Self-Paced Reading Task

Both are online measures of reading, but eye-tracking records natural eye movements — including skipping, regressions, and rereading — at high temporal resolution and distinguishes early from late measures, whereas self-paced reading imposes a serial word-by-word button press that prevents looking back and slows reading unnaturally. Self-paced reading wins on cost, simplicity, and online scalability and often replicates eye-tracking effects, but eye-tracking gives a richer, more natural, and finer-grained picture. Many researchers use self-paced reading for breadth and eye-tracking for depth and naturalness.

Spillover is the tendency for a processing-difficulty effect to appear not on the critical word itself but on the following region or two, because comprehension of a word continues after the reader has moved on. In self-paced reading this is common, so analysts pre-register and analyze one or more post-critical (spillover) regions in addition to the critical region. Ignoring spillover can make a real effect look absent or mislocate it; analyzing it correctly attributes the slowdown to the right manipulation.

In the non-cumulative moving window — the most common form — each new word appears and the previous word is re-masked, so only one region is visible at a time; this isolates per-region times but forbids rereading. In a cumulative window, revealed words remain on screen. Non-cumulative presentation gives cleaner region-by-region reading times and is the standard for processing studies, while cumulative presentation is occasionally used when keeping prior context visible is desired, at the cost of contaminating later-region times with rereading.