The self-reference effect on memory in early childhood.

The self-reference effect in memory is the advantage for information encoded about self, relative to other people. The early development of this effect was explored here using a concrete encoding paradigm. Trials comprised presentation of a self- or other-image paired with a concrete object. In Study 1, 4- to 6-year-old children (N = 53) were asked in each trial whether the child pictured would like the object. Recognition memory showed an advantage for self-paired objects. Study 2 (N = 55) replicated this finding in source memory. In Study 3 (N = 56), participants simply indicated object location. Again, recognition and source memory showed an advantage for self-paired items. These findings are discussed with reference to mechanisms that ensure information of potential self-relevance is reliably encoded.

An unforgettable apple: memory and attention for forbidden objects.

Are we humans drawn to the forbidden? From jumbo-sized soft drinks to illicit substances, the influence of prohibited ownership on subsequent demand has made this question a pressing one. We know that objects that we ourselves own have a heightened psychological saliency, relative to comparable objects that are owned by others, but do these kinds of effects extend from self-owned to "forbidden" objects? To address this question, we developed a modified version of the Turk shopping paradigm in which "purchased" items were assigned to various recipients. Participants sorted everyday objects labeled as "self-owned", "other-owned," and either "forbidden to oneself" (Experiment 1) or "forbidden to everyone" (Experiment 2). Subsequent surprise recognition memory tests revealed that forbidden objects with high (Experiment 1) but not with low (Experiment 2) self-relevance were recognized as well as were self-owned objects, and better than other-owned objects. In a third and final experiment, we used event-related potentials (ERPs) to determine whether self-owned and self-forbidden objects, which showed a common memory advantage, are in fact treated the same at a neurocognitive-affective level. We found that both object types were associated with enhanced cognitive analysis, relative to other-owned objects, as measured by the P300 ERP component. However, we also found that self-forbidden objects uniquely triggered an enhanced response preceding the P300, in an ERP component (the N2) that is sensitive to more rapid, affect-related processing. Our findings thus suggest that, whereas self-forbidden objects share a common cognitive signature with self-owned objects, they are unique in being identified more quickly at a neurocognitive level.

Survival of the selfish: contrasting self-referential and survival-based encoding.

Processing information in the context of personal survival scenarios elicits a memory advantage, relative to other rich encoding conditions such as self-referencing. However, previous research is unable to distinguish between the influence of survival and self-reference because personal survival is a self-referent encoding context. To resolve this issue, participants in the current study processed items in the context of their own survival and a familiar other person's survival, as well as in a semantic context. Recognition memory for the items revealed that personal survival elicited a memory advantage relative to semantic encoding, whereas other-survival did not. These findings reinforce suggestions that the survival effect is closely tied with self-referential encoding, ensuring that fitness information of potential importance to self is successfully retained in memory.

Divided attention selectively impairs memory for self-relevant information.

Information that is relevant to oneself tends to be remembered more than information that relates to other people, but the role of attention in eliciting this "self-reference effect" is unclear. In the present study, we assessed the importance of attention in self-referential encoding using an ownership paradigm, which required participants to encode items under conditions of imagined ownership by themselves or by another person. Previous work has established that this paradigm elicits a robust self-reference effect, with more "self-owned" items being remembered than "other-owned" items. Access to attentional resources was manipulated using divided-attention tasks at encoding. A significant self-reference effect emerged under full-attention conditions and was related to an increase in episodic recollection for self-owned items, but dividing attention eliminated this memory advantage. These findings are discussed in relation to the nature of self-referential cognition and the importance of attentional resources at encoding in the manifestation of the self-reference effect in memory.

Exploring early self-referential memory effects through ownership.

The self-reference effect (SRE) is the reliable memory advantage for information encoded about self over material encoded about other people. The developmental pathway of the SRE has proved difficult to chart, because the standard SRE task is unsuitable for young children. The current inquiry was designed to address this issue using an ownership paradigm, as encoding objects in the context of self-ownership have been shown to elicit self-referential memory advantages in adults. Pairs of 4- to 6-year-old children (n = 64) sorted toy pictures into self- and other-owned sets. A surprise recognition memory test revealed a significant advantage for toys owned by self, which decreased with age. Neither verbal ability nor theory of mind attainment predicted the size of the memory advantage for self-owned items. This finding suggests that contrary to some previous reports, memory in early childhood can be shaped by the same self-referential biases that pervade adult cognition.

Mine and me: exploring the neural basis of object ownership.

