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Being Barbie: the size of one's own body determines the perceived size of the world.

van der Hoort B, Guterstam A, Ehrsson HH - PLoS ONE (2011)

Bottom Line: These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures.Importantly, despite identical retinal input, this "body size effect" was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted.Thus, our own body size affects how we perceive the world.

View Article: PubMed Central - PubMed

Affiliation: Brain, Body and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden. bvdhoort@gmail.com

ABSTRACT
A classical question in philosophy and psychology is if the sense of one's body influences how one visually perceives the world. Several theoreticians have suggested that our own body serves as a fundamental reference in visual perception of sizes and distances, although compelling experimental evidence for this hypothesis is lacking. In contrast, modern textbooks typically explain the perception of object size and distance by the combination of information from different visual cues. Here, we describe full body illusions in which subjects experience the ownership of a doll's body (80 cm or 30 cm) and a giant's body (400 cm) and use these as tools to demonstrate that the size of one's sensed own body directly influences the perception of object size and distance. These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures. When participants experienced the tiny body as their own, they perceived objects to be larger and farther away, and when they experienced the large-body illusion, they perceived objects to be smaller and nearer. Importantly, despite identical retinal input, this "body size effect" was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted. These findings are fundamentally important as they suggest a causal relationship between the representations of body space and external space. Thus, our own body size affects how we perceive the world.

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Related in: MedlinePlus

Results of Experiments 1–4: Illusory ownership of tiny and huge artificial bodies.Average scores on illusion statements and control statements (see Table S1) after synchronous and asynchronous touching of small body (A) and large body (B), and average threat-evoked SCR after a period of synchronous and asynchronous touching of the small body (C) and the large body (D). * p<0.05, *** p<0.001. Error bars indicate SEM.
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pone-0020195-g002: Results of Experiments 1–4: Illusory ownership of tiny and huge artificial bodies.Average scores on illusion statements and control statements (see Table S1) after synchronous and asynchronous touching of small body (A) and large body (B), and average threat-evoked SCR after a period of synchronous and asynchronous touching of the small body (C) and the large body (D). * p<0.05, *** p<0.001. Error bars indicate SEM.

Mentions: In the experimental condition, the participant's body and the artificial body were touched synchronously for four minutes; in the control condition, the two bodies were touched asynchronously for the same duration, as this mode of stimulation is known to diminish the body-swap illusion significantly [33]. In Experiments 1 and 2, participants were asked to report their experiences by completing a questionnaire after each of these two conditions. The questionnaire consisted of three illusion statements designed to capture the subjective feeling of ownership of the artificial body and four statements to control for the effects of suggestibility and task compliance (see Table S1). The results showed that the participants strongly affirmed the illusion and gave significantly higher scores to the illusion statements compared with the control statements, but only during the synchronous condition (significant interaction between statement type and condition for the small body: n = 15, F(1, 14)  = 21.059, p<0.001, and the large body: n = 14, F(1, 13)  = 69.394 p<0.001; repeated measures ANOVA, see Figure 2A,B) (see Text S1 and Figure S1 for results for each individual statement).


Being Barbie: the size of one's own body determines the perceived size of the world.

van der Hoort B, Guterstam A, Ehrsson HH - PLoS ONE (2011)

Results of Experiments 1–4: Illusory ownership of tiny and huge artificial bodies.Average scores on illusion statements and control statements (see Table S1) after synchronous and asynchronous touching of small body (A) and large body (B), and average threat-evoked SCR after a period of synchronous and asynchronous touching of the small body (C) and the large body (D). * p<0.05, *** p<0.001. Error bars indicate SEM.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3102093&req=5

pone-0020195-g002: Results of Experiments 1–4: Illusory ownership of tiny and huge artificial bodies.Average scores on illusion statements and control statements (see Table S1) after synchronous and asynchronous touching of small body (A) and large body (B), and average threat-evoked SCR after a period of synchronous and asynchronous touching of the small body (C) and the large body (D). * p<0.05, *** p<0.001. Error bars indicate SEM.
Mentions: In the experimental condition, the participant's body and the artificial body were touched synchronously for four minutes; in the control condition, the two bodies were touched asynchronously for the same duration, as this mode of stimulation is known to diminish the body-swap illusion significantly [33]. In Experiments 1 and 2, participants were asked to report their experiences by completing a questionnaire after each of these two conditions. The questionnaire consisted of three illusion statements designed to capture the subjective feeling of ownership of the artificial body and four statements to control for the effects of suggestibility and task compliance (see Table S1). The results showed that the participants strongly affirmed the illusion and gave significantly higher scores to the illusion statements compared with the control statements, but only during the synchronous condition (significant interaction between statement type and condition for the small body: n = 15, F(1, 14)  = 21.059, p<0.001, and the large body: n = 14, F(1, 13)  = 69.394 p<0.001; repeated measures ANOVA, see Figure 2A,B) (see Text S1 and Figure S1 for results for each individual statement).

Bottom Line: These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures.Importantly, despite identical retinal input, this "body size effect" was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted.Thus, our own body size affects how we perceive the world.

View Article: PubMed Central - PubMed

Affiliation: Brain, Body and Self Laboratory, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden. bvdhoort@gmail.com

ABSTRACT
A classical question in philosophy and psychology is if the sense of one's body influences how one visually perceives the world. Several theoreticians have suggested that our own body serves as a fundamental reference in visual perception of sizes and distances, although compelling experimental evidence for this hypothesis is lacking. In contrast, modern textbooks typically explain the perception of object size and distance by the combination of information from different visual cues. Here, we describe full body illusions in which subjects experience the ownership of a doll's body (80 cm or 30 cm) and a giant's body (400 cm) and use these as tools to demonstrate that the size of one's sensed own body directly influences the perception of object size and distance. These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures. When participants experienced the tiny body as their own, they perceived objects to be larger and farther away, and when they experienced the large-body illusion, they perceived objects to be smaller and nearer. Importantly, despite identical retinal input, this "body size effect" was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted. These findings are fundamentally important as they suggest a causal relationship between the representations of body space and external space. Thus, our own body size affects how we perceive the world.

Show MeSH
Related in: MedlinePlus