Subcortical contributions to the sense of body ownership.

The sense of body ownership (i.e. the feeling that our body or its parts belong to us) plays a key role in bodily self-consciousness and is believed to stem from multisensory integration. Experimental paradigms such as the rubber hand illusion have been developed to allow the controlled manipulation of body ownership in laboratory settings, providing effective tools for investigating malleability in the sense of body ownership and the boundaries that distinguish self from other. Neuroimaging studies of body ownership converge on the involvement of several cortical regions, including the premotor cortex and posterior parietal cortex. However, relatively less attention has been paid to subcortical structures that may also contribute to body ownership perception, such as the cerebellum and putamen. Here, on the basis of neuroimaging and neuropsychological observations, we provide an overview of relevant subcortical regions and consider their potential role in generating and maintaining a sense of ownership over the body. We also suggest novel avenues for future research targeting the role of subcortical regions in making sense of the body as our own.

Scarcity affects cognitive biases: The case of the illusion of causality.

Previous research indicates that economic scarcity affects people's judgments, decisions, and cognition in a variety of contexts, and with various consequences. We hypothesized that scarcity could sometimes reduce cognitive biases. Specifically, it could reduce the causal illusion, a cognitive bias that is at the heart of superstitions and irrational thoughts, and consists of believing that two events are causally connected when they are not. In three experiments, participants played the role of doctors deciding whether to administer a drug to a series of patients. The drug was ineffective, because the percentage of patients recovering was identical regardless of whether they took the drug. We manipulated the budget available to buy the drugs, tough all participants had enough for all their patients. Even so, participants in the scarce group reduced the use of the drug and showed a lower causal illusion than participants in the wealthy group. Experiments 2 and 3 added a phase in which the budget changed. Participants who transitioned from scarcity to wealth exhibited a reduced use of resources and a lower causal illusion, whereas participants transitioning from wealth to scarcity were unaffected by their previous history.

Virtual embodiment in fibromyalgia.

Chronic pain alters the experience of owning a body and leads to disturbances in bodily perception. We tested whether women with fibromyalgia (FM) are receptive to bodily illusions of owning a visible and progressively invisible body in immersive virtual reality (VR), and what modulates this experience. Twenty patients participated in two experimental sessions; each session included two conditions in a counterbalanced order. We found that patients with FM could indeed experience virtual embodiment. Sentiment analysis revealed significantly more positive reactions to the progressively invisible body, yet twice as many patients declared they preferred the illusion of a visible virtual body. A linear mixed model revealed that the strength of embodiment was positively associated with body perception disturbances and negatively associated with FM symptoms intensity. No effect of pain during the VR experience nor interoception awareness on embodiment was found. The results indicated that patients with FM are receptive to virtual bodily illusions and that the impact of the embodiment depends on affective reactions, the level of cognitive body distortions, and the intensity of symptoms. Importantly, there is a large variation among patients which should be considered in future VR-based interventions.

The illusion of moral decline.

Anecdotal evidence indicates that people believe that morality is declining1,2. In a series of studies using both archival and original data (n = 12,492,983), we show that people in at least 60 nations around the world believe that morality is declining, that they have believed this for at least 70 years and that they attribute this decline both to the decreasing morality of individuals as they age and to the decreasing morality of successive generations. Next, we show that people's reports of the morality of their contemporaries have not declined over time, suggesting that the perception of moral decline is an illusion. Finally, we show how a simple mechanism based on two well-established psychological phenomena (biased exposure to information and biased memory for information) can produce an illusion of moral decline, and we report studies that confirm two of its predictions about the circumstances under which the perception of moral decline is attenuated, eliminated or reversed (that is, when respondents are asked about the morality of people they know well or people who lived before the respondent was born). Together, our studies show that the perception of moral decline is pervasive, perdurable, unfounded and easily produced. This illusion has implications for research on the misallocation of scarce resources3, the underuse of social support4 and social influence5.

Children perceive illusory faces in objects as male more often than female.

