Reading is believing: the truth effect and source credibility

Five experiments explored how source reliability influences people’s tendency to rate statements as more credible when they were encountered earlier (the truth effect). Undergraduates read statements from one reliable source and one unreliable source. Statements read multiple times were perceived as more valid and were more often correctly identified on a general knowledge test than statements read once or not at all. This occurred at varying retention intervals whether the statements originated from a reliable or unreliable source, when people had little memory for the statements themselves or their source, and when the discrediting information about the sources came either before or after reading the facts. While repetition aided recognition and source accuracy, both were unaffected by the reliability of the source. Consistent with the source monitoring framework, familiarity may create an illusion of truth for statements when people lack source-specifying cues, especially cues regarding the reliability of the source.     

How focus at encoding affects children’s source monitoring

Retention of source information is enhanced by focus on speakers’ feelings about statements even though recognition is reduced for both adults and children. However, does any focus on another person lead to enhanced source monitoring, or is a particular kind of focus required? Does other-focus enhance source monitoring, or does self-focus detract from it? In Experiment 1, 4- and 6-year-olds watched two speakers make statements in a no-focus control or with focus directed on how they (or a speaker) felt about the statements or on perceptual features about themselves (or the speaker). Source monitoring decisions were enhanced by other-focus in both the perceptual and emotional conditions. However, the effect was larger for the emotional condition, and source monitoring exceeded no-focus controls only for this condition. Experiment 2 showed no effect of other-focus versus self-focus on source monitoring when questions were semantic.     

Perceptual and lexical components of auditory repetition priming in young and older adults

In the present study, we examined whether age modulates the processing of lexical and perceptual information in auditory implicit and explicit memory tests. Young and older adults performed a surface encoding task on spoken and printed words and then either identified degraded words or made explicit recognition judgments. The implicit test of perceptual identification yielded no evidence of age-related declines in the processing of either lexical information or coarse perceptual details (modality of presentation). The same test, however, produced marked age-related declines in the processing of fine-grained perceptual details (voice) when subjects were not familiarized with the talkers' voices prior to the encoding task. Marked age differences were also observed in recognition memory. These findings suggest that although aging preserves the encoding and incidental retrieval of lexical and coarse perceptual information, it affects the encoding of fine-grained perceptual information and deliberate retrieval processes.     

Spinoza’s error: Memory for truth and falsity

Two theoretical frameworks have been proposed to account for the representation of truth and falsity in human memory: the Cartesian model and the Spinozan model. Both models presume that during information processing a mental representation of the information is stored along with a tag indicating its truth value. However, the two models disagree on the nature of these tags. According to the Cartesian model, true information receives a “true” tag and false information receives a “false” tag. In contrast, the Spinozan model claims that only false information receives a “false” tag, whereas untagged information is automatically accepted as true. To test the Cartesian and Spinozan models, we conducted two source memory experiments in which participants studied true and false trivia statements from three different sources differing in credibility (i.e., presenting 100% true, 50% true and 50% false, or 100% false statements). In Experiment 1, half of the participants were informed about the source credibility prior to the study phase. As compared to a control group, this precue group showed improved source memory for both true and false statements, but not for statements with an uncertain validity status. Moreover, memory did not differ for truth and falsity in the precue group. As Experiment 2 revealed, this finding is replicated even when using a 1-week rather than a 20-min retention interval between study and test phases. The results of both experiments clearly contradict the Spinozan model but can be explained in terms of the Cartesian model.     

Voice-specificity effects on auditory word priming

This research explores the nature of the memory traces that support spoken word identification. Specifically, do voice-specificity effects in implicit memory depend on information in a perceptual representational system or, alternatively, on the similarity of study and test exemplars? Memory for words and voices was assessed with two perceptual identification tests—the identification of words in noise and the identification of low-pass filtered words—after two encoding conditions (identification of words in noise and of words in the clear). At test, a word was presented in the same voice as at study or in a different voice. The data from the two experiments showed that study-to-test changes in voice reduced priming and that voice-specificity effects were greatest when the type of processing engaged at study overlapped with that required at test. Taken together, the results implicate the goodness of the processing match between encoding and test as the primary determinant of voice-specificity effects on perceptual identification tests and support the hypothesis that both voice and word information is represented within a single episodic memory system.     

