Revisiting the spread of sparing in the attentional blink

The attentional blink (AB) refers to a deficit in reporting the second of two targets (T2) in a rapid serial visual presentation (RSVP) stream when this target is presented less than 500 ms after the onset of the first target (T1). It is under debate whether the AB originates from a limitation of cognitive resources or from an attentional suppression process triggered by a distractor or by target discontinuity. In this study, we placed a distractor (D(inter)) or an extra target (T(inter)) between T1 and T2 while at the same time manipulating the time interval between D(inter) (or T(inter)) and T2 (0, 200, or 500 ms). The level of attentional enhancement induced by the detection of T1 was also manipulated by adding external noise to T1. The results showed that, as compared to the dual-target condition, T2 performance was better in the consecutive-target condition, when T2 was close in time to T(inter) (i.e., the spread of sparing), but was worse with a longer interval between T2 and the preceding item. Adding external noise to T1 improved T2 performance when T2 was close in time to the preceding item, irrespective of whether this item was D(inter) or T(inter). These findings present difficulties for the existing models of the AB, although the overall pattern observed is generally more consistent with the episodic simultaneous-type, serial-token (eSTST) model than with conventional resource accounts or distractor-based attentional selection accounts of the AB.