Ganzkörperillusionen

Ganzkörperillusionen, also known as full-body illusions, are perceptual phenomena where a person experiences a distortion or alteration of their own body image. These illusions can range from a feeling of the body shrinking or growing, to feeling as though one's limbs are no longer attached or have changed in size or shape. They are often studied in the context of neuroscience and psychology to understand how the brain constructs our sense of self and bodily ownership.

One common type of Ganzkörperillusion involves sensory manipulation. For example, the rubber hand illusion, when extended to a full body experience, can lead individuals to feel ownership over a prosthetic limb or even an object that is not theirs. This is often achieved by presenting synchronous visual and tactile stimuli. Another category involves visuomotor feedback, where altered visual information about body movements can lead to discrepancies between what is seen and what is felt, resulting in illusory sensations.

The underlying mechanisms of Ganzkörperillusionen are thought to involve the integration of sensory information from different modalities, such as vision, proprioception (the sense of the relative position of one's own parts of the body), and touch. When these inputs are incongruent, the brain may adapt by altering its representation of the body. Studies investigating these illusions have provided valuable insights into multisensory integration, body representation, and the neurobiological basis of body ownership. They are also relevant in understanding conditions like phantom limb pain and body dysmorphic disorder.