How have African moral worlds changed since the 1990s? Regimes of Responsibility in Africa analyses the transformations that discourses and practices of responsibility have undergone in Africa. By doing so, this collection of essays offers insight that develops a stronger grasp on the interaction between moral practices and discourses, and specific political, economic and social transformations taking place today in Africa. At the same time, while focusing on case studies from the African continent, the work enters into a dialogue with (...) the emerging corpus of studies in the field of ethics, providing to it a set of analytical perspectives that can help further enlarge its theoretical and geographical scope. (shrink)

Connectives and cue phrases are the most prototypical linguistic elements that signal coherence relations, but by limiting our attention to connectives, we are likely missing out on important other cues readers and listeners use when establishing coherence relations. However, defining the role of other types of linguistic elements in the signaling of coherence relations is not straightforward, and it is also not obvious why and how non-connective elements function as signals for coherence relations. In this paper, we aim to develop (...) a systematic way of categorizing segment-internal elements as signals of coherence relations on the basis of a literature review and evidence from parallel corpora. We propose a three-way distinction betweendivision of labor, agreement, andgeneral collocationto categorize the different ways in which elements inside discourse segments interact with connectives in the marking of coherence relations. In each type of interaction, segment-internal elements can function as signals for coherence relations, but the mechanism behind it is slightly different for each type. (shrink)

Supercommentary, with commentaries on Praśastapādabhāṣya, a work on Kaṇāda's Vaiśeṣikasūtra, treatise on the Vaiśeṣika school in Hindu philosophy.

I begin with a typology of reasoning and cross it with types of processes. I demonstrate that the thrust of Plato’s Republic is theory-building. This involves the critical and dialectic processes which are paradigms of Platonic methodology. Book I displays abductive analogical reasoning joined by an induction that is embedded in a deduction; hence there is a deduction–induction–abduction chain. In Book VI, Plato constructs a visual model of the divided line, which also displays model-based and abductive hypothesis generation that is (...) essential to theory building. Book VII provides an abductive metaphor model of the allegory of the cave. Both models depict degrees of reality and the ascendency of knowledge. The multimodal model-based allegory has far reaching applications from criminal justice to information systems. I conclude by capturing the narrative of the Republic as a critical and dialectic process of theory building using deductive–inductive–abductive chains, an abductive visual model and an abductive metaphor model. Hence, the Republic is simultaneously a masterpiece of deductive reasoning and a marvel of complex model-based abduction, involving visual models, analogies and metaphors. (shrink)

Abduction* is the genus with deduction and induction as species. Modus tollens is backward reasoning as an unknown proposition is inferred from a known proposition. Reductio ad absurdum is abductive because the conclusion is inferred by deriving a contradiction from an assumption. Inductive reasoning from effect to cause is also backward reasoning. But abduction* consists of forward reasoning as well. The generic structure of abductive* argumentation is universal among all cultures, occupations and disciplines.

First, ‘Is Justified True Belief Knowledge’ is imprecise but Gettier is explicit that ‘know’ is analysed as the definiendum is ‘S knows that P’. Second, Gettier does not misrepresent as Plato’s definition as the expressions used are ‘Plato considers’ and ‘seems to accept’. Third, Gettier is not mistaken to apply Plato’s definition to propositions since propositional knowledge is a species of Plato’s definition. Fourth, for Plato true belief temporally precedes an account. ‘Jones owns a Ford’ is never a true opinion, (...) hence no account for it can be given. The counterexample is reconstructed with temporality built into it. Fifth, Gettier does not fail to establish the equivalence of ‘believe’, ‘accepts’ and ‘sure’ in the three versions as this is implicitly established in the shifts made in the paper. Sixth, ‘entails’ logically is used only when the entailing proposition is true, but in the counterexamples a false proposition is taken to imply a true one. ‘Entail’ is to be taken in the ordinary sense of implies. Seventh, in Case I, the implication is preserved with the proper representation: → [Gy ↔ ], which implies { → [Gy ↔ ]}’. Eighth, the counterexample is reworked to avoid the objection that justification for p and justification for q may not be sufficient justification for ‘p & q’. (shrink)

