How fuzzy-trace theory predicts true and false memories for words,sentences, and narratives

Fuzzy-trace theory posits independent verbatim and gist memory processes, a distinction that has implications for such applied topics as eyewitness testimony. This distinction between precise, literal verbatim memory and meaning-based, intuitive gist accounts for memory paradoxes including dissociations between true and false memory, false memories outlasting true memories, and developmental increases in false memory. We provide an overview of fuzzy-trace theory, and, using mathematical modeling, also present results demonstrating verbatim and gist memory in true and false recognition of narrative sentences and inferences. Results supported fuzzy-trace theory's dual-process view of memory: verbatim memory was relied on to reject meaning-consistent, but unpresented, sentences (via recollection rejection). However, verbatim memory was often not retrieved, and gist memory supported acceptance of these sentences (via similarity judgment and phantom recollection). Thus, mathematical models of words can be extended to explain memory for complex stimuli, such as narratives, the kind of memory interrogated in law.     

Dual processes in decision making and developmental neuroscience: A fuzzy-trace model

From Piaget to the present, traditional and dual-process theories have predicted improvement in reasoning from childhood to adulthood, and improvement has been observed. However, developmental reversals—that reasoning biases emerge with development—have also been observed in a growing list of paradigms. We explain how fuzzy-trace theory predicts both improvement and developmental reversals in reasoning and decision making. Drawing on research on logical and quantitative reasoning, as well as on risky decision making in the laboratory and in life, we illustrate how the same small set of theoretical principles apply to typical neurodevelopment, encompassing childhood, adolescence, and adulthood, and to neurological conditions such as autism and Alzheimer’s disease. For example, framing effects—that risk preferences shift when the same decisions are phrased in terms of gains vs. losses—emerge in early adolescence as gist-based intuition develops. In autistic individuals, who rely less on gist-based intuition and more on verbatim-based analysis, framing biases are attenuated (i.e., they outperform typically developing control subjects). In adults, simple manipulations based on fuzzy-trace theory can make framing effects appear and disappear depending on whether gist-based intuition or verbatim-based analysis is induced. These theoretical principles are summarized and integrated in a new mathematical model that specifies how dual modes of reasoning combine to produce predictable variability in performance. In particular, we show how the most popular and extensively studied model of decision making—prospect theory—can be derived from fuzzy-trace theory by combining analytical (verbatim-based) and intuitive (gist-based) processes.     

Fuzzy-trace theory and memory development

We review recent applications of fuzzy-trace theory to memory development, organizing the presentation around two themes: the theory’s explanatory principles and experimental findings about memory development that follow as predictions from those principles. The featured explanatory principles are: parallel storage of verbatim and gist traces, dissociated retrieval of verbatim and gist traces, differential survival rates for verbatim and gist traces, retrieval phenomenology, and developmental trends in verbatim and gist memory. The experimental findings come from four different areas of research: the development of retrieval phenomenologies, “reversed” developmental trends in false memory, the development of mere testing effects, and the development of false persistence in memory.     

The role of phantom recollection in false recall

Although high levels of phantom recollection (illusory vivid experience of the prior "presentation" of unpresented items) have been found for false recognition, little is known about phantom recollection in recall. We examined this issue with Deese/Roediger-McDermott lists using two paradigms: repeated recall and conjoint recall. High levels of phantom recollection were observed with both standard behavioral measures and the parameters of fuzzy-trace theory's dual-recall model. In addition, phantom recollection and the true recollection that accompanies presented items appear to involve different retrieval processes, because they were dissociated by manipulations such as number of recall tests and list strength.     

Conjoint recognition and phantom recollection

A new methodology for measuring illusory conscious experience of the "presentation" of unstudied material (phantom recollection) is evaluated that extracts measurements directly from recognition responses, rather than indirectly from introspective reports. Application of this methodology in the Deese-Roediger-McDermott (DRM) paradigm (Experiments 1 and 2) and in a more conventional paradigm (Experiment 3) showed that 2 processes (phantom recollection and familiarity) contribute to false recognition of semantically related distractors. Phantom recollection was the larger contributor to false recognition of critical distractors in the DRM paradigm, but surprisingly, it was also the larger contributor to false recognition of other types of distractors. Variability in false recognition was tied to variability in phantom recollection. Experimental control of phantom recollection was achieved with manipulations that were motivated by fuzzy-trace theory's hypothesis that the phenomenon is gist-based.     

