Does sleep benefit source memory? Investigating 12-h retention intervals with a multinomial modeling approach

For retention intervals of up to 12 h, the active systems consolidation hypothesis predicts that sleep compared to wakefulness strengthens the context binding of memories previously established during encoding. Sleep should thus improve source memory. By comparing retention intervals filled with natural night sleep versus daytime wakefulness, we tested this prediction in two online source-monitoring experiments using intentionally learned pictures as items and incidentally learned screen positions and frame colors as source dimensions. In Experiment 1, we examined source memory by varying the spatial position of pictures on the computer screen. Multinomial modeling analyses revealed a significant sleep benefit in source memory. In Experiment 2, we manipulated both the spatial position and the frame color of pictures orthogonally to investigate source memory for two different source dimensions at the same time, also allowing exploration of bound memory for both source dimensions. The sleep benefit on spatial source memory replicated. In contrast, no source memory sleep benefit was observed for either frame color or bound memory of both source dimensions, probably as a consequence of a floor effect in incidental encoding of color associations. In sum, the results of both experiments show that sleep within a 12-h retention interval improves source memory for spatial positions, supporting the prediction of the active systems consolidation hypothesis. However, additional research is required to clarify the impact of sleep on source memory for other context features and bound memories of multiple source dimensions.

On the advantages of using AI-generated images of filler faces for creating fair lineups

Recent advances in artificial intelligence (AI) enable the generation of realistic facial images that can be used in police lineups. The use of AI image generation offers pragmatic advantages in that it allows practitioners to generate filler images directly from the description of the culprit using text-to-image generation, avoids the violation of identity rights of natural persons who are not suspects and eliminates the constraints of being bound to a database with a limited set of photographs. However, the risk exists that using AI-generated filler images provokes more biased selection of the suspect if eyewitnesses are able to distinguish AI-generated filler images from the photograph of the suspect's face. Using a model-based analysis, we compared biased suspect selection directly between lineups with AI-generated filler images and lineups with database-derived filler photographs. The results show that the lineups with AI-generated filler images were perfectly fair and, in fact, led to less biased suspect selection than the lineups with database-derived filler photographs used in previous experiments. These results are encouraging with regard to the potential of AI image generation for constructing fair lineups which should inspire more systematic research on the feasibility of adopting AI technology in forensic settings.

Representation of shared surface information and false memory for abstract versus concrete pictures in the conjoint recognition paradigm

An effective factor by which false memories can arise is relatedness which includes not only semantic associations but also perceptual resemblance. This issue raises questions about how patterns of perceptual features are represented in memory and how they relate to semantic representations. In five experiments, we investigated the memory processes underlying the false recognition of perceptually or semantically related pictures from the perspective of fuzzy trace theory. Multinomial processing tree model analyses for the conjoint recognition paradigm showed that the parameter representing gist trace retrieval not only contributes to false acceptances of semantically related pictures, but also underlies the false recognition of non-semantically related abstract shapes. These results challenged the hypothesis that the false recognition of non-semantically related distractors is solely due to interference with the verbatim suppression process. These experiments also showed that adding a surface feature (colour) to the category exemplars increases false recognition of related distractors by enhancing the contribution of the familiarity process, but only for pictures of real objects. Comparisons between experiments showed that different variants of the conjoint recognition model, used to analyse the effects of the same experimental manipulation, can lead to partially different conclusions.

Unraveling the brain mechanisms of source monitoring with non-invasive brain stimulation: A systematic review

Background/Objective

Source monitoring refers to the ability to determine the source of memories and encompasses three subprocesses: internal source monitoring, reality monitoring, and external source monitoring. Neuroimaging studies provide valuable insights about neural correlates of source monitoring, but the causal relationship between brain and behavior is lacking. This study aimed to identify brain circuits involved in source monitoring by synthesizing the effects of brain stimulation on source monitoring as a function of the targeted brain regions or circuits.

Method

We conducted a systematic review of interventional studies that have examined the effects of brain stimulation on source monitoring across six databases. The principal outcome was the difference of source monitoring performance between active and control stimulation conditions.

Results

23 studies (920 healthy participants and 54 patients with schizophrenia) were included. Our findings revealed the involvement of i) the lateral prefrontal and temporoparietal cortices in internal source monitoring, ii) the medial prefrontal and temporoparietal cortices in reality monitoring, and iii) the precuneus and the left angular gyrus in external source monitoring.

Conclusions

These findings deepen our understanding of the brain mechanisms of source monitoring and highlight specific stimulation targets to alleviate source monitoring deficits.

