The Role of Visual Active Self-Touch in Body Ownership

Table of Contents

1 Introduction

2 Theoretical background

2.1 Body ownership

2.2 The Rubber Hand Illusion

2.2.1 Psychometrics of body ownership

2.2.2 The neuropsychological mechanisms of the RHI

2.3 Self-touch

2.3.1 Self-Touch and body representations

2.3.2 Self-touch and body-ownership illusions

2.3.3 State of the art

2.3.4 Does active visual self-touch induce a greater ownership illusion than external touch?

2.4 Conceptual Hypotheses

3 Method

3.1 Experimental Design and operationalization of the independent variables

3.2 Measures of illusory ownership

3.2.1 RHI Questionnaire

3.2.2 Proprioceptive drift

3.3 Experimental setup

3.4 Participants

3.4.1 COVID-19

3.5 Procedure

3.5.1 Preparation

3.5.2 Illusion induction

3.6 Empirical hypotheses

4 Results

4.1 Data preparation

4.2 Descriptive statistics

4.3 Hypothesis testing

4.3.1 Testing of hypothesis 1

4.3.2 Testing of hypothesis 2

4.3.3 Testing of hypothesis 3

4.3.4 Explorative analysis

5 Discussion

5.1 Summary and discussion of results

5.2 Limitations

5.3 Future research and implications

5.4 Conclusion

Research Objectives and Topics

The primary objective of this study is to investigate how active visual self-touch influences ownership illusions during the Rubber Hand Illusion (RHI). It specifically seeks to determine whether self-touch modulates body ownership more effectively than external touch, and to what extent the location of the rubber hand relative to peripersonal space (PPS) and the presence of tactile stimulation influence the strength of the illusion.

• The impact of active visual self-touch on body ownership.
• The influence of peripersonal space (PPS) on illusion strength.
• The role of tactile stimulation versus non-tactile visual cues in embodiment.
• The dissociation between implicit (proprioceptive drift) and explicit (subjective questionnaire) measures of ownership.
• Interaction effects between touch source, touch type, and spatial location.

Excerpt from the Book

Summary of Chapters

1 Introduction: Provides an overview of body ownership and its clinical relevance, introducing the Rubber Hand Illusion as a paradigm for studying bodily self-representation and self-touch.

2 Theoretical background: Reviews the concept of body ownership, the Rubber Hand Illusion, the role of peripersonal space, and existing literature on self-touch.

3 Method: Outlines the 2x2x2 experimental design, describing the measures for illusory ownership (questionnaire and proprioceptive drift) and the procedure used for 23 participants.

4 Results: Presents the statistical findings from the repeated measures ANOVA, including main effects and interactions of self-touch, touch type, and rubber hand location on embodiment scores and proprioceptive drift.

5 Discussion: Interprets the findings regarding self-touch and PPS, discusses methodological limitations such as the mirror and paintbrush use, and proposes directions for future research in bodily self-consciousness.

Keywords

body ownership, embodiment, rubber hand illusion, peripersonal space, proprioceptive drift, body plasticity, self-touch, multisensory integration, body schema, subjective ownership, agency, efferent signals, motor control, bodily self-consciousness, mirror paradigm

Frequently Asked Questions

What is the fundamental focus of this research?

The work investigates the role of active visual self-touch in modulating the Rubber Hand Illusion (RHI) and how various factors like tactile input and peripersonal space interact to shape body ownership.

What are the central thematic fields?

The core themes include body ownership, bodily self-consciousness, multisensory integration, the influence of peripersonal space (PPS), and the comparison between active self-generated touch and externally administered touch.

What is the primary objective of the thesis?

The primary aim is to determine if active visual self-touch induces a stronger ownership illusion than external touch and to analyze the role of spatial proximity and physical contact in this process.

Which scientific method is applied?

The study employs a 2x2x2 within-subject experimental design, utilizing a repeated measures ANOVA to analyze both implicit (proprioceptive drift) and explicit (subjective questionnaire) measures of embodiment.

What topics are discussed in the main body?

The main sections cover the theoretical foundation of body ownership and self-touch, the detailed experimental methodology, the analysis of behavioral and questionnaire data, and a discussion of the observed results and their implications.

Which keywords define the work?

The work is defined by concepts such as body ownership, embodiment, rubber hand illusion, proprioceptive drift, multisensory integration, and the specific role of peripersonal space in self-representation.

Why did the study observe stronger illusions outside of the hypothesized PPS?

The unexpected result suggests a possible dynamic modulation of PPS representations or that the mirror setup used for the illusion might have affected the participants' ability to judge distance and space.

How did the use of a metronome affect the results?

The metronome standardized the stroking rhythm to ensure consistency across conditions, but the author notes that it may have reduced the "voluntary" aspect of active self-touch, which could be a factor in the lack of significant differences found between touch sources.