Candland, D. K., & Campbell, J. F. (1961). The senses. In D. K. Candland & J. F. Campbell, Exploring behavior: An introduction to psychology (pp. 31-39). New York, NY, US: Basic Books.
http://dx.doi.org/10.1037/13153-004
Psychologists have always been interested in understanding man's senses. Their interest is based upon the realization that an organism does not exhibit behavior unless it is stimulated and that in order to understand how behavior occurs one must therefore understand how man senses his environment. In studying man's sensory systems, it is apparent that many phenomena have no ready explanation. Even though we do not understand these phenomena, we make use of them. For example, the illusion that moving pictures "move" is based on the perceptual illusion called the phi-phenomenon. The fact that the phi-phenomenon is not completely understood has not prevented a large industry--motion picture production--from using it. The first step in understanding a sensory phenomenon is to determine the conditions necessary for its occurrence. Accordingly, psychologists have been concerned with controlled observation of phenomena in the laboratory. (PsycINFO Database Record (c) 2016 APA, all rights reserved)