BRIAN simulator

This post starts a series on the debate between rate-based and spike-based theories of neural computation and coding. My primary goal is to clarify the concepts. I will start by addressing a few common misconceptions about the debate. Misconception #1: “Both rate and spike timing are important for coding, so the truth is in between”. [...]

The sensorimotor theory of perception considers that to perceive is to understand the effect of active movements on sensory signals. Gibson’s ecological theory also places an emphasis on movements: information about the visual world is obtained by ... [More] producing movements and registering how the visual field changes in lawful ways. Poincaré also defined the notion of [...] [Less]

Marr described the brain as an information-processing system, and argued it had to be understood at three distinct conceptual levels: 1) The computational level: what does the system do? (for example: estimating the sound location of a sound source) ... [More] 2) The algorithmic/representational level: how does it do it? (for example: by calculating the maximum of [...] [Less]

In discussions of « neural coding » issues, I have often heard the idea that “the brain uses all available information”. This idea generally pops up in response to the observation that neural responses are complex and vary with stimuli in ways that are difficult to comprehend. In this variability there is information about stimuli, and as [...]

J’ai soumis une contribution aux assises de la recherche intitulée: « Une analyse économique du système de recherche« . Il s’agit de quelques remarques simples, mais d’une portée générale, sur l’organisation du système de recherche.  

In a recent paper, I explained how to compute with neural synchrony, by relating synchrony with the Gibsonian notion of sensory invariants. Here I will briefly recapitulate the arguments and try to explain what can and cannot be done with this approach. First of all, neural synchrony, as any other concept of neural code, should [...]

When one hears music or speech through earphones, it usually feels like the sound comes from “inside the head”. Yet, one also feels that the sound may come from the left or from the right, and even from the front or back when using head-related transfer functions or binaural recordings. This is why, when subjects [...]

I am writing this post from the Sensory Coding and Natural Environment conference in Vienna. It’s a very interesting conference about a topic that I like very much, but it strikes me that many approaches I have seen seem to miss the point of what is natural about natural sensory signals. So what is natural [...]

The 1.4 release of Brian is out! The major change in this version is the addition of a new Synapses class, which allows modeling everything synaptic: gap junctions, probabilistic synapses, nonlinear synapses, plasticity, etc. There are also a number ... [More] of other new features, bug fixes and improvements (see below). Brian is being developed by Romain [...] [Less]

Musical notes have a particular perceptual quality called “pitch”. Pitch is the percept corresponding to how low or high a musical note is. Vowels also have a pitch. To a large extent, the pitch of a periodic sound corresponds to its repetition rate. The important point is that what matters in pitch is more the [...]