Abstract
Visual Working Memory (VWM) is a temporary storage that can hold a limited amount of information (between 3-4 objects). Despite its limited capacity, there are robust and reliable individual differences in VWM capacity that correlate with important aptitude measures. In an attempt to understand the nature of these differences, Vogel et al. (2005) argued that filtering efficiency (i.e., the ability to ignore task irrelevant items) might explain individual differences in VWM capacity. They showed that filtering efficiency is highly correlated with VWM capacity, such that low-capacity individuals demonstrated poor filtering efficiency relative to high-capacity individuals. However, it is not clear how low-capacity individuals cope with our daily environment which is crowded with irrelevant information. Note that in previous studies, filtering trials were presented completely at random. Therefore, one option is that when the need to filter out information is known in advance, low-capacity individuals can compensate and perform better. In the current study we investigated the connection between VWM capacity and the ability to control filtering efficiency using a change-detection task modeled after Vogel et al. (2005) while ERPs were recorded. Participants viewed memory arrays that included either two targets, four targets, or two targets and two distractors (the filtering condition). However, filtering trials always appeared in pairs, such that while the first filtering trial remained random, the second one was 100% predictable. In separate experiments we either did or did not explicitly tell that to participants. We used the CDA (which is a waveform of the event-related potential that reflects the number of items encoded and maintained in VWM) to monitor changes in filtering efficiency. In both experiments we found no difference between the first (random) and the second (predictable) filtering trials suggesting that prior knowledge about when filtering occurs did not compensate for poor filtering efficiency in VWM.
Meeting abstract presented at VSS 2014