I argue for the possibility of knowledge by invention whch is neither á priori nor á posteriori. My conception of knowledge by invention evolves from Poincaré’s conventionalism, but unlike Poincaré’s conventions, propositions known by invention have a truth value. An individuating criteria for this type of knowledge is conjectured. The proposition known through invention is: gounded historically in the discipline to which it belongs; a result of the careful, sincere and objective quest and effort of the knower; chosen freely by (...) the inventer or knower; and, private in its invention but public once invented. I extend knowledge by invention to include the knowledge of the invented proposition by those who do not invent it but accept it as a convention for good reasons. Finally, knowledge by invention combined with a revisionist, Platonist definition of knowledge as actively justified true belief provides a pedagogical model reviving the proactive spirit of the Socratic method with an emphasis on invention and activity and a de-emphasis on information gathering and passivity. (shrink)

The inclusion of the truth condition in the definition of knowledge has been responsible for a number of paradoxes. Some epistemologists claim that in the case of knowledge justification entails truth or that belief implies truth as there is a causal relation between truth and belief. Truth hence becomes redundant in the definition of knowledge. I do not drop the truth condition for this reason because this denies the autonomy of the distinct conditions for knowledge. I argue that truth and (...) knowledge are inseparable. However. “that p is true” should not be a necessary condition in the definiens of the definiendum “S knows that p is true.” Whereas the quest of truth is a necessary condition for knowledge. While I drop the truth condition from the definition of knowing that p is true, I do not dropthe condition that p is false from the definition of knowing that p is false. This means that though I may know something that is not true, I cannot know something that is false. This is a compromised revision of the long standing intuition of epistemologists that if I know something then I cannot be wrong. Linda Zagzebski defines knowledge as: “Knowledge is a state of true belief arising out of acts of intellectual virtue.” (Zagzebski, 1996, 271). She has hence dropped the truth condition. Intellectual virtues direct us towards truth but they do not guarantee truth. In the ideal case whatever I know will be true, but in most cases it will be true to the best of my knowledge. (shrink)

In a Realist ontology relations are subsisting or existing entities distinct from ordinary things. Idealists claim that the notion of relations is subject to a vicious infinite regress. Nominalists claim that relations are particularized instances. In an attempt to search for the roots of a Realist conception of relations and to meet these challenges I investigate Plato's conception of relations in the Phaedo. ;Against the current of a majority of Plato scholars, Castaneda finds evidence for a distinction between relations and (...) properties at Phaedo 102 b-d. I enter the debate on Castaneda's side and find support for his interpretation of the passage in the context of the dialogue as a whole. The relation--quality distinction resolves the paradox of Simmias being both taller than Socrates and shorter than Phaedo at the same time, since Plato possesses relational characteristics of tallness and shortness, which are not contraries unlike the the contrary properties of hot and cold which could not coexist in an individual. Gallop offers the alternative essence--accident distinction which also resolves the paradox since tallness and shortness as accidents may coexist. The latter distinction however Aristotelianizes Plato. I have shown how the essence--accident distinction is incompatible with Plato's theory of Forms, as it leads to such odd conclusions as the admittance of accidental Forms. ;Castaneda claims that Plato reduces relations to Form-chains in which individuals participate in pairs. I offer the alternative of Plato's positing of relational Forms as distinct from monadic Forms. I survey the corpus of Platonic dialogues in search of support for the distinction between relations and properties. I find that in the Statesman there is a distinction between two types of Forms which generates the distinction between monadic Forms and relational Forms. ;I conclude that there is ample evidence in Plato's dialogues and in Aristotle's assessment of Plato to ascribe this distinction to Plato. Plato's explanation of relations in terms of Forms, which have the highest grade of reality for him, sets up the basis for any Realist theory of relations--for reductionist theories reducing relations to relational properties or some other subsisting entities, as well as for the irreducible concept of relations as abstract subsisting entities. (shrink)

