Abstract
To estimate the time course of iconic and post-iconic visual processing stages for form and/or color features, the results of two experiments using priming and comparison tasks were examined. In these experiments a prime preceded a probe at varying stimulus onset asynchronies (SOAs) and observers reported the form or color feature of the probe in the priming task, and whether or not the probe differed from the prime in the comparison task. In the first experiment (Jacob & Breitmeyer, 2012) prime-probe SOAs ranged from 0 to 1920 ms, and in the second from 253 to 4000 ms. The first experiment showed evidence for three processing stages: iconic visible persistence (0-130 ms), iconic informational persistence (130-700 ms), and visual working memory (VWM) (700-2000 ms). In the second experiment, comparison effects suggest the existence of an additional fourth stage of visual processing (2000-4000ms), possibly also in VWM. Additionally, priming effects in the first experiment show rapid decline after a peak at 133ms, and little, if any, priming effect past 650ms (consistent with Mattler, 2005). In contrast, priming effects in the second experiment last two times longer, ending around 1400 ms, suggesting that observers adopt different strategies for storing information briefly in sensori-motor memories; specifically, in priming tasks ranging over progressively longer SOAs, observers retain sensori-motor representations over longer intervals. Overall our data also suggest that the temporal dynamics of information processing differs due to 1) the existence of different processing stages in VSTM and 2) the SOA range at which processing in these stages is sampled.
Meeting abstract presented at VSS 2013