Complex sentence: In parapsychology, an apparitional experience is an anomalous experience characterized by the apparent perception of either a living being or an inanimate object without there being any material stimulus for such a perception.
Split into simpler sentences: In parapsychology, an apparitional experience is an anomalous, quasi-perceptual experience. It is characterized by the apparent perception of either a living being or an inanimate object without there being any material stimulus for such a perception.