Separating context and trial-by-trial effects in the negative priming paradigm

Abstract

The finding that responses to target stimuli are slowed down if these were distractors in the foregoing trial is known as negative priming (NP). In three experiments, the size of NP effects was influenced by the proportion of target-to-target and distractor-to-target repetitions of the previous block. A higher number of target-to-target repetitions in a previous practice block increased NP effects in an experimental block, in which the standard distribution of priming conditions usually conducted in NP experiments was used. In contrast, a higher number of distractor-to-target repetitions in the previous practice block decreased NP effects in a consecutive standard experimental block. Given such a design, this modulation of NP could not be explained in terms of local sequence effects on a trial-by-trial basis. Instead, experiment-wide contextual factors contribute to the proportion modulation of NP.

Notes

¹In fact, two of the priming conditions had 27 trials and one 26 trials, randomly selected by the computer.

²Reaction times that were 1.5 interquartile ranges above the third quartile with respect to the overall distribution of RTs.