MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'computation'. Sat, 03 Sep 2011 02:51:12 +0100 http://www.medworm.com/index.php?rid=4883742&cid=t_157329_122_f&fid=36506&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FBrainSciencePodcastBlog%2F%7E3%2FB5fVKg7dC8w%2Fbrain-networks-with-olaf-sporns-bsp-74.html Discussion of Brain Imaging, including Diffusion Imaging BSP 56: Interview with Dr. Eve Marder about the use of circuit theory in neuroscience BSP 61: Mapping the Brain (and generating huge amounts of data)  ANNOUNCEMENTS: The Brain Science Podcast will be returning to a monthly schedule on July 1, 2011. Please join the new Brain Science Podcast Discussion Forum at GoodReads.com. Get show notes automatically via our Newsletter. Dr. Campbell gave a talk in London last month entitled "Why Neuroscience Matters."(Available here.) Dr. Campbell will be a speaker at The Amazing Meeting 9, July 14-17,2011 in Las Vegas, NV. Don't forget to check out the Books and Ideas podcast and SCIENCEPODCASTERS.ORG. The Brain Science Podcast app is available for iPhone, Android, and iPad. If you hav... the Brain Science Podcast and Blog with Dr. Ginger Campbell blogs http://www.medworm.com/rss/comments.php?id=4883742 Tue, 31 May 2011 09:00:23 +0100 4883742 http://www.medworm.com/index.php?rid=4636555&cid=t_157329_122_f&fid=36506&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FBrainSciencePodcastBlog%2F%7E3%2F2MrgmzutFLQ%2Fembodied-cognition-with-lawrence-shapiro-bsp-73.html Discussion) Brooks, R. (1991) "New Approaches to Robotics," Science 253: 1227-32. Brooks, R. (1991) "Intelligence without Representation," Artificial Intelligence 47: 139-59. Clark, A. and Chalmer, D. (1998) "The Extended Mind." Analysis 58: 7-19. Glenberg, A. and Kaschak, M. (2002) "Grounding Lanquage in Action," Psychonomic Bulletin & Review 9: 558-65. Ehrlich, S., Levine, S., and Golden-Meadows, S. (2006) "The Importance of Gesture in Children's Spatial Reasoning," Developmental Psychology 42: 1259-68. Thelan, E. and Smith,L. (1994) A Dynamical Systems Approach to the Development of Cognition and Action (Cambridge: MIT Press) See Episode Transcript for additional references.  Subscribe to the Brain Science Podcast: Annoucements:   Join the discussion of this episode in... the Brain Science Podcast and Blog with Dr. Ginger Campbell blogs http://www.medworm.com/rss/comments.php?id=4636555 Fri, 25 Mar 2011 11:00:06 +0100 4636555 http://www.medworm.com/index.php?rid=4536195&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2011%2F03%2F02%2Fmemory-oriented-computing-and-from-microprocessors-to-nanostores%2F I’ve only skimmed this article by Ranganathan, but I find it notable because of the discussion of memory-oriented computing, in which processors are colocated with storage (he uses the word “nanostores”, which additionally implies that the memory is nonvolatile). One of the most important distinctions between neural architecture and present-day computing architecture is that brains appear to be built out of computing elements that do both processing and memory storage, whereas present-day computers have separate memory and CPU components (this separation is a key feature of what is called the “von Neumann” architecture). This separation means that computation is often rate-limited by the speed at which information can be transferred between memory and the CPU... neurodudes blogs http://www.medworm.com/rss/comments.php?id=4536195 Wed, 02 Mar 2011 05:26:10 +0100 4536195 http://www.medworm.com/index.php?rid=4281398&cid=t_157329_122_f&fid=36506&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FBrainSciencePodcastBlog%2F%7E3%2F7ey3Ju7TBKk%2Fcelebrating-4-years-of-the-brain-science-podcast-bsp-71.html Discussion Forum: Join our Facebook Fan Page: Send me feedback at gincampbell at mac dot com or leave voice mail at 205-202-0663.       (Source: the Brain Science Podcast and Blog with Dr. Ginger Campbell) the Brain Science Podcast and Blog with Dr. Ginger Campbell blogs http://www.medworm.com/rss/comments.php?id=4281398 Fri, 26 Nov 2010 16:08:44 +0100 4281398 http://www.medworm.com/index.php?rid=4098201&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2010%2F10%2F20%2Fsingle-neurons-can-distinguish-inward-temporal-sequences-from-outward%2F “activating synapses in a centrifugal sequence (outward from the soma) caused a different [lesser] [cortical pyramidal] neuronal response than activating the synapses in a centripetal (inward) sequence” summary: Alain Destexhe. Dendrites Do It in Sequences (24 September 2010) Science 329 (5999), 1611. article: Tiago Branco, Beverley A. Clark, and Michael Häusser. Dendritic Discrimination of Temporal Input Sequences in Cortical Neurons (24 September 2010) Science 329 (5999), 1671. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=4098201 Thu, 21 Oct 2010 00:07:54 +0100 4098201 http://www.medworm.com/index.php?rid=3566704&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2010%2F05%2F14%2Fdendritic-organization-of-sensory-input-to-cortical-neurons-in-vivo%2F Jia, H., Rochefort, N., Chen, X., & Konnerth, A. (2010). Dendritic organization of sensory input to cortical neurons in vivo Nature, 464 (7293), 1307-1312 DOI: 10.1038/nature08947 Consider a a cortical neuron in V1, layer 2/3, whose output shows sharp orientation tuning. What is the orientation tuning of the most important inputs to that neuron? What is the spatial distribution of these inputs in the neuron’s dendritic tree? Here’s three possibilities. (1) You might expect the neuron to collect inputs which are broadly tuned for that same orientation (the “weak-bias model”). (2) Or, you might expect that the neuron as a whole collects inputs with various tunings, but that each dendritic branches would tend to collect inputs with a certain orientation. (3) Or, ... neurodudes blogs http://www.medworm.com/rss/comments.php?id=3566704 Sat, 15 May 2010 02:21:09 +0100 3566704 http://www.medworm.com/index.php?rid=3133701&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F12%2F31%2Fcatalina-vallejos-statement-of-purpose-art%2F I devote my life to the momentary constructions for the purpose of maintaining a regular study of neural biochemistry, processes, patterns, and networks whose effects on a performance installation would successfully present a solution. An example of this is affecting a site’s mood initally set up by a pre-set design, with a resulting performance based upon the affected concentration of biochemicals in each present body. The modulation of mood and perception, as evoked or supressed by the artwork itself. A more specific example of this is the observation of different levels of dehydration which affect the integral effectiveness of body enzymes by varying concentrations. This type of work is relevant since exemplary leading behaviours are that which initiate communication before utterance ... neurodudes blogs http://www.medworm.com/rss/comments.php?id=3133701 Thu, 31 Dec 2009 05:23:25 +0100 3133701 http://www.medworm.com/index.php?rid=3133702&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F12%2F30%2Fnew-brain-model-applied-to-%25e2%2580%259cpythagorean-harmonics%25e2%2580%259d%2F Neurodudes kindly allowed me to post links to my “alternative brain models” in 2006 ( http://neurodudes.com/2006/09/14/new-brainmind-theory/ ) and 2007 ( http://neurodudes.com/2007/02/24/more-on-quad-nets-new-brainmind-theory/ ) and I hope a third occasion is permitted as there is no comparable resource for a person like me.  I am an amateur in brain science but have a solid technical background (B.S.E.E. MIT; M.A. Physics/Materials Science, UC Berkeley). I have developed a new class of proposed devices called “timing devices.”  Timing devices are idealized models of neurons, with a variety of forms and components.  The timing devices system resembles that of components (resistances, capacitances, transistors, etc.) used in standard electronic circuits.  In both cases, there is... neurodudes blogs http://www.medworm.com/rss/comments.php?id=3133702 Wed, 30 Dec 2009 17:51:53 +0100 3133702 http://www.medworm.com/index.php?rid=3059818&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F12%2F04%2Fibm-cat-brain-simulation-scuffle-symbolic%2F You’ve probably read by now about the announcement by IBM’s Cognitive Computing group that they had created a “computer system that simulates and emulates the brain’s abilities for sensation, perception, action, interaction and cognition” at the “scale of a cat cortex”.    For their work, the IBM team led by Dharmendra Modha was awarded the ACM Gordon Bell prize, which recognizes “outstanding achievement in high-performance computing”. A few days later, Henry Markram, leader of the Blue Brain Project at EPFL, sent off an e-mail to IBM CTO Bernard Meyerson harshly criticizing the IBM press release, and cc’ed several reporters. This brought a spate of shock media into the usually placid arena of computational neuroscience reporting, ... neurodudes blogs http://www.medworm.com/rss/comments.php?id=3059818 Fri, 04 Dec 2009 21:48:17 +0100 3059818 http://www.medworm.com/index.php?rid=2920353&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fwww.almaden.ibm.com%2Finstitute%2Fresources%2F2006%2FDisk2.avi We had read that Dr. Henry Markram of the Blue Brain project had given a talk at TED (technology, entertainment, design), but the video wasn’t released until this month.  This talk is geared towards a general audience, rather than getting into the specific details of the Blue Brain project, as he has before.  It is engaging and includes many suggestions towards the future of neuroscience and AI. Watch it online at the TED website. