Optimal viewing position effects in the processing of isolated Chinese words.

Previous studies have found that words are identified most quickly when the eyes fixate near the word center (the Optimal Viewing Position, OVP) in alphabetic languages. Two experiments were performed to determine the presence of OVP effects during the processing of isolated Chinese words. Participants' eye movements were recorded while they performed a lexical decision task. The results suggest that Chinese readers exhibit OVP effects and that the OVP tends to be the first character for 2-character words. For 3- and 4-character words, the OVP effects appear as a U-shaped curve with a minimum towards the second character. As fixations deviate from the OVP, word processing times increase at a rate of 30-70 ms per character, and fixation duration is strongly influenced by the initial viewing position. Moreover, the present study did not observe an I-OVP effect for first fixation durations nor a fixation-duration trade-off in two-fixation cases in the case of isolated Chinese words processing.