The prevention, treatment and management of disease are closely linked to how the causes of a particular disease are explained. For multi-factorial conditions, the causal explanations are inevitably complex and competing models may exist to explain the same condition. Selecting one particular causal explanation over another will carry practical and ethical consequences that are acutely relevant for health policy. In this paper our focus is two-fold; the different models of causal explanation that are put forward within current scientific literature for (...) the high and rising prevalence of the common complex conditions of coronary artery disease and type 2 diabetes mellitus ; and how these explanations are taken up within national health policy guidelines. We examine the causal explanations for these two conditions through a systematic database search of current scientific literature. By identifying different causal explanations we propose a three-tier taxonomy of the most prominent models of explanations: evolutionary, lifecourse, and lifestyle and environment. We elaborate this taxonomy with a micro-level thematic analysis to illustrate how some explanations are semantically and rhetorically foregrounded over others. We then investigate the uptake of the scientific causal explanations in health policy documents with regard to the prevention and management recommendations of current National Service Frameworks for CAD and T2D. Our findings indicate a lack of congruence between the complexity and frequent overlap of causal explanations evident in the scientific literature and the predominant focus on lifestyle recommendations found in the mainstream health policy documents. (shrink)

Mastery imagery has been shown to be associated with more positive cognitive and emotional responses to stress, but research is yet to investigate the influence of mastery imagery ability on imagery’s effectiveness in regulating responses to acute stress, such as competition. Furthermore, little research has examined imagery’s effectiveness in response to actual competition. This study examined (a), whether mastery imagery ability was associated with stress response changes to a competitive stress task, a car racing computer game, following an imagery intervention, (...) and (b), the effects of different guided imagery content on pre-task cognitive and emotional responses. In Session 1, 78 participants (M age = 20.03 years, SD = 1.28) completed ratings of pre-task anxiety intensity and direction, confidence, and perceived control. Imagery ability was also assessed before completing the task. In Session 2, participants were randomly allocated to an imagery condition (positive mastery, negative mastery, relaxation) or control group (no imagery) before completing the task and outcome measures again. For the negative mastery group, greater positive mastery imagery ability was associated with greater perceived control and perceiving anxiety as more facilitative. Furthermore, mastery imagery ability moderated the relationship between anxiety intensity and direction. Altogether, results suggest that positive mastery imagery ability may act as a potential buffer against the effects of negative images. (shrink)

Background:The severity of the Coronavirus pandemic has led to lockdowns in different countries to reduce the spread of the infection. These lockdown restrictions are likely to be detrimental to mental health and well-being in adolescents. Physical activity can be beneficial for mental health and well-being; however, research has yet to examine associations between adolescent physical activity and mental health and well-being during lockdown.Purpose:Examine the effects of adolescent perceived Coronavirus prevalence and fear on mental health and well-being and investigate the extent (...) to which physical activity can be a protective factor against these concerns.Methods:During United Kingdom lockdown restrictions, 165 participants (100 female, aged 13–19) completed an online questionnaire assessing perceived Coronavirus prevalence and fear, physical activity, and indicators of mental health and well-being (stress, anxiety, depression, fatigue, vitality, and perceived health). Separate hierarchical multiple linear regression analyses (with age, gender, perceived Coronavirus prevalence, and fear entered in step 1, and physical activity in step 2) were run to predict each well-being outcome.Results:Regression analyses indicated that in general, while Coronavirus fear was a negative predictor, physical activity was a positive and stronger predictor of enhanced mental health and well-being outcomes.Conclusion:Findings suggest that physical activity during the Coronavirus pandemic can counteract the negative effects of Coronavirus fear on adolescent mental health and well-being. Therefore, physical activity should be promoted during lockdown to support good mental health and well-being. (shrink)