Enhanced source memory for cheaters with higher resemblance to own-culture typical faces

Recent evidence suggests that culture-specific face typicality has an impact on making trait judgments. Additionally, facial resemblance to one's culture-typical faces causes them to be perceived as reliable, less dangerous, and more accurately recognized. When judging persons from other cultural origins, one's own culture's face standards might shape inferences, behavior, and memory. In this study, the partners' facial resemblance to participants' culturally typical faces was manipulated using target faces, considered to be higher or lower, similar to people living in the participants' hometown. Participants were asked to invest in a company together with partners who have a higher and lower resemblance to their own-culture typical faces in a cooperation game. The results showed that facial resemblance to own-culture typical faces affected investment preferences. Partners with a higher resemblance to own-culture typical faces were more correctly distinguished in the old-new recognition memory task. The study found that partners with a higher resemblance to own-culture typical faces had a source memory advantage for cheating behaviors. These results confirmed that a higher resemblance to own-culture typical faces provide an advantage in cross-cultural interactions, allowing them to become better recognized. Additionally, enhanced source memory for cheaters with higher resemblance to own-culture typical faces may indicate a flexible cognitive system that is sensitive to information that violates social expectations.

Coping with high advertising exposure: a source-monitoring perspective

Consumers are exposed to large amounts of advertising every day. One way to avoid being manipulated is to monitor the sources of persuasive messages. In the present study it was tested whether high exposure to advertising affects the memory and guessing processes underlying source attributions. Participants were exposed to high or low proportions of advertising messages that were intermixed with product statements from a trustworthy source. In a subsequent memory test, participants had to remember the sources of these statements. In Experiments 1 and 2, high advertising exposure led to increased source memory and decreased recognition of the statements in comparison to low advertising exposure. High advertising exposure also induced an increased tendency toward guessing that statements whose sources were not remembered came from advertising. The results of Experiment 3 suggest that the presence of advertising, relative to its absence, leads to a skeptical guessing bias. Being exposed to advertising thus has pronounced effects on the memory and guessing processes underlying source attributions. These changes in source monitoring can be interpreted as coping mechanisms that serve to protect against the persuasive influence of advertising messages.

Remedying the Metamemory Expectancy Illusion in Source Monitoring: Are there Effects on Restudy Choices and Source Memory?

Metamemory monitoring, study behavior, and memory are presumably causally connected. When people misjudge their memory, their study behavior should be biased accordingly. Remedying metamemory illusions should debias study behavior and improve memory. One metamemory illusion concerns source memory, a critical aspect of episodic memory. People predict better source memory for items that originated from an expected source (e.g., toothbrush in a bathroom) rather than an unexpected source (e.g., shampoo in a kitchen), whereas actual source memory shows the opposite: an inconsistency effect. This expectancy illusion biases restudy choices: Participants restudy more unexpected than expected source-item pairs. The authors tested the causal relationships between metamemory and source memory with a delay and a source-retrieval attempt between study and metamemory judgment to remedy the expectancy illusion and debias restudy choices. Debiased restudy choices should enhance source memory for expected items, thereby reducing the inconsistency effect. Two groups studied expected and unexpected source-item pairs. They made metamemory judgments and restudy choices immediately at study or after delay, restudied the selected pairs, and completed a source-monitoring test. After immediate judgments, participants predicted better source memory for expected pairs and selected more unexpected pairs for restudy. After delayed judgments, participants predicted a null effect of expectancy on source memory and selected equal numbers of expected and unexpected pairs. Thus, the expectancy illusion was partially remedied and restudy choices were debiased. Nevertheless, source memory was only weakly affected. The results challenge the presumed causal relationships between metamemory monitoring, study behavior, and source memory.

Computational Process of Sharing Emotion: An Authentic Information Perspective

Although results of many psychology studies have shown that sharing emotion achieves dyadic interaction, no report has explained a study of the transmission of authentic information from emotional expressions that can strengthen perceivers. For this study, we used computational modeling, which is a multinomial processing tree, for formal quantification of the process of sharing emotion that emphasizes the perception of authentic information for expressers’ feeling states from facial expressions. Results indicated that the ability to perceive authentic information of feeling states from a happy expression has a higher probability than the probability of judging authentic information from anger expressions. Next, happy facial expressions can activate both emotional elicitation and sharing emotion in perceivers, where emotional elicitation alone is working rather than sharing emotion for angry facial expressions. Third, parameters to detect anger experiences were found to be correlated positively with those of happiness. No robust correlation was found between the parameters extracted from this experiment task and questionnaire-measured emotional contagion, empathy, and social anxiety. Results of this study revealed the possibility that a new computational approach contributes to description of emotion sharing processes.

