Serial or Parallel? Sublexical Scanpath Analysis of Eye-movement Sequences in Single Word Reading

Are the letters of a written word processed sequentially or in parallel? Despite an abundance of research on visual word recognition, the evidence in this longstanding debate rests almost entirely on indirect inferences from word-length effects and conventional whole-word eye-movement measures. We sought direct evidence on the serial-parallel question by investigating sublexical gaze-fixation sequences-so-called scanpaths. This study is the first to apply scanpath analysis to fixation sequences within single words. Thirty-four Hebrew-speaking adult university students read aloud three-letter and five-letter real words and pseudowords while their eye movements were tracked. As expected, real words showed more parallel processing, whereas pseudowords displayed more sequential, letter-by-letter scanpaths. Surprisingly, longer words tended to elicit serial processing regardless of word familiarity. Our findings support the applicability of scanpath analysis in visual word recognition and its potential to open up new perspectives on word-recognition processes.