Abstract
When a target object is presented in peripheral vision and flanked by similar objects, the specific information carried by the target is no longer available to the observer. This form of inhibitory interaction between target and flankers is known as visual crowding. However, though the information carried by the target is not available in crowding, important target features may still be processed. There is psychophysical evidence that (low-level) priming, e.g., from oriented gratings (Faivre, & Kouider, 2011. Journal of Vision, 16, 1-13) as well as high-level semantic priming (Yeh, et al., 2012. Psychological Science, 23, 608-616) survive crowding. In the present study we report motion-priming effects in the non-crowded condition across all prime durations employed (i.e., 200, 500, 1000 and 2000 ms), showing its exponential decay as the prime duration increases. We also show that motion priming for globally translating dots does not survive crowding at any of the prime durations tested. Further experiments suggest that the absence of motion priming in the crowded condition does not depend on the lack of focused attention on the crowded prime. Indeed, pre-cueing the prime did not restore the priming effect. Several studies (see Levi D. M., 2008. Vision Research, 48, 635-654) suggest that crowding depends on the presence of large receptive fields in the retinal periphery. If target and flankers fall within the same receptive field the specific target information is suppressed, while the information of flankers and target is averaged. In a third experiment we showed that when a certain percentage (e.g., 40%) of flankers moved in the same motion direction as that of the prime, the priming effect was restored. Taken together these results suggest that in crowding motion signals are averaged, and such pooling is likely to be pre-attentive (Parkes, et al., 2001. Nature Neuroscience, 4, 739-744).
Meeting abstract presented at VSS 2014