The effects of precueing the target location on temporal crowding.

Spatial crowding refers to impaired target identification when it is surrounded by flankers in space. Temporal crowding refers to impaired target identification when it is surrounded by other stimuli in time. We have recently demonstrated that target identification is impaired by preceding and succeeding stimuli up to an ISI of 300 ms. Additionally, we did not find an interaction between the effect of spatially adjacent flankers and the effect of preceding and succeeding stimuli. This study focused on the role of spatial attention on temporal crowding. Specifically, previous studies suggest that transient attention alleviates spatial crowding. Here we examined whether it can also alleviate temporal crowding. We presented a sequence of 3 displays to the right or left of fixation. Each display included 1 letter. In one of these displays an oriented T appeared. Observers indicated the T's orientation. The other two displays included a distractor letter presented at the same spatial location as the target. The ISI between the displays varied between 125 - 450 ms. In the cued condition an auditory precue was presented to the left or right ear, prior to the onset of the letters sequence. This auditory precue indicated the onset of the sequence and its location (left vs. right). In the neutral condition, an auditory precue was presented simultaneously to both ears, indicating the sequence's onset but not its location. Similar to our previous study we found a long-lasting effect of ISI. However, precueing improved performance only when the target appeared in the first display. Moreover, there was no cueing x ISI interaction. These findings suggest that unlike spatial crowding, temporal crowding is not effected by transient attention. Still, because a visual cue may be a stronger attractor of visual attention we are currently testing the effects of a visual cue on temporal crowding. Meeting abstract presented at VSS 2015.