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1.
Sci Rep ; 11(1): 2221, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33500486

RESUMO

Embodying an artificial agent through immersive virtual reality (IVR) may lead to feeling vicariously somatosensory stimuli on one's body which are in fact never delivered. To explore whether vicarious touch in IVR reflects the basic individual and social features of real-life interpersonal interactions we tested heterosexual men/women and gay men/lesbian women reacting subjectively and physiologically to the observation of a gender-matched virtual body being touched on intimate taboo zones (like genitalia) by male and female avatars. All participants rated as most erogenous caresses on their embodied avatar taboo zones. Crucially, heterosexual men/women and gay men/lesbian women rated as most erogenous taboo touches delivered by their opposite and same gender avatar, respectively. Skin conductance was maximal when taboo touches were delivered by female avatars. Our study shows that IVR may trigger realistic experiences and ultimately allow the direct exploration of sensitive societal and individual issues that can otherwise be explored only through imagination.

2.
Psychol Res ; 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32524205

RESUMO

Frequency-specific tendon vibration (TV) elicits illusory kinesthetic sensations around the vibrated body parts. Studies indicate that vision plays a fundamental role in modulating such illusions. In our current study, we used immersive virtual reality (IVR) to investigate the role of body-related visual feedback in modulating illusory sensation of movement in the left arm. Thirty healthy participants were asked to evaluate the onset of motor illusion and four illusion-related features (vividness, duration, extension and aftereffect), in the presence and absence of real and virtual visual feedback. Additionally, subjective reports of the embodiment illusion (the sense of embodying a virtual surrogate) were collected in virtual conditions. Results showed a progressive decrease in the perception of the motor illusion along a continuum ranging from the absence of visual feedback (maximal illusory perception) to the observation of one's own real arm (minimal illusory perception). Interestingly, the appearance of the virtual limbs affected the movement illusion differently. Specifically, TV evoked a stronger kinesthetic illusion when observing the virtual hand detached from the limb than during the observation of the virtual full limb and virtual object. This suggests that a closer visual resemblance between the virtual and real limb results in a greater effect on proprioceptive processing. However, no significant correlation was found between the illusion of arm movement and the illusion of embodiment, indicating that the two phenomena may not be directly related. These findings provide new insight into the role of body-related visual feedback in modulating motor illusions.

3.
Cortex ; 127: 131-149, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32197149

RESUMO

Discrepancies between sensory predictions and action outcome are at the base of error coding. However, these phenomena have mainly been studied focussing on individual performance. Here, we explored EEG responses to motor prediction errors during a human-avatar interaction and show that Theta/Alpha activity of the frontal error-monitoring system works in phase with activity of the occipito-temporal node of the action observation network. Our motor interaction paradigm required healthy individuals to synchronize their reach-to-grasp movements with those of a virtual partner in conditions that did (Interactive) or did not require (Cued) movement prediction and adaptation to the partner's actions. Crucially, in 30% of the trials the virtual partner suddenly and unpredictably changed its movement trajectory thereby violating the human participant's expectation. These changes elicited error-related neuromarkers (ERN/Pe - Theta/Alpha modulations) over fronto-central electrodes during the Interactive condition. Source localization and connectivity analyses showed that the frontal Theta/Alpha activity induced by violations of the expected interactive movements was in phase with occipito-temporal Theta/Alpha activity. These results expand current knowledge about the neural correlates of on-line interpersonal motor interactions linking the frontal error-monitoring system to visual, body motion-related, responses.

4.
Sci Rep ; 10(1): 5412, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32214171

RESUMO

Body ownership (the feeling that one's body belongs to oneself) is commonly studied with Rubber hand illusion (RHI) paradigm that allows inducing a temporary illusory feeling of ownership of a life-sized rubber hand. However, it remains unclear whether illusory ownership of the fake hand relies on the same mechanisms as ownership of one's own real hand. Here, we directly compared ownership of the own hand (OH) and fake hand (FH) in the same set of conditions within immersive virtual reality. We obtained behavioral (proprioceptive drift) and subjective (questionnaire) measures of ownership and disownership for virtual OH, FH and object (Obj) that were located congruently or incongruently with the participant's real hand and were stimulated synchronously or asynchronously with the real hand. Both OH and FH (but not Obj) were embodied after synchronous stimulation in both locations. Crucially, subjective ownership of the OH was stronger than of the FH in congruent location after synchronous stimulation. It was also present after asynchronous stimulation, being stronger when the virtual OH was subjectively more similar to the real hand. The results suggest that the detailed appearance of the body might act as an additional component in the construction of body ownership.