In two pre-registered online studies during the COVID-19 pandemic and the early 2020 lockdown (one of which with a UK representative sample) we elicit risk-tolerance for 1,254 UK residents using four of the most widely applied risk-taking tasks in behavioral economics and psychology. Specifically, participants completed the incentive-compatible Balloon Analog Risk Task (BART) and the Binswanger-Eckel-Grossman (BEG) multiple lotteries task, as well as the Domain-Specific Risk-Taking Task (DOSPERT) and the self-reported questions for risk-taking used in the German Socio-economic Panel (SOEP) (...) study. In addition, participants in the UK representative sample answered a range of questions about COVID-19-related risky behaviors selected from the UCL COVID-19 Social Survey and the ICL-YouGov survey on COVID-19 behaviors. Consistently with pre-COVID-19 times, we find that risk tolerance during the UK lockdown (i) was higher in men than in women and (ii) decreased with age. Undocumented in pre-COVID-19 times, we find some evidence for healthier participants displaying significantly higher risk-tolerance for self-reported risk measures. We find no systematic nor robust patterns of association between the COVID-19 risky behaviors and the four risk-taking tasks in our study. Moreover, we find no evidence in support of the so-called “risk compensation” hypothesis. If anything, it appears that participants who took greater risk in real-life COVID-19-relevant risky behaviors (e.g., isolating or taking precautions) also exhibited higher risk-tolerance in our experimental and self-reported risk-taking measures. (shrink)

The need for research to advance scientific understanding must be balanced with ensuring the rights and wellbeing of participants are safeguarded, with some research topics posing more ethical quandaries for researchers than others. Moral injury is one such topic. Exposure to potentially morally injurious experiences can lead to significant distress, including post-traumatic stress disorder, depression, and selfinjury. In this article, we discuss how the rapid expansion of research in the field of moral injury could threaten the wellbeing, dignity and integrity (...) of participants. We also examine key guidance for carrying out ethically responsible research with participants’ rights to self-determination, confidentiality, non-maleficence and beneficence discussed in relation to the study of moral injury. We describe how investigations of moral injury are likely to pose several challenges for researchers including managing disclosures of potentially illegal acts, the risk of harm that repeated questioning about guilt and shame may pose to participant wellbeing in longitudinal studies, as well as the possible negative impact of exposure to vicarious trauma on researchers themselves. Finally, we offer several practical recommendations that researchers, research ethics committees and other regulatory bodies can take to protect participant rights, maximise the potential benefits of research outputs and ensure the field continues to expand in an ethically responsible way. (shrink)

Mastery imagery (i.e., images of being in control and coping in difficult situations) is used to regulate anxiety. The ability to image this content is associated with trait confidence and anxiety, but research examining mastery imagery ability's association with confidence and anxiety in response to a stressful event is scant. The present study examined whether trait mastery imagery ability mediated the relationship between confidence and anxiety, and the subsequent associations on performance in response to an acute psychological stress. Participants (N= (...) 130; 55% male;Mage= 19.94 years;SD= 1.07 years) completed assessments of mastery imagery ability and engaged in a standardized acute psychological stress task. Immediately prior to the task, confidence, cognitive and somatic anxiety intensity, and interpretation of anxiety symptoms regarding the task were assessed. Path analyses supported a model whereby mastery imagery ability mediated the relationship between confidence and cognitive and somatic anxiety interpretation. Greater mastery imagery ability and confidence were both directly associated with better performance on the stress task. Mastery imagery ability may help individuals experience more facilitative anxiety and perform better during stressful tasks. Improving mastery imagery ability by enhancing self-confidence may help individuals successfully cope with anxiety elicited during stressful situations. (shrink)

The Coronavirus pandemic has significantly affected psychological wellbeing in older adults, with cases of depression, anxiety and loneliness rising in the general population. Cognitive health has also potentially been affected, as social isolation can lead to cognitive decline. Worrying about cognitive health can be damaging to psychological wellbeing and is especially relevant to explore in the context of the Coronavirus pandemic. The objective of the present study was to explore the associations between cognitive health worries and wellbeing, and to investigate (...) whether physical activity and social contact can mitigate negative effects of the pandemic on psychological wellbeing. Older adults completed an online survey which included measures of cognitive health worries, depression, anxiety, loneliness, social isolation, fatigue, impact of the Coronavirus pandemic, quality of life, subjective vitality, and physical activity. Analyses indicated that cognitive health worries, lower levels of physical activity and smaller amounts of social interaction were associated with poorer psychological and physical wellbeing. Results showed that worrying about cognitive health is associated with poorer wellbeing, and so interventions are needed to encourage positive cognitive functioning in times of social isolation. Promoting physical activity and social interaction is also beneficial, as results show that exercise and social contact are linked with improved wellbeing. (shrink)