Conjoint recognition

The process-dissociation model has stimulated important advances in the study of dual-process conceptions of memory. The authors review some limiting properties of that model and consider the degree of support for its parent theory (the recollection-familiarity distinction). A 2nd-generation model (conjoint recognition) is proposed that addresses these limitations and supplies additional capabilities, such as goodness-of-fit tests, the ability to measure dual processes for false-memory responses, and statistical procedures for testing within- and between-conditions hypotheses about its parameters. The conjoint-recognition model also implements an alternative theoretical interpretation (the identity-similarity distinction of fuzzy-trace theory). Worked applications to data are provided.     

Recollection rejection of false narrative statements

Our research was focused on a false-memory editing operation that is posited in fuzzy-trace theory-recollection rejection. The main objectives were (a) to extend model-based measurement of this operation to a narrative task that ought to ensure high levels of recollection rejection and (b) to study five manipulations that ought to influence recollection rejection by affecting the accessibility of verbatim traces of narrative statements: recency of narrative presentation, narrative repetition, type of false-memory item, testing delay, and repeated testing. The results showed that the narrative task did indeed yield high levels of recollection, with an estimated 49% of gist-consistent distractors being rejected in this way on initial memory tests. Consistent with current theoretical conceptions of false-memory editing, the results also showed that recollection rejection increased as a function of manipulations that should enhance the accessibility of verbatim traces of narrative statements, with repeated testing delivering especially large increases in verbatim accessibility.     

What is false memory development the development of? Comment on Brainerd, Reyna, and Ceci (2008)

In this commentary, assumptions about the nature and development of children's false memories as described in a recent article by C. J. Brainerd, V. F. Reyna, and S. J. Ceci (2008) are reviewed. Specifically, questions are raised about what drives the development of false memories in fuzzy-trace theory (FTT). Recent studies that challenge a core assumption of FTT, that false memory illusions increase across development as children learn to establish meaningful connections across items (i.e., establish gist), are discussed. An alternative conceptualization of the development of false memory illusions, associative-activation theory (AAT), is presented. AAT provides as viable an account of the development of false memory illusions as does FTT and anticipates a unique set of outcomes that have recently appeared in the developmental literature on false memory illusions.     

Recollection rejection: how children edit their false memories.

A new methodology is presented for studying children's ability to suppress memory reports of false-but-gist-consistent events, one that measures children's use of a specific editing operation (recollection rejection) that suppresses false reports by accessing verbatim traces of true events. Children make memory reports under 2 instructional conditions, verbatim and gist, and the data are analyzed with fuzzy-trace theory's conjoint-recognition model. Application of the new methodology in studies of children's false memory for narrative events revealed that (a) false-memory editing increases dramatically between early and middle childhood, (b) even young children spontaneously edit their false memories, (c) measures of children's false-memory editing react appropriately to experimental manipulations, and (d) developmental reductions in the incidence of false-memory reports are primarily due to developmental improvements in verbatim memory ability (rather than to decreases in the formation of false memories). Implications for child forensic interviewing are discussed.     

Recollection rejection: false-memory editing in children and adults

Mechanisms for editing false events out of memory reports have fundamental implications for theories of false memory and for best practice in applied domains in which false reports must be minimized (e.g., forensic psychological interviews, sworn testimony). A mechanism posited in fuzzy-trace theory, recollection rejection, is considered. A process analysis of false-memory editing is presented, which assumes that false-but-gist-consistent events (e.g., the word SOFA, when the word COUCH was experienced) sometimes cue the retrieval of verbatim traces of the corresponding true events (COUCH), generating mismatches that counteract the high familiarity of false-but-gist-consistent events. Empirical support comes from 2 qualitative phenomena: recollective suppression of semantic false memory and inverted-U relations between retrieval time and semantic false memory. Further support comes from 2 quantitative methodologies: conjoint recognition and receiver operating characteristics. The analysis also predicts a novel false-memory phenomenon (erroneous recollection rejection), in which true events are inappropriately edited out of memory reports.     

