Remember,know, confidence and the mirror effect: Changes as a function of discriminability conditions

Recognition memory for Spanish-Catalan cognate and noncognate words was tested at retention intervals of 20 minutes, 1 hour, and 24 hours (Experiment 1) using a remember/know response procedure, and requiring a confidence judgement on the yes/no response. Noncognate words were accompanied by more “remember” responses than cognates, and overall A' was significantly different from remember A', except in the cognate condition at the longest retention interval. A strong mirror effect for the cognate-noncognate stimulus class was found for overall responding, and for high but not low confidence, indicating a differential use of recollection and familiarity in recognition. In general, the pattern of results was inconsistent with Donaldson's (1996) signal detection model, indicating that, when available, subjects use two different sources of information for discrimination. The examination of individual hits and false alarms as a function of confidence indicated that “remember” is uniformly associated with high confidence, but “know” shows a bipolar pattern. In Experiment 2, new and old words were repeated at test 2 and 3. Repetition greatly affected the difference between the discrimination indices, indicating that an increase in the familiarity of new words prevented the use of a dual source of information in recognition. Results are discussed in terms of Rajaram's distinctiveness (1996, 1998) and Reder, Nhouyvanisvong, Schunn, Ayers, Angstadt, and Hiraki's (2000) SAC theories.     

Familiarity and recollection in item and associative recognition

Recognition memory for item information (single words) and associative information (word pairs) was tested immediately and after retention intervals of 30 min and 1 day (Experiment 1) and 2 days and 7 days (Experiment 2) using Tulving's (1985) remember/know response procedure. Associative recognition decisions were accompanied by more "remember" responses and less "know" responses than item recognition decisions. Overall recognition performance and the proportion of remember responses declined at similar rates for item and associative information. The pattern of results for item recognition was consistent with Donaldson's (1996) single-factor signal detection model of remember/know responses, as comparisons based on A' between overall item recognition and remember item recognition showed no significant differences. For associative recognition, however, A' for remember responses was reliably greater than for overall recognition. The results show that recollection plays a significant role in associative recognition.     

Measuring the speed of the conscious components of recognition memory: remembering is faster than knowing

Three experiments investigated response times (RTs) for remember and know responses in recognition memory. RTs to remember responses were faster than RTs to know responses, regardless of whether the remember-know decision was preceded by an old/new decision (two-step procedure) or was made without a preceding old/new decision (one-step procedure). The finding of faster RTs for R responses was also found when remember-know decisions were made retrospectively. These findings are inconsistent with dual-process models of recognition memory, which predict that recollection is slower and more effortful than familiarity. Word frequency did not influence RTs, but remember responses were faster for words than for nonwords. We argue that the difference in RTs to remember and know responses reflects the time taken to make old/new decisions on the basis of the type of information activated at test.     

Binding of multidimensional context information as a distinctive characteristic of remember judgments

This research investigated the cognitive processes underlying remember-know judgments in terms of contextual binding in multidimensional source memory. Stochastic dependence between the retrieval of different context attributes, which formed the empirical criterion of binding, was observed for remembered items but not for known items. Experiment 1 showed that the qualitative difference in the stochastic relation holds even if quantitative source-memory performance is equated for items with remember and know judgments. Experiment 2 generalized the findings to context information from different modalities, and Experiment 3 ruled out a spurious stochastic dependence due to interindividual differences. Supporting recent dual-process models of remember-know judgments, the findings show that remember and know judgments differ with respect to binding processes that correspond to episodic recollection.     

Processing fluency affects subjective claims of recollection

Previous studies that have used the remember-know paradigm to investigate subjective awareness in memory have shown that fluency manipulations have an impact on "know" responses but not on "remember" responses (e.g., Rajaram, 1993), a finding typically accounted for by invoking inferential processing in judgments of familiarity but not of recollection. However, in light of several researchers' criticisms of this procedure, as well as findings documenting the influence of processing fluency on various subjective judgments, the present study was conducted in order to investigate whether judgments of recollection might also be subject to inferential processes and not solely the product of conscious retrieval. When the standard remember-know procedure was used (Experiment 1), manipulations of perceptual fluency increased "know" responses but had no effect on "remember" responses, replicating previous findings. However, when an independent ratings method was employed (Higham & Vokey, 2004), manipulations of perceptual fluency (Experiment 2) and conceptual fluency (Experiment 3) reliably increased claims of both familiarity and recollection, suggesting that the conclusion that fluency affects only "know" responses may be an artifact of the standard remember-know procedure.     

