Remembering versus knowing during face recognition in unilateral temporal lobe epilepsy patients with or without hippocampal sclerosis

Recognition memory involves knowing an item was learned (familiarity) and remembering contextual details about the prior learning episode (recollection). We tested three competing hypotheses about the role of the hippocampus in recollection and familiarity. It mediates either recollection or familiarity, or serves both processes. We further tested whether the left temporal lobe mediates recollection and the right temporal lobe familiarity (modes of processing view), or whether the two temporal lobes mediate remembering material specifically (material specificity view). We investigated 24-h face recognition using the "remember-know" procedure. We studied 23 left and 24 right temporal lobe epilepsy (LTLE/RTLE) patients with and without hippocampal sclerosis (HS+/HS-) and 31 healthy participants. HS+ patients made fewer know responses than HS- patients or healthy participants. RTLE was related to fewer remember responses than LTLE. Our results suggest the hippocampus has a critical role in familiarity. Further, our findings support the material specificity hypothesis of laterality.     

Effect of retention interval on the simultaneous cognate-noncognate and remember-know mirror effects

Recognition memory for Spanish-Catalan cognate and noncognate words was tested at retention intervals of 30 minutes, 3 days, and 7 days using a remember/know response procedure. We observed a clear mirror effect for the cognate-noncognate stimulus class and a remember-know response categorisation at the immediate retention interval. However, the cognate and noncognate mirror was still observed at 3 and 7 days, whereas the remember-know mirror disappeared at both retention intervals. Also, we ran a repeated testing condition to be able to carry out a sequential item analysis and observe the fate of the original remember and know responses 3 or 7 days later. The analysis supported the idea that there was a loss of contextual information that was at the root of the disappearance of the remember-know mirror effect. These results provide support to the idea that it is the imbalance between recollection and familiarity that is the most likely cause of the mirror effect.     

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.     

The<Emphasis Type="Italic">remember</Emphasis> response: Subject to bias,graded, and not a process-pure indicator of recollection

Recognition memory judgments have long been assumed to depend on the contributions of two underlying processes: recollection and familiarity. We measured recollection with receiver-operating characteristic (ROC) data and remember-know judgments. Under standard remember-know instructions, the two estimates of recollection diverged. When subjects were told they might need to justify theirremember responses to the experimenter, the two estimates were more likely to agree. The data support the conclusion thatremember responses are generally based on a continuous underlying process but that specific task instructions can produce data that appear consistent with a high-threshold recollective process. Models based on signal detection theory provide a better account of these data than does the dual-process model (Yonelinas, 1994) or process-pure interpretations.     

Effects of pair collaboration and word-frequency in recognition memory: a study with the remember-know procedure

The present study investigated the effects of pair collaboration and word-frequency on recognition memory, using the "remember-know" procedure. The aim was to test the predictions of the information-exchange hypothesis (Clark, Hori, Putnam & Martin, 2000), which states that collaborative facilitation occurs when participants are able to share their recollective memories with other members of the group. Results showed that recognition performance was significantly better in the collaborative than in the individual condition, and better for low-frequency than for high-frequency words. The advantage of collaborating dyads was produced by an increase of correct hits, coupled with a significant reduction of false alarms. Furthermore, the analysis of the "remember" (R) and "know" (K) responses indicated that the effects of both pair collaboration and word-frequency were larger on recollection than on familiarity processes. It is concluded that, in a collaborative condition, arguments based on the retrieval of the contextual details associated with the target words are more effective than those based on familiarity in increasing the proportions of correct hits. In addition, it is proposed that collaboration may lead to a reduction of the probability to accept new items on the basis of familiarity (K) responses.     

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.     

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.     

Cognitive mechanisms of false facial recognition in older adults

Older adults show elevated false alarm rates on recognition memory tests involving faces in comparison to younger adults. It has been proposed that this age-related increase in false facial recognition reflects a deficit in recollection and a corresponding increase in the use of familiarity when making memory decisions. To test this hypothesis, we examined the performance of 40 older adults and 40 younger adults on a face recognition memory paradigm involving three different types of lures with varying levels of familiarity. A robust age effect was found, with older adults demonstrating a markedly heightened false alarm rate in comparison to younger adults for "familiarized lures" that were exact repetitions of faces encountered earlier in the experiment, but outside the study list, and therefore required accurate recollection of contextual information to reject. By contrast, there were no age differences in false alarms to "conjunction lures" that recombined parts of study list faces, or to entirely new faces. Overall, the pattern of false recognition errors observed in older adults was consistent with excessive reliance on a familiarity-based response strategy. Specifically, in the absence of recollection older adults appeared to base their memory decisions on item familiarity, as evidenced by a linear increase in false alarm rates with increasing familiarity of the lures. These findings support the notion that automatic memory processes such as familiarity remain invariant with age, while more controlled memory processes such as recollection show age-related decline.     

