Relational information decays faster than object features in visual working memory.

Visual working memory (VWM) actively maintains visual information for a short period. While some researchers suggested that VWM representation consisted of slots storing bound objects (e.g., Luck et al., 2001), other researchers found that degradation of relational information decreased VWM capacity (e.g., Wilken et al., 2004). Recently, Brady et al. (2013) found that different features of objects decayed at different rates in long-term visual memory. However, the same hypothesis has not been tested in VWM. We investigated whether relational information among items decayed faster than object features in VWM. To test this hypothesis, we used a change detection task. We varied the retention intervals (short: 150 ms, long: 750 ms) and used different locations between test and memory arrays. The memory array was presented in the parafovea and the test array was presented around the fixation to prevent participants from utilizing sensory memory. There were three types of changes in the test array. In the color change condition, the color of one item was changed. Because colors of individual objects and relationship between colors were preserved, participants could use both object features and relational information. In the location change condition, relative location of one item was changed. Note that absolute locations of all items in test array were changed from those of the memory array because of the different locations between the test and memory arrays. Thus, only relational information was available in the location change condition. Finally, in the both change condition, both relative location and color of one item were changed. Change detection performance was similar at the short retention interval across the conditions. However, at the long retention interval, change detection performance of the location change condition decreased significantly more than the other conditions. These results suggest that relational information decays faster than object features in VWM. Meeting abstract presented at VSS 2015.