Backward masking during rapid serial visual presentation affects the amplitude but not the latency of the P3 event-related potential.

Masking of the first target in the attentional blink (AB) paradigm increases the magnitude of the AB relative to when the first target is not masked. We examined the underlying causes of this effect in an experiment in which a single target was presented in a rapid visual serial presentation stream. The P3 to the target was isolated by subtracting infrequent target category trials from frequent target category trials. The item immediately trailing the target (i.e., the mask) was present in the masked condition and replaced by a blank screen in the not-masked condition, reproducing conditions known to modulate the AB. Masking the target significantly reduced the amplitude of the target-locked P3 but had no effect on P3 latency. Results are discussed in relation to previous findings in the AB literature.