The influence of group membership on cross-contextual imitation

Research on mimicry has demonstrated that individuals imitate in-group members more strongly than out-group members. In the present study, we tested whether such top-down modulation also applies for more extreme forms of direct mapping, such as for cross-contextual imitation settings, in which individuals imitate others' movements without sharing a common goal or context. Models on self-other control suggest that top-down modulations are based merely on a direct link between social sensory processing and imitation. That is, perceived similarities between oneself and another person is sufficient to amplify a shared representation between own and others' actions, which then trigger imitation. However, motivational accounts explain such findings with the assumption that individuals are motivated to affiliate with others. Because imitation is linked to positive social consequences, individuals should imitate in-group members more strongly than out-group members. We tested these two theoretical accounts against each other by applying a cross-contextual imitation paradigm. The results demonstrate that in-group members are more strongly cross-contextually imitated than out-group members the higher individuals' motivation to affiliate with the in-group is. This supports motivational models but not self-other control accounts. Further theoretical implications are discussed

New frontiers in the neuroscience of the sense of agency

The sense that I am the author of my own actions, including the ability to distinguish my own from other people's actions, is a fundamental building block of our sense of self, on the one hand, and successful social interactions, on the other. Using cognitive neuroscience techniques, researchers have attempted to elucidate the functional basis of this intriguing phenomenon, also trying to explain pathological abnormalities of action awareness in certain psychiatric and neurological disturbances. Recent conceptual, technological, and methodological advances suggest several interesting and necessary new leads for future research on the neuroscience of agency. Here I will describe new frontiers for the field such as the need for novel and multifactorial paradigms, anatomically plausible network models for the sense of agency, investigations of the temporal dynamics during agentic processing and ecologically valid virtual reality (VR) applications

A multimodal investigation of matching mechanisms in automatic imitation

In recent years, research on imitation focused on investigating the underlying neural mechanisms; to this aim simple paradigms were developed to experimentally investigate the phenomenon. Following the natural tendency of humans to mimic gestures and postures of their conspecifics, paradigms of automatic imitation are nowadays widely used in the field. The main aim of my dissertation is to investigate how imitation occurs using an automatic imitation paradigm, in particular focusing on the matching processes that are required to map model and performers actions.The dissertation contains six chapters. In chapter 1, I will provide a brief background of the current theoretical accounts of imitation and of the concepts of automatic imitation and compatibility effects. I will particularly focus on the questions concerning automatic imitation that are still to be fully addressed, particularly those related to the distinction of imitative and spatial compatibility. I will also address the neuroimaging and neuropsychological literature on the neural correlates of imitation. In chapter 2, I will present a neuroimaging study I carried out to investigate the imitation components. Throughout all the studies of this thesis, we used a simple automatic imitation paradigm that is suitable to differentiate between the spatial compatibility and the imitative compatibility, due to the anatomical correspondence between model and performer. Results of the first study showed that the parietal opercula are active anytime the anatomical correspondence between model and performer is present. Hence, in chapter 3 I will present a study in which double-pulse TMS was used to investigate the role of the parietal opercula in automatic imitation, and in particular in coding the imitative compatibility. Results showed that when the activity in the parietal opercula is interfered by TMS, the imitative compatibility effect disappears. In the second part of my thesis I have investigated the factors that can interact with and modulate imitative behaviors. Chapter 4 contains an fMRI study in which the role of the model in imitation is investigated. Using a simplified version of the automatic imitation paradigm, I found that the fronto-parietal network, usually associated to imitation, is more active when participants perform actions that are compatible with those performed by a human model than by a non biological model. Moreover, in this study I have also investigated how different emotional contexts can influence the automatic tendency to imitate. The results showed that the activation of the fronto-parietal network is suppressed by emotional context, such as an angry face, that does not promote affiliative tendencies. In chapter 5 I will describe a neuropsychological study on brain damaged patients. Associations and dissociations between automatic imitation and action imitation were investigated, to analyze the differences between the two types of imitation. Moreover, the role of putative body representations in imitation and whether these body representations are needed for imitation has been investigated. Lastly, in chapter 6 I will wrap up the main results of my dissertation and I will argue that I was able to provide evidence that in automatic imitation an anatomical matching operates between the model and the performer, and that this is sustained by the parietal opercula. In addition I clarified the importance of the model, showing that the activity of fronto-parietal regions supporting imitative behaviors is modulated by model identity