Assuntos
Mãos/fisiologia , Ilusões/fisiologia , Percepção Visual/fisiologia , Adulto , Imagem Corporal , Feminino , Humanos , Masculino , Propriocepção/fisiologia , Percepção do Tato/fisiologia , Adulto Jovem
5.
Hum Mov Sci ; 70: 102569, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31950897

RESUMO

Over the last decades, virtual reality (VR) emerged as a potential tool for developing new rehabilitation treatments in neurological patients. However, despite the increasing number of studies, a clear comprehension about the impact of immersive VR-treatment on balance and posture is still scarce. In the present study, we aimed to investigate the effects of VR cues on balance performances of subjects affected by stroke, age-matched healthy subjects, and young healthy subjects. Fifteen patients with sub-acute stroke, fifteen healthy elderly subjects and fifteen healthy young adults took part in this study. All groups were immersed in a CAVE system on a stabilometric platform. The experiment consisted in fourteen trials: (i) ten VR trials, which differed in term of speed and movement direction; (ii) two-stabilometric static sessions, with opened and closed eyes (one at the start and one at the end of the experimental session). Results showed that VR trials increased the sway path length (representative of the body sway amplitudes), in young subjects. Elderly and patients showed less changes in postural sway during virtual reality stimulation than young group. These findings may suggest that a physiological postural performance is not simply evaluable assessing stability, but also assessing the ability of adapting body oscillations to the external stimuli.


Assuntos
Equilíbrio Postural , Reabilitação do Acidente Vascular Cerebral/métodos , Realidade Virtual , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Simulação por Computador , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Movimento , Desempenho Psicomotor , Adulto Jovem
6.
J Neurophysiol ; 123(1): 420-427, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31800367

RESUMO

Recent theories posit that physiological signals contribute to corporeal awareness, the basic feeling that one has a body (body ownership) that acts according to one's will (body agency) and occupies a specific position (body location). Combining physiological recordings with immersive virtual reality, we found that an ecological mapping of real respiratory patterns onto a virtual body illusorily changes corporeal awareness. This new way of inducing a respiratory bodily illusion, called "embreathment," revealed that breathing is almost as important as visual appearance for inducing body ownership and more important than any other cue for body agency. These effects were moderated by individual levels of interoception, as assessed through a standard heartbeat-counting task and a new "pneumoception" task. By showing that respiratory, visual, and spatial signals exert a specific and weighted influence on the fundamental feeling that one is an embodied agent, we pave the way for a comprehensive hierarchical model of corporeal awareness.NEW & NOTEWORTHY Our body is the only object we sense from the inside; however, it is unclear how much inner physiology contributes to the global sensation of having a body and controlling it. We combine respiration recordings with immersive virtual reality and find that making a virtual body breathe like the real body gives an illusory sense of ownership and agency over the avatar, elucidating the role of a key physiological process like breathing in corporeal awareness.

