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Cited by 956Virtual Reality Applications and ImpactsFree Will and AgencyTactile and Sensory Interactions

What is embodiment? A psychometric approach

Open access
Longo, Matthew R., Schüür, Friederike, Kammers, Marjolein P.M., Tsakiris, Manos, Haggard, Patrick·2008·Cognition
DOI 10.1016/j.cognition.2007.12.004
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Abstract

What is it like to have a body? The present study takes a psychometric approach to this question. We collected structured introspective reports of the rubber hand illusion, to systematically investigate the structure of bodily self-consciousness. Participants observed a rubber hand that was stroked either synchronously or asynchronously with their own hand and then made proprioceptive judgments of the location of their own hand and used Likert scales to rate their agreement or disagreement with 27 statements relating to their subjective experience of the illusion. Principal components analysis of this data revealed four major components of the experience across conditions, which we interpret as: embodiment of rubber hand, loss of own hand, movement, and affect. In the asynchronous condition, an additional fifth component, deafference, was found. Secondary analysis of the embodiment of runner hand component revealed three subcomponents in both conditions: ownership, location, and agency. The ownership and location components were independent significant predictors of proprioceptive biases induced by the illusion. These results suggest that psychometric tools may provide a rich method for studying the structure of conscious experience, and point the way towards an empirically rigorous phenomenology.

AI snapshot

Written from the paper’s full text.

TL;DR

This study applies psychometric methods (principal components analysis) to structured introspective reports of the rubber hand illusion to decompose the experience of embodiment. It identifies four components present in both synchronous and asynchronous conditions, with an additional deafference component in the asynchronous condition, and shows that ownership and location subcomponents independently predict proprioceptive drift.

Key findings

In the synchronous condition, PCA extracted four components accounting for 55.3% of variance: embodiment of rubber hand (26.3% of variance), loss of own hand, movement, and affect. In the asynchronous condition, five components emerged accounting for 59.4% of variance, with the same four plus a new deafference component (embodiment accounted for 24.6%). Secondary PCA on the ten embodiment items revealed three subcomponents in both conditions — ownership, location, and agency — accounting for 79.0% (synchronous) and 76.2% (asynchronous) of variance, with ownership comprising 35.4% and 34.3% respectively. Proprioceptive displacement toward the rubber hand was significant after synchronous stroking (1.34 cm, t(119) = 4.56, p < .0001) but not asynchronous (0.30 cm, n.s.), and was predicted by the embodiment component (β = 0.609, p < .001), specifically by the location (β = .485, p < .005) and ownership (β = .425, p < .01) subcomponents but not agency (β = .110, n.s.).

Methods

131 current and prospective UCL students (75 female; all but six right-handed) participated. Participants viewed a rubber hand stroked either synchronously or asynchronously (180° out of phase, ~1 Hz) with their own hand for 60 seconds, made pre- and post-test proprioceptive location judgments, and rated agreement with 27 statements on a 7-point Likert scale. Separate PCAs with varimax rotation were run per condition, followed by secondary PCAs on the embodiment items, ANOVAs on component scores, and multiple linear regression relating component scores to proprioceptive displacement.

Limitations

The paper states that the selection of questionnaire items restricts the potential structure that can emerge, and that additional components of embodiment may not have been covered; it also notes that the structure found may not generalise to other uses of the term "embodiment" (e.g., emphases on affect, sublinguistic thought, or social interaction). Evident from the text: proprioceptive judgments from 11 participants were missing or unusable, and the questionnaire items were designed based on qualitative research with only five participants.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.cognition.2007.12.004

Cites

76 of 76 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

0 of 11 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    In the asynchronous condition, PCA extracted five components together accounting for 59.4% of variance.

    “A similar analysis of the asynchronous condition led to the extraction of five components, together accounting for 59.4% of the variance in the data.”
    Quote in the paperSubstantial claim
  • Findingown data

    In the synchronous condition, PCA extracted four components that together accounted for 55.3% of variance.

    “In the synchronous condition, analysis of the scree plot and eigenvalues led to the extraction of four components which together accounted for 55.3% of variance in the data (see Table 1).”
    Quote in the paperSubstantial claim
  • Findingown data

    Secondary analysis of the embodiment of rubber hand component revealed three subcomponents in both conditions: ownership, location, and agency.