The quality of false memory over time: Is memory for misinformation “remembered” or “known”?

The conscious quality of eyewitness memory for misinformation after different retention intervals was investigated in two experiments. Participants viewed computer-projected slides depicting a crime (encoding phase), read a narrative containing misinformation, and took a recall test about the original event. Remember/know judgments were made for each response. A "remember" judgment indicated that the participant vividly recalled seeing a detail in the encoding phase. A "know" judgment indicated that the participant believed that a detail was presented but did not vividly remember it. Generally, misinformation was more likely to be associated with a know judgment than with a remember judgment after a short retention interval. This outcome suggests that, in many cases, misleading information is judged as having a different subjective quality than memory for actual events. However, over a relatively long retention interval, misinformation that simply added new information about the event was more often judged as remembered.     

Context, remember-know recognition judgements, and ROC parameters

Recent work (e.g., Dunn, 2004; Heathcote, 2003) has questioned the necessity of postulating two processes to explain recognition memory. As part of this trend, strength theories of the remember-know methodology have gained in support. We present three experiments with pictorial material in which we force participants to use differential contextual information at test. Participants were required to give remember-know judgements and confidence ratings for each test stimulus. Hits, false alarms, remember-know data, and discrimination indices indicated systematic variations as a function of the availability and use of contextual information. Moreover, when we normalised the receiver operating characteristic data in terms of z-scores, the slopes were lower than 1 and slightly concave. Additionally, we computed the same set of statistical indices suggested by Wixted and Stretch (2004), with mixed results. Overall, we think that the data support a two-factor theory of remember-know and recognition, although many results fit well signal detection views of the task. Finally, the idea that remember and know responses are pure manifestations of recollection and familiarity seems difficult to sustain. We think that a productive use of the remember-know methodology involves the minimisation of the bias factors that may contaminate the responses, in addition to the introduction of the experimental manipulations needed to promote recollective and/or familiarity processes.     

Boundaries of the relation between conscious recollection and source memory for perceptual details

The relation between conscious recollection and source memory for perceptual details was investigated in three experiments that combined the remember-know paradigm with a multidimensional source monitoring test. Experiment 1 replicated that source memory for perceptual details is better in the case of "remember" than "know" judgments. Experiment 2 showed that the relation between "remember" judgments and source memory for perceptual details is diminished by a semantic orienting task during encoding. Experiment 3 demonstrated that "remember" judgments are related to enhanced source memory for specific and unique kinds of perceptual source information, whereas memory for incomplete and global perceptual source information does not differentiate between "remember" and "know" judgments. The results show that the attentional focus during encoding and the specificity of retrieved source information form boundary conditions for the use of source memory for perceptual details as a basis of "remember" judgments.     

Modeling the conscious correlates of recognition memory: Reflections on the remember-know paradigm

Understanding how memory processes contribute to the conscious experience of memory is central to contemporary cognitive psychology. Recently, many investigators (e.g., Gardiner, 1988) have examined theremember-know paradigm to understand the conscious correlates of recognition memory. A variety of studies have demonstrated that variables have different effects on remember and know responses, and these findings have been interpreted in the context of dual-process models of recognition memory. This paper presents a single-process model of the remember-know paradigm, emphasizing the dependence of remember and know judgments on a set of common underlying processes (e.g., criterion setting). We use this model to demonstrate how a single-process model can give rise to the functional dissociations presented in the remember-know literature. We close by detailing procedures for testing our model and describing how those tests may facilitate the development of dual-process models.     