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2920353 Thu, 22 Oct 2009 17:20:25 +0100 2920353 http://www.medworm.com/index.php?rid=2855727&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F10%2F01%2Frobust-systems%2F A great essay by Gerald Sussman, “Robust Systems”. In the first half or so (my favorite part) he describes architectural principals of biological systems that contribute to robustness. In the second half, he gives proposals for making computers more robust. (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=2855727 Fri, 02 Oct 2009 03:11:47 +0100 2855727 http://www.medworm.com/index.php?rid=2705211&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F08%2F16%2Ffrontiers-in-neuroscience-journal%2F The journal, Frontiers in Neuroscience, edited by Idan Segev, has made it Volume 3, issue 1.  Launching last year at the Society for Neuroscience conference, its probably the newest Neuroscience-related journal. I’m a fan of it because it is an open-access journal featuring a “tiered system” and more.  From their website: The Frontiers Journal Series is not just another journal. It is a new approach to scientific publishing. As service to scientists, it is driven by researchers for researchers but it also serves the interests of the general public. Frontiers disseminates research in a tiered system that begins with original articles submitted to Specialty Journals. It evaluates research truly democratically and objectively based on the reading activity of the scienti... neurodudes blogs http://www.medworm.com/rss/comments.php?id=2705211 Sun, 16 Aug 2009 21:02:16 +0100 2705211 http://www.medworm.com/index.php?rid=2232621&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2009%2F03%2F03%2Ftheory-rising%2F Although it’s a few months old, Larry Abbott has an excellent article in Neuron on the recent (last 20 years) contributions of theoretical neuroscience. (He came by MIT last week to give a talk and that’s when I found out about the article.) It’s a review that is not too long and provides a good overview with both sufficient (though not overwhelming) detail and original perspective. It’s rare to find a short piece that is so informative. (And for a more experimentally-oriented review with an eye toward the future, see Rafael Yuste’s take on the grand challenges.) Click on for some of my favorite passages from the Abbott piece. Abbott uses the following problem of input decoding Spike counts and neuronal firing rates are positive quantities. This simple fact ha... neurodudes blogs http://www.medworm.com/rss/comments.php?id=2232621 Tue, 03 Mar 2009 05:05:59 +0100 2232621 http://www.medworm.com/index.php?rid=1856044&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2008%2F10%2F06%2Fadaptive-binning-in-the-retina%2F The Circadian Clock in the Retina Controls Rod-Cone Coupling (Christophe Ribelayga, Yu Cao, and Stuart C. Mangel) An amazing paper from Neuron demonstrating adaptive (circadian clock-governed) binning in the retina, based on dopamine modulation of gap junction (electrical) synapses between retinal photodetectors. During the day, abundant dopamine release weakens gap junctions coupling rods and cones together so that visual acuity is high. When light is scarce (at night), there is less dopamine and the electrical coupling between rods and cones is increased. This is analogous to on-chip binning in CCD (digital) cameras. Binning increases signal (in light-limited systems, eg. seeing at night) by increasing optical input area and by reducing single element noise (ie. noise at different pho... neurodudes blogs http://www.medworm.com/rss/comments.php?id=1856044 Mon, 06 Oct 2008 21:00:15 +0100 1856044 http://www.medworm.com/index.php?rid=1402967&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2008%2F04%2F27%2Fbest-way-to-describe-neuron-shape%2F Neurons come in many shapes and sizes. Frequently, the shape of a neuron is characteristic to its type. Several theoretical papers have demonstrated that the shape of a neuron can crucially determine its pattern of activity, independently of other factors (Mainen & Sejnowski, 1996, for example). Several resources on the web such as neuromorpho.org and the Cell Centered Database are dedicated to maintaining repositories of different neuronal shapes (also known as morphologies). Any computer scientist worth their salt, noticing this trend, is tempted to say: if neuronal shape is so important, maybe we ought to have good data standards to describe it. That’s just what a paper last year did. It surveyed the popular data standards for modeling, primarily in the NEURON and Genesis sim... neurodudes blogs http://www.medworm.com/rss/comments.php?id=1402967 Mon, 28 Apr 2008 02:29:17 +0100 1402967 http://www.medworm.com/index.php?rid=629034&cid=t_157329_122_f&fid=34757&url=http%3A%2F%2Fbraintechsci.blogspot.com%2F2007%2F05%2Fis-brain-spintronic-device.html Spintronics is a new paradigm of electronics based on the spin degree of freedom of the electron. Either