[ml] [Noisebridge-discuss] Technical question: Directionally sensitive photosensors

[Mike Schachter]

Also cc'ing this discussion to the neuro and ML lists, there are might be
people there that could help with the problem.

 mike



On Tue, Jun 11, 2013 at 9:25 AM, Mike Schachter
<mschachter at eigenminds.com>wrote:

> I suppose the basic idea is to create a chain of integrate-and-fire
> neurons.
>
> Referring to the attached diagram, each neuron gets input from it's own
> photosensor, and from the neuron to the left of it. You will also have to
> make it so that the signal from the photosensor to neuron *decreases* as
> you move right on the chain.
>
> The general idea is that movement to the right makes each neuron spike,
> which sends a spike to the neighboring neuron. If the inputs are timed
> right (which is probably the most tricky part), each successive neuron will
> spike more and send more input to it's neighbors. The last neuron, the
> readout neuron, will spike the most. You can look at the spike rate of the
> last neuron, and if it's high enough, then you declare movement to the
> right. The number of spikes of the last neuron could even be related to the
> velocity of the movement.
>
> Movement to the left shouldn't elicit a single spike from the readout
> neuron.
>
> Another option might be to build a Reichardt correlator:
>
> http://people.csail.mit.edu/rondror/Ronfiles/Research/reichardt.htm
>
> mike
>
>
>
> On Mon, Jun 10, 2013 at 11:46 PM, Christoph Maier <
> cm.hardware.software.elsewhere at gmail.com> wrote:
>
>> On Mon, Jun 10, 2013 at 5:49 PM, Mike Schachter
>> <mschachter at eigenminds.com> wrote:
>> > Oh ok! Well I'd be happy to help Chris with code to do
>> directional-selection
>> > given data from an array of photo-sensitive inputs if that would be
>> useful.
>> >
>> >  mike
>> >
>> >
>> >
>> > On Mon, Jun 10, 2013 at 5:20 PM, Norman <pryankster at gmail.com> wrote:
>> >>
>> >> Mike, that is exactly how a phased array works.
>> >>
>> >> Norman
>> >>
>> >>
>> >> On 6/10/2013 5:07 PM, Mike Schachter wrote:
>> >>
>> >> Can you just get an array of non-directional photosensors and do the
>> >> direction-selectivity computationally on an arduino or something?
>> >>
>> >>  mike
>>
>> Great!
>> Just tell me how to put code into this kind of computer ...
>> http://pony.noisebridge.net/~cmaier/neuromorphic/BIL2011/html/img10.html
>>
>
>
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