Previous research has shown that encoding information in the context of self-evaluation leads to memory enhancement, supported by activation in ventromedial pFC. Recent evidence suggests that similar self-memory advantages can be obtained under nonevaluative encoding conditions, such as when object ownership is used to evoke self-reference. Using fMRI, the current study explored the neural correlates of object ownership. During scanning, participants sorted everyday objects into self-owned or other-owned categories. Replicating previous research, a significant self-memory advantage for the objects was observed (i.e., self-owned > other-owned). In addition, encoding self-owned items was associated with unique activation in posterior dorsomedial pFC (dMPFC), left insula, and bilateral supramarginal gyri (SMG). Subsequent analysis showed that activation in a subset of these regions (dMPFC and left SMG) correlated with the magnitude of the self-memory advantage. Analysis of the time-to-peak data suggested a temporal model for processing ownership in which initial activation of dMPFC spreads to SMG and insula. These results indicate that a self-memory advantage can be elicited by object ownership and that this effect is underpinned by activity in a neural network that supports attentional, reward, and motor processing.

When "it" becomes "mine": attentional biases triggered by object ownership.

Previous research has demonstrated that higher-order cognitive processes associated with the allocation of selective attention are engaged when highly familiar self-relevant items are encountered, such as one's name, face, personal possessions and the like. The goal of our study was to determine whether these effects on attentional processing are triggered on-line at the moment self-relevance is established. In a pair of experiments, we recorded ERPs as participants viewed common objects (e.g., apple, socks, and ketchup) in the context of an "ownership" paradigm, where the presentation of each object was followed by a cue indicating whether the object nominally belonged either to the participant (a "self" cue) or the experimenter (an "other" cue). In Experiment 1, we found that "self" ownership cues were associated with increased attentional processing, as measured via the P300 component. In Experiment 2, we replicated this effect while demonstrating that at a visual-perceptual level, spatial attention became more narrowly focused on objects owned by self, as measured via the lateral occipital P1 ERP component. Taken together, our findings indicate that self-relevant attention effects are triggered by the act of taking ownership of objects associated with both perceptual and postperceptual processing in cortex.

Stereotype-based modulation of person perception.

A core social-psychological question is how cultural stereotypes shape our encounters with other people. While there is considerable evidence to suggest that unexpected targets-such as female airline pilots and male nurses-impact the inferential and memorial aspects of person construal, it has yet to be established if early perceptual operations are similarly sensitive to the stereotype-related status of individuals. To explore this issue, the current investigation measured neural activity while participants made social (i.e., sex categorization) and non-social (i.e., dot detection) judgments about men and women portrayed in expected and unexpected occupations. When participants categorized the stimuli according to sex, stereotype-inconsistent targets elicited increased activity in cortical areas associated with person perception and conflict resolution. Comparable effects did not emerge during a non-social judgment task. These findings begin to elucidate how and when stereotypic beliefs modulate the formation of person percepts in the brain.

Self-reflection and the temporal focus of the wandering mind.

Current accounts suggest that self-referential thought serves a pivotal function in the human ability to simulate the future during mind-wandering. Using experience sampling, this hypothesis was tested in two studies that explored the extent to which self-reflection impacts both retrospection and prospection during mind-wandering. Study 1 demonstrated that a brief period of self-reflection yielded a prospective bias during mind-wandering such that participants' engaged more frequently in spontaneous future than past thought. In Study 2, individual differences in the strength of self-referential thought - as indexed by the memorial advantage for self rather than other-encoded items - was shown to vary with future thinking during mind-wandering. Together these results confirm that self-reflection is a core component of future thinking during mind-wandering and provide novel evidence that a key function of the autobiographical memory system may be to mentally simulate events in the future.

Exploring the effects of ownership and choice on self-memory biases.

Objects encoded in the context of temporary ownership by self enjoy a memorial advantage over objects owned by other people. This memory effect has been linked to self-referential encoding processes. The current inquiry explored the extent to which the effects of ownership are influenced by the degree of personal choice involved in assigning ownership. In three experiments pairs of participants chose objects to keep for ownership by self, and rejected objects that were given to the other participant to own. Recognition memory for the objects was then assessed. Experiment 1 showed that participants recognised more items encoded as "self-owned" than "other-owned", but only when they had been chosen by self. Experiment 2 replicated this pattern when participants' sense of choice was illusory. A source memory test in Experiment 3 showed that self-chosen items were most likely to be correctly attributed to ownership by self. These findings are discussed with reference to the link between owned objects and the self, and the routes through which self-referential operations can impact on cognition.

Attention and awareness: Representation of visuomotor space in split-brain patients.