Face pareidolia is the experience of seeing illusory faces in inanimate objects. While children experience face pareidolia, it is unknown whether they perceive gender in illusory faces, as their face evaluation system is still developing in the first decade of life. In a sample of 412 children and adults from 4 to 80 years of age we found that like adults, children perceived many illusory faces in objects to have a gender and had a strong bias to see them as male rather than female, regardless of their own gender identification. These results provide evidence that the male bias for face pareidolia emerges early in life, even before the ability to discriminate gender from facial cues alone is fully developed. Further, the existence of a male bias in children suggests that any social context that elicits the cognitive bias to see faces as male has remained relatively consistent across generations.

The Dimensional Structure of the Gambling Attitudes and Beliefs Survey: Challenging the Assumption of the Unidimensionality of Gambling-Specific Cognitive Distortions.

The aim of the present study was to examine the dimensional structure of the Gambling Attitudes and Beliefs Survey (GABS). The GABS was administered to a sample of 415 individuals with self-reported problem or pathological gambling who were taking part in two different treatment studies preregistered with the German Clinical Trials Register (DRKS00013888) and ClinicalTrials.gov (NCT03372226). Exploratory factor analyses revealed a three-factor structure. We labeled the factors sensation seeking/illusion of control, luck/gambler's fallacy, and attitude/emotions. Subsequent confirmatory factor analyses proved the three-factor model superior to the one-factor model proposed by the developers of the GABS. All dimensions were significantly correlated with symptom severity scores. Group comparisons showed significantly higher factor scores on the first factor (sensation seeking/illusion of control) for individuals reporting both skill-based and chance-based gambling compared to those reporting only chance-based gambling. The present study questions the unidimensionality of the GABS. A multidimensional assessment of gambling-related cognitive biases, beliefs, and positively valued attitudes may be useful in determining treatment outcomes and goals and in the development of novel interventions.

On the Role of Interoception in Body and Object Perception: A Multisensory-Integration Account.

Various "embodied perception" phenomena suggest that what people sense of their body shapes what they perceive of the environment and that what they perceive of the environment shapes what they perceive of their bodies. For example, an observer's own hand can be felt where a fake hand is seen, events produced by own body movements seem to occur earlier than they did, and feeling a heavy weight at an observer's back may prompt hills to look steeper. Here we argue that such and various other phenomena are instances of multisensory integration of interoceptive signals from the body and exteroceptive signals from the environment. This overarching view provides a mechanistic description of what embodiment in perception means and how it works. It suggests new research questions while questioning a special role of the body itself and various phenomenon-specific explanations in terms of ownership, agency, or action-related scaling of visual information.

Splitting the Unity of Bodily Self: Toward a Comprehensive Review of Phenomenology and Psychopathology of Heautoscopy.

BACKGROUND: Heautoscopy refers to a pathological experience of visual reduplication of one's body with an ambiguous sense of self-location and a disturbing sensation of owning the illusory body. It has been recognized to occur in the course of strikingly diverse psychiatric and neurological disorders, such as schizophrenia, space-occupying lesions, frequently of the temporal or parietal lobes, migraine, epilepsy, and depression. The literature on the subject suffers from numerous conceptual inconsistencies, scarcity of clinical data, and a lack of theoretical integratory framework that could explain the uniqueness of these symptoms. AIMS: In the study, we aimed to review all case reports on heautoscopy we could cull from the literature with an attempt to extract common factors and to foster a theoretical synthesis. METHODS: All medical and psychological databases were rigorously searched, along with reference lists of the preselected articles. First-person reports were classified according to aspects of bodily self-consciousness primarily affected: body ownership, self-location, sense of agency and consequently, collated with their etiological backgrounds. RESULTS: Out of over 140 case studies, a total of only 9 patients with heautoscopy were selected as satisfying functional criteria, carefully distinguishing heautoscopy from other typically conflated full-body anomalies: autoscopy, out-of-body experience, or feeling of presence. Numerous cases turned out to be mislabeling autoscopy or out-of-body experience as heautoscopy. In addition, several problems with existing neuroimaging experiments were identified. CONCLUSION: Phenomenological analysis revealed that from the patients' perspective, heautoscopy resembles a somatesthetic-proprioceptive illusion, rather than a cognitive delusion, and occurs much less frequently than reported. A most peculiar symptom, described by some as a sense of "bilocation," appears to stem from dynamic shifts in self-location and expanded body ownership, rather than an expanded first-person perspective. Although extremely rare in its pure form, heautoscopy gives a unique opportunity to explore the brain limits to the plasticity of bodily boundaries and the origin of the first-person spatial perspective.

