Octopuses can experience the rubber hand illusion, suggesting they possess a sense of body ownership similar to that of humans.
This discovery is significant because it indicates that complex self-awareness and body representation can evolve in vastly different biological lineages. While humans and octopuses share a distant common ancestor, the presence of this illusion in both species suggests a convergent evolution of how brains map the physical self.
Researchers conducted the study to investigate how octopuses represent their own bodies [1]. The rubber hand illusion is a psychological phenomenon where a subject feels a prosthetic limb belongs to them after receiving synchronized sensory stimulation. In this experiment, scientists tested whether octopuses would integrate a fake limb into their own body schema [2].
The findings were published in the journal Current Biology in 2025 [3]. The study demonstrated that the octopuses fell for the illusion, mirroring the behavioral responses seen in human subjects [2]. This suggests that the ability to perceive the boundaries of one's own body is not exclusive to mammals or vertebrates.
Octopuses are known for their high intelligence and complex nervous systems, but this specific test focuses on proprioception and the integration of visual and tactile information [1]. By successfully inducing the illusion, the researchers showed that the octopus brain can be tricked into adopting an external object as part of its own physical form [3].
This research adds to a growing body of evidence regarding the cognitive capabilities of cephalopods. The study highlights the plasticity of the octopus nervous system and its ability to process spatial information in a way that mimics human perception [2].
“Octopuses can experience the rubber hand illusion, indicating they have a sense of body ownership similar to humans.”
The results suggest that the cognitive framework for body ownership is not a unique trait of the human brain or vertebrate evolution. Because cephalopods have a radically different nervous system architecture, the emergence of similar perceptual illusions indicates that there may be a universal biological requirement for a 'body map' to navigate and interact with the environment effectively.
