Interference effects and the consequences of recognition failures and successes

This investigation examined the contribution of memory awareness to interference, conceptualized as response competition that arises from the encoding of materials similar in appearance. Subjects performed incidental encoding tasks (counting vowels, counting syllables, and word association) on targets and non-targets that were orthographically similar (experimental condition) or dissimilar (control condition). The tasks were intended to make the memories of the studied words at test more or less accessible to subjects' awareness. During the test, fragments of the targets were intermixed with fragments of nonstudied words, and the task was to complete fragments with studied words or, in the absence of such memories, with the first words that came to mind. Response competition was expected to produce a blocking effect, consisting of fewer correct completions and more intrusions (or null responses) in the experimental condition than in the control condition. When the overall accessibility of the studied, orthographically similar words was optimized by the semantic association task, responses recognized as studied exhibited both more intrusions and fewer correct completions than in the control condition. When the accessibility of these words was curtailed by the vowel counting task, only unrecognized correct completions after the proactive interference treatment tended to be lower than in the control condition. These results suggest that memory awareness can modulate interference conceptualized as response competition.