    “Secondary analysis of the embodiment of rubber hand component revealed three subcomponents in both conditions: ownership, location, and agency.”
    • Also stated in: § *** INSERT TABLE 1 ABOUT HERE *** · plain
      “For both synchronous and asynchronous conditions three subcomponents of embodiment of rubber hand were identified, together account for 79.0% and 76.2% of the variance in the two conditions, respectively.We termed these the senses of ownership, location, and agency (see Table 2).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.
  • Findingown data

    In the asynchronous condition, an additional fifth component, deafference, was found.

    “In the asynchronous condition, an additional fifth component, deafference, was found.”
    • Also stated in: § Structure Underlying Subjective Reports · plain
      “However, the major difference was that an entirely new component appeared, which we termed deafference.”
    • Also stated in: § Discussion · plain
      “Furthermore, an additional component, deafference, emerged only in the asynchronous condition.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.
  • Findingown data

    The ownership and location components were independent significant predictors of proprioceptive biases induced by the illusion.

    “The ownership and location components were independent significant predictors of proprioceptive biases induced by the illusion.”
    • Also stated in: § Relations between Objective and Subjective Measures · plain
      “More interestingly, the ownership subcomponent also independently predicted proprioceptive drift, β = .425,t(116) = 2.85, p < .01,whereas the agency subcomponent did not, β = .110,t(116) = .75,p > .20.”
    • Also stated in: § Relations between Objective and Subjective Measures · plain
      “Unsurprisingly, the location subcomponent was a significant predictor of prioprioceptive displacement, β = .485,t(116) = 3.02, p < .005.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.
  • May combine two claims. 34
  • Classified as probably not a substantial claim. 15
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingown data

    The deafference component in the asynchronous condition related to sensation of pins-and-needles and numbness in one's hand, and experience of the hand being less vivid than normal.

    “This related to the sensation of pins-and-needles and numbness in one's hand, and the experience of the hand being less vivid than normal.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The same four components appeared in the asynchronous data, and the embodiment component accounted for 24.6% of variance.

    “The same four components appeared in this data, and again the embodiment component accounted for the bulk of the variance (24.6%).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The third component in the synchronous condition, movement, comprised two items relating to perceived motion of one's own hand and to movement of the rubber hand.

    “The third component we termed movement; it was comprised of two items relating to perceived motion of one's own hand, and to movement of the rubber hand.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The first component in the synchronous condition, embodiment of rubber hand, accounted for 26.3% of variance and comprised items 1-10 relating to feelings that the rubber hand belonged to the participant, the participant had control over it, the rubber hand and real hand were in the same location, and the rubber hand took on features of the actual hand.

    “The first component, which accounted for substantially more variance than any other (26.3%),we termed embodiment of rubber hand.It comprised items relating to the feelings that: the rubber hand belonged to the participant, the participant had control over the rubber hand, the rubber hand and real hand were in the same location, and the rubber hand had taken on features of the actual hand (items 1-”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Ownership comprised a large portion of variance (35.4% and 34.3% in synchronous and asynchronous conditions, respectively) and was composed of items related to feeling that the rubber hand was part of one's body, feeling of looking directly at one's hand, and rubber hand taking on characteristics of one's own hand.

    “Ownership comprised a large portion of the variance (35.4% and 34.3% in the synchronous and asynchronous conditions, respectively), and was composed of items related to the feeling that the rubber hand was part of one's body, the feeling of looking directly at one's hand, and the rubber hand taking on the characteristics of one's own hand.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Component scores were significantly higher following synchronous than asynchronous stroking for the embodiment of rubber hand, loss of own hand, and affect components.

    “Inspection of the component scores showed that these were significantly higher following synchronous than asynchronous stroking for the embodiment of rubber hand, loss of own hand, and affect components.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Findingown data

    There was a significant main effect of condition, F(1,130)=110.69, p<.0001, and a significant interaction of condition and subcomponent, F(2,260)=3.60, p<.05.

    “There was also a significant main effect of condition, F(1, 130) = 110.69,p < .0001,and a significant interaction of the two factors, F(2, 260) = 3.60, p < .05.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Findingown data

    On average, participants had the sense that the rubber hand was part of their body in the synchronous but not the asynchronous condition.

    “On average, participants had the sense that the rubber hand was part of their body in the synchronousbut not the asynchronouscondition.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Findingreasoning

    Agency scores were negative in both conditions, which was predicted since neither the participant's hand nor the rubber hand moved at any time.

