Changed photodiode drawing method so that full white is drawn at the start of each condition or block, and on all other frames, a scale factor is applied
Updated how different filters are created. I was initially working in
terms of frames, rather than time, which meant that the frequency bands
used were extremely low. Now they are actually done in terms of time,
so that the band-centers computed should be an accurate representation
of the dominant frequencies in the stimulus, in terms of Hertz.