An eye-movement-contingent probe paradigm.

A new eye-movement-contingent probe task is presented in which readers' eye movements are monitored as they read sentences and respond to a probe word; the timing of the display of the probe word is dependent on fixation of a target word. The present study examined semantic priming effects. The target word was either related (doctor) or unrelated (lawyer) to the probe word (nurse), and the probe appeared 120, 250, 500, or 750 msec after the reader first fixated on the target word. When the probe word appeared (in the location of the target word), the rest of the sentence disappeared until the participant named the probe word. Then the sentence reappeared, and the participant continued reading the sentence. Naming times to the probe word were recorded, as was sentence reading time and the eye movement behavior relative to the onset of the probe word. Priming effects were observed, since probe reaction time to related probes was faster than that to unrelated probes. Ways in which this paradigm can be used to study various issues in language processing are discussed.