Because it is fundamental in the training of a chemist, any new work on Thermodynamics is bound to evoke the interest of those who are engaged in teaching chemistry at higher levels. The present book is intended for University students taking Chemistry as a Degree subject. It is written in a straightforward style and the subject is developed clearly and logically. The laws of thermodynamics are treated adequately, the first and second getting fuller attention since they serve as a foundation (...) for the definition and consideration of free energy, entropy and other thermodynamical functions. The criteria of equilibrium are thoroughly examined and a considerable amount of data illustrative of the chief topics is given. Rather unusual but interesting and highly useful features include bond-energies, the Born-Haber Cycle, the velocity of an adiabatically expanded jet of gas, the stretching of rubber, high polymer solutions. (shrink)

When participants observed a rubber hand being touched, their sense of touch was activated . While this illusion might be caused by multi-modal integration, it may also be related to empathic function, which enables us to simulate the observed information. We examined individual differences in the RHI, including empathic and schizotypal personality traits, as previous research had suggested that schizophrenic patients would be more subject to the RHI. The results indicated that people who experience a stronger RHI might have (...) stronger empathic and schizotypal personalites simultaneously. We discussed these relationships in terms of self-other representations. (shrink)

Autism spectrum disorder is characterised by differences in unimodal and multimodal sensory and proprioceptive processing, with complex biases towards local over global processing. Many of these elements are implicated in versions of the rubber hand illusion, which were therefore studied in high-functioning individuals with ASD and a typically developing control group. Both groups experienced the illusion. A number of differences were found, related to proprioception and sensorimotor processes. The ASD group showed reduced sensitivity to visuotactile-proprioceptive discrepancy but more accurate (...) proprioception. This group also differed on acceleration in subsequent reach trials. Results are discussed in terms of weak top-down integration and precision-accuracy trade-offs. The RHI appears to be a useful tool for investigating multisensory processing in ASD. (shrink)

When subjects view stimulation of a rubber hand while feeling congruent stimulation of their own hand, they may come to feel that the rubber hand is part of their own body. This illusion of body ownership is termed ‘Rubber Hand Illusion’ . We investigated sensitivity of RHI to spatial mismatches between visual and somatic experience. We compared the effects of spatial mismatch between the stimulation of the two hands, and equivalent mismatches between the postures of the two (...) hands. We created the mismatch either by adjusting stimulation or posture of the subject’s hand, or, in a separate group of subjects, by adjusting stimulation or posture of the rubber hand. The matching processes underlying body ownership were asymmetrical. The illusion survived small changes in the subject’s hand posture, but disappeared when the same posture transformations were applied to the rubber hand. Mismatch between the stimulation delivered to the subject’s hand and the rubber hand abolished the illusion. The combination of these two situations is of particular interest. When the subject’s hand posture was slightly different from the rubber hand posture, the RHI remained as long as stimulation of the two hands was congruent in a hand-centred spatial reference frame, even though the altered posture of the subject’s hand meant that stimulation was incongruent in external space. Conversely, the RHI was reduced when the stimulation was incongruent in hand-centred space but congruent in external space. We conclude that the visual–tactile correlation that causes the RHI is computed within a hand-centred frame of reference, which is updated with changes in body posture. Current sensory evidence about what is ‘me’ is interpreted with respect to a prior mental body representation. (shrink)

