Computational Psychology and Psychiatry
From Biomatics.org
The mechanisms of hallucinations may be based on faulty Fourier transformations-A duck, and its Fourier Transform:

A duck with a missing shell of data:
If a segment of data is missing, features perpendicular to that segment will be blurred
. 

http://www.ysbl.york.ac.uk/~cowtan/fourier/fourier.html

