Aging selectively impairs recollection in recognition memory for pictures: Evidence from modeling and receiver operating characteristic curves.

Young and older adults were tested on recognition memory for pictures. The Yonelinas high threshold (YHT) model, a formal implementation of 2-process theory, fit the response distribution data of both young and older adults significantly better than a normal unequal variance signal-detection model. Consistent with this finding, nonlinear z-transformed receiver operating characteristic curves were obtained for both groups. Estimates of recollection from the YHT model were significantly higher for young than for older adults. This deficit was not a consequence of a general decline in memory; older adults showed comparable overall accuracy and in fact a nonsignificant increase in their familiarity scores. Implications of these results for theories of recognition memory and the mnemonic deficit associated with aging are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing signal-detection models of yes/no and two-alternative forced-choice recognition memory.

The current study compared 3 models of recognition memory in their ability to generalize across yes/no and 2-alternative forced-choice (2AFC) testing. The unequal-variance signal-detection model assumes a continuous memory strength process. The dual-process signal-detection model adds a thresholdlike recollection process to a continuous familiarity process. The mixture signal-detection model assumes a continuous memory strength process, but the old item distribution consists of a mixture of 2 distributions with different means. Prior efforts comparing the ability of the models to characterize data from both test formats did not consider the role of parameter reliability, which can be critical when comparing models that differ in flexibility. Parametric bootstrap simulations revealed that parameter regressions based on separate fits of each test type only served to identify the least flexible model. However, simultaneous fits of receiver-operating characteristic data from both test types with goodness-of-fit adjusted with Akaike’s information criterion (AIC) successfully recovered the true model that generated the data. With AIC and simultaneous fits to real data, the unequal-variance signal-detection model was found to provide the best account across yes/no and 2AFC testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory variability is due to the contribution of recollection and familiarity, not to encoding variability.

It is well established that the memory strength of studied items is more variable than the strength of new items on tests of recognition memory, but the reason why this occurs is poorly understood. One account for this old item variance effect is based on single-process theory, which proposes that this effect is due to variability in how well items are initially encoded into memory (i.e., the encoding variability account). In contrast, dual-process theory argues that old items are more variable because they are influenced by both recollection and familiarity, whereas recognition of new items relies primarily on familiarity. The present study shows that increasing encoding variability did not increase old item variance and that old item variance is directly related to the contribution of recollection. These results indicate that old item memory variability is due to the relative contribution of recollection and familiarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conjunction error rates on a continuous recognition memory test: Little evidence for recollection.

Two experiments examined conjunction memory errors on a continuous recognition task where the lag between parent words (e.g., blackmail, jailbird) and later conjunction lures (blackbird) was manipulated. In Experiment 1, contrary to expectations, the conjunction error rate was highest at the shortest lag (1 word) and decreased as the lag increased. In Experiment 2 the conjunction error rate increased significantly from a 0- to a 1-word lag, then decreased slightly from a 1- to a 5-word lag. The results provide mixed support for simple familiarity and dual-process accounts of recognition. Paradoxically, searching for an item in memory does not appear to be a good encoding task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Variations in recollection: The effects of complexity on source recognition.

Whether recollection is a threshold or signal detection process is highly controversial, and the controversy has centered in part on the shape of receiver operating characteristics (ROCs) and z-transformed ROCs (zROCs). U-shaped zROCs observed in tests thought to rely heavily on recollection, such as source memory tests, have provided evidence in favor of the threshold assumption, but zROCs are not always as U-shaped as threshold theory predicts. Source zROCs have been shown to become more linear when the contribution of familiarity to source discriminations is increased, and this may account for the existing results. However, another way in which source zROCs may become more linear is if the recollection threshold begins to break down and recollection becomes more graded and Gaussian. We tested the “graded recollection” account in the current study. We found that increasing stimulus complexity (i.e., changing from single words to sentences) or increasing source complexity (i.e., changing the sources from audio to videos of speakers) resulted in flatter source zROCs. In addition, conditions expected to reduce recollection (i.e., divided attention and amnesia) had comparable effects on source memory in simple and complex conditions, suggesting that differences between simple and complex conditions were due to differences in the nature of recollection, rather than differences in the utility of familiarity. The results suggest that under conditions of high complexity, recollection can appear more graded, and it can produce curved ROCs. The results have implications for measurement models and for current theories of recognition memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging, source memory, and misrecollections.