7.
Eur J Neurosci ; 51(3): 937-951, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31630450

RESUMO

Our research focused on the role of vision and proprioception in modulating a defensive reflex (hand blink reflex, HBR) whose magnitude is enhanced when the threatened hand is inside the peripersonal space of the face. We capitalized on virtual reality, which allows dissociating vision and proprioception by presenting a virtual limb in congruent/incongruent positions with respect to the participants' limb. In experiment 1, participants placed their own stimulated hand in far/near positions with respect to their face (postural manipulation task), while observing a virtual empty scenario. Vision was not informative, but the HBR was significantly enhanced in near compared with far position, suggesting that proprioception is sufficient for the HBR modulation to occur. In experiment 2, participants did not perform the postural manipulation but they (passively) observed the avatar's virtual limb performing it. Proprioceptive signals were not informative, but the HBR was significantly enhanced when the observed virtual limb was near to the face, suggesting that visual information plays a role in modulating the HBR. In experiment 3, both participants and avatar performed the postural manipulation, either congruently (both of them far/near) or incongruently (one of them far, the other near). The HBR modulation was present only in congruent conditions. In incongruent conditions, the conflict between vision and proprioception confounded the system, abolishing the difference between far and near positions. Taken together, these findings promote the view that observing a virtual limb modulates the HBR, providing also new evidence on the role of vision and proprioception in modulating this subcortical reflex.

8.
Exp Brain Res ; 237(10): 2621-2632, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31375863

RESUMO

Despite the many links between body representation, acting and perceiving the environment, no research has to date explored whether specific tool embodiment in conditions of sensorimotor deprivation influences extrapersonal space perception. We tested 20 spinal cord injured (SCI) individuals to investigate whether specific wheelchair embodiment interacts with extrapersonal space representation. As a measure of wheelchair embodiment, we used a Body View Enhancement Task in which participants (either sitting in their own wheelchair or in one which they had never used before) were asked to respond promptly to flashing lights presented on their above- and below-lesion body parts. Similar or slower reaction times (RT) to stimuli on the body and wheelchair indicate, respectively, the presence or absence of tool embodiment. The RTs showed that the participants embodied their own wheelchair but not the other one. Moreover, they coded their deprived lower limbs as external objects and, when not in their own wheelchair, also showed disownership of their intact upper limbs. To measure extrapersonal space perception, we used a novel, ad hoc designed paradigm in which the participants were asked to observe a 3D scenario by means of immersive virtual reality and estimate the distance of a flag positioned on a ramp. In healthy subjects, errors in estimation increased as the distance increased, suggesting that they mentally represent the physical distance. The same occurred with the SCI participants, but only when they were in their own wheelchair. The results demonstrate for the first time that tool embodiment modifies extrapersonal space estimations.


Assuntos
Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Cadeiras de Rodas , Adulto , Idoso , Imagem Corporal , Feminino , Corpo Humano , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação
9.
Acta Psychol (Amst) ; 196: 42-50, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30986565

RESUMO

The biological-tuning of the Action Observation Network is highly debated. A current open question relates to whether the morphological appearance (body shape) and/or the biological motion of the observed agent triggers action simulation processes. Motor simulation of the partner's action is critical for motor interactions, where two partners coordinate their actions in space and time. It supports interpersonal alignment and facilitates online coordination. However, motor simulation also leads to visuo-motor interference effects when people are required to coordinate with complementary actions, i.e. incongruent movements as compared to the observed ones. Movement kinematics of interactive partners allows us to capture their automatic tendency to simulate and imitate the partner's complementary movements. In an online reach-to-grasp task, we investigated whether visuo-motor interference effects, visible in the kinematics of complementary movements, are modulated by the visual presence of the interactor's body shape. We asked participants to interact with 1) a humanoid agent with a human-like body shape and with real human, biological, movement kinematics, or 2) a non-humanoid agent, which did not resemble the human body-shape but moved with the same real kinematics. Through the combination of inferential and Bayesian statistics, the results show no effect of interactor's body shape on visuo-motor interference in reaching and grasping kinematics during online motor coordination. We discuss the results and propose that the kinematics of the observed movements, during motor interactions, might be the key factor for visuo-motor interference to take place independently from the morphological appearance of the partner. This is particularly relevant in a technological society that constantly asks humans to interact with artificial agents.


