The ownership memory self-reference effect shifts recognition criterion but not recognition sensitivity.

Information referenced to the self is retrieved more accurately than information referenced to others, known as the memory self-reference effect. It is unclear, however, whether social context (identity of the other) or task factors alter decision-making processes. In a virtual object allocation task, female participants sorted objects into their own or another's (stranger or mother) basket based on a colour cue. Subsequently, they performed a recognition memory task in which they first indicated whether each object was old or new, and then whether it had been allocated to themselves or to the other. We obtained owner-specific hit rates and false-alarm rates and applied signal detection theory to derive separate recognition sensitivity (d') and recognition criterion parameters (c) for self- and other-owned objects. While there was no clear evidence of a recognition self-reference effect, or a change in sensitivity, participants adopted a more conservative recognition criterion for self- compared with other-owned objects, and particularly when the other-referent was the participant's mother compared with the stranger. Moreover, when discriminating whether the originally presented objects were self- or other-owned, participants were biased toward ascribing ownership to the 'other'. We speculate that these findings reflect ownership-based changes in decisional processing during the recognition memory self-reference paradigm.

Multisensory processing impacts memory for objects and their sources.

Multisensory object processing improves recognition memory for individual objects, but its impact on memory for neighboring visual objects and scene context remains largely unknown. It is therefore unclear how multisensory processing impacts episodic memory for information outside of the object itself. We conducted three experiments to test the prediction that the presence of audiovisual objects at encoding would improve memory for nearby visual objects, and improve memory for the environmental context in which they occurred. In Experiments 1a and 1b, participants viewed audiovisual-visual object pairs or visual-visual object pairs with a control sound during encoding and were subsequently tested on their memory for each object individually. In Experiment 2, objects were paired with semantically congruent or meaningless control sounds and appeared within four different scene environments. Memory for the environment was tested. Results from Experiments 1a and 1b showed that encoding a congruent audiovisual object did not significantly benefit memory for neighboring visual objects, but Experiment 2 showed that encoding a congruent audiovisual object did improve memory for the environments in which those objects were encoded. These findings suggest that multisensory processing can influence memory beyond the objects themselves and that it has a unique role in episodic memory formation. This is particularly important for understanding how memories and associations are formed in real-world situations, in which objects and their surroundings are often multimodal.

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.

Who said what to whom? Memory for sources and destinations in monolinguals and bilinguals.

Two experiments with monolingual and bilingual participants tested memory for sources (speakers) and destinations (listeners) in conversations consisting of self-referential statements. In Experiment 1, participants directly interacted in English conversations with audio-visually recorded confederates. In Experiment 2, participants observed recorded conversations among confederates. In both conversational situations, source memory was more accurate than destination memory, indicating that the attentional resources consumed by self-focus or sentence production/completion do not explain why destinations are less well remembered than sources in direct-interaction conversations. Source and destination memory were positively associated with item memory at the participant level, indicating that stronger item encoding is associated with stronger encoding of contextual information. In the observed conversations, source and destination accuracy were negatively associated at the trial level, indicating that these features of the memory episode are not encoded independently, and there is a tradeoff in the encoding of these contextual features. Item memory did not differ for monolinguals and bilinguals and was positively associated with proficiency only in conversations with direct interaction. In the observational setting (but not the direct-interaction setting), source and destination memory were more accurate for bilinguals than monolinguals. This finding suggests that bilinguals allocate attention more efficiently than monolinguals when the cognitive demands of sentence production are eliminated. Proficiency in English was positively associated with memory for the appropriate conversational partner only when participants had to produce sentence frames and complete them with self-generated information, suggesting that language proficiency is beneficial when cognitive demands are high.

The limited memory of value following value directed encoding.

Items associated with higher values during encoding are later recognized and recalled better than are lower valued items. During recall paradigms, these value directed encoding (VDE) effects heavily depend upon learned strategies acquired during repeated testing with earnings feedback. However, because VDE effects also occur in single test recognition designs, precluding such learning, it has been suggested that high value may automatically induce good encoding. We tested this by manipulating encoding instructions (Experiments 1a and 1b) and manipulating concurrent levels of processing (LOP) requirements during encoding (Experiment 2a and 2b). Two main findings emerged. First, subject initiated strategies played a dominant role in VDE effects with little evidence for automaticity. This was demonstrated in Experiment 1 by a more than three-fold increase in the VDE recognition effect when instructions specifically encouraged selective elaboration of high-value items. It was also shown by the complete elimination of VDE recognition effects in Experiment 2 when LOP tasks were concurrently performed during encoding. Critically, the blocking of VDE effects occurred even though a catch trial procedure verified that value was being processed during encoding and remained even when subjects had unlimited time to process the materials during encoding. Second, the data showed, for the first time, that when subjects attempted to specify the value of recognized items, they heavily depended upon a recognition heuristic in which increases in recognition strength, even when nondiagnostic, were inferred to reflect high encoding value. The tendency for subjects to conflate recognition strength and value may have important implications for behavioral economics.