The influence of action observation on action execution : dissociating the contribution of action on perception, perception on action, and resolving conflict

For more than 15 years, motor interference paradigms have been used to investigate the influence of action observation on action execution. Most research on so-called automatic imitation has focused on variables that play a modulating role or investigated potential confounding factors. Interestingly, furthermore, a number of functional magnetic resonance imaging (fMRI) studies have tried to shed light on the functional mechanisms and neural correlates involved in imitation inhibition. However, these fMRI studies, presumably due to poor temporal resolution, have primarily focused on high-level processes and have neglected the potential role of low-level motor and perceptual processes. In the current EEG study, we therefore aimed to disentangle the influence of low-level perceptual and motoric mechanisms from high-level cognitive mechanisms. We focused on potential congruency differences in the visual N190 - a component related to the processing of biological motion, the Readiness Potential - a component related to motor preparation, and the high-level P3 component. Interestingly, we detected congruency effects in each of these components, suggesting that the interference effect in an automatic imitation paradigm is not only related to high-level processes such as self-other distinction but also to more low-level influences of perception on action and action on perception. Moreover, we documented relationships of the neural effects with (autistic) behavior

The role of the temporoparietal junction in self-other distinction

Being able to discriminate between what originates from ourselves and what originates from others is critical for efficient interactions with our social environment. However, it remains an open question whether self-other distinction is a domain-general mechanism that is involved in various social-cognitive functions or whether specific 'self-other distinction mechanisms' exist for each of these functions. On the neural level, there is evidence that self-other distinction is related to a specific brain region at the border of the superior temporal and inferior parietal cortex, the temporoparietal junction (TPJ). Demonstrating that the TPJ plays a role in social processes that require self-other distinction would support the idea of a domain-general mechanism of self-other distinction. In the present paper, we review evidence coming from clinical observations, neuroimaging experiments and a meta-analysis indicating the involvement of the TPJ in various cognitive operations requiring self-other distinction. At the perceptual level, we discuss the human ability to identify one's own body and to distinguish it from others. At the action level, we review research on the human ability to experience agency and the control of imitative response tendencies. Finally, at the mental-state level, we discuss the ability to attribute mental states to others. Based on this integrative review, we suggest that the TPJ, and in particular its dorsal part, supports a domain general ability to enhance task-relevant representations when self-related and other-related representations are in conflict. Finally, this conception allows us to propose a unifying architecture for the emergence of numerous socio-cognitive abilities

Does the brain know who is at the origin of what in an imitative interaction?

Brain correlates of the sense of agency have recently received increased attention. However, the explorations remain largely restricted to the study of brains in isolation. The prototypical paradigm used so far consists of manipulating visual perception of own action while asking the subject to draw a distinction between self- versus externally caused action. However, the recent definition of agency as a multifactorial phenomenon combining bottom-up and top-down processes suggests the exploration of more complex situations. Notably there is a need of accounting for the dynamics of agency in a two-body context where we often experience the double faceted question of who is at the origin of what in an ongoing interaction. In a dyadic context of role switching indeed, each partner can feel body ownership, share a sense of agency and altogether alternate an ascription of the primacy of action to self and to other. To explore the brain correlates of these different aspects of agency, we recorded with dual EEG and video set-ups 22 subjects interacting via spontaneous versus induced imitation (II) of hand movements. The differences between the two conditions lie in the fact that the roles are either externally attributed (induced condition) or result from a negotiation between subjects (spontaneous condition). Results demonstrate dissociations between self- and other-ascription of action primacy in delta, alpha and beta frequency bands during the condition of II. By contrast a similar increase in the low gamma frequency band (38–47 Hz) was observed over the centro-parietal regions for the two roles in spontaneous imitation (SI). Taken together, the results highlight the different brain correlates of agency at play during live interactions