Assuntos
Força da Mão/fisiologia , Corpo Humano , Comportamento Imitativo/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Teorema de Bayes , Fenômenos Biomecânicos , Tamanho Corporal/fisiologia , Feminino , Humanos , Masculino , Movimento/fisiologia
10.
J Clin Med ; 9(1)2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31906009

RESUMO

We combined virtual reality and multisensory bodily illusion with the aim to characterize and reduce the perceptual (body overestimation) and the cognitive-emotional (body dissatisfaction) components of body image distortion (BID) in anorexia nervosa (AN). For each participant (20 anorexics, 20 healthy controls) we built personalized avatars that reproduced their own body size, shape, and verisimilar increases and losses of their original weight. Body overestimation and dissatisfaction were measured by asking participants to choose the avatar that best resembled their real and ideal body. Results show higher body dissatisfaction in AN, caused by the desire of a thinner body, and no body-size overestimation. Interpersonal multisensory stimulation (IMS) was then applied on the avatar reproducing participant's perceived body, and on the two avatars which reproduced increases and losses of 15% of it, all presented with a first-person perspective (1PP). Embodiment was stronger after synchronous IMS in both groups, but did not reduce BID in participants with AN. Interestingly, anorexics reported more negative emotions after embodying the fattest avatar, which scaled with symptoms severity. Overall, our findings suggest that the cognitive-emotional, more than the perceptual component of BID is severely altered in AN and that perspective (1PP vs. 3PP) from which a body is evaluated may play a crucial role. Future research and clinical trials might take advantage of virtual reality to reduce the emotional distress related to body dissatisfaction.

11.
J Cogn Neurosci ; 30(5): 737-751, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29308985

RESUMO

Although temporal coordination is a hallmark of motor interactions, joint action (JA) partners do not simply synchronize; rather, they dynamically adapt to each other to achieve a joint goal. We created a novel paradigm to tease apart the processes underlying synchronization and JA and tested the causal contribution of the left anterior intraparietal sulcus (aIPS) in these behaviors. Participants had to synchronize their congruent or incongruent movements with a virtual partner in two conditions: (i) being instructed on what specific action to perform, independently from what action the partner performed (synchronization), and (ii) being instructed to adapt online to the partner's action (JA). Offline noninvasive inhibitory brain stimulation (continuous theta-burst stimulation) over the left aIPS selectively modulated interpersonal synchrony in JA by boosting synchrony during congruent interactions and impairing it during incongruent ones, while leaving performance in the synchronization condition unaffected. These results suggest that the left aIPS plays a causal role in supporting online adaptation to a partner's action goal, whereas it is not necessarily engaged in social situations where the goal of the partner is irrelevant. This indicates that, during JAs, the integration of one's own and the partner's action goal is supported by aIPS.


Assuntos
Relações Interpessoais , Movimento , Lobo Parietal/fisiologia , Desempenho Psicomotor , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Tempo de Reação , Estimulação Magnética Transcraniana , Adulto Jovem
12.
Expert Rev Med Devices ; 15(2): 107-117, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29313388

RESUMO

INTRODUCTION: Over recent decades many researchers and clinicians have started to use Virtual Reality (VR) as a new technology for implementing innovative rehabilitation treatments in cognitive and motor domains. However, the expression 'VR' has often also been improperly used to refer to video games. Further, VR efficacy, often confused with that of video-game exercises, is still debated. AREAS COVERED: In this review, we provide the scientific rationale for the advantages of using VR systems in rehabilitation and investigate whether the VR could really be a promising technique for the future of rehabilitation of patients, or if it is just an entertainment for scientists. In addition, we describe some of the most used devices in VR with their potential advantages for research and provide an overview of the recent evidence and meta-analyses in rehabilitation. EXPERT COMMENTARY: We highlight the efficacy and fallacies of VR in neurorehabilitation and discuss the important factors emerging from the use of VR, including the sense of presence and the embodiment over a virtual avatar, in developing future applications in cognitive and motor rehabilitation.


