Is recognition without awareness possible?
In a second study, the team discovered that subjects performed better on tests of episodic memory when they paid divided attention rather than full attention, further validating their findings. In their 2009 paper they concluded by stating that "our findings add weight to the proposal that nonhuman animals utilize visual fluency without episodic memory when performing tasks intended to probe episodic memory."
However, contrary results have recently been published in this month's Learning & Memory. In a replication study Jeneson, Kirwan, and Squire, found that recognition was better when subjects paid full attention to the visual stimuli compared to paying partial attention. In addition, recognition was better when subjects reported some level of confidence as compared to a guess.
Vass and Paller responded to the disconfirming study by running a further study of their own. To resolve the apparent discrepancy they added a simple manipulation to encourage either guessing or confident responding. They found that encouraging guessing increased prevalence and accuracy of guesses relative to the confident responding condition. The authors suggest that both the prevalence and accuracy of guessing can be influenced by whether subjects adopt guessing-friendly strategies. So the lesson here is...guess away!
Voss JL, & Paller KA (2009). Recognition without awareness in humans and its implications for animal models of episodic memory. Communicative & integrative biology, 2 (3), 203-4 PMID: 19641728
Jeneson A, Kirwan CB, & Squire LR (2010). Recognition without awareness: An elusive phenomenon. Learning & memory (Cold Spring Harbor, N.Y.), 17 (9), 454-9 PMID: 20810620
Voss JL, & Paller KA (2010). What makes recognition without awareness appear to be elusive? Strategic factors that influence the accuracy of guesses. Learning & memory (Cold Spring Harbor, N.Y.), 17 (9), 460-8 PMID: 20810621