Exploring the development of high-level contributions to body representation using the rubber hand illusion and the monkey hand illusion.

During development our body undergoes significant changes, yet we are able to maintain a coherent experience of our body and sense of self. Bodily experience is thought to comprise integration of multisensory signals (vision, touch, and proprioception) constrained by top-down knowledge of body appearance. Evidence from developmental studies suggests that low-level multisensory integration develops throughout childhood, reaching adult levels by 10 years of age. However, how high-level cognitive knowledge changes during childhood to constrain our multisensory body experience is unknown. This study describes four experiments examining high-level contributions to the bodily experience in children compared with adults using the rubber hand illusion and a monkey hand illusion. We found that children (5-17 years of age) exhibited more flexible body representations, showing stronger illusions for small and fantastical (monkey) fake hands compared with adults. Conversely, using a task indirectly capturing changes in hand size, we found that children and adults demonstrated statistically equivalent increases and decreases in hand size following illusions over large and small hands, respectively. Interestingly, at baseline children showed a bias in reporting larger hand size judgments that decreased with age. Finally, we did not find a relationship between individual differences in fantasy proneness and illusion strength for a fantastical (monkey) hand for children or adults, suggesting that developmental changes of top-down constraints are not purely driven by more diffuse boundaries between imagination and reality. These data suggest that high-level constraints acting on our multisensory body experience change during development, allowing children a more flexible bodily experience compared with adults.

Pareidolia in a Built Environment as a Complex Phenomenological Ambiguous Stimuli.

Pareidolia is a kind of misperception caused by meaningless, ambiguous stimuli perceived with meaning. Pareidolia in a built environment may trigger the emotions of residents, and the most frequently observed pareidolian images are human faces. Through a pilot experiment and an in-depth questionnaire survey, this research aims to compare built environmental pareidolian phenomena at different time points (6 a.m., 12 p.m., 2 a.m.) and to determine people's sensitivity and reactions towards pareidolia in the built environment. Our findings indicate that the differences in stress level do not influence the sensitivity and reactions towards pareidolia in the built environment; however, age does, and the age of 40 seems to be a watershed. Females are more likely to identify pareidolian faces than males. Smokers, topers, and long-term medicine users are more sensitive to pareidolian images in the built environment. An unexpected finding is that most pareidolian images in built environments are much more easily detected in the early morning and at midnight but remain much less able to be perceived at midday. The results help architects better understand people's reactions to pareidolia in the built environment, thus allowing them to decide whether to incorporate it appropriately or avoid it consciously in building design.

Self-other distinction modulates the social softness illusion.

The social softness illusion (i.e., the tendency to perceive another person's skin as softer than our own) is thought to promote the sharing of social-emotional experiences because of the rewarding properties of receiving and giving social affective touch. Here we investigated whether the ability to distinguish someone else's body from our own modulates the social softness illusion. In particular, we tested whether the spatial perspective taken by the participants and seeing or not the touched arms could alter this illusion. Pairs of female participants were assigned the roles of either the giver (i.e., delivering the touches) or the receiver (i.e., being touched). We manipulated the location of the touch (palm or forearm), the spatial perspective of the receiver's body with respect to the giver's body (egocentric or allocentric perspective), and the vision of the touched body part (the giver could either see both her own and the receiver's body part, or she was blindfolded). Consistently with previous findings, the skin of another person was perceived as softer than the own one. Additionally, the illusion was present for both the forearm and the palm, and it was stronger in allocentric compared to the egocentric perspective (i.e., when the self-other distinction was clearer). These findings show that the mechanisms underpinning the ability to represent another person's body as distinct from our own modulates the social softness illusion, and thus support the role of the social softness illusion in fostering social relationships.