Assuntos
Transtornos Cognitivos/reabilitação , Transtornos Motores/reabilitação , Realidade Virtual , Humanos , Reabilitação Neurológica , Robótica , Reabilitação do Acidente Vascular Cerebral/métodos , Jogos de Vídeo
13.
Soc Cogn Affect Neurosci ; 12(11): 1793-1802, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29140533

RESUMO

Limb apraxia (LA) is a high-order motor disorder linked to left-hemisphere damage. It is characterized by defective execution of purposeful actions upon delayed imitation, or verbal command when the actions are performed in isolated, non-naturalistic, conditions. Whether interpersonal interactions provide social affordances that activate neural resources different from those requested by individual action execution, which may improve LA performance, is unknown. To fill this gap, we measured interaction performance, behavioral and kinematic indexes of left-brain damaged patients with/without LA in a social reach-to-grasp task involving two different degrees of spatio-temporal interactivity with an avatar. We found that LA patients' impairment in coordinating with the virtual partner was abolished in highly interactive conditions (where patients selected their actions on-line based on the behavior of the virtual partner) with respect to low interactive conditions (where actions were selected beforehand based on abstract instructions). Voxel-based-Lesion-Symptom-Mapping indicated that impairments in low-interactive conditions were underpinned by lesions of premotor, motor and insular areas, and of the basal ganglia. Our approach expands current understanding of the behavioral and neural correlates of interactive motor performance by highlighting the important role of social affordances, and provides novel, potentially important, views on rehabilitation of higher-order motor cognition disorders.


Assuntos
Apraxias/fisiopatologia , Desempenho Psicomotor/fisiologia , Interface Usuário-Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos/fisiologia , Feminino , Força da Mão/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade
14.
Eur J Neurosci ; 45(9): 1141-1151, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28222235

RESUMO

To explore the link between Sense of Embodiment (SoE) over a virtual hand and physiological regulation of skin temperature, 24 healthy participants were immersed in virtual reality through a Head Mounted Display and had their real limb temperature recorded by means of a high-sensitivity infrared camera. Participants observed a virtual right upper limb (appearing either normally, or with the hand detached from the forearm) or limb-shaped non-corporeal control objects (continuous or discontinuous wooden blocks) from a first-person perspective. Subjective ratings of SoE were collected in each observation condition, as well as temperatures of the right and left hand, wrist and forearm. The observation of these complex, body and body-related virtual scenes resulted in increased real hand temperature when compared to a baseline condition in which a 3d virtual ball was presented. Crucially, observation of non-natural appearances of the virtual limb (discontinuous limb) and limb-shaped non-corporeal objects elicited high increase in real hand temperature and low SoE. In contrast, observation of the full virtual limb caused high SoE and low temperature changes in the real hand with respect to the other conditions. Interestingly, the temperature difference across the different conditions occurred according to a topographic rule that included both hands. Our study sheds new light on the role of an external hand's visual appearance and suggests a tight link between higher-order bodily self-representations and topographic regulation of skin temperature.


Assuntos
Mãos/fisiologia , Temperatura Cutânea/fisiologia , Realidade Virtual , Percepção Visual/fisiologia , Adulto , Temperatura Corporal , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Interface Usuário-Computador
15.
Front Psychol ; 7: 481, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27065937

RESUMO

Over the last few years, the efforts to reveal through neuroscientific lens the relations between the mind, body, and built environment have set a promising direction of using neuroscience for architecture. However, little has been achieved thus far in developing a systematic account that could be employed for interpreting current results and providing a consistent framework for subsequent scientific experimentation. In this context, the enactive perspective is proposed as a guide to studying architectural experience for two key reasons. Firstly, the enactive approach is specifically selected for its capacity to account for the profound connectedness of the organism and the world in an active and dynamic relationship, which is primarily shaped by the features of the body. Thus, particular emphasis is placed on the issues of embodiment and motivational factors as underlying constituents of the body-architecture interactions. Moreover, enactive understanding of the relational coupling between body schema and affordances of architectural spaces singles out the two-way bodily communication between architecture and its inhabitants, which can be also explored in immersive virtual reality settings. Secondly, enactivism has a strong foothold in phenomenological thinking that corresponds to the existing phenomenological discourse in architectural theory and qualitative design approaches. In this way, the enactive approach acknowledges the available common ground between neuroscience and architecture and thus allows a more accurate definition of investigative goals. Accordingly, the outlined model of architectural subject in enactive terms-that is, a model of a human being as embodied, enactive, and situated agent, is proposed as a basis of neuroscientific and phenomenological interpretation of architectural experience.