    “Agency scores were negative in both conditions, which was predicted since neither the participant's hand nor the rubber hand moved at any time.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Additional ANOVA including sex and rubber hand laterality found a significant main effect of sex, F(1,127)=4.06, p<.05, with females showing significantly more agreement with questionnaire items generally (-.055) than males (-.324).

    “There was a significant main effect of sex, F(1, 127) = 4.06, p < .05,with females showing significantly more agreement with questionnaire items generally (-.055), than males (-.324), consistent with findings that females are, on average, slightly more suggestible than males (e.g., Page & Green, 2007).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Location related to feeling that the rubber hand and one's own hand were in the same place, and also to sensations of causation between the seen and felt touches.

    “Location related to the feeling that the rubber hand and one's own hand were in the same place, and also to sensations of causation between the seen and felt touches.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Component scores for embodiment of rubber hand were significantly positive following synchronous stroking, but significantly negative following asynchronous stroking.

    “In contrast, component scores for embodiment of rubber hand were significantly positive following synchronous stroking, but significantly negative following asynchronous stroking.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Findingown data

    Component scores for ownership and location were positive following synchronous stroking, but negative following asynchronous stroking.

    “Component scores for ownership and location were positive following synchronous stroking, but negative following asynchronous stroking.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • Classified as probably not a substantial claim.

    Findingown data

    Agency related to feelings of being able to move the rubber hand, and control over it.

    “Agency related to the feelings of being able to move the rubber hand, and control over it.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Ownership and location components are highly correlated, as they were merged in the primary PCA and separated only at a secondary stage.

    “Indeed, ownership and location were merged in our primary PCA, and separated only at a secondary stage, suggesting that these components are highly correlated.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Experience of one's own body is not a single dimension, but a composite of several different subjective components, organised with a characteristic structure.

    “Our study demonstrates for the first time that experience of one's own body is not a single dimension, but a composite of several different subjective components, organised with a characteristic structure.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The rubber hand illusion is an experimental model of embodiment.

  • May combine two claims.

    Findingown data

    Ownership and location along with the sense of agency grouped together in the omnibus PCA, suggesting that these three components of embodiment, while dissociable in a focused analysis, form a coherent cluster of experience.

    “Nevertheless, ownership and location along with the sense of agency grouped together in the omnibus PCA, suggesting that these three components of embodiment, while dissociable in a focused analysis, form a coherent cluster of experience.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The richer description confirmed significant embodiment of the rubber hand following synchronous but not asynchronous stroking.

    “This richer description confirmed significant embodiment of the rubber hand following synchronousbut not asynchronousstroking.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The rubber hand illusion is an experimental model of embodiment.

  • May combine two claims.

    Interpretationown data

    Psychometric tools may provide a rich method for studying the structure of conscious experience, and point the way towards an empirically rigorous phenomenology.

    “These results suggest that psychometric tools may provide a rich method for studying the structure of conscious experience, and point the way towards an empirically rigorous phenomenology.”
    • Also stated in: § Discussion · hedged
      “These results suggest that psychometric methods can be useful tools in elucidating structure underlying complex conscious experience.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The emergence of an additional component in the asynchronous condition only suggests that the structure underlying conscious experience in the two conditions, while similar, is not identical.

    “The emergence of an additional component in the asynchronous condition only suggests that the structure underlying conscious experience in the two conditions, while similar, is not identical.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Proprioceptive judgments from 11 participants were missing or unusable due to experimenter error or failure of participants to follow instructions.

    “Proprioceptive judgments from 11 participants were missing or unusable due to experimenter error or failure of participants to follow instructions.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data

    The three subcomponents of embodiment were termed ownership, location, and agency.

    “We termed these the senses of ownership, location, and agency (see Table 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The effect of sex did not interact with component or synchrony, suggesting it is not related to the rubber hand illusion, or to embodiment.

    “This effect of sex did not interact, however, with component or synchrony, suggesting that it is not related to the rubber hand illusion, or to embodiment.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    While the three subcomponents of embodiment bundled together in the primary analysis, suggesting they are tightly interrelated in experience, more focused analysis was able to separate them, suggesting they are dissociable components of experience.

    “Thus, while these three components of experience bundled together in the primary analysis, suggesting that they are tightly interrelated in experience, more focused analysis was able to separate them, suggesting that they are dissociable components of experience.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    For affect and movement components, synchronous stroking exaggerated the effects of asynchronous stroking, whether positive or negative; synchrony sharpened these aspects of experience but did not qualitatively alter them.

