Abstract
The attentional blink (AB), a refractory time following correct identification of a target item T1 within a sequence of rapidly presented visual stimuli, results in impaired ability to identify a second target T2. However evoked response potentials (ERPs) indicate that the visual information is at least partially processed though controversy exists about the degree to which the P300 which is associated with working memory, is inhibited. The present study used psychophysics and elctrophysiolgical techniques to examine conscious awareness of T2 within RSVP sequences of variable length comprising Navon figures with T1 6 characters from the start and T2 (if present) 6 characters from the end of the sequencewith regard to the likelihood of error (false alarms), in 10 young adult participants. Null trials (50% of trials with no T2) matched the T2 containing trials in all other aspects. Event-related potentials (ERPs) were measured from scalp sites to clarify the effect of the AB on perceptual awareness using the P300 component of the ERP. Additionally, the association between T2 detection accuracy and the ability to differentiate between the presence and absence of T2 was examined. No P300 was observed during the AB, however an enduring negative waveform was generated in its place. The false alarm rate made in null trials followed a similar pattern to T2 accuracy in dual-target trials, with false alarm rate increasing with trial length, indicating that as the number of items increased, expectancy of presence of T2 increased and criteria for certainty decreased.