g., Wixted, 2007). Some researchers like Donaldson (1996) and Dunn (2008), for example, have argued that evidence from Remember/Know judgments, Confidence judgments (e.g., ROC curves) and even Source judgments can be re-interpreted in terms of a single dimension of memory strength (i.e., without needing to appeal to qualitatively distinct processes of familiarity and recollection; see recent exchange in Trends in Cognitive Science, 2011, Issue 15). Moreover, the precise nature of the empirical dissociation – for example,

a single, double, or cross-over dissociation – has also been questioned, particularly in neuroimaging data where the mapping 3-Methyladenine clinical trial between hemodynamic LBH589 in vivo measures and theoretical concepts like memory strength, for example, may be nonlinear ( Henson, 2006; Squire et al., 2007). Nonetheless, the popularity of the recollection/familiarity distinction is due largely to the convergence of empirical dissociations across a range of paradigms, most of which appear relatively easy to explain in terms of two distinct processes of recollection and familiarity. In a standard recognition memory paradigm, a series of items are presented in a Study phase (“studied” items), which participants then have to distinguish, when presented again in a later Test phase, from randomly intermixed “unstudied” items

that were not Selleck Fludarabine presented at Study. As elaborated in other articles in this special issue, recollection in this paradigm generally refers to retrieval (recall) of contextual information that was present at Study, but that is not present at Test. Examples of this contextual information include spatial location of an item, or other thoughts/associations prompted by that item (corresponding to “external” and “internal” “source” information respectively; Johnson et al., 1993). Conversely, familiarity generally refers to a unitary, acontextual signal associated with the test cue itself, owing for example to residual effects of its recent processing in the Study phase (though

may also have other causes; see below), which is attributed to the Study phase by the participant. One variant of the recognition memory paradigm that has been used to support the recollection/familiarity distinction was introduced by Jacoby and Whitehouse (1989). In the “masked” version of this paradigm, each item in the Test phase is preceded by a brief, masked stimulus, for which participants typically have little to no awareness (or at least, do not appear to spontaneously identify). When the masked stimulus (prime) matches the test item (target), for example corresponding to the same word just in a different letter case (see ahead to Fig. 1), participants are more likely to call the test item “old” (i.e.