Who hasn’t dreamed of having an invisibility cloak like Harry Potter’s? Many of the hypothetical possibilities that open to a person rendered invisible have been well explored in the worlds of science fiction and philosophy, not to mention the minds of imaginative adolescents.
But the concept of invisibility may not be limited only to the realm of science fiction. In these days more pragmatic-minded scientists, engineers and even neuroscientists believe that invisibility cloaking of the human body may be possible in the near future. However, they have no idea how invisibility can affect our body perception and embodied cognition.
Based on this dilemma, researchers from Department of Neuroscience, Karolinska Institutet, Sweden decided to start new study which aimed to answer one of the most interesting question – „What is it like to be invisible?“.
Firstly, Swedish team hypothesized that multisensory integrative mechanisms that underlie the invisible hand illusion can be generalized to the illusion of having an entire body invisible. In this hand illusion, a subject is made to believe that a rubber hand is in fact your own hand, which is hidden from view, to the point of pulling your own hand away if the rubber hand is attacked. And so it seems our minds can be tricked not only into disowning parts of our bodies, but also into owning parts that don’t actually belong to us — in this case, a rubber hand. This illusion has been used in many domains of psychology (research on pain, body ownership, agency) and is of clinical importance.
Secondly, researchers examined the illusion experience in 125 participants who were asked to stand in an upright position with their head tilted and to look down at their body. To induce the illusion, the experimenter stroked the participant’s body with a large paintbrush while simultaneously moving another paintbrush in the corresponding location in the empty space below the cameras, as if he were touching an ‘‘invisible body’’ that was in this location. The author of experiment touched five different body parts: the abdomen, the left and right lower arms, and the left and right lower legs and feet.
To determine participants feelings, researchers tested how participants felt when they stood in front of a small crowd that was asked to stare at them.
Results demonstrated that healthy individuals can experience the illusion of owning an invisible full-body. This perceptual illusion arises when participants observe a paintbrush moving in an empty space and defining the contours of an invisible body, while receiving simultaneous touches on the corresponding parts of their real body that is hidden from view. Also, from an applied neuroscience perspective, these findings showed that the invisible body illusion had an important role in the treatment of social anxiety – those who felt they were invisible had lower heart rates and the level of stress was significantly decreased.
Invisibility has long been an ability exclusively enjoyed by teenage wannabe-wizards, super heroes, and the ultra-advanced civilizations from the realm of science fiction. But now, when modern science is rapidly advancing research into this field, it is really interesting to explore how we will feel when actually being invisible…