Noisy patterns

[joschaschmiedt]

Noisy patterns are often used for receptive field mapping, e.g. Niell and Stryker, 2008 (http://www.jneurosci.org/content/jneuro/28/30/7520.full.pdf):

Gaussian noise movies were created by first generating a random spatiotemporal frequency spectrum in the Fourier domain with defined spectral characteristics. To drive as many simultaneously recorded units as possible, we used a spatial frequency spectrum that dropped off as A(f) ~ 1/(f+fc), with fc = 0.05 cpd, and a sharp cutoff at 0.12 cpd, to approximately match the stimulus energy to the distribution of spatial frequency preferences. The temporal frequency spectrum was flat with a sharp low-pass cutoff at 4 Hz. This three-dimensional (ox,oy,ot) spectrum was then inverted to generate a spatiotemporal movie. This stimulus is related to the subspace reverse correlation method (Ringach et al., 1997), in that both explicitly restrict the region of frequency space that is sampled. To provide contrast modulation, this movie was multiplied by a sinusoidally varying contrast.

To make them available in ARCADE we have two options:

• Implement them in HLSL using procedural noise (Perlin, Simplex, ...). This is computationlly very efficient and can be changed at runtime. However, we need to make sure that we can fully reconstruct the image post-hoc based on the seed(s).
• Use movies (#81). This would also allow naturalistic scences etc. but comes with certain limitations (stimulus size, length, frame rate)

Maybe Perlin and/or Simplex noise is interesting:
http://weber.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
https://github.com/ashima/webgl-noise
https://www.cs.utah.edu/~aek/research/noise.pdf
https://thebookofshaders.com/11/