Ilusão, criatividade e paradoxo: pré-condições para a capacidade de brincar / Ilusión, creatividad y paradoja: condiciones previas para la capacidad de jugar / Illusion, creativity and paradox: preconditions for the ability to play / Illusion, créativité et paradoxe: conditions préalables à la capacité de jouer

Inscrevendo-se de maneira singular na tradição psicanalítica, Winnicott estabelece uma situação de observação padronizada de bebês em que o brincar surge como critério diagnóstico e terapêutico para o desenvolvimento infantil. Esta observação passa a operar como uma matriz do pensamento winnicottiano, a partir da qual será elaborada a teoria do desenvolvimento emocional primitivo. O presente artigo busca destacar quais seriam as precondições para o desenvolvimento da capacidade de brincar do bebê humano, identificando alguns pontos de continuidade e inflexão com relação à teorização freudo-kleiniana sobre o brincar e o desenvolvimento emocional da criança: as relações entre a critividade, ilusão e o paradoxo

Suscribiéndose de una manera única a la tradición psicoanalítica, Winnicott establece una situación de observación estandarizada de bebés en la que el juego aparece como un criterio diagnóstico y terapéutico para el desarrollo infantil. Esta observación comienza a funcionar como una matriz del pensamiento winnicotiano a partir del cual se elaborará la teoría del desarrollo emocional primitivo. El presente artículo busca resaltar cuáles son las condiciones previas para el desarrollo de la capacidad de juego del bebé humano, identificando algunos puntos de continuidad e inflexión en relación con la teorización freudo-kleiniana sobre el juego del niño y el desarrollo emocional: las relaciones entre la crítica, ilusión y la paradoja

Subscribing in a unique way to the psychoanalytic tradition, Winnicott establishes a situation of standardized observation of babies in which playing appears as a diagnostic and therapeutic criterion for child development. This observation starts to operate as a matrix of Winnicottian thought from which the theory of primitive emotional development will be elaborated. The present article seeks to highlight which are the preconditions for the development of the human baby's ability to play, identifying some points of continuity and inflection in relation to Freudo-Kleinian theorizing about the child's play and emotional development: the relationships between criticism , illusion and the paradox

S'inscrivant de façon unique à la tradition psychanalytique, Winnicott établit une situation d'observation standardisée des bébés dans laquelle le jeu apparaît comme un critère diagnostique et thérapeutique du développement de l'enfant. Cette observation commence à fonctionner comme une matrice de la pensée winnicottienne, à partir de laquelle la théorie du développement émotionnel primitif sera élaborée. Cet article cherche à mettre en évidence quelles sont les conditions préalables au développement de la capacité de jeu du bébé humain, en identifiant quelques points de continuité et d'inflexion en relation avec la théorisation freudo-kleinienne du jeu et du développement émotionnel de l'enfant: les relations entre critique, illusion et paradoxe.

The effects of subliminal or supraliminal sadness induction on the sense of body ownership and the role of dissociative symptoms.

