Prime-trial processing demands and their impact on distractor processing in a spatial negative priming task.

A spatial negative priming (NP) paradigm was used where trials were presented in pairs, first the 'prime' and then the 'probe', and where participants responded manually to a target's location. In Experiment 1, three prime-trial types were used: distractor-plus-target, predictable distractor-only, and unpredictable distractor-only, with prime-probe trial onset delays of 2, 5 or 10 s (NP longevity). In Experiment 2, the latter two prime-trials were employed with onset delays of 75 and 750 ms (distractor response activation-inhibition sequence). With the exception of the 10 s onset delay, the spatial NP effect data (NP size, longevity, distractor response activation-inhibition sequence) was the same for all three prime-trial types. Thus, the varying processing demands associated with each of the prime-trial types (e.g., selection, intervening response) did not alter prime distractor processing so that they differentially contributed to the spatial NP process. The three prime-trial types can be used interchangeably, within limits, to study the NP process.