The Phenomenological Origins of Property

This thesis delineates the phenomenological basis of ownership and property. The phenomenological theory of property has three main elements: the minimal self, the relationship between the sense of agency and the sense of ownership, and the psychological phenomenon of associative self-anchoring. The well established neurocognitive concept of the minimal self encapsulates a person’s immediate self-consciousness, and the non-conceptual senses of agency and ownership are two integral constituents of this immediate sensory experience. Notably, this sense of self is typified by a motor intentionality (i.e., the minimal self is primed for goal-directed actions). The motor character of the minimal self primarily manifests itself in the construct of the body schema—a dynamic mental model of the body that functions as an instrument of directed action. A remarkable feature of the body schema is that it expands to incorporate extracorporeal objects that are objectively controlled by the person (e.g., grasping a pen or holding an umbrella). Moreover, this embodiment of extracorporeal objects is accompanied by the phenomenological feeling of ownership towards the embodied objects. In fact, I demonstrate with the aid of empirical evidence from cognitive neuroscience and neuropsychology that the sense of ownership and the sense of agency are inextricably linked, and that the sense of agency modulates (engenders) the sense of ownership. In other words, the mere experience of agency over an object is capable of evoking the sense of ownership—the influence of the sense of agency in eliciting the sense of ownership is moderated by gestalt-like principles of priority, consistency, and exclusivity. In addendum, the non-conceptual sense of ownership is shaped and strengthened by the formation of implicit self-object associations—people psychologically associate themselves with their possessions. Altogether, the motor-intentional nature of the self, the inherent sensory experience of ownership, and the capacity to establish self-object psychological associations make the concept of personal property a natural correlate of mechanisms that lead to the development of self-perception and representation. The phenomenological theory also elucidates the psychological literature on ownership judgments and the vague concept of intellectual property. It is also emphasised that aspects of this property theory are analogous to Hegel’s theory of property. As a result, the phenomenological theory may have implications for Hegelian conceptions of property, and can aid them in determining legitimate property relations—these typically denote a close connection between property and personhood

Hypnotic Suggestions: Their Nature and Applicability in Studying Executive Functions