Previous research has shown that emotions can alter our sense of ownership. Whether this relationship is modulated by differences in emotion experience and awareness, however, remains unclear. We investigated this by comparing the susceptibility to the rubber hand illusion (RHI) between participants who were either exposed to a low-arousing emotion induction (sadness) or placed in a neutral control group. Several factors that might influence this relationship were considered: dissociative symptoms were included to observe if a sadness induction led to a higher RHI score in participants scoring high in dissociation, as a result of detached emotion experience. Whether the level of awareness of the emotion mattered was also tested, as subliminal processing was shown to require less focal attention. Therefore, our sample (N = 122) was divided into three experimental groups: Sad pictures were presented to two of the three groups differing in presentation mode (subliminal: n = 40, supraliminal: n = 41), neutral pictures were presented supraliminally to the control group (n = 41). Additionally, the effects of slow (3 cm/s) and fast (30 cm/s) stroking, applied either synchronously or asynchronously, were examined as the comforting effects of stroking might interfere with the emotion induction. Results showed that the supraliminal sadness induction was associated with a stronger subjective illusion, but not with a higher proprioceptive drift compared to the subliminal induction. In addition, a stronger subjective illusion after fast and synchronous stroking was found compared to slow and asynchronous stroking. A significant proprioceptive drift was detected independent of group and stroking style. Both slow and synchronous stroking were perceived as more comforting than their respective counterparts. Participants with higher dissociative symptoms were more susceptible to the subjective illusion, especially in the supraliminal group in the synchronous condition. We concluded that individual differences in emotion experience are likely to play a role in body ownership. However, we cannot clarify at this stage whether differences in proprioception and the subjective illusion depend on the type of emotion experienced (e.g. different levels of arousal) and on concomitant changes in multisensory integration processes.

The color phi phenomenon: Not so special, after all?

We show how anomalous time reversal of stimuli and their associated responses can exist in very small connectionist models. These networks are built from dynamical toy model neurons which adhere to a minimal set of biologically plausible properties. The appearance of a "ghost" response, temporally and spatially located in between responses caused by actual stimuli, as in the phi phenomenon, is demonstrated in a similar small network, where it is caused by priming and long-distance feedforward paths. We then demonstrate that the color phi phenomenon can be present in an echo state network, a recurrent neural network, without explicitly training for the presence of the effect, such that it emerges as an artifact of the dynamical processing. Our results suggest that the color phi phenomenon might simply be a feature of the inherent dynamical and nonlinear sensory processing in the brain and in and of itself is not related to consciousness.

Locomotor illusions are generated by perceptual body-environment organization.

While one is walking, the stimulation by one's body forms a structure with the stimulation by the environment. This locomotor array of stimulation corresponds to the human-environment relation that one's body forms with the environment it is moving through. Thus, the perceptual experience of walking may arise from such a locomotor array of stimulation. Humans can also experience walking while they are sitting. In this case, there is no stimulation by one's walking body. Hence, one can experience walking although a basic component of a locomotor array of stimulation is missing. This may be facilitated by perception organizing the sensory input about one's body and environment into a perceptual structure that corresponds to a locomotor array of stimulation. We examined whether locomotor illusions are generated by this perceptual formation of a locomotor structure. We exposed sixteen seated individuals to environmental stimuli that elicited either the perceptual formation of a locomotor structure or that of a control structure. The study participants experienced distinct locomotor illusions when they were presented with environmental stimuli that elicited the perceptual formation of a locomotor structure. They did not experience distinct locomotor illusions when the stimuli instead elicited the perceptual formation of the control structure. These findings suggest that locomotor illusions are generated by the perceptual organization of sensory input about one's body and environment into a locomotor structure. This perceptual body-environment organization elucidates why seated human individuals experience the sensation of walking without any proprioceptive or kinaesthetic stimulation.

Relationships among driving styles, desire for control, illusion of control, and self-reported driving behaviors.

OBJECTIVE: A correlational study examined relationships among driving styles, 4 subfactors of desire for control, illusion of control, accident concern, self-rated likelihood of being involved in an accident, self-rated driving skill, and self-reported accidents, violations, and close calls. METHODS: An online sample of participants (N = 601) completed (1) the Multidimensional Driving Style Inventory (MDSI); (2) the Desirability of Control Scale (DCS); (3) an Illusion of Control Scale; (4) an accident concern self-rating, (5) a 3-item speed questionnaire; (6) a 4-item accidents, violations, and close calls questionnaire; (7) a driving skill self-rating; and (8) a demographic questionnaire. Scales were analyzed using exploratory factor analysis where appropriate. Exploratory correlational analyses examined relationships among factor scores for subscales and other variables of interest. RESULTS: The MDSI factored into 6 distinct driving styles, and the DCS factored in 4 subfactors of desire for control. Relationships among driving styles and other variables were used to create profiles of each of 6 driving styles-angry, anxious, cautious, dissociative, risky, and stress reduction-based on relationships among variables examined. CONCLUSIONS: Our results may help to identify traits that are related to driving behaviors. In general, our results showed that several maladaptive driving styles (dissociative, risky, and angry) were negatively correlated with 2 subscales of desire for control (desire to proactively seek control and desire to control making decisions) and positively correlated with illusion of control. Cautious driving style, which is adaptive, showed the opposite pattern. We also produced evidence to support the construct validity of the MDSI and added to the growing literature suggesting that the MDSI factors into 6 distinct driving styles.