The authors propose an illusory recollection account of why cognitive aging is associated with episodic memory deficits. After listening to statements presented by either a female or a male speaker, older adults were prone to misrecollecting past events. The authors' illusory recollection account is instantiated in a new illusory recollection signal detection model that provides a better fit of older adults' data than does the standard signal detection model. They observed that age-related differences in source memory (as measured by source d′ scores) virtually disappear after accounting for the occurrence of illusory recollections. These data suggest that age-related source memory impairments are not due to older adults' remembering less diagnostic source information and having to guess more. Instead, older adults appear to misremember past events more often than younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing a neurocomputational model of recollection, familiarity, and source recognition.

The authors assess whether the complementary learning systems model of the medial temporal lobes (Norman & O'Reilly, 2003) is able to account for source recognition receiver operating characteristics (ROCs). The model assumes that recognition reflects the contribution of a hippocampally mediated recollection process and a cortically mediated familiarity process. The hippocampal process is found to produce threshold output functions that lead to U-shaped zROCs, whereas the cortical process produces Gaussian signal detection functions and linear zROCs. The model is consistent with several dual process theories of recognition and is capable of producing the types of zROCs observed in studies of item and source recognition. In addition, the model makes the novel prediction that as the level of feature similarity across items increases, the ability of the hippocampus to encode distinct representations for each stimulus will diminish, and the threshold nature of recollection will break down, leading source zROCs to become more linear. The authors conducted 3 new behavioral source experiments that confirmed the model's prediction. The results demonstrate that the model provides a viable account of item and source recognition performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dual-Process Models of Associative Recognition in Young and Older Adults: Evidence From Receiver Operating Characteristics.

In 3 experiments, young and older adults studied lists of unrelated word pairs and were given confidence-rated item and associative recognition tests. Several different models of recognition were fit to the confidence-rating data using techniques described by S. Macho (2002, 2004). Concordant with previous findings, item recognition data were best fit by an unequal-variance signal detection theory model for both young and older adults. For both age groups, associative recognition performance was best explained by models incorporating both recollection and familiarity components. Examination of parameter estimates supported the conclusion that recollection is reduced in old age, but inferences about age differences in familiarity were highly model dependent. Implications for dual-process models of memory in old age are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Differentiation and response bias in episodic memory: Evidence from reaction time distributions.

In differentiation models, the processes of encoding and retrieval produce an increase in the distribution of memory strength for targets and a decrease in the distribution of memory strength for foils as the amount of encoding increases. This produces an increase in the hit rate and decrease in the false-alarm rate for a strongly encoded compared with a weakly encoded list, consistent with empirical data. Other models assume that the foil distribution is unaffected by encoding manipulations or the foil distribution increases as a function of target strength. They account for the empirical data by adopting a stricter criterion for strongly encoded lists relative to weakly encoded lists. The differentiation and criterion shift explanations have been difficult to discriminate with accuracy measures alone. In this article, reaction time distributions and accuracy measures are collected in a list-strength paradigm and in a response bias paradigm in which the proportion of test items that are targets is manipulated. Diffusion model analyses showed that encoding strength is primarily accounted for by changes in the rate of accumulation of evidence (i.e., drift rate) for both targets and foils and manipulating the proportion of targets is primarily accounted for by changes in response bias (i.e., starting point). The diffusion model analyses is interpreted in terms of predictions of the differentiation models in which subjective memory strength is mapped directly onto drift rate and criterion placement is mapped onto starting point. Criterion shift models require at least 2 types of shifts to account for these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examining the relationships among item recognition, source recognition, and recall from an individual differences perspective.

The authors of the current study examined the relationships among item-recognition, source-recognition, free recall, and other memory and cognitive ability tasks via an individual differences analysis. Two independent sources of variance contributed to item-recognition and source-recognition performance, and these two constructs related differentially to other memory and cognitive ability constructs. The results are in accordance with a dual-process theory of memory retrieval in which a familiarity process can support judgments of previous occurrence and a more strategic recollection process is needed for controlled search of long-term memory. Furthermore, the authors offer additional evidence in favor of a dual-process model by showing validity for these two unique sources of variance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in temporal and item memory.

Three experiments tested whether the relationship between age differences in temporal and item memory depends on the degree to which the item memory measure relies on memory for context. The authors predicted a stronger relationship of temporal memory to free recall than to recognition memory. Results showed that age differences in temporal memory could be eliminated after controlling for free recall but not recognition memory performance. Under some conditions recognition memory accounted for a significant portion of age-related variance in temporal memory. These results challenge past research that has interpreted age differences in temporal and item memory as independent and suggest that a generalized decline in context memory may underlie reduced performance in older adults on all types of memory tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Test sequence priming in recognition memory.