adding the spin degree of freedom to conventional charge-based electronic devices or using the spin alone has the potential advantages of nonvolatility, increased data processing speed, decreased electric power consumption, and increased integration densities compared with conventional semiconductor devices.All spintronic devices act according to the simple scheme: (1) information is stored (written) into spins as a particular spin orientation (up or down), (2) the spins, being attached to mobile electrons, carry the information along a wire, and (3) the information is read at a terminal. Spin orientation of conduction electrons survives for a relatively long time (nanoseconds, compared... BrainTechSci blogs http://www.medworm.com/rss/comments.php?id=629034 Sun, 20 May 2007 23:11:00 +0100 629034 http://www.medworm.com/index.php?rid=589150&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F05%2F03%2Fhuman-20-new-minds-new-bodies-new-identites%2F The MIT Media Lab is holding a conference on May 9th, “Human 2.0: New Minds, New Bodies, New Identites” which will launch a number of new initiatives centered around the goal of inventing a better future via direct engineering of the human. Amongst these things will be the initiation of the MIT Center for Human Augmentation, and the launch of a number of novel applied Neurotechnology Projects. Guest speakers on May 9th will include MIT professors (Roz Picard, Hugh Herr, myself, etc.) and many legendary speakers such as Oliver Sacks and John Donoghue. Registration may be close to being full, but it will be webcast. More information at: http://h20.media.mit.edu - Ed (Source: neurodudes) neurodudes blogs http://www.medworm.com/rss/comments.php?id=589150 Fri, 04 May 2007 05:09:31 +0100 589150 http://www.medworm.com/index.php?rid=534121&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F04%2F09%2Fenabling-neural-engineering-ought-to-be-the-goal-of-neuroscience%2F The field of neuroscience naturally focuses its inquiry into neurons. This approach to understanding the brain by studying its parts has been thought to have a greater potential than that of psychology to understand how the brain works, a comment made by no less than Daniel L. Schacter, chair of Harvard’s Department of Psychology, in his book, The Seven Sins of Memory. However promising the field has been thus far, even the most accomplished neuroscientists will admit that we still do not understand how the brain really works. I would submit that the current reductionist nature of neuroscience has shed much light on the dynamics of how neurons work, but has to a far lesser degree shed light on how neurons process information. The difference between these two lines of inquiry is impo... neurodudes blogs http://www.medworm.com/rss/comments.php?id=534121 Tue, 10 Apr 2007 05:52:39 +0100 534121 http://www.medworm.com/index.php?rid=486195&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F02%2F24%2Fmore-on-quad-nets-new-brainmind-theory%2F In September, 2006, I described my “new brain/mind theory” here and received some challenging criticism from Eric Thomson and Mike S. (see below). To meet these challenges, I prepared a reduced model discussed in a web page linked to a paper in .pdf form. Since my approach is based on little-known thermodynamics, I have also written about mechanical metaphors that may be helpful in explaining my ideas. “Timing devices” in the new paper are like RISC (Reduced Instruction Set Computers) in comparison to Quad Nets that are like CISC (Complex Instruction Set Computers). “Quad Nets” is based on “critical point thermodynamics” and I am confident that they are new. However, “timing devices” may have been explored by others and I will... neurodudes blogs http://www.medworm.com/rss/comments.php?id=486195 Sat, 24 Feb 2007 15:43:25 +0100 486195 http://www.medworm.com/index.php?rid=486197&cid=t_157329_122_f&fid=35066&url=http%3A%2F%2Fneurodudes.com%2F2007%2F02%2F20%2Fso-how-do-real-neuronal-networks-compute%2F What is the right level of biological realism to model neuronal systems in order to understand their computational properties? Some recent papers may help shed some light on the subject. Models of the computational properties of local networks of neurons are starting to come into their own. This year has already seen at least two articles published in experimentalist journals based on the same core of theoretical work. To bring you up to speed, I need to remind you what is going on in the world of experimental neuroscience. Experimentalists are now able to record the single-cell activities of a whole population of neurons simultaneously. From Briggman, Abarbanel, Kristan (2006): By using multi-electrode arrays or optical imaging, investigators can now record from many individual neurons... neurodudes blogs http://www.medworm.com/rss/comments.php?id=486197 Tue, 20 Feb 2007 20:24:48 +0100 486197