Fuzzy-trace theory

Fuzzy-trace theory (FTT) is a theory of cognition originally proposed by Charles Brainerd and Valerie F. Reyna that draws upon dual-trace conceptions to predict and explain cognitive phenomena, particularly in the memory and reasoning domains. The theory has been used in areas such as cognitive psychology, human development, and social psychology to explain, for instance, false memory and its development, probability judgments, medical decision making, risk perception and estimation, and biases and fallacies in decision making. Fuzzy-trace theory (FTT) is a theory of cognition originally proposed by Charles Brainerd and Valerie F. Reyna that draws upon dual-trace conceptions to predict and explain cognitive phenomena, particularly in the memory and reasoning domains. The theory has been used in areas such as cognitive psychology, human development, and social psychology to explain, for instance, false memory and its development, probability judgments, medical decision making, risk perception and estimation, and biases and fallacies in decision making. FTT was initially proposed in the 1990s as an attempt to unify findings from the memory and reasoning domains that could not be predicted or explained by earlier approaches to cognition and its development (e.g., constructivism and information processing). One of such challenges was the statistical independence between memory and reasoning, that is, memory for background facts of problem situations is often unrelated to accuracy in reasoning tasks. Such findings called for a rethinking of the memory-reasoning relation, which in FTT took the form of a dual-process theory linking basic concepts from psycholinguistic and Gestalt theory to memory and reasoning. More specifically, FTT posits that people form two types of mental representations about a past event, called verbatim and gist traces. Gist traces are fuzzy representations of a past event (e.g., its bottom-line meaning), hence the name fuzzy-trace theory, whereas verbatim traces are detailed representations of a past event. Although people are capable of processing both verbatim and gist information, they prefer to reason with gist traces rather than verbatim. This implies, for example, that even if people are capable of understanding ratio concepts like probabilities and prevalence rates, which are the standard for the presentation of health- and risk-related data, their choice in decision situations will usually be governed by the bottom-line meaning of it (e.g., 'the risk is high' or 'the risk is low'; 'the outcome is bad' or 'the outcome is good') rather than the actual numbers. More importantly, in FTT, memory-reasoning independence can be explained in terms of preferred modes of processing when one performs a memory task (e.g., retrieval of verbatim traces) relative to when one performs a reasoning task (e.g., preference for reasoning with gist traces). In 1999, a similar approach was applied to human vision. It suggested that human vision has two types of processing: one that aggregates local spatial receptive fields, and one that parses the local receptive field. People used prior experience, gists, to decide which process dominates a perceptual decision. The work attempted to link Gestalt theory and psychophysics (i.e., independent linear filters). This theory was further developed into fuzzy image processing and used in information processing technology and edge detection. FTT posits two types of memory processes (verbatim and gist) and, therefore, it is often referred to as a dual process theory of memory. According to FTT, retrieval of verbatim traces (recollective retrieval) is characterized by mental reinstatement of the contextual features of a past event, whereas retrieval of gist traces (nonrecollective retrieval) is not. In fact, gist processes form representations of an event's semantic features rather than its surface details, the latter being a property of verbatim processes. In the memory domain, FTT's notion of verbatim and gist representations has been influential in explaining true memories (i.e., memories about events that actually happened) as well as false memories (i.e., memories about events that never happened). The following five principles have been used to predict and explain true and false memory phenomena: The principle of parallel storage asserts that the encoding and storage of verbatim and gist information operate in parallel rather than in a serial fashion. For instance, suppose that a person is presented with the word 'apple' in red color. On the one hand, according to the principle of parallel storage of verbatim and gist traces, verbatim features of the target item (e.g., the word was apple, it was presented in red, printed in boldface and italic, and all but the first letter were presented in lowercase) and gist features (e.g., the word was a type of fruit) would be encoded and stored simultaneously via distinct pathways. Conversely, if verbatim and gist traces are stored in a serial fashion, then gist features of the target item (the word was a type of fruit) would be derived from its verbatim features and, therefore, the formation of gist traces would depend on the encoding and storage of verbatim traces. The latter idea was often assumed by early memory models. However, despite the intuitive appeal of the serial processing approach, research suggests that the encoding and storage of gist traces do not depend on verbatim ones. Several studies have converged on the finding that the meaning of target items is encoded independently of, and even prior to, the encoding of the surface form of the same items. Ankrum and Palmer, for example, found that when participants are presented with a familiar word (e.g., apple) for a very brief period (100 milliseconds), they are able to identify the word itself ('was it apple?') better than its letters ('did it contain the letter L?'). Similar to the principle of parallel storage, retrieval of verbatim and gist traces also occur via dissociated pathways. According to the principle of dissociated retrieval, recollective and nonrecollective retrieval processes are independent of each other. Consequently, this principle allows verbatim and gist processes to be differentially influenced by factors such as the type of retrieval cues and the availability of each form of representation. In connection with Tulving's encoding specificity principle, items that were