In the rubber hand illusion one’s hand is hidden, and a fake hand is visible. We explored the situation in which visual information was available indirectly in a mirror. In the mirror condition, compared to the standard condition , we found no reduction of the RHI following synchronised stimulation, as measured by crossmanual pointing and by a questionnaire. We replicated the finding with a smaller mirror that prevented visibility of the face. The RHI was eliminated when a wooden block (...) replaced the fake hand, or when the hand belonged to another person or mannequin. We conclude that awareness of the reflection is the critical variable, despite the distant visual localisation of the hand in a mirror and the third-person perspective. Stimuli seen in a mirror activate the same response as stimuli seen in peripersonal space, through knowledge that they are near one’s body. (shrink)

Animal data suggest that jet fuels such as JP-8 are associated with hearing deficits when combined with noise and that the effect is more pronounced than with noise exposure alone. Some studies suggest peripheral dysfunction while others suggest central auditory dysfunction. Human data are limited in this regard. The aim of this study was to investigate the possible chronic adverse effects of JP-8 combined with noise exposure on the peripheral and central auditory systems in humans. Fifty-seven participants who were current (...) personnel from the Royal Australian Air Force were selected. Based on their levels of exposure to jet fuels, participants were divided into three exposure groups. Groups were also categorised based on their noise exposure levels. All participants were evaluated by tympanometry, pure-tone audiometry, distortion product otoacoustic emissions, auditory brainstem response, words-in-noise, compressed speech, dichotic digit test, pitch pattern sequence test, duration pattern sequence test and adaptive test of temporal resolution. All auditory tests were carried out after the participants were away from the Air Force base for a minimum of two weeks, thus two weeks without jet fuel and noise exposure. Jet fuel exposure was significantly associated with hearing thresholds at 4 and 8 kHz; average hearing thresholds across frequencies in the better ear; DPOAEs at 2.8, 4 and 6 kHz; ABR wave V latency in the right ear; compressed speech and words-in-noise. Further analyses revealed that participants with low exposure level to jet fuels showed significantly better results for the aforementioned procedures than participants with moderate and high exposure levels. All results were controlled for the covariates of age and noise exposure levels. The results suggest that jet fuel exposure, when combined with noise exposure, has an adverse effect on audibility in humans. Taking all the test results into consideration, jet fuel exposure combined with noise exposure specifically seems to affect the peripheral hearing system in humans. (shrink)

On the one hand, it is often assumed that the Rubber Hand Illusion (RHI) is constrained by a structural body model so that one cannot implement supernumerary limbs. On the other hand, several recent studies reported illusory duplication of the right hand in subjects exposed to two adjacent rubber hands. The present study tested whether spatial constraints may affect the possibility of inducing the sense of ownership to two rubber hands located side by side to the left (...) of the subject's hand. We found that only the closest rubber hand appeared both objectively (proprioceptive drift) and subjectively (ownership rating) embodied. Crucially, synchronous touch of a second, but farther, rubber hand disrupted the objective measure of the RHI, but not the subjective one. We concluded that, in order to elicit a genuine RHI for multiple rubber hands, the two rubber hands must be at the same distance from the subject's hand/body. (shrink)

In this essay, I discuss a few ways in which songs are used, ways in which listeners engage with and find meaning in music. I am most interested in sad songs—those that typically feature narratives about lost love, separation, missed opportunity, regret, hardship, and all manner of heartache. Many of us are drawn to sad songs in moments of emotional distress. The problem is that sad songs do not always make us feel better; to the contrary, they often make us (...) feel worse. So, why do we listen to sad songs? I argue that we seek out sad songs, partly, to intensify distress, which helps us reflect on situations of profound personal significance. (shrink)

Models of purgatory tend to come paired with an operative conception of what perfection consists in. In the recent philosophical literature, two models, the satisfaction model and the sanctification model, have been pitted against one another. The former focuses on innocence before the law and makes purgatory out to be a place where a debt of punishment is paid. The latter focuses on moral character and describes purgatory in terms of character formation. If perfection consists in a certain way of (...) being related to God, however, then there is a third model that merits our attention that focuses on relational dynamics. (shrink)