Each cerebral hemisphere primarily controls and receives sensory input with regard to the contralateral hand. In the disconnected brain (split-brain), when the hands are uncrossed, direct visual access to each hand is available to the controlling (contralateral) hemisphere. However, when a hand crosses the midline, visual and tactile information regarding the hand are presented to different hemispheres. It is unknown how a contralateral hemisphere codes the position and orientation of a visually inaccessible hand in the disconnected brain. The present work addresses this issue. We ask how each hemisphere represents "its" hand across hand positions that span the midline in the absence of cortical input from the contralateral hemisphere. In other words, when a hand is placed across the midline and is visually inaccessible, is it represented by the controlling hemisphere: (1) in accordance with its new position with respect to the body (e.g., a left hand "becomes" a right effector when it crosses the midline), (2) with left/right position information unaltered (e.g., the left hand is represented as "left" regardless of its location), or (3) stripped of its location information altogether? The relationship between hand position and the spatial codes assigned to potential responses (an index of hand representation) was investigated in two split-brain patients using direct (Experiment 1) and orthogonal (Experiment 2) S-R compatibility paradigms. S-R compatibility effects in split-brain patients were consistent with those displayed by typical individuals. These findings suggest that position-based compatibility effects do not rely on cross-cortical connections. Rather, each hemisphere can accurately represent the full visuomotor space, a process that appears to be subserved by subcortical connections between the hemispheres.

Self-memory biases in explicit and incidental encoding of trait adjectives.

An extensive literature has demonstrated that encoding information in a self-referential manner enhances subsequent memory performance. This 'self-reference effect' (i.e., better memory for self-referent than other-referent information) is generally elicited in paradigms that require participants to evaluate the self-descriptiveness of personality characteristics. Extending work of this kind, the current research explored the possibility that explicit evaluative processing is not a necessary precondition for the emergence of this effect. Rather, responses to self cues may enhance item encoding even in the absence of explicit evaluative instructions. We explored this hypothesis by testing memory for items encoded in either an evaluative or relational context. The relational context was achieved by requesting participants to report the spatial relationship between target stimuli, and visual or verbal referent cues. The results revealed a self-referent memory advantage, regardless of the encoding context or triggering cue. The theoretical implications of these findings are considered.

Yours or mine? Ownership and memory.

An important function of the self is to identify external objects that are potentially personally relevant. We suggest that such objects may be identified through mere ownership. Extant research suggests that encoding information in a self-relevant context enhances memory (the so-called 'self-reference effect'), thus an experiment was designed to test the impact of ownership on memory performance. Participants either moved or observed the movement of picture cards into two baskets; one of which belonged to self and one which belonged to another participant. A subsequent recognition test revealed that there was a significant memory advantage for objects that were owned by self. Acting on items (i.e., moving them) had no impact on memory. Results are discussed with reference to the importance of self-object associations in cognition.

Mike or me? Self-recognition in a split-brain patient.

A split-brain patient (epileptic individual whose corpus callosum had been severed to minimize the spread of seizure activity) was asked to recognize morphed facial stimuli--presented separately to each hemisphere--as either himself or a familiar other. Both hemispheres were capable of face recognition, but the left hemisphere showed a recognition bias for self and the right hemisphere a bias for familiar others. These findings suggest a possible dissociation between self-recognition and more generalized face processing within the human brain.

The I in autism: Severity and social functioning in autism are related to self-processing.

It is well established that children with autism spectrum disorder (ASD) show impaired understanding of others and deficits within social functioning. However, it is still unknown whether self-processing is related to these impairments and to what extent self impacts social functioning and communication. Using an ownership paradigm, we show that children with ASD and chronological- and verbal-age-matched typically developing (TD) children do show the self-referential effect in memory. In addition, the self-bias was dependent on symptom severity and socio-communicative ability. Children with milder ASD symptoms were more likely to have a high self-bias, consistent with a low attention to others relative to self. In contrast, severe ASD symptoms were associated with reduced self-bias, consistent with an 'absent-self' hypothesis. These findings indicate that deficits in self-processing may be related to impairments in social cognition for those on the lower end of the autism spectrum. Statement of contribution What is already known on this subject? Impaired self-processing in autism is linked to social and cognitive deficits. There are discrepancies across the literature, with reports of both intact and impaired self-processing in autism. Ownership tasks are developmentally appropriate and have shown to induce self-memory bias in young children. What does this study add? Using an ownership task, children with autism showed a significant self-memory bias, greater than typical peers. Severity was negatively correlated with level of self-bias, potentially explaining the previous discrepancies. Severe autism symptoms are associated with an 'absent self', and mild autism symptoms reduce attention to others.

The self-relevance system?

