[OPTICAL REVIEW Vol. 2, No. 1 (1995) 72-80]

Learning to Recognize Patterns: Changes in the Visual Field with Familiarity

James M. BEBKO, Keiji UCHIKAWA, Shinya SAIDA and Mitsuo IKEDA

Department of Information Processing, Tokyo Institute of Technology Graduate School, 4259, Nagatsuta, Midori-ku, Yokohama, 226 Japan

(Received July 6, 1994; Accepted October 27, 1994)

Two studies were conducted to investigate changes which take place in the visual information processing of novel stimuli as they become familiar. Japanese writing characters (Hiragana and Kanji) which were unfamiliar to two native English speaking subjects were presented using a moving window technique to restrict their visual fields. Study time for visual recognition was recorded across repeated sessions, and with varying visual field restrictions. The critical visual field was defined as the size of the visual field beyond which further increases did not improve the speed of recognition performance. In the first study, when the Hiragana patterns were novel, subjects needed to see about half of the entire pattern simultaneously to maintain optimal performance. However, the critical visual field size decreased as familiarity with the patterns increased. These results were replicated in the second study with more complex Kanji characters. In addition, the critical field size decreased as pattern complexity decreased. We propose a three component model of pattern perception. In the first stage a representation of the stimulus must be constructed by the subject, and restricting of the visual field interferes dramatically with this component when stimuli are unfamiliar. With increased familiarity, subjects become able to reconstruct a previous representation from very small, unique segments of the pattern, analogous to the informativeness areas hypothesized by Loftus and Mackworth [J. Exp. Psychol., 4 (1978) 565].

Key words : learning, familiarity, visual field, pattern recognition, eye movement