Perhaps one of the most controversial aspects of Hegel's Philosophy of Right for contemporary interpreters is its discussion of the constitutional monarch. This is true despite the general agreement amongst virtually all interpreters that Hegel's monarch is no more powerful than modern constitutional monarchs and is an institution worthy of little attention or concern. In this article, I will examine whether or not it matters who is the monarch and what domestic and foreign powers he has. I argue against the (...) virtual consensus of recent interpreters that Hegel's monarch is far more powerful than has been understood previously. In part, Hegel's monarch is perhaps even more powerful than Hegel himself may have realized and I will demonstrate certain inconsistencies with some of his claims. My reading represents a distinctive break from the virtual consensus, without endorsing the view that Hegel was a totalitarian. (shrink)

Describes Israel's transformation from a society held together by national liberation to a liberal democracy that must make room for individual Israelis.

Inducing the rubber hand illusion (RHI) requires that participants look at an imitation hand while it is stroked in synchrony with their occluded biological hand. Previous explanations of the RHI have emphasized multisensory integration, and excluded higher cognitive functions. We investigated the relationship between the RHI and higher cognitive functions by experimentally testing task switch (as measured by switch cost) and mind wandering (as measured by SART score); we also included a questionnaire for attentional control that comprises two subscales, (...) attention-shift and attention-focus. To assess experience of RHI, the Botvinick and Cohen (1998) questionnaire was used and illusion onset time was recorded. Our results indicate that rapidity of onset reliably indicates illusion strength. Regression analysis revealed that participants evincing less switch cost and higher attention-shift scores had faster RHI onset times, and that those with higher attention-shift scores experienced the RHI more vividly. These results suggest that the multi-sensory hypothesis is not sufficient to explain the illusion: higher cognitive functions should be taken into account when explaining variation in the experience of ownership for the rubber hand. (shrink)

In rubber hand illusions and full body illusions, touch sensations are projected to non-body objects such as rubber hands, dolls or virtual bodies. The robustness, limits and further perceptual consequences of such illusions are not yet fully explored or understood. A number of experiments are reported that test the limits of a variant of the rubber hand illusion. Methodology/Principal Findings -/- A variant of the rubber hand illusion is explored, in which the real and foreign hands (...) are aligned in personal space. The presence of the illusion is ascertained with participants' scores and temperature changes of the real arm. This generates a basic illusion of touch projected to a foreign arm. Participants are presented with further, unusual visuotactile stimuli subsequent to onset of the basic illusion. Such further visuotactile stimulation is found to generate very unusual experiences of supernatural touch and touch on a non-hand object. The finding of touch on a non-hand object conflicts with prior findings, and to resolve this conflict a further hypothesis is successfully tested: that without prior onset of the basic illusion this unusual experience does not occur. Conclusions/Significance -/- A rubber hand illusion is found that can arise when the real and the foreign arm are aligned in personal space. This illusion persists through periods of no tactile stimulation and is strong enough to allow very unusual experiences of touch felt on a cardboard box and experiences of touch produced at a distance, as if by supernatural causation. These findings suggest that one's visual body image is explained away during experience of the illusion and they may be of further importance to understanding the role of experience in delusion formation. The findings of touch on non-hand objects may help reconcile conflicting results in this area of research. In addition, new evidence is provided that relates to the recently discovered psychologically induced temperature changes that occur during the illusion. (shrink)

The brain represents the body in different ways for different purposes. Several concepts and even more numerous labels have historically been proposed to define these representations in operational terms. Recent evidence of embodiment of external objects has added complexity to an already quite intricate picture. In particular, because of their perceptual and motor effects, both rubber hands and tools can be conceived as embodied, that is, represented in the brain as if they were parts of one's own body. But (...) are there any limits to what we can embody? What constraints lay upon embodiment? And are they similar both for motor embodiment and for perceptual embodiment? Here, we consider the implications emerging from the different, and up-to-now relatively separate research domains of tool use and rubber hand illusion for understanding the rules of embodiment. In particular, we compare what the embodiment of tools and prostheses may or may not have in common. We conclude that in both cases, although for different reasons and with different constraints, embodiment is only partial. (shrink)