    “In the case of the affect and movement components, synchronous stroking simply exaggerated the effects of asynchronous stroking, whether they were positive or negative respectively.That is, synchrony sharpened these aspects of experience, but did not qualitatively alter them.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Interpretationown data

    There were no other main effects or interactions involving sex or rubber hand laterality, suggesting that these factors do not strongly influence the rubber hand illusion.

    “There were no other main effects or interactions involving sex or rubber hand laterality, suggesting that these factors do not strongly influence the rubber hand illusion.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The presence of ownership following synchronous stimulation does not necessarily cause a corresponding positive sense of agency, suggesting that these are dissociable aspects of experience.

    “The presence of ownership following synchronous stimulation does not necessarily cause a corresponding positive sense of agency, suggesting that these are dissociable aspects of experience (cf.Sato & Yasuda, 2005;Synofzik, Vosgerau, & Newen, in press;Tsakiris et al., 2006).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Two specific aspects of embodiment are manipulated in the rubber hand illusion: the sense of ownership of the rubber hand and perceived location of the hand.

    “In summary, two specific aspects of embodiment are manipulated in the rubber hand illusion.These are the sense of ownership of the rubber hand and perceived location of the hand.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • May combine two claims.

    Interpretationown data

    Proprioceptive displacement appears to be a genuine by-product of embodiment, but also related specifically to body ownership, but not agency.

    “Proprioceptive displacement therefore appears to be a genuine by-product of embodiment, but also related specifically to body ownership, but not agency.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Participants were randomly assigned to either the right-hand (N=67) or left-hand (N=64) apparatus.

    “Participants were randomly assigned to either the right-(N = 67) or left-hand (N = 64) apparatus.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The order of the synchronous and asynchronous conditions was alternated across participants.

    “The order of the synchronous and asynchronous conditions was alternated across participants.Sixty-six participants completed the synchronous condition first; sixty-five completed the asynchronous condition first.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The 27 questionnaire items were designed based on qualitative research with five participants who freely reported their experiences during the illusion.

    “We designed 27 items based on qualitiative research with five participants, who were asked to freely report their experiences during the illusion.Analysis of these transcripts motivated a selection of questionnaire items.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Combining an experimental manipulation of the experience of one's own body and a structured psychometric approach to measuring that experience allowed the authors to characterize what sort of experience embodiment is, and decompose it into sub-aspects.

    “By combining an experimental manipulation of the experience of one's own body, and a structured psychometric approach to measuring that experience, we were able to characterize what sort of experience embodiment is, and decompose it into sub-aspects.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The order of subsequent questionnaire items was randomized separately for each participant in each condition.

    “The first two items presented were always items (20 and 21) relating to the experience being interesting and enjoyable; the order of subsequent items was randomized separately for each participant in each condition.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationown data

    This pattern represents the characteristic structure of the rubber hand illusion, one of the few experimental models of embodiment.

    “This pattern represents the characteristic structure of the rubber hand illusion, one of the few experimental models of embodiment.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    A random ruler offset that varied from trial to trial was used to discourage participants from re-using remembered verbal labels from prior trials.

    “A random ruler offset that varied from trial to trial was used to discourage participants from re-using remembered verbal labels from prior trials.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    The results support the claim that affect associated with somatic sensations is separable from other forms of afferent input, as the pleasantness of touch loaded on the affect component, whereas the sense of causation associated with touch loaded on the location component.

    “Our results, furthermore, support the claim that affect associated with somatic sensations is separable from other forms of afferent input (cf.Rolls et al., 2003), as the pleasantness of touch loaded on the affect component, whereas the sense of causation associated with touch loaded on the location component”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Rolls et al., 2003 source

      Not checked in the free run.

  • May combine two claims. The quote only partly states this claim.

    Study design and conductown data

    Structured introspective reports are a rigorous tool for the study of bodily self-consciousness, validated by showing systematic structure across participants and relation of individual differences to proprioceptive displacement.

    “We validated the use of structured introspective reports as a rigorous tool for the study of bodily self-consciousness in two ways: first, by showing that systematic structure emerges in the pattern of responses across participants, and that such structure is similar across experimental conditions, and second, by showing that individual differences between participants were nevertheless related to”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    Components of experiences are selectively related to proprioceptive biases, attesting to the validity of the method.

    “That comparable structure emerged in both the synchronous and asynchronous conditions speaks to the reliability of our method; that components of experiences are selectively related to proprioceptive biases attests to its validity.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    If a potential component of the experience of embodiment was not reflected by any of the items used, it could not have emerged in the analysis.