The effects of forewarning and divided attention on context retrieval in false recognition.

After studying a list of words that are semantically associated to a critical lure, participants are more likely to attribute a falsely recognised critical lure to the context of its strong than weak semantic associates. This is known as the source-strength effect. The current study investigated the roles of automatic and controlled processing in context retrieval in false recognition that is demonstrated by the source-strength effect. The results revealed that the source-strength effect was impervious to forewarning (Experiment 1) and remained intact when attentional resources at encoding were reduced (Experiment 2), suggesting that context retrieval in false recognition is based on automatic processes that are not amenable to conscious control and do not require many attentional resources. This interpretation is consistent with the associative activation theory, which proposes that context retrieval in false recognition is based on memory associations between contexts and critical lures that are automatically created when critical lures become automatically activated via spreading activation process.

Enhanced source memory for emotionally valenced sources: does an affective orienting task make the difference?

Previous research on whether source memory is enhanced for emotionally valenced sources yielded inconclusive results. To identify potential boundary conditions, we tested whether encoding instructions that promote affective versus different types of non-affective item-source-processing foster versus hamper source-valence effects. In both experiments, we used neutral words as items superimposed on emotional (positive & negative) or neutral pictures as sources. Source pictures were selected based on valence and arousal ratings collected in a pre-study such that only valence varied across sources. Source memory was measured via multinomial modelling. In Experiment 1, we applied an affective, item-focused orienting task (OT; i.e. word-pleasantness ratings) during item-source encoding and found enhanced source memory for emotionally valenced (positive & negative) compared to neutral sources. In Experiment 2, we systematically manipulated encoding instructions and again found enhanced source memory for emotionally valenced sources with an affective OT. No such effects occurred in the non-affective conditions, where participants were instructed to integrate item and source (item-source-fit judgments), to focus on the item (living-non-living judgments), or to encode the items only, respectively. With intentional item encoding, however, source memory was surprisingly better for positive than negative sources. We conclude that source-valence effects might unfold only under affective processing.

Retrieving effectively from source memory: Evidence for differentiation and local matching processes.

The ability to distinguish between different explanations of human memory abilities continues to be the subject of many ongoing theoretical debates. These debates attempt to account for a growing corpus of empirical phenomena in item-memory judgments, which include the list strength effect, the strength-based mirror effect, and output interference. One of the main theoretical contenders is the Retrieving Effectively from Memory (REM) model. We show that REM, in its current form, has difficulties in accounting for source-memory judgments - a situation that calls for its revision. We propose an extended REM model that assumes a local-matching process for source judgments alongside source differentiation. We report a first evaluation of this model's predictions using three experiments in which we manipulated the relative source-memory strength of different lists of items. Analogous to item-memory judgments, we observed a null list strength effect and a strength-based mirror effect in the case of source memory. In a second evaluation, which relied on a novel experiment alongside two previously published datasets, we evaluated the model's predictions regarding the manifestation of output interference in item and lack of it in source memory judgments. Our results showed output interference severely affecting the accuracy of item-memory judgments but having a null or negligible impact when it comes to source-memory judgments. Altogether, these results support REM's core notion of differentiation (for both item and source information) as well as the concept of local matching proposed by the present extension.

Brain representations of space and time in episodic memory: A systematic review and meta-analysis.

All experiences preserved within episodic memory contain information on the space and time of events. The hippocampus is the main brain region involved in processing spatial and temporal information for incorporation within episodic memory representations. However, the other brain regions involved in the encoding and retrieval of spatial and temporal information within episodic memory are unclear, because a systematic review of related studies is lacking and the findings are scattered. The present study was designed to integrate the results of functional magnetic resonance imaging and positron emission tomography studies by means of a systematic review and meta-analysis to provide converging evidence. In particular, we focused on identifying the brain regions involved in the retrieval of spatial and temporal information. We identified a spatial retrieval network consisting of the inferior temporal gyrus, parahippocampal gyrus, superior parietal lobule, angular gyrus, and precuneus. Temporal context retrieval was supported by the dorsolateral prefrontal cortex. Thus, the retrieval of spatial and temporal information is supported by different brain regions, highlighting their different natures within episodic memory.

