Näköpseudohallusinaatiot

Näköpseudohallusinaatio, also known as visual pseudohallucination, refers to a perceptual experience in which vivid, often complex visual images are perceived without an external stimulus. Unlike true hallucinations, which are typically associated with psychiatric disorders such as schizophrenia, näköpseudohallusinations are generally recognized by the individual as non-real or imagined. This distinction is key in differentiating them from genuine hallucinations, where the experience is often mistaken for reality.

The phenomenon is most commonly observed in conditions involving sensory deprivation, such as severe visual impairment or blindness. Individuals with advanced age-related macular degeneration (AMD) or retinitis pigmentosa may develop näköpseudohallusinations as their vision deteriorates. These visual experiences can take various forms, including shapes, colors, faces, or even entire scenes, and are often described as highly detailed and persistent.

Research suggests that näköpseudohallusinations may arise from the brain’s attempt to compensate for lost sensory input. The visual cortex, deprived of external stimuli, may generate spontaneous neural activity, leading to these vivid perceptions. The experience is typically not distressing and does not interfere with daily functioning, though it can be puzzling for those who encounter it.

Unlike hallucinations in psychiatric disorders, näköpseudohallusinations are not linked to delusions or other cognitive impairments. They are generally considered a benign phenomenon, though further study is needed to fully understand their mechanisms and implications. The condition is often discussed in the context of neuroplasticity, highlighting how the brain adapts to significant sensory loss.