Facilitation and Inhibition Effects in Selective Attention during Working Memory

Studies have shown that our ability to ignore distraction in Working Memory (WM) is a key basis for understanding our limited WM capacity. Studies have also shown that our ability to inhibit distraction is also an important process to maintain focus on task-relevant information with the limited resources of Selective Attention (SA). Yet, the mechanisms underlying these processes, shared or otherwise, have not yet been fully understood. Data from previous behavioural and neuroimaging studies show a conflict of whether or not distractors are actively inhibited during distractor resistance. By embedding an attention positive and negative priming task into a visuospatial WM task, this study attempted to use a dual-task paradigm to measure facilitation and inhibition effects while task-relevant information was maintained in WM. The first study proved that facilitation effects of positive priming could be observed in this paradigm, yet did not observe any inhibition effects of negative priming. This was replicated in a similar task condition in the second study. However, a more challenging condition with greater target-distractor similarity showed that inhibition too could be observed in the paradigm, albeit this time with the absence of facilitation effects. In the third study, a sequential presentation version of the paradigm was used, where both effects were observed with the earlier attention probe, but neither with the later (final) item on the WM encoding sequence. The findings across the studies show that facilitation and inhibition effects during WM vary depending on the demands of the task, supporting different models under different circumstances. The implications, limitations, and future considerations of the studies were also discussed.