Color and context: An ERP study on intrinsic and extrinsic feature binding in episodic memory

Episodic memory for intrinsic item and extrinsic context information is postulated to rely on two distinct types of representation: object and episodic tokens. These provide the basis for familiarity and recollection, respectively. Electrophysiological indices of these processes (ERP old-new effects) were used together with behavioral data to test these assumptions. We manipulated an intrinsic object feature (color; Experiment 1) and a contextual feature (background; Experiments 1 and 2). In an inclusion task (Experiment 1), the study-test manipulation of color affected object recognition performance and modulated ERP old-new effects associated with both familiarity and recollection. In contrast, a contextual manipulation had no effect, although both intrinsic and extrinsic information was available in a direct feature (source memory) test. When made task relevant (exclusion task; Experiment 2), however, context affected the ERP recollection effect, while still leaving the ERP familiarity effect uninfluenced. We conclude that intrinsic features bound in object tokens are involuntarily processed during object recognition, thus influencing familiarity, whereas context features bound in episodic tokens are voluntarily accessed, exclusively influencing recollection. Figures depicting all the electrodes analyzed are available in an online supplement at www.psychonomic.org/archive.     

Consciousness, control, and confidence: the 3 Cs of recognition memory

The contributions of recollection and familiarity to recognition memory performance were examined using the process dissociation, remember-know, and receiver operating characteristic (ROC) procedures. Under standard test conditions the 3 measurement procedures led to process estimates that were almost identical and to similar conclusions regarding the effects of different encoding manipulations. Dividing attention led to a large decrease in recollection and a smaller, sometimes nonsignificant, decrease in familiarity. Semantic compared with perceptual processing led to a large increase in recollection and a moderate increase in familiarity. Moreover, the results showed that familiarity was well described by classical signal-detection theory but that recollection reflected a threshold process. The convergence observed across the 3 measurement procedures shows that the 3 procedures tap similar underlying processes and that recollection and familiarity differ in terms of conscious awareness, intentional control, and the manner in which they contribute to the shape of response confidence ROCs.     

Decision-making models of remember-know judgments: comment on Rotello, Macmillan, and Reeder (2004)

The sum-difference theory of remembering and knowing (STREAK) provides a sophisticated account of many interactions in the remember-know (R-K) area (C. M. Rotello, N. A. Macmillan, & J. A. Reeder, 2004). It assumes 2 orthogonal strength dimensions and oblique criterion planes. Another dual-process model (J. T. Wixted & V. Stretch, 2004) with one decision axis has also been applied to R-K judgments with considerable success and provides new insights into the processes involved. An analysis of the 4 major R-K interactions can also be explained by a simpler one-dimensional signal detection theory (J. C. Dunn, 2004a). However these models do not make contact with standard work on recognition memory, so their scope is limited. To bridge this gap, a global-matching model (a theory of distributed associative memory [TODAM]) for R-K judgments is proposed. This model can produce good fits to the data, and there are established experimental manipulations with which to test it. It provides further support for the idea that R judgments are based on associative information, whereas K judgments are based on item information.     

Imaging recollection and familiarity in the medial temporal lobe: a three-component model

The medial temporal lobe (MTL) plays a crucial role in supporting memory for events, but the functional organization of regions in the MTL remains controversial, especially regarding the extent to which different subregions support recognition based on familiarity or recollection. Here we review results from functional neuroimaging studies showing that, whereas activity in the hippocampus and posterior parahippocampal gyrus is disproportionately associated with recollection, activity in the anterior parahippocampal gyrus is disproportionately associated with familiarity. The results are consistent with the idea that the parahippocampal cortex (located in the posterior parahippocampal gyrus) supports recollection by encoding and retrieving contextual information, whereas the hippocampus supports recollection by associating item and context information. By contrast, perirhinal cortex (located in the anterior parahippocampal gyrus) supports familiarity by encoding and retrieving specific item information. We discuss the implications of a 'binding of item and context' (BIC) model for studies of recognition memory. This model argues that there is no simple mapping between MTL regions and recollection and familiarity, but rather that the involvement of MTL regions in these processes depends on the specific demands of the task and the type of information involved. We highlight several predictions for future imaging studies that follow from the BIC model.     

The effects of repeating a recognition test in lorazepam-induced amnesia: Evidence for impaired contextual memory as a cause of amnesia

In two experiments, a recognition test for an earlier presented list was given twice in immediate succession (Test 1 and Test 2). On the hypothesis that anterograde amnesia for episodic memory involves a deficit in contextual memory, amnesic subjects should confuse familiarity with distractor items gained during Test 1 with familiarity gained during original list presentation. As a result, they should think that they recognize more items on Test 2. This will lower recognition efficiency in Test 2 by increasing false alarms rather than by reducing hits. For subjects with an amnesia induced by lorazepam, but not for control subjects, recognition efficiency was substantially reduced in Test 2 in both experiments. As predicted, this impairment was due to a large increase in false alarms, with no decrease in the number of hits. The impairment could not be explained by a difference in recognition level between lorazepam and control subjects on Test 1. These findings therefore support the contextual memory deficit hypothesis of anterograde amnesia. Their implications for understanding the relationship between recall and recognition in amnesia are discussed.     