Cognitive load decreases cooperation and moral punishment in a Prisoner's Dilemma game with punishment option

The present study serves to test whether cooperation and moral punishment are affected by cognitive load. Dual-process theories postulate that moral behavior is intuitive which leads to the prediction that cooperation and moral punishment should remain unaffected or may even increase when cognitive load is induced by a secondary task. However, it has also been proposed that cognitive control and deliberation are necessary to choose an economically costly but morally justified option. A third perspective implies that the effects of cognitive load may depend on the specific processes involved in social dilemmas. In the present study, participants played a simultaneous Prisoner’s Dilemma game with a punishment option. First, both players decided to cooperate or defect. Then they had the opportunity to punish the partners. In the cognitive-load group, cognitive load was induced by a continuous tone classification task while the no-load group had no distractor task. Under cognitive load, cooperation and moral punishment decreased in comparison to the no-load condition. By contrast, hypocritical and antisocial punishment were not influenced by the dual-task manipulation. Increased cognitive load was associated with a bias to punish the partners irrespective of the outcome of the Prisoner’s Dilemma game, suggesting that punishment was applied less purposefully in the cognitive-load condition. The present findings are thus in line with the idea that the availability of cognitive resources does not always have a suppressive effect on moral behaviors, but can have facilitating effects on cooperation and moral punishment.

Source memory for advertisements: The role of advertising message credibility

Advertising is seen as an untrustworthy source because of the perceived self-interest of the advertisers in presenting product information in a biased or misleading way. Regulations require advertising messages in print and online media to be labeled as advertisements to allow recipients to take source information into account when judging the credibility of the messages. To date, little is known about how these source tags are remembered. Research within the source-monitoring framework suggests that source attributions are not only based on veridical source memory but are often reconstructed through schematic guessing. In two experiments, we examined how the credibility of advertising messages affects these source attribution processes. The source of the messages affected judgments of credibility at the time of encoding, but the source tags were forgotten after a short period of time. Retrospective source attributions in the absence of memory for the source tags were strongly influenced by the a priori credibility of the messages: Statements with a low a priori credibility were more likely to be (mis)attributed to advertising than statements with high a priori credibility. These findings suggest that the mere labeling of untrustworthy sources is of limited use because source information is quickly forgotten and memory-based source attributions are strongly biased by schematic influences.

A multinomial modelling approach to face identity recognition during instructed threat

To organise future behaviour, it is important to remember both the central and contextual aspects of a situation. We examined the impact of contextual threat or safety, learned through verbal instructions, on face identity recognition. In two studies (N = 140), 72 face-context compounds were presented each once within an encoding session, and an unexpected item/source recognition task was performed afterwards (including 24 new faces). Hierarchical multinomial processing tree modelling served to estimate individual parameters of item (face identity) and source memory (threat or safety context) as well as guessing behaviour. Results show that language was highly effective in establishing threatening and safe context conditions. In Study 1, a fleeting picture stream (1 s per picture) led to poor item and source recognition. Prolonged presentation times (Study 2 with 6 s per picture) improved face memory but no contextual modulation was observed. Thus, incidental face learning was surprisingly poor and rapidly changing contextual settings might have interfered with the accurate encoding of face identity information and item-source binding.

A novel paradigm to assess storage of sources in memory: the source recognition test with reinstatement

The present research aimed to devise a test of source recognition that facilitates access to source information stored in memory. Therefore, we extended the standard source-monitoring paradigm, in which items are presented in a source-neutral manner during test, by a second, subsequent test with source reinstatement. In this second test, items (i.e., words) were presented with both study sources (i.e., two speakers) consecutively such that for originally studied words, one test presentation was the exact reinstatement of the original source. To validate our assumption that the test with reinstatement primarily assesses source storage, we manipulated source storage by varying encoding frequency between-participants (repetition vs. no repetition of each item-source-pair). Additionally, we varied source similarity between-participants (similar vs. dissimilar speakers). Data analyses (N = 146) based on multinomial and signal detection models showed a source memory enhancement in the second test with reinstatement compared to the first standard test, especially for similar sources. Additionally, repetition selectively benefited source memory in the second test, validating our interpretation of the second test as a measure for source storage. Altogether, our novel source recognition test offers a promising method for investigating various well-known source memory phenomena more comprehensively.