The distinctiveness effect in forenames: The role of subjective experiences and recognition memory

We describe two experiments that tested the prediction that distinctive forenames would be better recognized than typical forenames and which investigated whether this distinctiveness effect, if obtained, occurred in subjective experiences of the recollective or familiarity components of recognition memory. To that end, the remember‐know paradigm was used to measure people's experiences of recollection or familiarity. The results revealed that distinctive forenames were more memorable than typical forenames and that that this distinctiveness effect was present only in the subjective experience of remembering. Additionally, the present research showed that these distinctiveness effects were present after retention intervals of both 1 and 7 days. These results replicate and extend past research on distinctiveness effects and also provide support for Rajaram's (1996) distinctiveness‐fluency account of the 2 states of subjective awareness.     

The dimensionality of the remember-know task: a state-trace analysis

This article addresses the issue of whether the remember-know (RK) task is best explained by a single-process or a dual-process model. All single-process models propose that remember and know responses reflect different levels of a single strength-of-evidence dimension. Thus, across conditions in which response criteria are held constant, these models predict that the RK task is unidimensional. Many dual-process models propose that remember and know responses reflect two qualitatively distinct processes underlying recognition memory, often characterized as recollection and familiarity. These models predict that the RK task is bidimensional. Using data from 37 studies, the author conducted a state-trace analysis to determine the dimensionality of the RK task. In those studies, non-memory-related differences between conditions were eliminated via decision criteria constrained to be constant across all levels of the independent variables. The results reveal little or no evidence of bidimensionality and lend additional support to the unequal-variance signal detection model. Other arguments supporting a bidimensional interpretation are examined, and the author concludes there is insufficient evidence for the RK task to be used to identify qualitatively different memory components.     

Context effects on remembering and knowing: the expectancy heuristic

Three experiments are reported examining the effect of context on remember-know judgments. In Experiments 1 and 2, medium-frequency words were intermixed with high-frequency or low-frequency words at study or at test, respectively. Remember responses were greater for medium-frequency targets when they were studied or tested among high-frequency, as compared with low-frequency, words. The authors proposed a decision-based mechanism called "the expectancy heuristic" to explain why remember responses were more likely when items were studied or tested in the context of words that were relatively less distinct. According to the expectancy heuristic, when items on a recognition test exceed an expected level of memorability they will be given a remember judgment but when they do not, but are still more familiar than new words, they will be given a know judgment. Experiment 3, which varied expectancies about the strength of tested targets, demonstrated the use of the expectancy heuristic, indicating that it operates by selectively influencing the remember criterion rather than by influencing recollection of studied items.     

The influence of decision criteria upon remembering and knowing in recognition memory.

One may recognise an item as 'old' on basis of a recollective experience or by a feeling of familiarity without specific recollection. The former is called a 'remember' judgement; the latter a 'know' judgement. It has been claimed that remember and know responses reflect qualitatively distinct components of recognition memory, and not just derive from gradual differences in perceived trace strength or subjective certainty (i.e. remember judgments include memories of which one is more confident). Nonetheless, the present study examined the possibility that the distinction does relate to decision criteria placed upon a single familiarity axis (see Donaldson, 1996; Hirshman & Master, 1997). To this purpose, two groups of subjects were compared: one, which was instructed to be very conservative in their old-new judgements, while the other group was stimulated to be very lenient instead. Remember hit rates increased with more lenient criteria, whereas know hit rates did not, but false alarm rates did. While remember sensitivity was equal in the two groups, know sensitivity was lower with liberal criteria. Also it correlated with overall response bias. This lends support to the possibility that subjects not only apply an old-new decision criterion, but also set a remember-know criterion, which is affected in a similar way by liberal versus conservative instructions.     

Positive and negative remember judgments and ROCs in the plurals paradigm: Evidence for alternative decision strategies

Using old-new ratings and remember-know judgments we explored the plurals paradigm, in which studied words must be distinguished from plurality-changed lures. The paradigm allowed us to investigate negative remembering—that is, the remembering of a plural-altered study item; capacity for this judgment was found to be poorer than or equivalent to the conventional positive remembering. A response-bias manipulation affected positive but not negative remembering. The ratings were used to construct ROC curves and test the prediction of the most common dual-process theory of recognition memory (Yonelinas, 2001) that the amount of recollection can be independently estimated from ROC curves and from remember judgments. By fitting the individual data with pure signal detection theory (SDT) models and dual-process models that combined SDT and high-threshold components (HTSDT), we identified two types of subjects. For those who were better described by HTSDT, the predicted convergence of remember-know and ROC measures was observed. For those who were better described by SDT, the ROC intercept could not predict the remember rate. The data are consistent with the idea that all subjects rely on the same representation but base their decisions on different partitions of a decision space.     

