Abstract
The limited capacity of visual working memory (VWM) requires an efficient information selection mechanism. However, an uneconomical object-based encoding manner of VWM has been consistently found in previous studies. That is, not only the target feature, but also the task-irrelevant features from the same object are extracted into VWM. Besides the totally task-irrelevant feature which is never useful throughout the whole task, there is another kind of “irrelevant feature” that is necessary initially but no longer useful for the left task, termed as key feature in Chen & Wyble (2015)’s Attribute Amnesia studies. Previous studies showed that despite participants could not explicitly report the key feature in a surprise memory test, they had some memory traces for this unreportable information that could still produce an inter-trial priming effect. The current study sought to investigate the status of memory representation of a key feature by directly comparing it with the memory representation of a totally irrelevant feature from the same object (which serves as a baseline). In a series of experiments, participants were asked to memorize one feature of a single object, and then performed a visual search task in which there was either one of the distractors matching the task-irrelevant feature or key feature of the memory item, or there was no match between the memory and search display. Surprisingly, the results convergingly showed that despite a reliable WM-driven attentional bias effect (i.e., longer search time in the match condition than the no-match neutral condition) was generated by a task-irrelevant feature of an object, there was no such an effect triggered by the key feature. These findings suggested that participants might tend to actively inhibit just used information (i.e., key feature), resulting in even weaker memory representation of such information as compared to that of completely task-irrelevant features.
Acknowledgement: NSFC (No.31771201) and Humanities and Social Sciences Foundation of the Ministry of Education of China (No.17YJA190001)