The metamemory expectancy illusion in source monitoring affects metamemory control and memory

In source monitoring, schematic expectations affect both memory and metamemory. In metamemory judgments, people predict better source memory for items that originated from an expected source (e.g., oven in the kitchen) than for items that originated from an unexpected source (e.g., hairdryer in the kitchen; expectancy effect; Schaper et al., 2019a). By contrast, actual source memory is either unaffected by expectations or better for unexpected sources (inconsistency effect; Kuhlmann & Bayen, 2016). Thus, the metamemory expectancy effect is illusory. This research is the first to test the hypotheses that such metamemory monitoring of source memory affects metamemory control (i.e., measures taken to achieve a desired level of memory; Nelson & Narens, 1990) and memory. Due to their expectancy illusion, people should choose to restudy unexpected source-item pairs more often. Three participant groups (n = 36 each) studied expected and unexpected source-item pairs. One group rendered metamemory judgments and chose pairs for restudy. A second group made restudy choices only. These two groups then restudied the chosen pairs. A third group did not make restudy choices and restudied a random half of the pairs. All participants completed a source-monitoring test. As predicted, participants chose unexpected pairs more often for restudy based on their illusory conviction that they would remember unexpected sources more poorly. These restudy choices concurred with an inconsistency effect on source memory not shown in the group without restudy choices. Thus, the metamemory illusion related to control and memory in source monitoring.

Levels-of-processing effects on context and target recollection for words and pictures

The effects of levels of processing (LoP) on memory performance have been extensively studied in cognitive psychology for about half a century. The initial observation of superior memory for words studied under a semantic orienting task rather than a perceptual orienting task elicited a theoretical debate about the underlying mechanisms of this effect. Next, research on LoP effects was extended to pictorial stimuli and connected with analyses of recollection and familiarity processes of recognition memory. The main aim of the current study was to explore the effects of LoP on two distinct components of recollection memory: context recollection, and target recollection-processes recently differentiated in dual-recollection theory. Verbal and pictorial materials were used in several experiments and the participants were asked to remember the study context defined by the kind of orienting task performed. LoP effects were confirmed for context and target recollection when words were used as stimuli. However, reversed LoP effects for context recollection were found in experiments using pictures as the to-be-remembered material. The function of the distinctiveness of pictorial material and the role of the effortfulness of cognitive operations for recollection were analysed and discussed from the perspective of the sensory-semantic model and the source monitoring framework.

Memory and metamemory for social interactions: Evidence for a metamemory expectancy illusion

People do not always have accurate metacognitive awareness of the conditions that lead to good source memory. In Experiment 1, participants studied words referring to bathroom and kitchen items that were either paired with an expected or unexpected room as the source. Participants provided judgments of item and source learning after each item–source pair. In line with previous studies, participants incorrectly predicted their memory to be better for expected than for unexpected sources. Here, we show that this metamemory expectancy illusion generalizes to socially relevant stimuli. In Experiment 2, participants played a prisoner’s dilemma game with trustworthy-looking and untrustworthy-looking partners who either cooperated or cheated. After each round of the game, participants provided metamemory judgments about how well they were going to remember the partner’s face and behavior. On average, participants predicted their source memory to be better for behaviors that were expected based on the facial appearances of the partners. This stands in contrast to the established finding that veridical source memory is better for unexpected than expected information. Asking participants to provide metamemory judgments at encoding selectively enhanced source memory for the expected information. These results are consistent with how schematic expectations affect source memory and metamemory for nonsocial information, suggesting that both are governed by general rather than by domain-specific principles. Differences between experiments may be linked to the fact that people may have special beliefs about memory for social stimuli, such as the belief that cheaters are particularly memorable (Experiment 3).

P3a amplitude is related to conclusion specificity during category-based induction

Category-based induction involves the generalization of a novel property (conclusion property) to a new category (conclusion category), based on the knowledge that a category exemplar (premise category) has the respective novel property. Previous studies have shown that conclusion specificity (i.e., specific [S] or generic categories [G]) influences category-based induction. However, the timing of brain activity underlying this effect is not well known, especially with controlling the similarities of premise and conclusion categories between S and G arguments. In this study, the event-related potential (ERP) responses to category-based induction between S and G arguments were compared under both congruent (+, premise and conclusion categories are related) and incongruent (-, premise and conclusion categories are unrelated) arguments; additionally, the similarities of premise and conclusion categories between S and G arguments were controlled. The results showed that replicating this effect, S+ arguments have increased “strong” response rates compared to G+ arguments, suggesting that category-based induction is contingent on factors beyond matched similarities. Moreover, S arguments have more liberal inductive decision thresholds than G arguments, which suggest that conclusion specificity affects the inductive decision reflected by inductive decision thresholds. Furthermore, G+ arguments elicit greater P3a amplitudes than S+ arguments, which suggest greater attention resources allocation to the review of decisions for G+ arguments than that for S+ arguments. Taken together, the conclusion specificity effect during semantic category-based induction can be revealed by “strong” response rates, inductive decision thresholds, and P3a component after controlling the premise-conclusion similarity, providing evidence that category-based induction rely on more than simple similarity judgment and conclusion specificity would affect category-based induction.