Recall,recognition, and the hippocampus: Reply to Yonelinas et al. (2004)

Two recent studies disagree about whether recall is more impaired than recognition (and recollection more than familiarity) in patients with damage limited to the hippocampus (Manns, Hopkins, Reed, Kitchener, & Squire, 2003; Yonelinas et al., 2002). Wixted and Squire (2004) pointed out that the disagreement about recall and recognition stems entirely from an outlying recognition score obtained by 1 of 55 control subjects in Yonelinas et al. (2002). In their comment on our paper, Yonelinas et al. (2004) minimize the importance of this result and argue that the role of the hippocampus in recollection and familiarity is best studied using different methods that attempt to measure these processes directly. Here, we argue that the recall versus recognition comparison is the strongest test because it relies on the fewest controversial assumptions, and that the other approaches explored by Yonelinas et al. (2002) rely on questionable, theory-laden assumptions. We also rehearse the reasons for concluding that the patients studied by Manns et al. (2003) have damage limited to the hippocampal region (hippocampus proper, dentate gyrus, and subiculum), and we emphasize that important questions remain about the patients studied by Yonelinas et al. (2002), inasmuch as no neuroanatomical information and minimal neuropsychological information has been provided.     

Contributions of familiarity and recollection rejection to recognition: evidence from the time course of false recognition for semantic and conjunction lures

It has been suggested that both familiarity and recollection contribute to the recognition decision process. In this paper we leverage the form of false alarm rate functions--in which false alarm rates describe an inverted U-shaped function as the time between study and test increases--to assess how these processes support retention of semantic and surface form information from previously studied words. We directly compare the maxima of these functions for lures that are semantically related and lures that are related by surface form to previously studied material. This analysis reveals a more rapid loss of access to surface form than to semantic information. To separate the contributions of item familiarity and reminding-induced recollection rejection to this effect, we use a simple multinomial process model; this analysis reveals that this loss of access reflects both a more rapid loss of familiarity and lower rates of recollection for surface form information.     

Dual processes in recognition: Does a focus on measurement operations provide a sufficient foundation?

Current theoretical thinking about dual processes in recognition relies heavily on the measurement operations embodied within the process dissociation procedure. We critically evaluate the ability of this procedure to support this theoretical enterprise. We show that there are alternative processes that would produce a rough invariance in familiarity (a key prediction of the dual-processing approach) and that the process dissociation procedure does not have the power to differentiate between these alternative possibilities. We also show that attempts to relate parameters estimated by the process dissociation procedure to subjective reports (remember-know judgments) cannot differentiate between alternative dual-processing models and that there are problems with some of the historical evidence and with obtaining converging evidence. Our conclusion is that more specific theories incorporating ideas about representation and process are required.     

The effects of unitization on familiarity-based source memory: testing a behavioral prediction derived from neuroimaging data

Performance on tests of source memory is typically based on recollection of contextual information associated with an item. However, recent neuroimaging results have suggested that the perirhinal cortex, a region thought to support familiarity-based item recognition, may support source attributions if source information is encoded as a feature of the relevant item (i.e., "unitized"). The authors hypothesized that familiarity may contribute to source memory performance if item and source information are unitized during encoding, whereas performance may rely more heavily on recollection if source information is encoded as an arbitrary contextual association. Three source recognition experiments examining receiver operating characteristics and response deadline performance indicated that familiarity makes a greater contribution to source memory if source and item information are unitized during encoding. These findings suggest that familiarity can contribute to source recognition and that its contribution depends critically on the way item and source information are initially processed.     

ROC parameters in item and context recognition

Conflicting theories argue that recognition is achieved either by familiarity exclusively, or by a mixture of familiarity and recollection. We explore in three experiments the goodness of fit of both positions to experimental data in which context information is manipulated. In Experiments 1 and 2, we explore the availability of context information in recognition, testing the focus stimulus, its context, and their associative relation. In Experiment 3, participants were confronted with a plurality task in an attempt to force them to use the peripheral information in recognition. The results show that people acquire specific associative information, and although overall recognition performance was not affected by the use of context, receiver operating characteristic (ROC) analysis showed that people use a duality of processes in recognition.     

“Remembering” emotional words is based on response bias,not recollection

Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are “remembered” (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects’ data: two versions of a one-dimensional signaldetection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of “remembering.” However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.     

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.