The Attentional Blink

• The role of attention is to sift through the myriad of stimuli we are exposed to everyday and limit the flow of information so that we are only aware of information that is most critical to us. Many of our studies use a phenomenon known as the "attentional blink" (AB), which allows us to look at the costs of attending to a stimulus over time. In these studies two targets are presented amongst distractors. Stimuli are all presented in the same location in space but one at a time at a rate of about 10/sec. (RSVP). Generally, report accuracy for the second target (T2) is good when the first target (T1) can be ignored (single task). However, accuracy for T2 is poor if it is presented within half a second of T1 when both targets must be attended - as if attention blinks. [PDF of original AB article.]

• In the Attention Lab we perform an ongoing series of AB studies (some with ERPs and some without) to better understand the nature of the AB. For example, several of our studies have focused on the question of whether the AB is the result of modality specific limitations or a more central, amodal limitation. [e.g., PDF of a cross-modality behavioural study, and PDF of a cross-modality ERP study.]

Dual-Task Variations on the AB

• Some of our studies also examine variations of the AB paradigm where one of the targets is unmasked and may or may not require a speeded response. For example, when the mask is removed from the second target, and responses are speeded, T2 RTs and P3 ERP latencies are lengthened at close target temmporal separations (see below for a P3 example). The nature of these dual-task costs can then be compared with those from the AB paradigm to isolate the critical factors underlying each type of interference. [[e.g., PDF]

The AB from an Individual Differences Perspective

• Participants differ markedly in the sizes and durations of the ABs they show, even under identiical stimulus presentation conditions. What determines why some participants have a small AB and others a large one? We are now performing individual differences studies of the AB where we use behavioural performance from other cognitive tasks and ERPs to examine correlates of RSVP target accuracy and AB size. [e.g., PDF]

Emotion & Attention

• Recently, we have also performed some studies of attention and emotion. Most of these have varied the nature of emotionally laden words presented in RSVP streams. We have observed that the size of the AB increases for highly arousing words that are sexual and/or taboo in nature, and that even when they are presented as to-be-ignored distractors these same words set-off an AB for subsequent emotionally neutral targets. Memory is also heightened for these sexual/taboo words, as are N400 and P3 ERPs, suggesting that sexual/taboo words receive preferential activatioon and attention. Investigations of these effects are ongoing. [e.g., PDF]