Testing Interactions in Multinomial Processing Tree Models

Multinomial processing tree (MPT) models allow testing hypotheses on latent psychological processes that underlie human behavior. However, past applications of this model class have mainly been restricted to the analysis of main effects. In this paper, we adopt the interaction concept as defined in log-linear models and show why it is appropriate for MPT models. We then explain how to implement and test ordinal and disordinal two-way interaction hypotheses in MPT models. We also show how our method generalizes to higher-order interactions involving three or more factors. An empirical example from source memory and aging demonstrates the applicability of this method and allows for directly testing the associative deficit theory that age differences are larger in associative (e.g., source) memory as opposed to item memory. Throughout the paper, we explain how most analytic steps can be easily implemented in the freely available software multiTree.

More evidence against the Spinozan model: Cognitive load diminishes memory for "true" feedback

We tested two competing models on the memory representation of truth-value information: the Spinozan model and the Cartesian model. Both models assume that truth-value information is represented with memory "tags," but the models differ in their coding scheme. According to the Cartesian model, true information is stored with a "true" tag, and false information is stored with a "false" tag. In contrast, the Spinozan model proposes that only false information receives "false" tags. All other (i.e., untagged) information is considered as true by default. Hence, in case of cognitive load during feedback encoding, the latter model predicts a load effect on memory for "false" feedback, but not on memory for "true" feedback. To test this prediction, participants studied trivia statements (Experiment 1) or nonsense statements that allegedly represented foreign-language translations (Experiment 2). After each statement, participants received feedback on the (alleged) truth value of the statement. Importantly, half of the participants experienced cognitive load during feedback processing. For the trivia statements of Experiment 1, we observed a load effect on memory for both "false" and "true" feedback. In contrast, for the nonsense statements of Experiment 2, we found a load effect on memory for "true" feedback only. Both findings clearly contradict the Spinozan model. However, our results are also only partially in line with the predictions of the Cartesian model. For this reason, we suggest a more flexible model that allows for an optional and context-dependent encoding of "true" tags and "false" tags.

Adaptive memory: enhanced source memory for animate entities

The animacy effect refers to enhanced memory for animate over inanimate items. In two studies, we examined whether this memory advantage generalises to source memory. A multinomial processing tree model was used to disentangle item recognition, source memory, and guessing processes. In Study 1, animate and inanimate words were presented at different spatial locations on the screen. Animacy was associated with enhanced source memory for the spatial locations of the items. In Study 2, pseudowords were associated with animate and inanimate properties. Replicating previous results, the pseudowords were better remembered when they were associated with animate properties than when they were associated with inanimate properties. What is more, participants had enhanced source memory for the association between the pseudowords and the animate properties. The results strengthen the idea that animate items are associated with richer mnemonic representations than inanimate items.

Self-Serving Bias in Memories

Abstract. Protecting one’s positive self-image from damage is a fundamental need of human beings. Forgetting is an effective strategy in this respect. Individuals show inferior recall of negative feedback about themselves but unimpaired recognition of self-related negative feedback. This discrepancy may imply that individuals retain negative information but forget that the information is associated with the self. In two experiments, participants judged whether two-character trait adjectives (positive or negative) described themselves or others. Subsequently, they completed old-new judgments (Experiment 2) and attribution tasks (Experiments 1 and 2). Neither old-new recognition nor source guessing bias was influenced by word valence. Participants’ source memory was worse in the negative self-referenced word processing condition than in the other conditions. These results suggest there is a self-serving bias in memory for the connection between valence information and the self.

Separating conditional and unconditional cooperation in a sequential Prisoner's Dilemma game

Most theories of social exchange distinguish between two different types of cooperation, depending on whether or not cooperation occurs conditional upon the partner’s previous behaviors. Here, we used a multinomial processing tree model to distinguish between positive and negative reciprocity and cooperation bias in a sequential Prisoner’s Dilemma game. In Experiments 1 and 2, the facial expressions of the partners were varied to manipulate cooperation bias. In Experiment 3, an extinction instruction was used to manipulate reciprocity. The results confirm that people show a stronger cooperation bias when interacting with smiling compared to angry-looking partners, supporting the notion that a smiling facial expression in comparison to an angry facial expression helps to construe a situation as cooperative rather than competitive. Reciprocity was enhanced for appearance-incongruent behaviors, but only when participants were encouraged to form expectations about the partners’ future behaviors. Negative reciprocity was not stronger than positive reciprocity, regardless of whether expectations were manipulated or not. Experiment 3 suggests that people are able to ignore previous episodes of cheating as well as previous episodes of cooperation if these turn out to be irrelevant for predicting a partner’s future behavior. The results provide important insights into the mechanisms of social cooperation.