Effects of perceptual modality on verbatim and gist memory

In two experiments, predictions of the fuzzy-trace theory of memory were tested. Perceptual information may play a role in retrieval and recognition processes for verbatim, but not for gist, memory. Perceptual modality effects were assessed in the present study by presenting three-sentence stories (e.g.,The bird is in the cage. The cage is over the table. The bird is yellow) and then testing recognition of probes that varied on three dimensions: (1) semantic accuracy (true vs. false), (2) wording (all original words vs. one novel word included), and (3) sentence type (premise vs. inference). In Experiment 1, study modality (auditory vs. visual) was manipulated, and in Experiment 2, both study and test modalities were manipulated. Despite replicating a number of findings consistent with fuzzy-trace theory (e.g., instruction and probe type effects), the results of both experiments failed to support the idea that perceptual information plays a role in performance on verbatim memory tests.     

Illusory recollection and dual-process models of recognition memory

Higham and Vokey (2000, Exps.1 & 3)demonstrated that a slight increase in the display duration of a briefly presented word prior to displaying it in the clear for a recognition response increased the bias to respond “old”. In the current research, three experiments investigated the phenomenology associated with this illusion of memory using the standard remember-know procedure and a new, independent-scales methodology. Contrary to expectations based on the fluency heuristic, which predicts effects of display duration on subjective familiarity only, the results indicated that the illusion was reported as both familiarity and recollection. Furthermore, manipulations of prime duration induced reports of false recollection in all experiments. The results—in particular, the implications of illusory recollection—are discussed in terms of dual-process, fuzzy-trace, two-criteria signal detection models and attribution models of recognition memory.     

Processes underlying developmental reversals in false-memory formation: comment on Brainerd, Reyna, and Ceci (2008)

C. J. Brainerd, V. F. Reyna, and S. J. Ceci (2008) reviewed compelling evidence of developmental reversals in false-memory formation (i.e., younger children exhibit lower false-memory rates than do older children and adults) and proposed that this phenomenon depends on the development of gist processing (i.e., the ability to identify and process the semantic theme of word lists, events, etc.). A full understanding of development reversals, however, cannot be achieved without further characterizing the role played by complementary or opposing processes. Suggestions for future research are made from this perspective.     

Developmental reversals in false memory: now you see them, now you don't!

A developmental reversal in false memory is the counterintuitive phenomenon of higher levels of false memory in older children, adolescents, and adults than in younger children. The ability of verbatim memory to suppress this age trend in false memory was evaluated using the Deese-Roediger-McDermott (DRM) paradigm. Seven and 11-year-old children studied DRM lists either in a standard condition (whole words) that normally produces high levels of false memory or in an alternative condition that should enhance verbatim memory (word fragments). Half the children took 1 recognition test, and the other half took 3 recognition tests. In the single-test condition, the typical age difference in false memory was found for the word condition (higher false memory for 11-year-olds than for 7-year-olds), but in the word fragment condition false memory was lower in the older children. In the word condition, false memory increased over successive recognition tests. Our findings are consistent with 2 principles of fuzzy-trace theory's explanation of false memories: (a) reliance on verbatim rather than gist memory causes such errors to decline with age, and (b) repeated testing increases reliance on gist memory in older children and adults who spontaneously connect meaning across events.     

Comparing single‐ and dual‐process models of memory development

This experiment examined single‐process and dual‐process accounts of the development of visual recognition memory. The participants, 6–7‐year‐olds, 9–10‐year‐olds and adults, were presented with a list of pictures which they encoded under shallow or deep conditions. They then made recognition and confidence judgments about a list containing old and new items. We replicated the main trends reported by Ghetti and Angelini ( 2008 ) in that recognition hit rates increased from 6 to 9 years of age, with larger age changes following deep than shallow encoding. Formal versions of the dual‐process high threshold signal detection model and several single‐process models (equal variance signal detection, unequal variance signal detection, mixture signal detection) were fit to the developmental data. The unequal variance and mixture signal detection models gave a better account of the data than either of the other models. A state‐trace analysis found evidence for only one underlying memory process across the age range tested. These results suggest that single‐process memory models based on memory strength are a viable alternative to dual‐process models for explaining memory development.     

