Cognitive Backward Masking: A Window Into the Formation of a Short-Term Memory Trace

Working memory consolidation denotes the process that enables sensory information to be stored in short-term memory. What is currently unclear is how long this process takes and whether it continues after a stimulus has been masked. Here, we address these matters by examining whether the consolidation of visual stimuli can still be disturbed even after they have been masked. Participants viewed brief and masked displays of letters or Kanji characters that had to be memorized and that could be followed at varying stimulus onset asynchronies (SOA) by a visual or auditory discrimination task. Memory performance improved as SOA increased from 100 to 1000 ms, revealing what may be called a “cognitive backward masking effect” caused by the discrimination tasks. Taken together, the results show that working memory consolidation is a time-consuming but volatile process that continues after a stimulus has been masked and that can be disrupted by executing another task.