Abstract
Attentional blink (AB) is a transient deficit in reporting second target (T2) when the first target (T1) is successfully reported in RSVP. The current study investigated how the signal strength ratio of T1 to T2 influenced the amount of AB. We tested this hypothesis using either simple orientation discrimination task or letter identification task. In Experiment 1, we wanted to test whether AB occurred even for discriminating ±45° gratings. Using QUEST, we first measured each participant's contrast threshold for deciding what would constitute for targets and distractors. The targets were ±45° gratings and the distractors were either horizontal or vertical gratings. The contrast of all stimuli was twice of the threshold. We found AB occurred even in this simple orientation discrimination task. In Experiment 2, we used the same stimuli and the task as in Experiment 1, but varied T2 contrast. The amount of AB was the largest when T2 contrast was half of T1 contrast, whereas it became smaller as T2 contrast increased up to twice of T1 contrast. In Experiment 3, we used the letter identification task and again varied the contrast ratio of T1 to T2. Consistent with the results of Experiment 2, we found that the amount of AB decreased as T2 contrast increased. Our findings suggest that the signal strength ratio could modulate the effect of AB regardless of the task type.
This research was supported by the Cognitive Neuroscience Research Program of the Korea Ministry of Science and Technology.