[HN Gopher] Spiking Neural Networks
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       Spiking Neural Networks
        
       Author : orbifold
       Score  : 39 points
       Date   : 2021-12-13 20:31 UTC (2 hours ago)
        
 (HTM) web link (simons.berkeley.edu)
 (TXT) w3m dump (simons.berkeley.edu)
        
       | periheli0n wrote:
       | Neuromorphic hardware has been usable for 10 years now. Since
       | then, algorithms for neuromorphic hardware (i.e. spiking
       | networks) always performed 'almost as good' as ANN solutions on
       | GPUs (meaning: inferior). But each year a new generation of GPUs
       | comes out, using modern processes, with excellent toolchains. In
       | a direct comparison of power efficiency, GPUs win over NMHW most
       | of the time.
       | 
       | I would love to see Spiking Networks and NMHW take over machine
       | learning but it has such a long way to go. And I seriously doubt
       | the strategy, followed by most players, to try to beat good old
       | ANNs at their own game.
       | 
       | Unless we identify a problem set where event-based computing with
       | spikes is the inherently natural solution, I find it hard to
       | imagine that spiking networks will ever outcompete ANN solutions.
        
         | a-dub wrote:
         | > Unless we identify a problem set where event-based computing
         | with spikes is the inherently natural solution, I find it hard
         | to imagine that spiking networks will ever outcompete ANN
         | solutions.
         | 
         | i'd guess that domain would be real time (unbuffered /
         | unbatched) processing of raw sensory data. it seems reasonable
         | that biological neural systems evolved for optimal processing
         | of sensory information encoded temporally in spike trains, yet
         | the few papers on neuromorphic computing i've seen tend to try
         | and hammer spiking neural networks into a classic batch based
         | machine learning paradigm and then score them against batch
         | based anns.
        
           | periheli0n wrote:
           | This very much so.
           | 
           | On the other hand, even biology often uses rate codes which
           | are inefficient and limited in what they can represent,
           | compared to all those timing-sensitive codes, like latency
           | codes, rank order codes, phase codes, pattern codes,
           | population codes etc.
           | 
           | And when we look at the technical domain, event-based vision
           | cameras spew out what could pass as spikes; but even in that
           | area spiking networks have proven too limited compared to
           | event-based algorithms that were only vaguely bioinspired.
           | And this technology took about 20 years from conception to
           | making a breakthrough on the market.
           | 
           | So the question is whether spiking networks are indeed the
           | future of computation. But without doubt, the concept is very
           | interesting academically. A bit like Haskell :D
        
             | a-dub wrote:
             | > And when we look at the technical domain, event-based
             | vision cameras spew out what could pass as spikes
             | 
             | i have not seen these, i'm curious. do they try and mimic
             | early stages of the human visual system? (ie, a mechanical
             | v1, with outputs that actually look like the spatial and
             | frequency tuning that is often found in v1 neurons?)
             | 
             | edit: <3 wikipedia:
             | https://en.wikipedia.org/wiki/Event_camera
             | 
             | > So the question is whether spiking networks are indeed
             | the future of computation. But without doubt, the concept
             | is very interesting academically. A bit like Haskell :D
             | 
             | or if it will be something we hand code at all... i suspect
             | that the future of computation will be derived by the
             | machines themselves. if one can use GANs to generate entire
             | novel cryptosystems (i read a while back that google was
             | doing this), it seems only natural that they could be used
             | for finding optimal computational paradigms.
             | 
             | although many would argue that optimal computation is
             | computation that is best understood by humans.
        
               | periheli0n wrote:
               | > i have not seen these, i'm curious.
               | 
               | The original incarnation goes by the name of Dynamic
               | Vision Sensor (DVS), marketed by inivation, an ETH Zurich
               | spinoff. Prophesee is another manufacturer with their own
               | IP. I think Sony makes event-based camera's too; perhaps
               | others as well (Samsung? or was it Huawei?)
               | 
               | They mimic the retina, each pixel emitting events
               | ('spikes' if you wish) when luminance crosses a
               | threshold. There is no frame clock, each pixel works
               | asynchronously. The technology is known for extremely low
               | latency, high temporal resolution and ultra-high dynamic
               | range. Have a look ;)
        
       | JackFr wrote:
       | Makes me think that we can send a man to the moon but we can't
       | come up with a practical aircraft powered by flapping wings.
       | 
       | Evolved biological process can be very subtle. They're worth
       | studying for their own sake but not necessarily best to solve
       | general problems.
        
       | cblconfederate wrote:
       | I don't get the appeal of spiking networks. They struggle to
       | solve problems that have already readily been solved by ANNs and
       | they don't offer much in terms of biological realism - they don't
       | account for neuronal geometry and dendritic nonlinear phenomena,
       | nor do they explain the protein dependence of LTP.
        
         | periheli0n wrote:
         | These are two disparate applications of spiking networks. 1.
         | Machine learning--yes, many in the field seem to be trying to
         | reinvent ANNs with spikes. Not very useful in my opinion. 2.
         | Modeling biological processes. A lot of progress has been made
         | in neuroscience research thanks to spiking network models,
         | coupled with dendritic computation and all other sorts of
         | biological detail. But one would not normally use neuromorphic
         | hardware if the end goal is biological realism.
         | 
         | Only if biological realism is required in real time and on a
         | constrained power budget, such as on a robot, is Neuromorphic
         | hardware the weapon of choice.
        
       | nynx wrote:
       | Source: I'm an undergrad doing research in neuromorphic
       | computing.
       | 
       | A lot of information about SNNs misses a lot of recent findings
       | on the effect of astrocytes on the dynamical state of the
       | network. If you look in the recent literature on SNNs, you'll
       | find that including astrocyte models in the networks improves
       | memory and accuracy significantly in many cases.
       | 
       | It's too bad this article doesn't mention that.
        
         | klowrey wrote:
         | Have any links you would recommend?
        
         | orbifold wrote:
         | One of my first memorable PhD experiences was getting invited
         | to an impromptu meeting in Lithuania, where we met a Finish and
         | Lithuanian scientist both working on astrocyte models and
         | wondering how that could be applicable to neuromorphic
         | hardware. Needless to say this didn't go anywhere, but at least
         | we got to sample some really nice Lithuanian food.
        
       | periheli0n wrote:
       | Spiking networks are to Machine Learning like Haskell to C++ and
       | Python: While not really used to solve many real-world problems,
       | they are extremely interesting academically, and important
       | concepts have ended up in the mainstream, like event-based
       | sensing and control, or event-driven signal processing.
        
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