We suggest that the Self Attention Network (SAN) maybe part of a larger self-regulatory system, which we term the Self-Relevance System (SRS) of which the "core" or default network is a major part. It is within the core network that memories are generated and the future imagined. Such memories and imaginings are the basis of preoccupations. Within the SRS then preoccupations drive the emergence of attentional biases (ABs). ABs in turn are modulated by the SAN activating and inhibiting circuits that shape behavior. We consider briefly how this might function in dysfunctional appetitive behaviors, e.g., substance abuse.

We are more selfish than we think: The endowment effect and reward processing within the human medial-frontal cortex.

Perceived ownership has been shown to impact a variety of cognitive processes: attention, memory, and--more recently--reward processing. In the present experiment we examined whether or not perceived ownership would interact with the construct of value-the relative worth of an object. Participants completed a simple gambling game in which they gambled either for themselves or for another while electroencephalographic data were recorded. In a key manipulation, gambles for oneself or for another were for either small or large rewards. We tested the hypothesis that value affects the neural response to self-gamble outcomes, but not other-gamble outcomes. Our experimental data revealed that while participants learned the correct response option for both self and other gambles, the reward positivity evoked by wins was impacted by value only when gambling for oneself. Importantly, our findings provide additional evidence for a self-ownership bias in cognitive processing and further demonstrate the insensitivity of the medial-frontal reward system to gambles for another.

A preliminary investigation into the neural basis of the production effect.

Items that are produced (e.g., read aloud) during encoding typically are better remembered than items that are not produced (e.g., read silently). This "production effect" has been explained by distinctiveness: Produced items have more distinct features than nonproduced items, leading to enhanced retrieval. The goal of the current study was to use electroencephalography (EEG) to examine the neural basis of the production effect. During study, participants were presented with words that they were required to read silently, read aloud, or sing while EEG data were recorded. Subsequent memory performance was tested using a yes/no recognition test. Analysis focused on the event-related brain potentials (ERPs) evoked by the encoding instruction cue for each instruction condition. Our data revealed enhanced memory performance for produced items and a greater P300 ERP amplitude for instructions to sing or read aloud compared with instructions to read silently. Our results demonstrate that the amplitude of the P300 is modulated by at least 1 aspect of production, vocalization (singing/reading aloud relative to reading silently), and are consistent with the distinctiveness account of the production effect. The ERP methodology is a viable tool for investigating the production effect. (PsycINFO Database Record

Out of contact, out of mind: the distributed nature of the self.

A truly remarkable aspect of human existence is the unitary sense of self that exists across time and place. Understanding the nature of self-what it is and what it does-has challenged scholars since antiquity. How can empirical research measure what it is to have a sense of self? We propose that the sense of self may emerge from the functions of a left hemisphere "interpreter". First, we examine evidence for the existence of self-processing mechanisms in the intact brain, from behavioral and functional neuroimaging research. The available evidence suggests that the sense of self is widely distributed throughout the brain. Second, we discuss these findings in relation to what is known about higher cognitive functions in humans who have undergone a surgical procedure to sever the connection between the two cerebral hemispheres. Split-brain research has facilitated an understanding of the way in which each cerebral hemisphere independently processes information. Research in this area has shown that each cerebral hemisphere features distinct information-processing capabilities. This cognitive asymmetry is reflected in the notion of a left hemisphere interpreter module which, we have argued, generates a unitary sense of consciousness even in the disconnected brain. This chapter describes how this interpreter may also give rise to a unified sense of self.

Eye rivalry and object rivalry in the intact and split-brain.

Both the eye of origin and the images themselves have been found to rival during binocular rivalry. We presented traditional binocular rivalry stimuli (face to one eye, house to the other) and Diaz-Caneja stimuli (half of each image to each eye) centrally to both a split-brain participant and a control group. With traditional rivalry stimuli both the split-brain participant and age-matched controls perceived more coherent percepts (synchronised across the hemifields) than non-synchrony, but our split-brain participant perceived more non-synchrony than our controls. For rival stimuli in the Diaz-Caneja presentation condition, object rivalry gave way to eye rivalry with all participants reporting more non-synchrony than coherent percepts. We have shown that splitting the stimuli across the hemifields between the eyes leads to greater eye than object rivalry, but that when traditional rival stimuli are split as the result of the severed corpus callosum, traditional rivalry persists but to a lesser extent than in the intact brain. These results suggest that communication between the early visual areas is not essential for synchrony in traditional rivalry stimuli, and that other routes for interhemispheric interactions such as subcortical connections may mediate rivalry in a traditional binocular rivalry condition.