Abstract
Multiple studies have shown that visual working memory (VWM) fills within hundreds of milliseconds (Vogel, Woodman, & Luck, 2006) and additional encoding time does not allow for more items to be stored (e.g. Luck & Vogel, 1997). In contrast, recent studies have suggested that there is a VWM capacity benefit for real-world objects at long encoding times (i.e. multiple seconds). For example, Brady, Störmer, & Alvarez (2016) showed that VWM performance for real-world objects is better than for simple colors at long encoding times, supporting the claim that realistic items have more information that can be encoded given sufficient time. Additionally, they measured the contralateral delay activity (a neural marker for the amount of information stored in VWM) and found an increase in CDA amplitude for real-world objects compared to colors for large set sizes at long encoding times, suggesting that this increase in performance is due to an effect of VWM capacity and not long-term memory. In our first experiment, we attempted a direct replication of Brady et al.'s behavioral phenomenon with a larger number of subjects (N=25) and more trials per condition (50 trials per condition). Subjects were asked to remember six real-world objects or colors after a presentation time of 200ms, 1s, or 2s. We failed to replicate their primary behavioral result, instead finding that performance was improved for both colors and real-world objects at longer encoding times. There was no significant difference between VWM performance for colors and real-world objects. Our second experiment was another attempt at a direct replication (N=25) that also included a stronger articulatory suppression manipulation and again we found no performance benefit for real-world objects at long encoding times. These results suggest that there is no additional benefit for real-world objects compared to simple colors under extended viewing conditions.
Meeting abstract presented at VSS 2017