Emotional dissociations in temporal associations: opposing effects of arousal on memory for details surrounding unpleasant events.

Research targeting emotion's impact on relational episodic memory has largely focused on spatial aspects, but less is known about emotion's impact on memory for an event's temporal associations. The present research investigated this topic. Participants viewed a series of interspersed negative and neutral images with instructions to create stories linking successive images. Later, participants performed a surprise memory test, which measured temporal associations between pairs of consecutive pictures where one picture was negative and one was neutral. Analyses focused on how the order of negative and neutral images during encoding influenced retrieval accuracy. Converging results from a discovery study (N = 72) and pre-registered replication study (N = 150) revealed a "forward-favouring" effect of emotion in temporal memory encoding: Participants encoded associations between negative stimuli and subsequent neutral stimuli more strongly than associations between negative stimuli and preceding neutral stimuli. This finding may reflect a novel trade-off regarding emotion's effects on memory and is relevant for understanding affective disorders, as key clinical symptoms can be conceptualised as maladaptive memory retrieval of temporal details.

Differentiating the DF effect in episodic memory: evaluating the contribution of the procedures of collaborative memory.

Existing research has demonstrated a significant directed forgetting (DF) effect in memory. However, it remains unclear whether this phenomenon would occur in the context of interpersonal collaboration. Additionally, the contribution of emotional valence to the DF effect in item memory and source memory (which are subtypes of episodic memory) also needs to be explored. To address these issues, we conducted two experiments that combined the collaborative memory paradigm with the item-method procedure of DF. In both experiments, positive, neutral, or negative words were presented as stimuli, each followed by an R/F cue during encoding. We conducted two recalls, labeled Recall 1 and Recall 2, which consisted of both memory tasks. Recall 1 was performed either individually or collaboratively, whereas Recall 2 was done individually. Experiment 1 and Experiment 2 adopted the free-flowing procedure and the turn-taking procedure of collaborative memory, respectively. We obtained three implications from our current findings. (a) The occurrence of the DF effect in item memory was found regardless of the procedure of collaborative memory, and it was insensitive to the emotional valence of words or to whether participants had collaborated or not. These patterns demonstrate that both the mechanisms of elaborative rehearsal and active suppression/encoding blocking were engaged across words of different emotional valences and in nominal and collaborative circumstances. (b) In source memory, the DF effect showed different patterns in ongoing and post-collaborative memory, which underpins the dual-process models. (c) The amplitude of the DF effect was sensitive to the interaction of emotional valence by the status of collaboration, and the impact of collaboration differed between the two experiments, offering telling evidence of different aspects of the retrieval strategy disruption hypothesis (RSDH). Directions for identifying more influential factors are put forward.

Not so different after all? An event-related potential study on item and source memory for object-scene pairs in German and Chinese young adults.

In recent years, several cross-cultural studies reported that Westerners focus more on central aspects of a scene (e.g., an object) relative to peripheral aspects (e.g., the background), whereas Easterners more evenly allocate attention to central and peripheral aspects. In memory tasks, Easterners exhibit worse recognition for the central object when peripheral aspects are changed, whereas Westerners are less affected by peripheral changes. However, most of these studies rely on hit rates without correcting for response bias, whereas studies accounting for response bias failed to replicate cultural differences in memory tasks. In this event-related potential (ERP) study, we investigated item and source memory for semantically unrelated object-scene pairs in German and Chinese young adults using memory measures corrected for response bias (i.e., the discrimination index Pr). Both groups completed study-test cycles with either item memory tests or source memory tests. In item memory blocks, participants completed an old/new recognition test for the central object. Source memory blocks entailed an associative recognition test for the association between object and background. Item and source memory were better for intact than for recombined pairs. However, as verified with frequentist and Bayesian analyzes, this context effect was not modulated by culture. The ERP results revealed an old/new effect for the item memory task in both groups which was again not modulated by culture. Our findings suggest that cultural differences in young adults do not manifest in intentional memory tasks probing memory for object-scene pairs without semantic relations when using bias-corrected memory measures.

Sensitivity of late ERP old/new effects in source memory to self-referential encoding focus and stimulus emotionality.

