Language
Country/Area
No result found
A curious experiment in the rubber hand illusion: Why do we think a prosthetic hand is ours?
While conducting psychological research, a striking phenomenon once appeared: a person will feel that a part of his body that is not his own is actually his own. This phenomenon is called "body transfer hallucination". Not only does it challenge our definition of self, it also provokes deep thinking about human perception and body ownership.
The body transfer illusion is the illusion of possessing a body part or an entire body other than one's own, usually produced in the laboratory by manipulating visual angles.
Experiments on the Rubber Hand Illusion
This interesting concept was first experimented by Botvinick and Cohen in 1998, when the topic focused on the rubber hand illusion. In the experiment, the researchers hid the volunteer's left hand and placed a rubber hand that was almost identical to his left hand in front of him. Subsequently, the researchers used a paintbrush to stimulate the volunteers' real hands and rubber hands at the same time. The results found that when the stimulation was synchronized and in the same direction, the volunteers began to perceive the rubber hand as their own hand. Many people actually pointed to the rubber hand when answering where their left hand was.
This experiment shows how congruence between tactile stimulation of the left hand and visual information about the rubber hand changes an individual's perception of ownership.
Hallucinations induced in virtual reality
Another research method that highlights the illusion of body transfer is conducted in a virtual reality environment. In this experiment, male participants were placed in a simulated virtual human body. Through the simulated overall image, the participants began to perceive the virtual body as their own body. The results showed that threat to the virtual body caused a decrease in heart rate, further supporting the idea of integration of visual and tactile signals.
Clinical application and therapeutic effect
The body transfer illusion is also used to treat phantom limb pain. At this time, mirror boxes and other methods are used to provide visual feedback of the missing limb, allowing people to "see" and "manipulate" the missing limb, thereby alleviating pain. Virtual reality also provides patients with this kind of interactive experience, allowing them to re-establish a sense of connection to the limb in a safe environment.
Exploration of neurological basis
From a physiological perspective, the generation of the body transfer illusion requires perfect integration between tactile stimulation and visual information. Input from different senses must work together, which allows an individual to more fluidly perceive the position of the body as it experiences movement. However, the establishment of this illusion has not yet ruled out the possibility of visual dominance.
The emergence of multisensory fusion activity in the brain, especially the interaction between the ventrolateral motor cortex and posterior parietal regions, provides important clues to the body transfer illusion.
The effect of drugs on hallucinations
Studies have shown that participants' sensitivity to phantom limb ownership increases significantly during the use of drugs such as ketamine. This effect suggests that the drug appears to attenuate sensitivity to dissonance between visual and tactile information, allowing hallucinatory experiences to persist even in the presence of sensory desynchrony.
The connection between mind and body
Human body experience is composed of continuous awareness of oneself and various parts of the body, and this perception of self-attributes has been discussed in philosophy and neuroscientific theories. Although we all have a sense of self-positioning, it is still unclear whether this experience exists innately or is simply constructed through sensory experience.
Questions about the effect of imagination
Research on body transfer illusions has continued in recent years, and a 2022 study pointed out that previous experiments may not have adequately controlled participants' expectancy factors. This raises questions about whether body transfer hallucinations are simply an imagination-induced effect.
These amazing discoveries not only amaze us at the complexity of human perception, but also make us think further: In this era of rapid technological development, what can the nature of the body and its relationship with the mind bring to us? What about revelation?
