Abstract
In a single-target RSVP task where participants were asked to identify the only white letter in a sequence of blue letters, Ariga & Yokosawa (2005) found that targets are usually missed when they appear early in the stream. They interpret this effect as a modulation of temporal attention, with attentional tuning gradually increasing over the first few hundred milliseconds of the search stream. Here, we tested whether similar mechanisms are at play in this effect and in the attentional blink (AB). Specifically, we asked whether the start itself of an RSVP stream leads to a blink-like effect on T1. Whereas in the AB, processing of T1 impairs the identification of a second target (T2) presented shortly after T1, we hypothesized that processing the onset itself of the letter stream could cause an analogous impairment to identification of targets presented shortly after the onset of the stream. We modified Ariga & Yokosawa's task to include two targets and manipulated location of T1 in the stream and T1–T2 lag (2 or 8). We found strong modulations of T1 identification accuracy by T1 location, with impairments for early T1s, replicating Ariga & Yokosawa. We also observed a robust AB at all T1 locations. Surprisingly, we also found that early in the RSVP stream T1 accuracy was modulated by both T2 lag and T2 accuracy. Subsequent experiments looked at the role of the leading item in the RSVP stream (T1, letter or non-letter mask) and at lag-one sparing early in the RSVP stream.
NSF award# 0527361 to A.L.