actually presented in the past are better cues for verbatim traces than items that were not. Similarly, items that were not presented in the past but preserve the meaning of presented items are usually better cues for gist traces. Suppose, for example, that subjects of an experiment are presented with a word list containing several dog breeds, such as poodle, bulldog, greyhound, doberman, beagle, collie, boxer, mastif, husky, and terrier. During a recognition test, the words poodle, spaniel, and chair are presented. According to the principle of dissociated retrieval, retrieval of verbatim and gist traces does not depend on each other and, therefore, different types of test probes might serve as better cues to one type of trace than another. In this example, test probes such as poodle (targets, or studied items) will be better retrieval cues for verbatim traces than gist, whereas test probes such as spaniel (related distractors, non-studied items but related to targets) will be better retrieval cues for gist traces than verbatim. Chair, on the other hand, would neither be a better cue for verbatim traces nor for gist traces because it was not presented and is not related to dogs. If verbatim and gist processes were dependent, then factors that affect one process would also affect the other in the same direction. However, several experiments showing, for example, differential forgetting rates between memory for the surface details and memory for the bottom-line meaning of past events favor the notion of dissociated retrieval of verbatim and gist traces. In the case of forgetting rates, those experiments have shown that, over time, verbatim traces become inaccessible at a faster rate than gist traces. Brainerd, Reyna, and Kneer, for instance, found that delay drives true recognition rates (supported by both verbatim and gist traces) and false recognition rates (supported by gist and suppressed by verbatim traces) in opposite directions, namely true memory decays over time while false memory increases. The principle of opponent processes describes the interaction between verbatim and gist processes in creating true and false memories. Whereas true memory is supported by both verbatim and gist processes, false memory is supported by gist processes and suppressed by verbatim processes. In other words, verbatim and gist processes work in opposition to one another when it comes to false memories. Suppose, for example, that one is presented with a word list such as lemon, apple, pear, and citrus. During a recognition test, the items lemon (target), orange (related distractor), and fan (unrelated distractor) are shown. In this case, retrieval of a gist trace (fruits) supports acceptance of both test probes lemon (true memory) and orange (false memory), whereas retrieval of a verbatim trace (lemon) only supports acceptance of the test probe lemon. In addition, retrieval of an exclusory verbatim trace ('I saw only the words lemon, apple, pear, and citrus') suppresses acceptance of false but related items such as orange through an operation known as recollection rejection. If neither verbatim nor gist traces are retrieved, then one might accept any test probe on the basis of response bias.This principle plays a key role in FTT's explanation of experimental dissociations between true and false memories (e.g., when a variable affects one type of memory without affecting the other, or when it produces opposite effects on them). The time of exposure of each word during study and the number of repetitions have been shown to produce such dissociations. More specifically, while true memory follows a monotonically increasing function when plotted against presentation duration, false memory rates exhibit an inverted-U pattern when plotted as a function of presentation duration. Similarly, repetition is monotonically related to true memory (true memory increases as a function of the number of repetitions) and is non-monotonically related to false memory (repetition produces an inverted-U relation with false memory). Retrieval phenomenologies are spontaneous mental experiences associated with the act of remembering. It was first systematically characterized by E. K. Strong in the early 1900s. Strong identified two distinct types of introspective phenomena associated with memory retrieval that have since been termed recollection (or remembrance) and familiarity. Whereas the former is characterized as retrieval associated with recollection of past experiences, the latter lacks such association. The two forms of experiences can be illustrated by everyday expressions such as 'I remember that!' (recollection) and 'That seems familiar...' (familiarity). In FTT, retrieval of verbatim traces often produces recollective phenomenology and thus is frequently referred to as recollective retrieval. However, one feature of FTT is that recollective phenomenology is not particular to one type of memory process as posited by other dual-process theories of memory. Instead, FTT posits that retrieval of gist traces can also produce recollective phenomenology under some circumstances. When gist resemblance between a false item and memory is high and compelling, this gives rise to a phenomenon called phantom recollection, which is a vivid, but false, memory deemed to be true. The principle of developmental variability in dual processes posits that verbatim and gist processes show variability across the lifespan. More specifically, verbatim and gist processes have been shown to improve between early childhood and young adulthood. Regarding verbatim processes, older children are better at retrieval of verbatim traces than younger children, although even very young children (4-year-olds) are able to retrieve verbatim information at above chance level. For instance, source memory accuracy greatly increases between 4-year-olds and 6-year-olds, and memory for nonsense words (i.e., words without a meaning, such as neppez) has been shown to increase between 7- and 10-year-olds. Gist processes also improve with age. For example, semantic clustering in free recall increases from 8-year-olds to 14-year-olds, and meaning connection across words and sentences has been shown to improve between 6- and 9-year-olds. In particular, the notion that gist memory improves with age plays a central role in FTT's prediction of age increases in false memory, a counterintuitive pattern that has been called developmental reversal.