monthly archives: June 2009

  • Time as a teacher

    By Derek James | June 28, 2009

    teacherAnother guest editor here... I met Max at this year's ICCNS and he suggested writing a guest entry for Neurdon. The ideas hopefully compliment some of the stuff Ethan blogged about.

    I'm a 4th-year PhD student in the Institute of Cognitive Science at The University of Louisiana at Lafayette. When I entered the program, I was mostly interested in AI and evolutionary algorithms. I wanted to evolve a Go-playing program. But my interests shifted, especially in my first year when I read Jeff Hawkins' On Intelligence. I thought it was great stuff, and I liked two things central to his framework: 1) The temporal aspect of cognition, and 2) The crucial role of feedback. He made a convincing case that every modality and skill is essentially a matter of learning and processing sequences. So that's where I started focusing my attention. Read the rest of this entry »

  • What IT does

    By Jeff Markowitz | June 9, 2009

    What are we doing?First, a hearty welcome to Ethan, you're starting to make this whole enterprise a little less incestuous! Anyway, your recent post raises a number of interesting issues regarding inferotemporal cortex (IT), most prominently: how does IT learn to do what we think it does?

    I'd first like to address what we think IT does, which is a step I find myself skipping quite a lot (awful scientist am I!). Based a number of classical studies which compared lesions of IT with lesions of parietal cortex, for example, it was determined that IT mediated some form of visual discrimination and perhaps limited `size constancy', or at least was a key pathway in whatever area in fact does this (see here, here, and here, for instance). The presumption, based on newer electrophysiology in macaque TE and TEO (analogous to anterior IT, ITa, and posterior IT, ITp, respectively) is that IT performs some sort of hashing to signal the presence of an object across sizes, retinal translations, clutter conditions, whatever.

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  • Creating invariance in IT

    By Ethan Meyers | June 4, 2009

    objectsMax asked me to post some information about how time could act as a ‘supervising’ learning signal to create invariant representations in IT (particular in reference to Jim DiCarlo’s work in this area). Since I am lazy, the below post is a modified section of the background from my thesis proposal - hopefully it’s not too boring….

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