Cognitive Load Does Not Affect the Behavioral and Cognitive Foundations of Social Cooperation

The present study serves to test whether the cognitive mechanisms underlying social cooperation are affected by cognitive load. Participants interacted with trustworthy-looking and untrustworthy-looking partners in a sequential Prisoner's Dilemma Game. Facial trustworthiness was manipulated to stimulate expectations about the future behavior of the partners which were either violated or confirmed by the partners' cheating or cooperation during the game. In a source memory test, participants were required to recognize the partners and to classify them as cheaters or cooperators. A multinomial model was used to disentangle item memory, source memory and guessing processes. We found an expectancy-congruent bias toward guessing that trustworthy-looking partners were more likely to be associated with cooperation than untrustworthy-looking partners. Source memory was enhanced for cheating that violated the participants' positive expectations about trustworthy-looking partners. We were interested in whether or not this expectancy-violation effect-that helps to revise unjustified expectations about trustworthy-looking partners-depends on cognitive load induced via a secondary continuous reaction time task. Although this secondary task interfered with working memory processes in a validation study, both the expectancy-congruent guessing bias as well as the expectancy-violation effect were obtained with and without cognitive load. These findings support the hypothesis that the expectancy-violation effect is due to a simple mechanism that does not rely on demanding elaborative processes. We conclude that most cognitive mechanisms underlying social cooperation presumably operate automatically so that they remain unaffected by cognitive load.

The infamous among us: Enhanced reputational memory for uncooperative ingroup members

People remember uncooperative individuals better than cooperative ones. We hypothesize that this is particularly true when uncooperative individuals belong to one's ingroup, as their behavior violates positive expectations. Two studies examined the effect of minimal group categorization on reputational memory of the social behavior of particular ingroup and outgroup members. We manipulated uncooperative behavior as the unfair sharing of resources with ingroup members (Study 1), or as descriptions of cheating (Study 2). Participants evaluated several uncooperative and cooperative (and neutral) ingroup and outgroup members. In a surprise memory test, they had to recognize target faces and recall their behavior. We disentangled face recognition, reputational memory, and guessing biases with multinomial models of source monitoring. The results show enhanced reputational memory for uncooperative ingroup members, but not uncooperative outgroup members. In contrast, guessing behavior indicated that participants assumed more ingroup cooperation than outgroup cooperation. Our findings integrate prior research on memory for uncooperative person behavior and person memory in group contexts. We suggest that the ability to remember the uncooperative amidst the supposedly cooperative ingroup could stabilize intragroup cooperation.

Source Memory for Mental Imagery: Influences of the Stimuli's Ease of Imagery

The present study investigated how ease of imagery influences source monitoring accuracy. Two experiments were conducted in order to examine how ease of imagery influences the probability of source confusions of perceived and imagined completions of natural symmetric shapes. The stimuli consisted of binary pictures of natural objects, namely symmetric pictures of birds, butterflies, insects, and leaves. The ease of imagery (indicating the similarity of the sources) and the discriminability (indicating the similarity of the items) of each stimulus were estimated in a pretest and included as predictors of the memory performance for these stimuli. It was found that confusion of the sources becomes more likely when the imagery process was relatively easy. However, if the different processes of source monitoring—item memory, source memory and guessing biases—are disentangled, both experiments support the assumption that the effect of decreased source memory for easily imagined stimuli is due to decision processes and misinformation at retrieval rather than encoding processes and memory retention. The data were modeled with a Bayesian hierarchical implementation of the one high threshold source monitoring model.

Event-related potentials in response to cheating and cooperation in a social dilemma game

A sequential prisoner's dilemma game was combined with psychophysiological measures to examine the cognitive underpinnings of reciprocal exchange. Participants played four rounds of the game with partners who either cooperated or cheated. In a control condition, the partners' faces were shown, but no interaction took place. The partners' behaviors were consistent in the first three rounds of the game, but in the last round some of the partners unexpectedly changed strategies. In the first round of the game, the feedback about a partner's decision elicited a feedback P300, which was more pronounced for cooperation and cheating in comparison to the control condition, but did not vary as a function of feedback valence. In the last round, both the feedback negativity and the feedback P300 were sensitive to expectancy violations. There was no consistent evidence for a negativity bias, that is, enhanced allocation of attention to feedback about another person's cheating in comparison to feedback about another person's cooperation. Instead, participants focused on both positive and negative information, and flexibly adjusted their processing biases to the diagnosticity of the information. This conclusion was corroborated by the ERP correlates of memory retrieval. Successful retrieval of a partner's reputation was associated with an anterior positivity between 400 and 600 ms after face onset. This anterior positivity was more pronounced for both cooperator and cheater faces in comparison to control faces. The results suggest that it is not the negativity of social information, but rather its motivational and behavioral relevance that determines its processing.

