An attentional blink for moving stimuli and for tasks combining form and motion perception

Attentive processing of a target stimulus (T1) embedded in a sequence of serially and rapidly presented distractor stimuli results in a transient impairment of detecting a second, subsequently presented target stimulus (T2). This impairment is known as the attentional blink. In the majority of previous studies of this phenomenon T1 and T2 were stationary visual stimuli. Considering the two cortical processing pathways for form and motion, we explored whether an attentional blink also occurs for stimuli and tasks relying on the dorsal visual pathway. In addition, we examined how processing along one pathway affects processing along the other. We conducted four experiments using moving random dot patterns and stationary letter stimuli and tested each possible combination of motion and letter as T1 and T2. Subjects had to either only detect T2 (single task) or had to identify T1 and detect T2 (dual task). We found a pronounced impairment in detecting T2 after identification of T1 for all combinations, which lasted for approximately 300ms. The point of maximum impairment differed between conditions and occurred around 100-300ms after presentation onset of T1. Subjects usually missed more than one third of T2 stimuli presented at that point in time in the sequence. Our results document an attentional blink for motion processing and support the hypothesis that it reflects a global attentional effect that is not restricted to one of the two processing pathways in the visual cortex. Meeting abstract presented at VSS 2013