Through a Prism, Straightly?

Reviews the book, Perceptual Modification: Adapting to Altered Sensory Environments by Robert B. Welch (1978). The myth of perfect adaptation followed by a perfect negative after effect is certainly not to be found in Stratton's writings, or in any of those who repeated his study. What has emerged from distorting spectacles research is a wide spectrum- some would say a tangle-of divergent effects. Here is a sample of what Welch finds in some 500 studies over a century of work. Some sort of compensation occurs for every stable lens system tried: inverting lenses, reversing lenses, magnifying or minifying lenses, tilting prisms, displacing prisms (the most studied), contact lenses, split-field lenses (analogous to bifocals), underwater visors, and even auditory analogs of these such as reversing headphones. Welch's theory is an integrative one, incorporating those elements of previous theories that have survived experimental test, and it also has the merit of linking adaptation theory to more general theories of learning. (PsycINFO Database Record (c) 2016 APA, all rights reserved)