Eye movements guided by morphological structure: Evidence from the Uighur language

•We used Uighur scripts which are known for their rich suffixes.•The influences of number of suffixes on initial landing positions and refixation probability independent of frequency.•These results are difficult to explain by purely low-level guidance of eye movements.•Morphological structure of parafoveal words can influence saccade program.

It is generally accepted that low-level features (e.g., inter-word spaces) are responsible for saccade-target selection in eye-movement control during reading. In two experiments using Uighur script known for its rich suffixes, we demonstrate that, in addition to word length and launch site, the number of suffixes influences initial landing positions. We also demonstrate an influence of word frequency. These results are difficult to explain purely by low-level guidance of eye movements and indicate that due to properties specific to Uighur script low-level visual information and high-level information such as morphological structure of parafoveal words jointly influence saccade programming.