Remembering makes evidence compelling: retrieval from memory can give rise to the illusion of truth

The illusion of truth is traditionally described as the increase in perceived validity of statements when they are repeated (Hasher, Goldstein, & Toppino, 1977). However, subsequent work has demonstrated that the effect can arise due to the increased familiarity or fluency afforded by repetition and not necessarily to repetition per se. We examine the case of information retrieved from memory. Recently experienced information is expected to be subsequently reexperienced as more fluent and familiar than novel information (Jacoby, 1983; Jacoby & Dallas, 1981). Therefore, the possibility exists that information retrieved from memory, because it is subjectively re-experienced at retrieval, would be more fluent or familiar than when it was first learned and would thus lead to an increase in perceived validity. Using a method to indirectly poll the perceived truth of factual statements, our experiment demonstrated that information retrieved from memory does indeed give rise to an illusion of truth. The effect was larger than when statements were explicitly repeated twice and was of comparable size to when statements were repeated 4 times. We conclude that memory retrieval is a powerful method for increasing the perceived validity of statements (and subsequent illusion of truth) and that the illusion of truth is a robust effect that can be observed even without directly polling the factual statements in question.     

Enhanced processing fluency leads to biases in source memory

The present experiments were conducted to determine whether processing fluency affects source memory decisions. In the first three experiments, participants decided whether test items appeared in the same sensory modality (Experiments 1A, 1B) or perceptual form (font type, Experiment 2) at study and test. The results were consistent across the three studies and showed that perceptual priming leads to an increase in reports that stimuli were presented in the same sensory or perceptual form during the study and test phase. Experiment 3 showed that conceptual fluency affects source attributions in much the same way as perceptual fluency, and Experiment 4 showed that fluency is associated with a subjective experience of familiarity even when it might serve as a basis for source inference. These results are consistent with recent neuropsychological and neuroimaging evidence that familiarity-based processes contribute to source memory decisions under some circumstances, such as when items and contexts are unitized rather than merely bound together at encoding.     

Enhanced processing fluency leads to biases in source memory

The present experiments were conducted to determine whether processing fluency affects source memory decisions. In the first three experiments, participants decided whether test items appeared in the same sensory modality (Experiments 1A, 1B) or perceptual form (font type, Experiment 2) at study and test. The results were consistent across the three studies and showed that perceptual priming leads to an increase in reports that stimuli were presented in the same sensory or perceptual form during the study and test phase. Experiment 3 showed that conceptual fluency affects source attributions in much the same way as perceptual fluency, and Experiment 4 showed that fluency is associated with a subjective experience of familiarity even when it might serve as a basis for source inference. These results are consistent with recent neuropsychological and neuroimaging evidence that familiarity-based processes contribute to source memory decisions under some circumstances, such as when items and contexts are unitized rather than merely bound together at encoding.     

Effects of Perceptual and Conceptual Processing on Memory for Words and Voice: Different Patterns for Young and Old

In two experiments younger and older adults listened to a list of words presented auditorily by two speakers. The subjects processed each word either perceptually (voice judgements) or conceptually (pleasantness judgements), and were then given memory tasks for the words and the presenting voice. In the word-recognition task the two age groups benefited equally from conceptual as opposed to perceptual processing. In the voice memory task, however, conceptual processing improved performance relative to perceptual processing in the younger subjects (significantly so in Experiment 1), but conceptual processing was associated with decreased performance in the older group (significantly so in Experiment 2). These results suggest that whereas older subjects exhibit a trade-off in memory for item and attribute information, younger subjects exhibit a pattern of support, in which conceptual processing benefits memory for both items and their attributes.     