Influences of Age and Emotion on Source Guessing: Are Older Adults More Likely to Show Fear-Relevant Illusory Correlations?

OBJECTIVES

The present study investigates age differences in the vulnerability to illusory correlations between fear-relevant stimuli and threatening information.

METHOD

Younger and older adults saw pictures of threatening snakes and nonthreatening fish, paired with threatening and nonthreatening context information ("poisonous" and "nonpoisonous") with a null contingency between animal type and poisonousness. In a source monitoring test, participants were required to remember whether an animal was associated with poisonousness or nonpoisonousness. Illusory correlations were implicitly measured via a multinomial model. One advantage of this approach is that memory and guessing processes can be assessed independently. An illusory correlation would be reflected in a higher probability of guessing that a snake rather than a fish was poisonous if the poisonousness of the animal was not remembered.

RESULTS

Older adults showed evidence of illusory correlations in source guessing while younger adults did not; instead they showed evidence of probability matching. Moreover, snake fear was associated with increased vulnerability to illusory correlations in older adults.

DISCUSSION

The findings confirm that older adults are more susceptible to fear-relevant illusory correlations than younger adults.

Context reinstatement and memory for intrinsic versus extrinsic context: the role of item generation at encoding or retrieval

According to many theoretical accounts, reinstating study context at the time of test creates optimal circumstances for item retrieval. The role of context reinstatement was tested in reference to context memory in several experiments. On the encoding phase, participants were presented with words printed in two different font colors (intrinsic context) or two different sides of the computer screen (extrinsic context). At test, the context was reinstated or changed and participants were asked to recognize words and recollect their study context. Moreover, a read-generate manipulation was introduced at encoding and retrieval, which was intended to influence the relative salience of item and context information. The results showed that context reinstatement had no effect on memory for extrinsic context but affected memory for intrinsic context when the item was generated at encoding and read at test. These results supported the hypothesis that context information is reconstructed at retrieval only when context was poorly encoded at study.

How selfish is memory for cheaters? Evidence for moral and egoistic biases

We remember very well when another person has cheated us, but is this due to the cheating's immorality or due to its negative consequences? Theories claiming that reputational memory helps retaliate cheating imply that we should be sensitive both to the norm violation and to the personal consequences of another person's cheating. In the present study, faces were presented with descriptions of immoral and moral behavior. In contrast to previous studies, the morality and the personal consequences of the behaviors were orthogonally manipulated (both cheating and trustworthy behavior could lead to personal benefits or costs). In a surprise memory test, participants were required to remember whether the faces were associated with moral or immoral behaviors, or with personal benefits or costs. Overall, the morality of the behaviors was better remembered than were the personal consequences of the same behaviors. However, the immorality of morally questionable behaviors was well remembered when associated with personal costs, and poorly remembered when associated with personal benefits. Apparently, people's categorization of the social environment is based on moral judgments, but also reflects self-serving biases.

Analyzing Stochastic Dependence of Cognitive Processes in Multidimensional Source Recognition

Stochastic dependence among cognitive processes can be modeled in different ways, and the family of multinomial processing tree models provides a flexible framework for analyzing stochastic dependence among discrete cognitive states. This article presents a multinomial model of multidimensional source recognition that specifies stochastic dependence by a parameter for the joint retrieval of multiple source attributes together with parameters for stochastically independent retrieval. The new model is equivalent to a previous multinomial model of multidimensional source memory for a subset of the parameter space. An empirical application illustrates the advantages of the new multinomial model of joint source recognition. The new model allows for a direct comparison of joint source retrieval across conditions, it avoids statistical problems due to inflated confidence intervals and does not imply a conceptual imbalance between source dimensions. Model selection criteria that take model complexity into account corroborate the new model of joint source recognition.