The authors examined priming within the test sequence in 3 recognition memory experiments. A probe primed its successor whenever both probes shared a feature with the same studied item (interjacent priming), indicating that the study item like the probe is central to the decision. Interjacent priming occurred even when the 2 probes did not themselves share any features: A lure that shared a single feature with a study item primed a lure that shared a different feature with the same study item. The experiments distinguished interjacent priming from other types of facilitation. Interjacent priming indicates that a study item that is like the probe is more relevant to the decision than other study items, contrary to global memory models. It also shows that negative decisions depend on contradiction, not insufficient familiarity, because lures, as well as targets, benefited. The data are discussed in terms of a recall check within a dual-process theory, but the authors prefer a single-process resonance model with separate decision mechanisms for yes and no responses (D. J. K. Mewhort & E. E. Johns, 2005). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging on the neural correlates of successful item and source memory encoding.

To investigate the neural basis of age-related source memory (SM) deficits, young and older adults were scanned with fMRI while encoding faces, scenes, and face-scene pairs. Successful encoding activity was identified by comparing encoding activity for subsequently remembered versus forgotten items or pairs. Age deficits in successful encoding activity in hippocampal and prefrontal regions were more pronounced for SM (pairs) as compared with item memory (faces and scenes). Age-related reductions were also found in regions specialized in processing faces (fusiform face area) and scenes (parahippocampal place area), but these reductions were similar for item and SM. Functional connectivity between the hippocampus and the rest of the brain was also affected by aging; whereas connections with posterior cortices were weaker in older adults, connections with anterior cortices, including prefrontal regions, were stronger in older adults. Taken together, the results provide a link between SM deficits in older adults and reduced recruitment of hippocampal and prefrontal regions during encoding. The functional connectivity findings are consistent with a posterior-anterior shift with aging previously reported in several cognitive domains and linked to functional compensation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strong memories are hard to scale.

People are generally skilled at using a confidence scale to rate the strength of their memories over a wide range. Specifically, low-confidence recognition decisions are often associated with close-to-chance accuracy, whereas high-confidence recognition decisions can be associated with close-to-perfect accuracy. However, using a 20-point rating scale, the authors found that the ability to scale memory strength had its limitations in that a high proportion of list items received the highest rating of 20. Efforts to induce participants to differentiate between these strong memories using emphatic instructions and alternative scales were not successful. Remember/know judgments indicated that these strong and hard-to-scale memories were often based on familiarity (not just recollection). Providing error feedback on a plurals discrimination task finally produced a high-confidence criterion shift. The authors suggest that the ability to scale strong (and almost perfectly accurate) memories may be limited because of the absence of differential error feedback for very strong memories in the past (the kind of differential error feedback that may account for the memory-scaling expertise that participants otherwise exhibit). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Regularities of source recognition: ROC analysis.

Source memory has become the focus of a growing number of investigations in a variety of fields. An appropriate model for source memory is, therefore, of increasing importance. A simple 2-dimensional signal-detection model of source recognition is presented. The receiver operating characteristics (ROCs) obtained from 3 experiments are then used to test the model. The data demonstrate 3 regularities: convex ROCs, z-ROCs with linear slopes of 1.00, and slightly concave z-ROCs. Two of these regularities support the model. The 3rd requires a revision of the model. This revised model is fitted to the data. The implications of these regularities for other theories are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, source memory, and emotion.

In 2 experiments we assessed younger and older adults' ability to remember contextual information about an event. Each experiment examined memory for 3 different types of contextual information: (a) perceptual information (e.g., location of an item); (b) conceptual, nonemotional information (e.g., quality of an item); and (c) conceptual, emotional information (e.g., safety of an item). Consistent with a large literature on aging and source memory, younger adults outperformed older adults when the contextual information was perceptual in nature and when it was conceptual, but not emotional. Age differences in source memory were eliminated, however, when participants recalled emotional source information. These findings suggest that emotional information differentially engages older adults, possibly evoking enhanced elaborations and associations. The data are also consistent with a growing literature, suggesting that emotional processing remains stable with age (e.g., Carstensen & Turk-Charles, 1994, 1998; Isaacowitz, Charles, & Carstensen, 2000). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and IQ on item and associative memory.

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60–74 years old, and 75–90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The role of recollection and partial information in source monitoring.

Two experiments were conducted to assess the degree to which source monitoring required recollective details or could be based on vaguer partial information. Source judgments were followed by remember-know judgments during testing. On the authors' assumption that remember judgments are highly correlated with the presence of recollective details, the results showed that accurate source monitoring did not necessarily require such recollective details. Rather, the high proportion of correct source judgments that were associated with know responses suggests that source-monitoring processes can successfully use the partial information that is recorded in vaguer memories. Consequently, source monitoring can be based on recollection but can also effectively use qualitative characteristics that lack clarity and sufficient amounts of details to give rise to the subjective feeling of remembering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)