    “If a potential component of the experience of embodiment was not reflected by any of the items we used, it could not have emerged in our analysis.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    There are at least two types of cause of the rubber hand illusion: purely visual information from the perception of the hand in plausible configuration, and multisensory synchrony.

    “This suggests that there are at least two types of cause of the rubber hand illusion: purely visual information from the perception of the hand in plausible configuration, and multisensory synchrony.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Some aspects of embodiment reflect bottom-up sensory factors (as captured by the location component), while others reflect top-down influences of an explicit model of the body as an object (such as the loss of own hand component).

    “Thus, some aspects of embodiment clearly reflect bottom-up sensory factors (as captured by our location component), while others reflect top-down influences of an explicit model of the body as an object (such as our loss of own hand component).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The rubber hand illusion is an experimental model of embodiment.

  • May combine two claims.

    Study design and conductown data

    Comparable structure emerged in both the synchronous and asynchronous conditions, speaking to the reliability of the method.

    “That comparable structure emerged in both the synchronous and asynchronous conditions speaks to the reliability of our method; that components of experiences are selectively related to proprioceptive biases attests to its validity.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    Most psychological models of conscious experience focus on simple qualia.

    “Most psychological models of conscious experience focus on simple qualia.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Embodiment, at least in the model instance of the rubber hand illusion studied here, is a genuine but complex experience with a common structure, and identifiable subcomponents.

    “To conclude, our results suggest that embodiment, at least in the model instance of the rubber hand illusion studied here, is a genuine but complex experience with a common structure, and identifiable subcomponents.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The rubber hand illusion is an experimental model of embodiment.

  • Classified as probably not a substantial claim.

    Study design and conductnone given

    The selection of questionnaire items restricts the potential structure that can emerge from psychometric studies.

    “The selection of questionnaire items always restricts the potential structure that can emerge from psychometric studies.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisenone given

    This study represents the first systematic application of psychometric methods to investigate complex conscious experience elicited under controlled, experimental conditions, and to identify subcomponents of that experience by systematic questioning.

    “To our knowledge, however, this study represents the first systematic application of psychometric methods to investigate complex conscious experience elicited under controlled, experimental conditions, and to identify subcomponents of that experience by systematic questioning.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    The psychometric structure found here may or may not generalise to other instances of embodiment.

    “The psychometric structure found here may or may not generalise to such other instances of embodiment.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    There are additional components of embodiment which were not covered by the questionnaire.

    “However, there are no doubt additional components of embodiment which were not covered by our questionnaire.”
    Quote in the paperNot a substantial claim
49 of 49

  • The paper relies on this without support.

    The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.

    “The same visual and tactile stimulation delivered asynchronously has a quite different phenomenology.”

  • The paper relies on this without support.

    Most studies simply report the occurrence of the illusion, or a behavioural or neural proxy of it such as a change in the perceived position of the participant's own hand, without systematic description or quantitative measurement of the changed sense of embodiment.

    “However, most studies simply report the occurrence of the illusion, or a behavioural or neural proxy of it such as a change in the perceived position of the participant's own hand, without systematic description or quantitative measurement of the changed sense of embodiment.”

  • The paper relies on this without support.

    Recognition of the importance of embodiment has not been matched by theoretical clarity about what embodiment is or involves.

    “However, recognition of the importance of embodiment has not been matched by theoretical clarity about what embodiment is or involves.”

  • The paper relies on this without support.

    The phenomenological tradition has not offered the operational working definitions and measures needed for rigorous empirical research.

    “However, it has not offered the operational working definitions and measures needed for rigorous empirical research.”

  • The paper relies on this without support.

    The present findings represent the first systematic attempt to measure embodiment.

    “To our knowledge, the present findings represent the first systematic attempt to measure embodiment.”

  • The paper relies on this without support.

    The rubber hand illusion is an experimental model of embodiment.

    “While the rubber hand illusion is well accepted as an experimental model of embodiment, there has been less consensus on how to measure the illusion.”

  • The paper relies on this without support.

    The rubber hand illusion can be elicited under systematically controlled experimental conditions.

    “Second, we have focussed on the rubber hand illusion as an initial model for embodiment, because it is subjectively compelling for many people, and can elicited under systematically controlled experimental conditions.”

  • The paper relies on this without support.

    The rubber hand illusion is subjectively compelling for many people.