Recollection can be weak and familiarity can be strong

The remember-know procedure is widely used to investigate recollection and familiarity in recognition memory, but almost all of the results obtained with that procedure can be readily accommodated by a unidimensional model based on signal-detection theory. The unidimensional model holds that remember judgments reflect strong memories (associated with high confidence, high accuracy, and fast reaction times), whereas know judgments reflect weaker memories (associated with lower confidence, lower accuracy, and slower reaction times). Although this is invariably true on average, a new 2-dimensional account (the continuous dual-process model) suggests that remember judgments made with low confidence should be associated with lower old-new accuracy but higher source accuracy than know judgments made with high confidence. We tested this prediction--and found evidence to support it--using a modified remember-know procedure in which participants were first asked to indicate a degree of recollection-based or familiarity-based confidence for each word presented on a recognition test and were then asked to recollect the color (red or blue) and screen location (top or bottom) associated with the word at study. For familiarity-based decisions, old-new accuracy increased with old-new confidence, but source accuracy did not (suggesting that stronger old-new memory was supported by higher degrees of familiarity). For recollection-based decisions, both old-new accuracy and source accuracy increased with old-new confidence (suggesting that stronger old-new memory was supported by higher degrees of recollection). These findings suggest that recollection and familiarity are continuous processes and that participants can indicate which process mainly contributed to their recognition decisions.     

Sum-difference theory of remembering and knowing: a two-dimensional signal-detection model

In the remember-know paradigm for studying recognition memory, participants distinguish items whose presentations are episodically remembered from those that are merely familiar. A one-dimensional model postulates that remember responses are just high-confidence old judgments, but a meta-analysis of 373 experiments shows that the receiver operating characteristic (ROC) curves predicted by this model have the wrong slope. According to the new sum-difference Theory of remembering and knowing (STREAK), old items differ from new ones in both global and specific memory strength: The old-new judgment is based on a weighted sum of these dimensions, and the remember- know judgment is based on a weighted difference. STREAK accounts for the form of several novel kinds of ROC curves and for existing remember-know and item-recognition data.     

Retention interval modulates the effect of negative arousing pictures on recognition memory

This study examined the modulation of retention interval in the effect of emotion as elicited from negative and positive arousing pictures on recognition memory. Participants underwent seven encoding sessions and one testing session. The encoding sessions were separated by certain lengths of intervals such that there were seven levels of time gaps between encoding and testing. In each encoding session, participants learned a list of 30 pictures (including 10 neutral, 10 positive and 10 negative pictures). In the testing session, they were presented with a list of 210 old and 210 new pictures and made “old/new” and “remember/know” judgements. The results showed that negative arousing pictures enhanced overall recognition in the 2-week interval and enhanced recollection in both the 2-week and 3-week intervals. However, neither negative nor positive arousing pictures had any effect on familiarity regardless of retention interval. The current study contributes to the literature by suggesting that longer retention intervals do not necessarily lead to more pronounced effects of negative arousing pictures and that the modulation of retention interval depends on the specific components of recognition memory.     

Remember-know: a matter of confidence

This article critically examines the view that the signal detection theory (SDT) interpretation of the remember-know (RK) paradigm has been ruled out by the evidence. The author evaluates 5 empirical arguments against a database of 72 studies reporting RK data under 400 different conditions. These arguments concern (a). the functional independence of remember and know rates, (b). the invariance of estimates of sensitivity, (c). the relationship between remember rates and overall hit and false alarm rates, (d). the relationship between RK responses and confidence judgments, and (e). dissociations between remember and overall hit rates. Each of these arguments is shown to be flawed, and despite being open to refutation, the SDT interpretation is consistent with existing data from both the RK and remember-know-guess paradigms and offers a basis for further theoretical development.