16.
J Neurosci ; 36(2): 268-79, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26758821

RESUMO

UNLABELLED: Brain monitoring of errors in one's own and other's actions is crucial for a variety of processes, ranging from the fine-tuning of motor skill learning to important social functions, such as reading out and anticipating the intentions of others. Here, we combined immersive virtual reality and EEG recording to explore whether embodying the errors of an avatar by seeing it from a first-person perspective may activate the error monitoring system in the brain of an onlooker. We asked healthy participants to observe, from a first- or third-person perspective, an avatar performing a correct or an incorrect reach-to-grasp movement toward one of two virtual mugs placed on a table. At the end of each trial, participants reported verbally how much they embodied the avatar's arm. Ratings were maximal in first-person perspective, indicating that immersive virtual reality can be a powerful tool to induce embodiment of an artificial agent, even through mere visual perception and in the absence of any cross-modal boosting. Observation of erroneous grasping from a first-person perspective enhanced error-related negativity and medial-frontal theta power in the trials where human onlookers embodied the virtual character, hinting at the tight link between early, automatic coding of error detection and sense of embodiment. Error positivity was similar in 1PP and 3PP, suggesting that conscious coding of errors is similar for self and other. Thus, embodiment plays an important role in activating specific components of the action monitoring system when others' errors are coded as if they are one's own errors. SIGNIFICANCE STATEMENT: Detecting errors in other's actions is crucial for social functions, such as reading out and anticipating the intentions of others. Using immersive virtual reality and EEG recording, we explored how the brain of an onlooker reacted to the errors of an avatar seen from a first-person perspective. We found that mere observation of erroneous actions enhances electrocortical markers of error detection in the trials where human onlookers embodied the virtual character. Thus, the cerebral system for action monitoring is maximally activated when others' errors are coded as if they are one's own errors. The results have important implications for understanding how the brain can control the external world and thus creating new brain-computer interfaces.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Relações Interpessoais , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Ondas Encefálicas , Eletroencefalografia , Potenciais Evocados , Feminino , Análise de Fourier , Humanos , Masculino , Observação , Estimulação Luminosa , Tempo de Reação/fisiologia , Fatores de Tempo , Interface Usuário-Computador , Adulto Jovem
17.
Sci Rep ; 5: 17139, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26602036

RESUMO

When we look at our hands we are immediately aware that they belong to us and we rarely doubt about the integrity, continuity and sense of ownership of our bodies. Here we explored whether the mere manipulation of the visual appearance of a virtual limb could influence the subjective feeling of ownership and the physiological responses (Skin Conductance Responses, SCRs) associated to a threatening stimulus approaching the virtual hand. Participants observed in first person perspective a virtual body having the right hand-forearm (i) connected by a normal wrist (Full-Limb) or a thin rigid wire connection (Wire) or (ii) disconnected because of a missing wrist (m-Wrist) or a missing wrist plus a plexiglass panel positioned between the hand and the forearm (Plexiglass). While the analysis of subjective ratings revealed that only the observation of natural full connected virtual limb elicited high levels of ownership, high amplitudes of SCRs were found also during observation of the non-natural, rigid wire connection condition. This result suggests that the conscious embodiment of an artificial limb requires a natural looking visual body appearance while implicit reactivity to threat may require physical body continuity, even non-naturally looking, that allows the implementation of protective reactions to threat.


