"A circular test field was surrounded by several spots of light (inducers), which were equidistant from the test field. The luminance threshold of the test field was determined as a function of the luminance, number, and location of inducers in the fovea and in the periphery." Test threshold rose as inducing luminance increased and as the number of inducers increased. The rise in threshold produced by a given number of inducers increased as the distance between them increased. "Varying the luminance, number, or location of inducers produced larger effects in the periphery than in the fovea." (PsycINFO Database Record (c) 2006 APA, all rights reserved)