Internal reinstatement hides cuing effects in source memory tasks

Reinstating source details at test often has no impact on source memory. We tested the proposition that participants internally reinstate source cues when such cues are not provided by the experimenter, thus making the external cues redundant. Participants studied words paired with either a male or a female face and were later asked to specify the gender of the face studied with each word. To disrupt the ability to internally reinstate sources, some participants saw eight male faces and eight female faces throughout the study list (multiple-face condition), making it difficult to determine which face should be internally reinstated for uncued test trials. Other participants saw only a single face for each gender (single-face condition), which should facilitate internal reinstatement. Across three experiments, participants in the multiple-face condition showed improved source discrimination when the studied faces were reinstated at test, as compared to uncued trials. In contrast, participants in the single-face condition showed no effect of the face cues. Moreover, the cuing effect for the multiple-face condition disappeared when the test structure facilitated internal reinstatement. Overall, the experiments support the contention that internal reinstatement is a natural part of source retrieval that can mask the effects of external cues.

Generation Difficulty and Memory for Source

The role of the word predictability from sentence context for reality monitoring and external source monitoring was examined in two experiments. In a reality-monitoring task, discrimination of an internal source was better in the hard than in the easy condition. It is probable that extra cognitive operations engaged during word generation in the hard condition were effective cues for reality-monitoring judgements. In contrast, in an external source-monitoring task (recognition memory of item's colour), the hard condition resulted in worse source memory for generated words than did the easy condition. This result is consistent both with an item–context trade-off hypothesis and a processing hypothesis. Greater effort involved at the time of generation might limit resources available for encoding of an external source. It is also possible that for generated words, the hard condition promoted conceptual processing instead of perceptual processing; therefore the item's colour was not effectively encoded.

The good, the bad, and the rare: memory for partners in social interactions

For cooperation to evolve via direct reciprocity, individuals must track their partners' behavior to avoid exploitation. With increasing size of the interaction group, however, memory becomes error prone. To decrease memory effort, people could categorize partners into types, distinguishing cooperators and cheaters. We explored two ways in which people might preferentially track one partner type: remember cheaters or remember the rare type in the population. We assigned participants to one of three interaction groups which differed in the proportion of computer partners' types (defectors rare, equal proportion, or cooperators rare). We extended research on both hypotheses in two ways. First, participants experienced their partners repeatedly by interacting in Prisoner's Dilemma games. Second, we tested categorization of partners as cooperators or defectors in memory tests after a short and long retention interval (10 min and 1 week). Participants remembered rare partner types better than they remembered common ones at both retention intervals. We propose that the flexibility of responding to the environment suggests an ecologically rational memory strategy in social interactions.

Threshold models of recognition and the recognition heuristic

According to the recognition heuristic (RH) theory, decisions follow the recognition principle: Given a high validity of the recognition cue, people should prefer recognized choice options compared to unrecognized ones. Assuming that the memory strength of choice options is strongly correlated with both the choice criterion and recognition judgments, the RH is a reasonable strategy that approximates optimal decisions with a minimum of cognitive effort (Davis-Stober, Dana, & Budescu, 2010). However, theories of recognition memory are not generally compatible with this assumption. For example, some threshold models of recognition presume that recognition judgments can arise from two types of cognitive states: (1) certainty states in which judgments are almost perfectly correlated with memory strength and (2) uncertainty states in which recognition judgments reflect guessing rather than differences in memory strength. We report an experiment designed to test the prediction that the RH applies to certainty states only. Our results show that memory states rather than recognition judgments affect use of recognition information in binary decisions.

Signal Detection and Threshold Models of Source Memory

Recently, several authors claimed that the curvilinear shape of rating-based source memory receiver operating characteristics (ROCs) refutes threshold models. However, rating-based ROCs are not diagnostic to disprove threshold models. Furthermore, source memory ROC-analyses ignore influences of other processes like old-new-detection and old-new-response-tendencies, so direct estimation of parameters is preferable. Five source monitoring experiments with different response bias manipulations and materials were conducted. We fitted the Two High Threshold Multinomial Model of Source Monitoring by Bayen, Murnane, and Erdfelder (1996) and the Multivariate Signal Detection Model for Selection by DeCarlo (2003) . We also included rating-based ROCs. The results suggest that both models are at least equally valid as measurement tools which capture bias processes in the corresponding parameters, and they can perhaps be integrated theoretically.

Enhanced Source Memory for Names of Cheaters

The present experiment shows that source memory for names associated with a history of cheating is better than source memory for names associated with irrelevant or trustworthy behavior, whereas old-new discrimination is not affected by whether a name was associated with cheating. This data pattern closely replicates findings obtained in previous experiments using facial stimuli, thus demonstrating that enhanced source memory for cheaters is not due to a cheater-detection module closely tied to the face processing system, but is rather due to a more general bias towards remembering the source of information associated with cheating.