Abstract
Visual short-term memory (VSTM) is a vital cognitive resource that allows storing visual information over short time periods. Current theories postulate that stimuli are encoded and stored individually in VSTM. However, studies on the relational account of attention have shown that stimuli are often encoded in a relational, context-dependent manner (e.g., as larger, redder, darker), and it is well-known that attention is closely linked to VSTM. The present study critically tests whether the relational account of attention can be extended to VSTM, viz., whether stimuli are also stored in a context-dependent manner in VSTM. In a change detection task, we used a range of similar colours (green to blue, yellow to red, etc.) and compared performance when a stimulus changed such as to retain its relative colour (e.g., the reddest item changed to a different shade of red, whilst still being the reddest item in the test display) versus when it evoked a relational change (e.g., the reddest item changed such that another item became the reddest item). Although the magnitude of the colour change was the same in both conditions, participants were significantly more likely to notice the change when the relative colour of the item changed than when it remained the same, indicating that information about relative colours was stored in VSTM. In a second experiment, we compared the CDA component in the EEG of participants to determine whether the CDA is sensitive to feature relationships. Preliminary results show that the CDA was smaller when displays allowed storing information in terms of simple feature relationships (rather than, e.g., encoding and storing dissimilar colours). Collectively, these results suggest that elementary features such as colours are encoded and stored in VSTM in a relational, context-dependent manner, rather than individually and independently.
Meeting abstract presented at VSS 2018