Introspection during short-term memory scanning.

The literature in metacognition has argued for many years that introspective access to our own mental content is restricted to the cognitive states associated with the response to a task, such as the level of confidence in a decision or the estimation of the response time; however, the cognitive processes that underlie such states were deemed inaccessible to participants' consciousness. Here, we ask whether participants could introspectively distinguish the cognitive processes that underlie two short-term memory tasks. For this purpose, we asked participants, on a trial-by-trial basis, to report the number of items that they mentally scanned during their short-term memory retrieval, which we have named "subjective number of scanned items." The subjective number of scanned items index was evaluated, in Experiment 1, immediately after a judgment of recency task and, in Experiment 2, after an item recognition task. Finally, in Experiment 3, both tasks were randomly mixed. The results showed that participants' introspection successfully accessed the complexity of the decisional processes.