In episodic memory, the old/new effect, the contrast of the waveforms elicited by the correctly recognized studied items and the correctly rejected novel items, has been broadly concerned. However, the contribution of self-referential encoding to the old/new effect in source memory (i.e., source-SRE), is far from clarification; further, it remains unclear whether the contribution is susceptible to the factor of stimulus emotionality. To address these issues, adopting the event-related potential (ERP) technique, this study applied words of three types of emotional valences (positive, neutral, vs. negative) in the self-focus vs. external-focus encoding tasks. In the course of the test, four ERP old/new effects were identified: (a) the familiarity- and recollection-reflected mid-frontal effect (FN400) and late positive component (LPC) were both independent of source-SRE and stimulus emotionality; (b) the reconstruction-driven late posterior negativity (LPN) exhibited an adverse pattern of source-SRE and was susceptible to the emotional valence by encoding focus; and (c) the right frontal old/new effect (RFE), reflecting post-retrieval process, exhibited a source-SRE in emotional words. These effects provide compelling evidence for the influences of both stimulus valence and encoding focus on SRE in source memory, especially during the late processes. Further directions considering more perspectives are put forward.

Does Expecting Matter? The Impact of Experimentally Established Expectations on Subsequent Memory Retrieval of Emotional Words.

Previous studies have confirmed that different degrees of expectation, including the bipolarity of the expected and unexpected, as well as an intermediate level (no expectation), can affect memory. However, only a few investigations have manipulated expectation through experimentally established schema, with no consideration of how expectation impacts both item and source memory. Furthermore, stimulus emotionality may also impact memory. Therefore, we conducted a study to investigate the effects of three levels of expectation on item and source memory while considering the impact of stimulus emotionality. The experiment began with a phase dedicated to learning the rules. In the subsequent study phase, negative and neutral words were manipulated as expected, no expectation, and unexpected, based on these rules. This was followed by tasks focused on item and source memory. The study found that there was a "U-shape" relationship between expectation and item memory. Additionally, the study revealed the distinct impacts of expectation on item and source memory. When it came to item memory, both expected and unexpected words were better remembered than those with no expectations. In source memory, expected words showed memory inferiority for expectation-irrelevant source information, but an advantage for expectation-relevant source information. Stimulus emotionality modulated the effect of expectation on both item and source memory. Our findings provide behavioral evidence for the schema-linked interactions between medial prefrontal and medial temporal regions (SLIMM) theory, which proposes that congruent and incongruent events enhance memory through different brain regions. The different patterns between item and source memory also support dual-process models. Moreover, we speculate that processing events with varying levels of emotionality may undermine the impact of expectation, as implied by other neural investigations.

The temporal development of memory processes in source monitoring: An investigation with mouse tracking.

The present study investigated whether we first remember an item (e.g., a word itself) and then its source (e.g., position on the screen) or whether the retrieval of item and source information can (partially) overlap. Participants were tested on the source either in immediate sequence to item recognition (as standard in source-monitoring research) or following as a separate block after full completion of the item recognition test to separate these processes in time, providing a baseline. Using the mouse-tracking procedure during the item and source tests, we analyzed how item and source decisions unfolded qualitatively over time. Despite no significant difference in the aggregated trajectory curvatures, more thorough analyses based on the individual trajectories revealed differences across the test formats. In the standard format, trajectories were less curved in the source than in the item test. In contrast, in the blocked format, this difference was in the other direction with source showing more curved trajectories than item. Alternative interpretations of mouse-trajectory curvatures on the source-monitoring paradigm and what their difference may imply for item and source processing are discussed.

Loneliness is associated with a greater self-reference effect in episodic memory when compared against a close friend.

Loneliness describes a negative experience associated with perceived social disconnection. Despite the clear links between loneliness and mental and physical health, relatively little is known about how loneliness affects cognition. In this study, we tested the effect of loneliness on cognitive distance between the self and others, using a task in which participants completed a surprise memory task for adjectives implicitly encoded in relation to the self, a close friend or a celebrity. We assessed item memory sensitivity, metacognitive sensitivity, metacognitive efficiency and source memory for positive and negative words. In addition, participants reported their trait loneliness and depression. Results revealed an overall self-referential advantage compared with both friend and celebrity encoded items. Likewise, a friend-referential advantage was identified compared to celebrity-encoded items. Individuals who experienced more loneliness showed a greater self-referential bias in comparison to words encoded in relation to a close friend, and a smaller friend-referential bias in comparison to words encoded in relation to celebrity. These findings suggest that loneliness is reflected in a greater cognitive distance between the self and close friends in relation to memory biases. The results have important implications for understanding the social contextual effects on memory and the cognitive ramifications of loneliness.

