Abstract
Priming and comparison tasks were used to assess the time course of iconic and post-iconic processing in visual short-term memory (VSTM) for form and/or color features. A prime preceded a probe at varying stimulus onset asynchronies (SOAs); observers reported the probe's form or color feature in the priming task, and whether or not the probe matched the prime in the comparison task. Three SOA ranges were used: short (0-1920 ms); long (0-4160 ms), and another long (253-3950 ms). Using the short range, Jacob, Breitmeyer & Treviño (2013) obtained evidence for three stages of VSTM processing: iconic visible persistence (0-130 ms), informational persistence (130-700 ms), and visual working memory (700-2000 ms). In the present study, both the 0-1920 ms and 0-4160 ms ranges yielded priming effects that rapidly declined after peaking at 40ms and 133ms, respectively; no significant effects occurred beyond a 700-ms SOA. In contrast, priming effects in the 253-3950 ms range lasted twice as long, ending at the 1500-ms SOA, suggesting that participants may be strategically retaining prime information for longer intervals in the sensorimotor system when SOAs are sampled at long SOA ranges excluding the lowest SOAs. Additionally, comparison effects in both long-range SOAs yielded evidence for a fourth VSTM stage. Our results indicate that information is processed differently at different post-stimulus intervals due to variations 1) of the processing stages in VSTM and (2) of cognitive strategies induced by variations of the SOA range at which VSTM processing is assessed.
Meeting abstract presented at VSS 2014