Abstract
The ability to perceptive a uniquely colored target, embedded within a rapid sequence of nontarget letters of homogenous color, is impaired when the target appears during a relatively earlier part of the sequence. This phenomenon, referred to as “attentional awakening,” is thought to occur due to the gradual modulation of temporal attention, such that signal detection should be improved commensurate with later target onset. We investigated this possibility with two types of task. Experiment 1 replicated a typical attentional awakening effect by using a singleton-detection task in which a uniquely colored target was embedded within a rapid stream of 21 nontarget grey letters, presented at a rate of 10 frames per second (3,000 ms in total). Target identification accuracy during the first temporal bin (300-500 ms) was significantly lower compared with the third and fourth bins (1,500-1,700 ms and 2,100-2,300 ms, respectively), indicative of attentional awakening. Experiment 2 tested whether attentional awakening could be elicited by a direction-judgment task, of dots moving with 30% coherence. Participants indicated the direction of motion (up, down, left, or right) during a randomly selected 100 ms period of motion (total period of motion = 3,000 ms). Coherent motion occurred within the same temporal bin used in Experiment 1. The results indicated an absence of attentional awakening, with coherent motion direction accuracy not differing across temporal bins. This is inconsistent with the notion that attentional awakening reflects gradual modulation of temporal attention. We suggest that attentional awakening is task-dependent and might reflect a state of inattention elicited by mandatory processing of the initial letters of a sequence.
Meeting abstract presented at VSS 2015