Lack of source memory as a potential marker of early assimilation of novel items into current knowledge.

In daily life, humans process a plethora of new information that can be either consistent (familiar) or inconsistent (novel) with prior knowledge. Over time, both types of information can integrate into our accumulated knowledge base via distinct pathways. However, the mnemonic processes supporting the integration of information that is inconsistent with prior knowledge remain under-characterized. In the current study, we used functional magnetic resonance imaging (fMRI) to examine the initial assimilation of novel items into the semantic network. Participants saw three repetitions of adjective-noun word pairs that were either consistent or inconsistent with prior knowledge. Twenty-four hours later, they were presented with the same stimuli again while undergoing fMRI scans. Outside the scanner, participants completed a surprise recognition test. We found that when the episodic context associated with initially inconsistent items was irretrievable, the neural signature of these items was indistinguishable from that of consistent items. In contrast, initially inconsistent items with accessible episodic contexts showed neural signatures that differed from those associated with consistent items. We suggest that, at least one day post encoding, items inconsistent with prior knowledge can show early assimilation into the semantic network only when their episodic contexts become inaccessible during retrieval, thus evoking a sense of familiarity.

The spatiotemporal gradient of intrusion errors in continuous outcome source memory: Source retrieval is affected by both guessing and intrusions.

Previous research has characterized source retrieval as a thresholded process, which fails on a proportion of trials and leads to guessing, as opposed to a continuous process, in which response precision varies across trials but is never zero. The thresholded view of source retrieval is largely based on the observation of heavy tailed distributions of response errors, thought to reflect a large proportion of "memoryless" trials. In this study, we investigate whether these errors might instead reflect systematic intrusions from other list items which can mimic source guessing. Using the circular diffusion model of decision making, which accounts for both response errors and RTs we found that intrusions account for some, but not all, errors in a continuous-report source memory task. We found that intrusion errors were more likely to come from items studied in nearby locations and times, and were well-described by a spatiotemporal gradient model, but not from semantically or perceptually similar cues. Our findings support a thresholded view of source retrieval but suggest that previous work has overestimated the proportion of guesses which have been conflated with intrusions.

Negative comments and social media: How cognitive biases relate to body image concerns.

Body image concern (BIC) is a prevalent issue thought to be exacerbated by social media. In addition to sociocultural factors, cognitive biases may also contribute to BIC. We explore whether cognitive biases in memory for body image-related words, presented in a mock social-media context, are associated with BIC in young adult women. A sample of 150 university students was presented with a series of body image-related comments aimed at either themselves, a close friend, or a celebrity in a recognisable social media context. Afterwards, a surprise memory task was completed that assessed the participant's memory for body image-related words (item memory), their insight (metamemory), and to whom a specific word was directed (source memory). Self-referential biases were identified for both item memory and source memory. Individuals with greater BIC displayed a greater self-referential bias for correctly and incorrectly sourcing negative words to themselves compared with both friend and celebrity. A greater self-referential effect in metacognitive sensitivity was also associated with higher BIC. We provide novel evidence for a cognitive bias in sourcing negative body image-related information to the self in individuals with higher BIC. The results should inform cognitive remediation programmes aimed at treating individuals with body and eating-related disorders.

Impaired cognitive performance in older adults is associated with deficits in item memory and memory for object features.

Amnestic mild cognitive impairment (aMCI) is associated with damage to the perirhinal/entorhinal cortex, and consequently, deficits in item/object memory. However, cognitive assessments commonly used to identify individuals with aMCI require a clinician to administer and interpret the test. We developed a novel self-administered global cognitive assessment, called the Cognitive Assessment via Keyboard (CAKe). To assess the relationship between CAKe performance and perirhinal/entorhinal cortex-dependent memory function, participants completed the CAKe, a feature source memory task, and a context memory task. During the memory tasks, participants studied line drawings with either a green or orange internal color (feature memory runs) or external color (context memory runs) and then classified each item as old and previously presented with a "green" or "orange" color, or "new". CAKe scores were correlated with item memory accuracies and source memory accuracies on both tasks. Participants with 'impaired' CAKe performance had worse item memory and worse feature source memory accuracies than those with 'normal' CAKe performance. These results demonstrate specific deficits in item memory and feature source memory and suggest that our assessments may be a valid predictor of aMCI memory deficits.