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Re: tapping hardware & software


Follow-up:  I just realized that you will probably want to 
analyze your data with Peri-Stimulus Time Histograms.  If 
so, please note that Daqarta has a built-in PSTH option.  
You can even use it to create real-time PSTHs, without the 
need to record and analyze as separate steps.  Besides the 
speed and convenience of "instant" analysis, this also 
makes it easy to insure that everything is set up properly 
at the time of the experiment.  You won't run into the 
situation where you collect a mountain of data, send the 
subjects home, and only later discover there was something 
wrong with the system.  (It may still be worth recording at 
the same time, in case you want to go back and change the 
PSTH bin widths or something.)

I'd be glad to help you set up Daqarta for this.

Best regards,

Bob Masta

On 24 Mar 2011 at 9:35, Bob Masta wrote:

> Daniele:
> I concur with Christian's idea of using a cheap microphone 
> to record the tapping, assuming the subjects listen with 
> headphones to avoid crosstalk.  However, to get accurate 
> timing measurements you will need to record the mic and the 
> stimulus on separate (L and R) sound card channels.  (Sound 
> card L and R inputs are always synchronous with each other, 
> and L and R outputs are synchronous with each other, but 
> the outputs are not synchronous with the inputs, so you 
> need to record the output as an input.)
> Since sound card Mic inputs are always mono, you will need 
> to use Line In, with an external preamp to boost the mic.  
> (You might be able to get away without the preamp, since 
> this task doesn't require high fidelity and the mic can be 
> placed very close to the subject... the subject could even 
> tap directly on the mic.)  Then all you need is to route 
> the stimulus to (say) the left Line In, and the mic output 
> to the right.  This will require some "trick" cabling, 
> either by cannibalizing cheap sound card cables or buying 
> "splitter" cables.
> I think my Daqarta software for Windows can do the whole 
> job.  It can do all sorts of pulse and tone burst 
> generation (and just about anything else you can think of), 
> and it can play sound recordings as stimuli as well.  Let 
> me know the details of what you want, and I can help you 
> create a stimulus setup.  Daqarta can then record the 
> combined signal to a file.
> As far as analysis goes, I have no experience with 
> Christian's suggestion of Octave, but it sounds like it 
> would do the job.  Daqarta can do some of this 
> intrinsically:  You can scroll through the file manually, 
> of course, and measure the relative times with on-screen 
> cursors.  But a better way is to use the Trigger controls 
> in Single mode, such that the file scrolls automatically to 
> the next tap or stimulus event (which would be under one 
> cursor), and you'd then place the other cursor on the other 
> event (stimulus or tap) and read the timing difference 
> directly on the Delta cursor readout.  Then you hit the 
> Trigger button to advance to the next event.
> Daqarta has a macro scripting facility, so in principle 
> much or all of this could be automated.  But some of the 
> features needed to do this particular task won't be 
> available for a couple of months yet. 
> A Daqarta Professional license is US$99, but you can try 
> everything free for 30 sessions or 30 days.  After that, 
> you can still analyze files, but you can't record from the 
> inputs.  So if you can collect all your data in one month, 
> you can do everything for free!
> Best regards,
> Bob Masta
> =======================
> On 24 Mar 2011 at 9:32, daniele schon wrote:
> > Dear all,
> > I am trying to think to a simple and cheap solution to record children 
> > in a tapping task (eg along with a metronome or a piece of music).
> > I have up to now found several solutions commonly used, but none of them 
> > is cheap. For instance, using a software such as Presentation to send 
> > the auditory stimulus and record with the space bar (requires 
> > Presentation/E-Prime license), or using Cakewalk and a tapping pad 
> > (requires Cakewalk license and a tapping pad).
> > So I would be glad if you could share your advice on the "optimal" 
> > solution, optimizing the real cost (in euros), the precision (in 
> > milliseconds) and the other cost (the hours I'll spend analyzing data, 
> > for instance recording the tapping on a microphone ...).
> > 
> > my warmest regards
> > daniele
> > 
> > -- 
> > Daniele Schön
> > Equipe Langage, Musique et Motricité
> > Institut de Neurosciences Cognitives de la Méditerranée
> > C.N.R.S, 31, Chemin Joseph-Aiguier
> > 13402 Marseille Cedex 20, France
> > Tel: 0033 (0) 4 91 16 41 30
> > Fax: 0033 (0) 4 91 16 44 98
> > 
> > http://www.incm.cnrs-mrs.fr/pperso/danieleschon.php
> > 
========================Bob Masta
            D A Q A R T A
Data AcQuisition And Real-Time Analysis
Scope, Spectrum, Spectrogram, Signal Generator
    Science with your sound card!