How to compute fft of the rat's licking time?

I have data which measures the time when a rat licks a sugar water. When I computer the inter lick interval (ILI), sometimes I see that ILI is less than 40 miliseconds which I don't think a rat can lick this fast, and I am assuming this is coming from a noise from the sensor. I want use fft in matlab to compute the frequency of my licking signal. What all I have is the time when the rat has licked sugar water. Can somebody please tell me how I can compute the frequency of my signal.

Answer 1

[Star Strider]

That has to be the most interesting biomedical signal processing problem I’ve ever read on MATLAB Answers!

The best documentation for the fft is the R2015a version. (Click on the link.)

If you attach your data (use the ’paperclip’ icon, and do everything it tells you to do), I’ll see what I can do to process it. I realise it’s your research, but I find your study absolutely fascinating!

Answer 2

[Jeremy]

There has to be good a joke there somewhere...

So your data is a set of timestamps when rat licks? Is this coming from a pressure sensor or accelerometer on the bottle? To use FFT you will need to have some signal that is sampled at regular intervals. If you really do just have timestamps that could be turned into a time history by making all times 0 when the rat is not licking and 1 when it is. This may not give you a very clean spectra, but certainly worth a try. Have you tried a historgram of the intervals?