Exekutive Funktionen (EF) sind eine Gruppe von Top-Down-Prozessen, die in neuartigen Situationen eingesetzt werden, um neue Trigger-Response-Assoziationen herzustellen oder vorhandene Handlungsoptionen an neue Situationen anzupassen. Obwohl EF erschöpfend untersucht wurden, bleiben wichtige Fragen offen. Beispiele dafür sind (a) Sind Exekutivfunktionen vollständig trennbar oder beruhen sie auf einem gemeinsamen neurokognitiven System? (b) Was messen verschiedene Versionen der Stroop-Aufgabe, einer der meist-verwendeten Aufgaben zur Prüfung der Inhibitionsfunktion? (c) Muss Inhibition immer Ressourcen-fordernd sein, oder gibt es eine Form der Inhibition, die mühelos implementiert werden kann? Zur Beantwortung dieser Fragen, habe ich neurokognitive Korrelate von EF und ihrer Verbesserung mithilfe posthypnotischer Suggestionen (PHS) und Ereigniskorrelierter Hirnpotentiale (EKP) untersucht. Zusammenfassend ergaben sich folgende Antworten: (a) Psychometrische und EKP-Daten aus den Studien zur Gedächtnisaktualisierung und Inhibition sowie deren Verbesserung anhand PHS zeigten sowohl funktionsspezifische als auch gemeinsame neurokognitive Prozesse der Inhibition und Aktualisierung. (b) Obwohl sowohl die vokale als auch die manuelle Version der Stroop-Aufgabe Inhibitionsfunktionen erfordern, ist die vokale Version Ressourcen-fordernder, da sie mindestens einen zusätzlichen Lokus der Interferenz im Antwort-Produktionsprozess aufweist, der nicht mit PHS beeinflussbar ist und der in der manuellen Version fehlt. (c) Unter Verwendung PHS zur Erhöhung der Präferenzen für kalorienarme Lebensmittel untersuchte ich die Auflösung von Konflikten. Die EKP-Ergebnisse zeigten, dass auch Konflikt-Auflösung, ähnlich wie Inhibition, Ressourcen konsumiert. Insgesamt zeigt dieses Projekt, dass die Verwendung Aufgaben-bezogener PHS in Kombination mit Neuroimaging-Techniken einen fruchtbaren Ansatz für die Untersuchung ungeklärter Fragen über Exekutivfunktionen darstellt.Executive functions (EF) are a group of top-down processes used in novel situations to develop or adapt existing responses to the task at hand. Even though EFs are studied exhaustively, several important questions remain unanswered: (a) Are EFs entirely separated, or do they rely on a common system? (b) What do different versions of the Stroop task measure? (c) Does inhibition always need to be effortful? To address these questions, I investigated neurocognitive correlates of EFs and their enhancements by means of posthypnotic suggestions (PHS) and event-related potentials (ERP). However, before one can use PHSs, it must be elucidated whether and how they affect EFs. Although PHSs are used repeatedly for improving inhibition, it is unclear whether their effects are mediated by bottom-up or top-down processes. By using an updating task, I showed that effects of PHSs can be attributed to top-down processes. Accordingly, a new theory of hypnosis was proposed and empirically tested by modeling hypnotizability scores with structural equation modeling. In short, the simulation-adaption theory suggests that several top-down processes are employed for responding to suggestions. After elucidating the driving mechanism of PHSs is mentally practicing a novel strategy, PHSs were used for addressing the questions regarding EFs. Summarizing (a) the psychometric and ERP results from several studies indicated that different EFs rely on both function-specific and shared neurocognitive processes. (b) Even though different versions of the Stroop task are tapping into inhibition, the vocal compared to the manual version has at least an extra response-production-related locus of interference. (c) Using PHSs for increasing preferences for low-calorie food items, it is shown that resolve is effortful to implement, as indicated by increased P300 amplitudes. Together, this project shows how PHSs, along with neuroimaging techniques, can provide a novel approach for investigating EFs

Investigating social gaze as an action-perception online performance

Gaze represents a major non-verbal communication channel in social interactions. In this respect, when facing another person, one's gaze should not be examined as a purely perceptive process but also as an action-perception online performance. However, little is known about processes involved in the real-time self-regulation of social gaze. The present study investigates the impact of a gaze-contingent viewing window on fixation patterns and the awareness of being the agent moving the window. In face-to-face scenarios played by a virtual human character, the task for the 18 adult participants was to interpret an equivocal sentence which could be disambiguated by examining the emotional expressions of the character speaking. The virtual character was embedded in naturalistic backgrounds to enhance realism. Eye-tracking data showed that the viewing window induced changes in gaze behavior, notably longer visual fixations. Notwithstanding, only half of the participants ascribed the window displacements to their eye movements. These participants also spent more time looking at the eyes and mouth regions of the virtual human character. The outcomes of the study highlight the dissociation between non-volitional gaze adaptation and the self-ascription of agency. Such dissociation provides support for a two-step account of the sense of agency composed of pre-noetic monitoring mechanisms and reflexive processes, linked by bottom-up and top-down processes. We comment upon these results, which illustrate the relevance of our method for studying online social cognition, in particular concerning autism spectrum disorders (ASD) where the poor pragmatic understanding of oral speech is considered linked to visual peculiarities that impede facial exploration