Assuntos
Emoções/fisiologia , Pele/metabolismo , Percepção Visual/fisiologia , Adulto , Condutividade Elétrica , Mãos/fisiologia , Humanos , Modelos Logísticos , Masculino , Estimulação Luminosa , Inquéritos e Questionários
18.
Cogn Process ; 16 Suppl 1: 425-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26224275

RESUMO

The recent efforts aimed at providing neuroscientific explanations of how people perceive and experience architectural environments have largely justified the initial belief in the value of neuroscience for architecture. However, a systematic development of a coherent theoretical and experimental framework is missing. To investigate the neurophysiological reactions related to the appreciation of ambiances, we recorded the electroencephalographic (EEG) signals in an immersive virtual reality during the appreciation of interior designs. Such data have been analyzed according to the working hypothesis that appreciated environments involve embodied simulation mechanisms and circuits mediating approaching stimuli. EEG recordings of 12 healthy subjects have been performed during the perception of three-dimensional interiors that have been simulated in a CAVE system and judged according to dimensions of familiarity, novelty, comfort, pleasantness, arousal and presence. A correlation analysis on personal judgments returned that scores of novelty, pleasantness and comfort are positively correlated, while familiarity and novelty are in negative way. Statistical spectral maps reveal that pleasant, novel and comfortable interiors produce a de-synchronization of the mu rhythm over left sensorimotor areas. Interiors judged more pleasant and less familiar generate an activation of left frontal areas (theta and alpha bands), along an involvement of areas devoted to spatial navigation. An increase in comfort returns an enhancement of the theta frontal midline activity. Cerebral activations underlying appreciation of architecture could involve different mechanisms regulating corporeal, emotional and cognitive reactions. Therefore, it might be suggested that people's experience of architectural environments is intrinsically structured by the possibilities for action.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Emoções , Meio Ambiente , Motivação/fisiologia , Percepção/fisiologia , Adulto , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Análise Espectral , Estatística como Assunto , Interface Usuário-Computador
19.
Front Psychol ; 6: 1944, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26733924

RESUMO

Nowadays there is the hope that neuroscientific findings will contribute to the improvement of building design in order to create environments which satisfy man's demands. This can be achieved through the understanding of neurophysiological correlates of architectural perception. To this aim, the electroencephalographic (EEG) signals of 12 healthy subjects were recorded during the perception of three immersive virtual reality environments (VEs). Afterwards, participants were asked to describe their experience in terms of Familiarity, Novelty, Comfort, Pleasantness, Arousal, and Presence using a rating scale from 1 to 9. These perceptual dimensions are hypothesized to influence the pattern of cerebral spectral activity, while Presence is used to assess the realism of the virtual stimulation. Hence, the collected scores were used to analyze the Power Spectral Density (PSD) of the EEG for each behavioral dimension in the theta, alpha and mu bands by means of time-frequency analysis and topographic statistical maps. Analysis of Presence resulted in the activation of the frontal-midline theta, indicating the involvement of sensorimotor integration mechanisms when subjects expressed to feel more present in the VEs. Similar patterns also characterized the experience of familiar and comfortable VEs. In addition, pleasant VEs increased the theta power across visuomotor circuits and activated the alpha band in areas devoted to visuospatial exploration and processing of categorical spatial relations. Finally, the de-synchronization of the mu rhythm described the perception of pleasant and comfortable VEs, showing the involvement of left motor areas and embodied mechanisms for environment appreciation. Overall, these results show the possibility to measure EEG correlates of architectural perception involving the cerebral circuits of sensorimotor integration, spatial navigation, and embodiment. These observations can help testing architectural hypotheses in order to design environments matching the changing needs of humans.

20.
Exp Brain Res ; 207(1-2): 95-103, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20931177

RESUMO

A series of experiments provide evidence that affordances rely not only on the mutual appropriateness of the features of an object and the abilities of an individual, but also on the fact that those features fall within her own reachable space, thus being really ready-to-her-own-hand. We used a spatial alignment effect paradigm and systematically examined this effect when the visually presented object was located either within or outside the peripersonal space of the participants, both from a metric (Experiment 1) and from a functional point of view (Experiment 2). We found that objectual features evoke actions only when the object is presented within the portion of the peripersonal space that is effectively reachable by the participants. Experiments 3 and 4 ruled out that our results could be merely accounted for by differences in the visual salience of the presented objects. Our data suggest that the power of an object to automatically trigger an action is strictly linked to the effective possibility that an individual has to interact with it.


Assuntos
Atividade Motora/fisiologia , Percepção Espacial/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Percepção Visual/fisiologia
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