ArticlesDiscrete stochastic process underlying perceptual rivalryMurata, Tsutomu1,CA; Matsui, Nobuyuki2; Miyauchi, Satoru1; Kakita, Yuki3; Yanagida, Toshio1,4 Author Information 1Kansai Advanced Research Center, Communications Research Laboratory, Iwaoka, Kobe-shi, Hyogo 651–2492; 2Computer Engineering Division, Graduate School of Engineering, Himeji Institute of Technology, Shosha, Himeji-shi, Hyogo 671–2201; 3Department of Human Information Sciences, Kanazawa Institute of Technology, Ohgigaoka, Nonoichi-machi, Ishikawa 921–8501; 4Laboratories for Nanobiology, Graduate School of Frontier Biosciences, Osaka University, Yamadaoka, Suita-shi, Osaka 565–0871, Japan CACorresponding Author: [email protected] Received 5 December 2002; accepted 7 April 2003 NeuroReport: July 18, 2003 - Volume 14 - Issue 10 - p 1347-1352 doi: 10.1097/01.wnr.0000077553.91466.41 Buy Metrics Abstract In perceptual rivalry such as ambiguous figure perception and binocular rivalry, the conscious percept spontaneously alternates between two stable interpretations of an unchanging stimulus. It is well known that the time intervals of the perceptual alternation follow a gamma distribution (GD), but its implication for the alternation mechanism has not been clarified. We examined quantitatively GDs fitted to alternation intervals, and found that the shape-determining parameter a of the GDs took natural numbers. Because a GD determined by a natural number α is mathematically obtained from a discrete stochastic process (Poisson process), our result indicates that such a stochastic process underlies perceptual rivalry and that the α-time accumulation of the discrete events causes a perceptual alternation. © 2003 Lippincott Williams & Wilkins, Inc.