    “Second, we have focussed on the rubber hand illusion as an initial model for embodiment, because it is subjectively compelling for many people, and can elicited under systematically controlled experimental conditions.”
8 of 8

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • ConsistentF(3, 390) = 107.41reported p < .0001 · recomputed p < .001

    “F(3, 390) = 107.41,p < .0001”

  • ConsistentF(1, 130) = 29.05reported p < .0001 · recomputed p < .001

    “F(1, 130) = 29.05,p < .0001”

  • ConsistentF(3, 390) = 69.24reported p < .0001 · recomputed p < .001

    “F(3, 390) = 69.24,p < .0001”

  • ConsistentF(2, 260) = 11.26reported p < .0001 · recomputed p < .001

    “F(2, 260) = 11.26,p < .0001”

  • ConsistentF(1, 130) = 110.69reported p < .0001 · recomputed p < .001

    “F(1, 130) = 110.69,p < .0001”

  • ConsistentF(2, 260) = 3.6reported p < .05 · recomputed p = .029

    “F(2, 260) = 3.60, p < .05”

  • ConsistentF(1, 127) = 4.06reported p < .05 · recomputed p = .046

    “F(1, 127) = 4.06, p < .05”

  • Consistentt(119) = 2.43reported p < .05 · recomputed p = .017

    “t(119) = 2.43, p < .05”

  • Consistentt(119) = 4.56reported p < .0001 · recomputed p < .001

    “t(119) = 4.56, p < .0001”

  • Consistentt(119) = 1.2reported n.s. · recomputed p = .233

    “t(119) = 1.20, n.s.”

  • Consistentt(119) = 3.22reported p < .005 · recomputed p = .002

    “t(119) = 3.22, p < .005”

  • Consistentt(115) = 3.4reported p < .001 · recomputed p < .001

    “t(115) = 3.40, p < .001”

  • Consistentt(115) = 1.68reported p = .096 · recomputed p = .096

    “t(115) = 1.68, p = .096”

  • Consistentt(118) = -0.53reported p > .2 · recomputed p = .597

    “t(118) = -.53,p > .20”

  • Consistentt(116) = 3.02reported p < .005 · recomputed p = .003

    “t(116) = 3.02, p < .005”

  • Consistentt(116) = 2.85reported p < .01 · recomputed p = .005

    “t(116) = 2.85, p < .01”

  • Consistentt(116) = 0.75reported p > .2 · recomputed p = .455

    “t(116) = .75,p > .20”

17 of 17

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Self-check results appear here once an independent check has confirmed them.

Cites

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Related

Authors
Longo, M. R., Schüür, F., Kammers, M. P. M., Tsakiris, M., & Haggard, P.
Affiliations
  • University College London (GB)
  • Radboud University Nijmegen (NL)
  • Utrecht University (NL)
Corresponding author
Longo, Matthew R.
ORCID
Venue
Cognition
Publisher
Elsevier BV
Published
2008-06
Volume
107
Issue
3
Pages
978-998
ISSN
0010-0277 (ISSN-L)
DOI
10.1016/j.cognition.2007.12.004
OpenAlex
W2017142040
Semantic Scholar
76b6e7c63ec2052504d447ca18f61930b57a773d
Cited by
956
References
75
Citations by year
2026: 45 · 2025: 56 · 2024: 65 · 2023: 53 · 2022: 85 · 2021: 102 · 2020: 82 · 2019: 71 · 2018: 67 · 2017: 57 · 2016: 51 · 2015: 41 · 2014: 43 · 2013: 42 · 2012: 21
FWCI
60.31
Type
journal article
Language
en
Open access
Licence
Locations
  • Cognition (publishedVersion, other-oa)
  • PubMed (publishedVersion)
  • BIROn (Birkbeck, University of London) (acceptedVersion)
  • UCL Discovery (University College London) (submittedVersion)
  • Royal Holloway Digital Repository (Royal Holloway University of London) (submittedVersion)
Funders
  • Fundação Bial
  • Directorate for Biological Sciences
  • Biotechnology and Biological Sciences Research Council (BB/D009529/1)
Topics
  • Physical Sciences › Computer Science › Human-Computer Interaction › Virtual Reality Applications and Impacts
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Free Will and Agency
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Tactile and Sensory Interactions
Keywords
embodiment, rubber hand illusion, bodily self-consciousness, proprioception, body ownership, body location, bodily agency, introspective reports, subjective experience, phenomenology, psychometric structure
MeSH terms
Humans, Perception, Proprioception, Psychometrics

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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