Temporal constraints on conscious vision: on the ubiquitous nature of the attentional blink.

The attentional blink (AB) refers to the finding that observers often miss the second of two masked visual targets (T1 and T2, e.g., letters) appearing within 200-500 ms. Although the presence of a T1 mask is thought to be required for this effect, we recently found that an AB deficit can be observed even in the absence of a T1 mask if T2 is shown very briefly and followed by a pattern mask (M. R. Nieuwenstein, M. C. Potter, & J. Theeuwes, 2009). Using such a sensitive T2 task, the present study sought to determine the minimum requirements for eliciting an AB deficit. To this end, we examined if the occurrence of an AB depends on T1 exposure duration, the requirement to perform a task for T1, and awareness of T1. The results showed that an AB deficit occurs regardless of the presentation duration of T1, and regardless of whether there is a T1 task. A boundary condition for the occurrence of an AB was found in conscious awareness of T1. With a near-threshold detection task for T1, attention blinked when T1 was seen, but not when T1 was missed. Accordingly, we conclude that the minimum requirement for an AB deficit is T1 awareness.