Statistical inference of body representation in the macaque brain

Area of Science:

• Neuroscience
• Cognitive Science
• Primate Research

Background:

• The sense of body ownership is fundamental to self-consciousness.
• Investigating body ownership illusions can reveal underlying computational and neural mechanisms.
• Previous research has primarily focused on human models of body ownership.

Purpose of the Study:

• To develop and implement a nonhuman primate model of the rubber-hand illusion.
• To determine the computational and neuronal mechanisms of body ownership in primates.
• To quantitatively assess body representation using a causal inference model.

Main Methods:

• A video-based rubber-hand illusion system was implemented in a reaching task for monkeys.
• A causal inference model was used to objectively quantify body representation.
• Neural signals were recorded from the premotor cortex during the illusion.

Main Results:

• Monkeys exhibited a rubber-hand illusion, similar to humans.
• The strength of the illusion correlated with the congruence between visual and proprioceptive signals (dynamics and features).
• Premotor cortex activity reflected the strength of the illusion and the likelihood of misattributing the artificial limb.

Conclusions:

• The study successfully established a nonhuman primate model for studying body ownership.
• Computational principles governing body representation in primates are similar to those in humans.
• Neural correlates of body ownership were identified in the primate premotor cortex, indicating a cortical representation of self-body attribution.