Recognition confidence under violated and confirmed memory expectations.

Individuals' memory experiences typically covary with those of others' around them, and on average, an item is more likely to be familiar if a companion recommends it as such. Although it would be ideal if observers could use the external recommendations of others' as statistical priors during recognition decisions, it is currently unclear how or if they do so. Furthermore, understanding the sensitivity of recognition judgments to such external cues is critical for understanding memory conformity and eyewitness suggestibility phenomena. To address this we examined recognition accuracy and confidence following cues from an external source (e.g., "Likely Old") that forecast the likely status of upcoming memory probes. Three regularities emerged. First, hit and correct-rejection rates expectedly fell when participants were invalidly versus validly cued. Second, hit confidence was generally higher than correct-rejection confidence, regardless of cue validity. Finally, and most noteworthy, cue validity interacted with judgment confidence such that validity heavily influenced the confidence of correct rejections but had no discernible influence on the confidence of hits. Bootstrap-informed Monte Carlo simulation supported a dual process recognition model under which familiarity and recollection processes counteract to heavily dampen the influence of external cues on average reported confidence. A 3rd experiment tested this model using source memory. As predicted, because source memory is heavily governed by contextual recollection, cue validity again did not affect confidence, although as with recognition it clearly altered accuracy.