Aging and Source Monitoring of Characters in Literary Texts

This research examines adult age differences in source monitoring for literary texts. Source monitoring refers to processes that lead to attributions regarding the source or origin of information (Johnson, Hashtroudi, & Lindsay, 1993). Young and older adults read a literary play (Experiment 1) or short story (Experiment 2). In a later source-monitoring test, participants decided whether statements originated from Character A, Character B, Character C, or none of them. Recognition memory for statements was lower for older adults. Age differences in source monitoring were also consistently observed in both experiments, suggesting that older adults are impaired in everyday source-monitoring tasks that involve written discourse.     

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).     

The informative value of type of repetition: Perceptual and conceptual fluency influences on judgments of truth

We contrast the effects of conceptual and perceptual fluency resulting from repetition in the truth effect. In Experiment 1, participants judged either verbatim or paraphrased repetitions, which reduce perceptual similarity to original statements. Judgments were made either immediately after the first exposure to the statements or after one week. Illusions of truth emerged for both types of repetition, with delay reducing both effects. In Experiment 2, participants judged verbatim and paraphrased repetitions with either the same or a contradictory meaning of original statements. In immediate judgments, illusions of truth emerged for repetitions with the same meaning and illusions of falseness for contradictory repetitions. In the delayed session, the illusion of falseness disappeared for contradictory statements. Results are discussed in terms of the contributions of recollection of stimulus details and of perceptual and conceptual fluency to illusions of truth at different time intervals and judgmental context conditions.     

Similarities and Differences in Semantic and Phonological Processing with Age Patterns of Functional MRI Activation

Abstract

In a study modelled after Hashtroudi, Johnson, and Chrosniak (1989), young and older adults were examined in two conditions requiring reality monitoring (i.e., discriminating between one external and one internal source) and two conditions requiring source monitoring (i.e., discriminating between two external or two internal sources). Results indicated age-related deficits in internal source monitoring, although the two age groups did not differ in reality monitoring or external source monitoring. Explicit instructions to remember the source of information had no effect on performance. In addition, performance on putative tests of frontal lobe functioning (i.e., the Wisconsin Card Sorting Test and tests of verbal fluency) was unrelated to source memory performance. the results are discussed relative to the view that aging may affect the ability to encode perceptual information in a distinctive manner, as well as the ability to reconstruct perceptual information and its relationship to item information.     

Contributions of surface and conceptual information to recognition memory

The present experiments were designed to determine whether memory for the voice in which a word is spoken is retained in a memory system that is separate from episodic memory or, instead, whether episodic memory represents both word and voice information. These two positions were evaluated by assessing the effects of study-to-test changes in voice on recognition memory after a variety of encoding tasks that varied in processing requirements. In three experiments, the subjects studied a list of words produced by six voices. The voice in which the word was spoken during a subsequent explicit recognition test was either the same as or different from the voice used in the study phase. The results showed that word recognition was affected by changes in voice after each encoding condition and that the magnitude of the voice effect was unaffected by the type of encoding task. The results suggest that spoken words are represented in long-term memory as episodic traces that contain talker-specific perceptual information.     

Monitoring item and source information: Evidence for a negative generation effect in source memory

Item memory and source memory were assessed in a task that simulated a social conversation. Participants generated answers to questions or read statements presented by one of three sources (faces on a computer screen). Positive generation effects were observed for item memory. That is, participants remembered topics of conversation better if they were asked questions about the topics than if they simply read statements about topics. However, a negative generation effect occurred for source memory. That is, remembering the source of some information was disrupted if participants were required to answer questions pertaining to that information. These findings support the notion that item and source memory are mediated, as least in part, by different processes during encoding.     

Direct comparison of auditory implicit memory tests

In this experiment, we examined the degree to which four implicit tests and two explicit tests, all involving auditory presentation, were sensitive to the perceptual characteristics of the stimuli presented during study. Presenting stimuli visually decreased priming in all the implicit memory tests, relative to auditory presentation. However, changing voice between study and test decreased priming only in the implicit memory tests requiring identification of words degraded by noise or by low-pass filtering, but not in those tests requiring generation from word portions (stems and fragments). Modality effects without voice effects were observed in cued recall, but the opposite pattern of results (voice effects without modality effects) was obtained in recognition. The primary new finding is the demonstration that auditory memory tests, both explicit and implicit, differ in their sensitivity to the perceptual information encoded during study.     

