Humans exhibit a remarkable cognitive flexibility to adapt to novel contexts. This great flexibility for new contexts relies on three cognitive abilities in concert. First, one must maintain goal-relevant representations in working memory (WM). Second, achieving one’s goal depends on the anticipation of upcoming events, and one must act in such a way that the future outcome will be in accordance with the desired outcome. Third, such anticipation relies on one’s past experiences associated with goal-relevant information for a particular context. Together, one must use past experiences or prior knowledge to prepare for appropriate actions while adjusting behaviors toward the goal based on the context.
WM allows us to hold and manipulate information that is relevant to our current task goals for a given contextual episode over a short period of time. The critical role of WM is to bridge the gap between perception and higher-level mental processes such as long-term memory, thinking, reasoning, and language. However, the capacity of WM is highly limited. While previous investigations have revealed that attention is important in controlling the contents of WM, it remains unexplored whether task context can influence WM. This study aimed to investigate whether context-driven selection history can modulate the efficacy of attention allocation in WM (Kuo, 2016)
. In this study, the participants performed a visual WM task in which a display of one item (low WM load) or three/four items (high WM load) was shown for the participants to hold in their WM. Following a short retention interval, the participants judged whether a probe item was in the memory display. Selection history was defined as the number of items attended across trials in the task context within a block, manipulated by the stimulus set-size in contexts with fewer possible stimuli (4- or 5-item context) or more possible stimuli (8- or 9-item context) from which the memorized content was selected. In the context of fewer possible stimuli, fewer memorized contents from the previous trials interfered with the processing of task-relevant items in the current trial. In the more possible stimuli context, more representations from previous trials interfered with stimulus processing in the current trial.
Across four behavioral experiments, the results revealed that the WM capacity was significantly reduced in the more possible stimuli context relative to the fewer possible stimuli context (see Figure 1). Moreover, the reduction in capacity was significant for high WM loads but was not observed when the focus was on only a single item. Together, these findings indicate that context-driven selection history and focused attention influence WM capacity. The findings from this study also provide the intellectual impetus for in-depth work on this essential aspect of human cognition, namely, the manner in which task contexts can proactively affect behavior.
Figure 1. Across four behavioral experiments, the results revealed that the WM capacity was significantly reduced in the more possible stimuli context relative to the fewer possible stimuli context.
Acknowledgements
This work was supported by the National Taiwan University Cutting Edge Steering Research Project (NTU-CESRP-103R104951).
Reference
Bo-Cheng Kuo (2016). Selection history modulates working memory capacity. Frontiers in Psychology, 7(1564). DOI: 10.3389/fpsyg.2016.01564
Associate Professor Bo-Cheng Kuo
Department of Psychology
bckuo@ntu.edu.tw