Behavioral and electrophysiological investigations of effects of temporal regularity on illusory-figure processing.

The allocation of limited processing resources at an appropriate timing should be critical for selecting incoming signals. On the other hand, perceptual organization, which relatively automatically integrates fragmentary elements into coherent objects, should also be critical to decrease the processing load. By indexing behavioral measures and event-related potentials (ERPs), this study examined the effects of temporal regularity, which makes it possible to predict the time at which stimuli occur, on task-unrelated early processing of perceptual organization. Twenty-six volunteers participated in a task to discriminate central targets that were simultaneously but infrequently presented inside a Kanizsa-type illusory figure (KF) or a control stimulus (CS) without perception of an illusory figure. Inter-stimulus intervals were fixed or varied in different blocks. Both temporal regularity and the illusory figure accelerated behavioral responses and enlarged negative ERP amplitudes at 120-160 ms and 280-320 ms post-stimulus over posterior electrode sites. However, importantly, there was no evidence indicating that temporal regularity modulates illusory-figure processing. The finding may suggest that temporal expectation operates in parallel with implicit perceptual organization, although further examinations that involve spatial attention or individual differences are required.

Pareidolias and Creativity in Patients with Mental Disorders.

OBJECTIVE: Pareidolias are ilusionary misjudgments and are seen as the result of deliberately or unconsciously caused misinterpretations by the human brain, which tends to complete diffuse and apparently incomplete perceptual images. The psychopathological value of pareidolia in the context of neuropsychiatric diseases has, however, been little researched so far. METHODS: In this pilot study, a total of 25 patients (mean age 43.3 years, SD 16.2) with an affective disorder or schizophrenic disease (ICD-10: F3.X or F2.X) and 25 healthy volunteers (mean age 46.1 years, SD 15.4) were compared for sociodemographic factors and psychometric findings, as well as pareidolias and creativity. RESULTS: We found that the patients identified significantly fewer pareidolias than healthy controls (p = 0.002) and that patients with schizophrenia, in particular, had a significantly lower hit rate (p = 0.005). Across the whole group, there were clear positive correlations between pareidolia and high creativity, as well as personality traits such as impulsiveness/spontaneity, extraversion, and conscientiousness. CONCLUSIONS: Unexpectedly, having less nosology-specific features than individual specific properties such as creativity and extraversion, and especially openness and verbal intelligence, in patients with affective disorder or schizophrenia promotes the recognition of pareidolia as a specific form of illusionary misperception.

Awareness of voluntary action, rather than body ownership, improves motor control.

Awareness of the body is essential for accurate motor control. However, how this awareness influences motor control is poorly understood. The awareness of the body includes awareness of visible body parts as one's own (sense of body ownership) and awareness of voluntary actions over that visible body part (sense of agency). Here, I show that sense of agency over a visible hand improves the initiation of movement, regardless of sense of body ownership. The present study combined the moving rubber hand illusion, which allows experimental manipulation of agency and body ownership, and the finger-tracking paradigm, which allows behavioral quantification of motor control by the ability to coordinate eye with hand movements. This eye-hand coordination requires awareness of the hand to track the hand with the eye. I found that eye-hand coordination is improved when participants experience a sense of agency over a tracked artificial hand, regardless of their sense of body ownership. This improvement was selective for the initiation, but not maintenance, of eye-hand coordination. These results reveal that the prospective experience of explicit sense of agency improves motor control, suggesting that artificial manipulation of prospective agency may be beneficial to rehabilitation and sports training techniques.