Auditory registration without learning

In 3 studies, the authors explore how repeated exposure to a spoken word affects memory for perceptual attributes associated with the word (such as a talker's voice or a word's plurality). Subjects heard a list of words; particular words were repeated differing numbers of times. At test, subjects estimated the frequency of each word, with instructions to give frequency judgments of "zero" to words with changed attributes. The experiments demonstrate that memory for perceptual attributes improves very little after the first few repetitions, although word memory continues to improve. The experiments extend the registration without learning effect (D. L. Hintzman, T. Curran, & B. Oppy, 1992) to auditory words, to complex attributes (voice), and to conditions of low and high stimulus variability (two or many voices).     

Neuroimaging evidence for agenda-dependent monitoring of different features during short-term source memory tests

A short-term source monitoring procedure with functional magnetic resonance imaging assessed neural activity when participants made judgments about the format of 1 of 4 studied items (picture, word), the encoding task performed (cost, place), or whether an item was old or new. The results support findings from long-term memory studies showing that left anterior ventrolateral prefrontal cortex (PFC) is engaged when people make source attributions about reflectively generated information (cognitive operations, conceptual features). The findings also point to a role for right lateral PFC in attention to perceptual features and/or familiarity in making source decisions. Activity in posterior regions also differed depending on what was evaluated. These results provide neuroimaging evidence for theoretical approaches emphasizing that agendas influence which features are monitored during remembering (e.g., M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993). They also support the hypothesis that some of the activity in left lateral PFC and posterior regions associated with remembering specific information is not unique to long-term memory but rather is associated with agenda-driven source monitoring processes common to working memory and long-term memory.     

Verification of Statements about Story Worlds That Deviate from Normal Conceptions of Time: What Is True aboutEinstein''s Dreams?

College students read chapters from a novel written by Alan Lightman (Einstein's Dreams) and later provided verification judgments on the truth/falsity of test statements. Each chapter described a different fictional village that incorporated assumptions about time that deviate from our normal TIME schema, e.g., citizens knowing exactly when the world will end, time flowing backward instead of forward. These novel assumptions about time provided interesting insights about life and reality. In two experiments, we examined whether readers could accurately incorporate these novel assumptions about time in the fictional story worlds, as manifested in the verification judgments for statements after story comprehension. The test statements included verbatim typical, verbatim atypical, inference typical, and inference atypical information from the perspective of mundane reality that meshes with a normal TIME schema. Verification ratings were collected on a 6-point scale in Experiment 1, whereas Experiment 2 used a signal–response technique in which binary true/false decisions were extracted at −.5, 1.5, 3.5, 5.5, and 10.0 s. The college students were measured on literary expertise, reading skill, working memory span, and reading time. Readers with comparatively high literary expertise showed truth discrimination scores that were compatible with aschema copy plus tagmodel, which assumes that readers are good at detecting and remembering atypical verbatim information; this model predicts better (and faster) truth discrimination for verbatim atypical statements than for verbatim typical statements. In contrast, fast readers with comparatively low literary expertise were compatible with afilteringmodel; this model predicts that readers gloss over (or suppress) atypical verbatim information and show advantages for verbatim typical information. All groups of readers had trouble inferentially propagating the novel assumptions about time in a fictional story world, but the slower readers were more accurate in their verification of the atypical inferences. Aconstruction–integrationmodel could explain the interactions among literary expertise, reading time, and the typicality of test statements.     

Source monitoring and suggestibility to misinformation: adult age‐related differences

We compared young and older adults' source monitoring performance on an explicit source identification test using the misinformation paradigm. Several age‐related differences in source memory were demonstrated: (a) older adults were more likely than were young adults to say that they saw information that was actually only suggested to them; (b) older adults were more confident in their false memories than were young adults; (c) older adults were less confident in their accurate memory for the source of information than were young adults. Together, the data suggest that older adults either lacked or failed to use helpful diagnostic source information (e.g. perceptual details or temporal information), and that their confidence in their false memories reflected an over‐weighting of semantic information. Copyright © 2002 John Wiley & Sons, Ltd.