some controversy; the spatial reach of the LFP has [...]... Read more »

Lindén H, Tetzlaff T, Potjans TC, Pettersen KH, Grün S, Diesmann M, & Einevoll GT. (2011) Modeling the spatial reach of the LFP. Neuron, 72(5), 859-72. PMID: 22153380  

  • May 1, 2012
  • 02:31 PM
  • 815 views

Is beer the answer?

by Patrick Mineault in xcorr

Well-meaning friends and family members may suggest that you have a couple of drinks after living through a stressful event. A friend of mine had a bike accident recently that sent her over a car door and miraculously left her with only a few bruises. Having a couple of drinks immediately after this will of [...]... Read more »

  • April 23, 2012
  • 05:20 PM
  • 1,009 views

A presentation on mouse vision

by Patrick Mineault in xcorr

We had a lab meeting on Thursday, and it was my turn to present. Since I’m waiting for data to come through, I didn’t have original research to present, so I did a presentation on mouse vision, which I’ve been reading a lot about recently. I recorded the narration, and if you have Powerpoint, you [...]... Read more »

  • April 8, 2012
  • 09:44 PM
  • 1,072 views

Connectomics in the retina

by Patrick Mineault in xcorr

Connectomics and some of its promises made news last week when Sebastian Seung and Tony Movshon went head to head in a debate broadcast by Radiolab (archived here). I didn’t watch the webcast, but I wanted to point out a quite fascinating recent study by Briggman, Helmstaedter and Denk (2011) that shows some of the [...]... Read more »

  • April 5, 2012
  • 02:14 AM
  • 1,072 views

Topography conquers all

by Patrick Mineault in xcorr

The eye faithfully maps visual space to different positions on the retina. This retinotopy is preserved as the signal is forwarded from retinal ganglion cells to the LGN, then to V1, and onwards. Cells which are physically adjacent on a retinotopic map have receptive fields corresponding to similar positions in space. More generally, properties like [...]... Read more »

  • March 31, 2012
  • 11:51 PM
  • 1,117 views

Big ideas: Focus on computation

by Patrick Mineault in xcorr

Matteo Carandini has an editorial in the latest issue of Nature Neuroscience arguing that we should focus energy on studying neural computation. In this context, neural computation is understood as an intermediate level of complexity between low-level neural circuits and high-level behavior. He argues that trying to go from physical descriptions of circuits to large-scale [...]... Read more »

  • March 19, 2012
  • 03:47 PM
  • 1,598 views

Normalization as a canonical neural computation

by Patrick Mineault in xcorr

There’s an excellent review on normalization in the January 2012 edition of Nature Reviews Neuroscience by Carandini and Heeger. The theory and mathematics of normalization have stayed consistent since the seminal papers Heeger (1992) and  Carandini and Heeger (1994). The response of a given neuron is divided by the summed output of a normalization pool, [...]... Read more »

  • March 3, 2012
  • 07:46 PM
  • 1,080 views

Spikes trigger LFP waves: the rebuttal

by Patrick Mineault in xcorr

Nauhaus, Busse, Carandini and Dario Ringach published an influential paper in 2009 with pretty convincing evidence that spikes trigger traveling waves of activity visible in LFPs; that these waves travel laterally; and because the dynamics of these waves change during stimulation compared to spontaneous activity, that stimulation modulates functional connectivity. This could imply that a [...]... Read more »

  • November 20, 2011
  • 03:37 PM
  • 1,587 views

What’s the maximal frame rate humans can perceive?

by Patrick Mineault in xcorr

Danny Kopping asked on my Twitter account what’s the maximal frame rate that humans can perceive. It’s a tricky question, mostly because it can be interpreted in different ways. Let’s break it down into these two scenarios: 1. At what frequency should a display (say a CRT) refresh so that it doesn’t appear to flicker [...]... Read more »

  • September 24, 2011
  • 05:52 PM
  • 1,459 views

Decoding fMRI activity evoked by natural movies

by Patrick Mineault in xcorr

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’ more interested in the nitty gritty computational/statistical details. The idea is to train an encoding model using fMRI responses during natural [...]... Read more »

Shinji Nishimoto, An T. Vu, Thomas Naselaris, Yuval Benjamini, Bin Yu, & Jack L. Gallant. (2011) Reconstructing visual experiences from brain activity evoked by natural movies. Current Biology. info:/10.1016/j.cub.2011.08.031

  • September 16, 2011
  • 08:53 PM
  • 1,509 views

How many pixels make an object? Like, 30

by Patrick Mineault in xcorr

There’s a neat paper on the psychophysics of scene and object recognition in super-low resolution scenarios in Visual Neuroscience by A. Torralba (2009). The author sought to answer a rather interesting question: what image resolution is needed to support scene and object recognition? He took images from databases and created several different versions of them, [...]... Read more »

Torralba A. (2009) How many pixels make an image?. Visual neuroscience, 26(1), 123-31. PMID: 19216820  

  • September 14, 2011
  • 05:40 PM
  • 1,620 views

Spikes trigger LFP waves – not so fast

by Patrick Mineault in xcorr

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 [...]... Read more »

  • August 10, 2011
  • 08:00 PM
  • 1,319 views

Temporal precision in the LGN

by Patrick Mineault in xcorr

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 [...]... Read more »

Peter Dayan, & Larry Abbott. (2001) Theoretical Neuroscience. MIT Press. info:other/0262041995

Berry MJ 2nd, & Meister M. (1998) Refractoriness and neural precision. The Journal of neuroscience : the official journal of the Society for Neuroscience, 18(6), 2200-11. PMID: 9482804  

Butts DA, Weng C, Jin J, Yeh CI, Lesica NA, Alonso JM, & Stanley GB. (2007) Temporal precision in the neural code and the timescales of natural vision. Nature, 449(7158), 92-5. PMID: 17805296  

  • July 5, 2011
  • 04:44 PM
  • 1,778 views

Hexagonal orientation maps in V1

by Patrick Mineault in xcorr

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 [...]... Read more »

  • June 15, 2011
  • 08:47 PM
  • 2,508 views

The far-reaching influence of sparse coding in V1

by Patrick Mineault in xcorr

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 [...]... Read more »

Honglak Lee, Alexis Battle, Rajat Raina, & Andrew Y. Ng. (2007) Efficient Sparse Coding Algorithms. Advances in Neural Information Processing Systems, 801-808. info:/

  • May 12, 2011
  • 02:59 PM
  • 1,257 views

LFPs above 50Hz: is it all garbage?

by Patrick Mineault in xcorr

There’s a recent paper by the Maunsell lab in PLoS Biology that examines the origins of local field potentials in the low-gamma (30-80Hz) and high-gamma ranges (> 80 Hz)  ranges. The paper uses a clever experimental paradigm that allows one to dissociate LFPs and spike activity through the phenomenon of surround suppression. Basically, in surround [...]... Read more »

join us!

Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.

If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.

Register Now

Research Blogging is powered by SMG Technology.

To learn more, visit seedmediagroup.com.