Isoontunneisuus

Isoontunneisuus, meaning "feeling of being large" or "feeling of bigness," is a perceptual phenomenon that can affect how an individual experiences their own body or the surrounding environment. It is not a formally recognized medical condition but rather a subjective sensation. This feeling can manifest in various ways. Some individuals might report a sensation of their body expanding or becoming disproportionately large compared to its actual physical size. Others might perceive objects or spaces in their environment as shrinking or becoming smaller, leading to a feeling of their own relative bigness.

The experience of isoontunneisuus can be transient and may occur under certain circumstances. Factors such as fatigue, stress, or even certain types of sensory deprivation have been anecdotally linked to its occurrence. It is also sometimes reported by individuals undergoing altered states of consciousness, such as those induced by certain recreational substances or during vivid dreams. While the exact underlying mechanisms are not fully understood, it is thought to involve disruptions in the brain's processing of sensory information, particularly related to proprioception (the sense of the relative position of one's own parts of the body) and spatial awareness. It is generally considered a benign perceptual anomaly, and most individuals experiencing it do not require medical intervention.