In-Depth Notes on Full-Body Illusions and Minimal Phenomenal Selfhood

Full-body illusions and selfhood

• Research highlights the link between body perception and self-consciousness.
• Global aspects of bodily self-consciousness are underexplored.
• Questions posed:
• What are the minimal conditions for a phenomenal self?
• What are necessary conditions for self-consciousness in different systems?

Minimal Phenomenal Selfhood (MPS)

• MPS is crucial for understanding the basic aspects of self-consciousness, independent of explicit cognition and language.
• It involves:
• Global identification with the entire body
• Spatiotemporal self-location
• First-person perspective (1PP)
• Distinction between ownership for body parts (rubber-hand illusion) and global ownership (full-body illusion).

Key Concepts

• Agency: Experience of action, control, motor selection, and will.
• Cognitive 1PP: A more complex self-representation.
• Self-identification: Level of identification with body representation.
• Self-location: Volumetric position of self within spatial boundaries.
• Weak 1PP: Basic point of view, geometrical feature.
• Strong 1PP: Representation of self actively knowing or recognizing itself.

Conceptual Framework for MPS

• Features of MPS:

1. Global identification with the body
2. Self-location in space and time
3. Weak and strong versions of first-person perspective (1PP)

• The system represents itself as directed at objects and is capable of subjective consciousness.

Disturbances in MPS

• Breakdown of MPS leads to experiences such as out-of-body experiences.
• Different clinical conditions:
• Somatoparaphrenia: Misattribution of body parts (e.g., contralesional hand)
• Out-of-body experiences: Localization outside the bodily borders.

Neural Mechanisms of MPS

• Distinct neurons in primary and higher-order somatosensory cortex may contribute to body ownership and identification.

Experimental Manipulations of MPS

• Techniques include using multisensory manipulations (mirrors, virtual reality) that alter self-identification and self-location.
• Full-body illusions demonstrate the malleability of bodily self-consciousness and the experience of self-location.
• Results show clear evidence that visual perception dominates tactile sensations.

Implications for Future Research

• Future studies should focus on isolating minimal forms of self-consciousness and explore causal roles of agency as a background condition.
• MPS can be expressed through integrated and transparent representations absent of complex cognitive self-references, allowing for deeper insights into human self-awareness.

Acknowledgements

• Support from various foundations for ongoing research into cognitive neuroscience of self-consciousness and body perception.