Do children have to remember to reason? A fuzzy-trace theory of transitivity development

An idea that has become commonplace in the literature on cognitive development is that the solution of thinking and reasoning problems requires that children retain accurate representations of certain background facts in short-term memory. This reasoning/remembering hypothesis is reexamined with reference to the one childhood cognitive task for which the validity of the hypothesis seems to be firmly established, transitive inference. Although the hypothesis says that children's transitive inferences are critically dependent on memory for the initial premise information, it is shown in six experiments that transitivity and premise memory are independent abilities in children. A fuzzy-trace theory is developed to explain this surprising independence effect. The theory assumes that children retain only degraded, schematic representations (fuzzy traces) of the overall pattern of an ordered series and that performance on subsequent test trials is mediated by processing operations that flesh out vague pattern information. Some further experiments that were designed to test various predictions of the fuzzy-trace theory are reported. Last, it is shown that reasoning and remembering are independent abilities in some other childhood cognitive tasks for which the initial background facts are not logically inescapable components of the eventual solution. These reasoning/remembering independence effects argue for an increased emphasis on encoding selectivity in theories of cognitive development.     

Children's cognitive triage: optimal retrieval or effortful processing?

Cognitive triage is a surprising nonmonotonic relationship that exists between the order in which children read words out of long-term memory and the memory strengths of those same words. Two forgetting experiments with 7- and 12-year-old children are reported in which fuzzy-trace theory's explanation of this effect was pitted against an effortful processing explanation. The two explanations make different predictions about the relative rates of forgetting for words that are recalled at the primacy and recency positions of output queues. The data consistently favored fuzzy-trace theory's predictions. We discuss the implications of our results for two assumptions that are commonly made in theories of memory development--namely, that recall accuracy is a monotonic-increasing function of memory strength and that recall order is a monotonic-decreasing function of memory strength.     

Overdistribution in source memory

Semantic false memories are confounded with a second type of error, overdistribution, in which items are attributed to contradictory episodic states. Overdistribution errors have proved to be more common than false memories when the 2 are disentangled. We investigated whether overdistribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly overdistribution errors, but unlike semantic false memory, overdistribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of overdistribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that (a) overdistribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions.     

Robust recollection rejection in the memory conjunction paradigm

The present research provides compelling evidence for recollection rejection in the memory conjunction paradigm. In Experiment 1, warnings provided at time of test were shown to reduce memory conjunction errors. Moreover, the authors found substantial evidence of recollection rejection and phantom recollection. In Experiment 2, the authors manipulated how often study items were presented. Participants were told that they could earn a cash payoff for being accurate. Recognition of conjunction lures was lower in the multiple presentation condition. However, the payoff manipulation did not significantly interact with item type. The authors obtained evidence of robust recollection rejection from 3 different dependent measures. Consistent with Experiment 1, they also found evidence of phantom recollection. These findings provide evidence that recollection rejection can be quite robust in the memory conjunction paradigm.     

Disjunction and conjunction fallacies in episodic memory

It has recently been found that episodic memory displays analogues of the well-known disjunction and conjunction fallacies of probability judgement. The aim of the present research was, for the first time, to study these memory fallacies together under the same conditions, and test theoretical predictions about the reasons for each. The focus was on predictions about the influence of semantic gist, target versus context recollection, and proactive versus retroactive interference. Disjunction and conjunction fallacies increased in conditions in which subjects were able to form semantic connections among list words. In addition, disjunction fallacies were increased by manipulations that minimised proactive interference, whereas conjunction fallacies were increased by manipulations that minimised retroactive interference. That pattern suggests that disjunction fallacies are more dependent on target recollection, whereas conjunction fallacies are more dependent on context recollection.