Psychoprojective telepathy was a telepathic ability of the Halanans. It apparently entailed projecting a seemingly solid image of ones' self, which could act out subconscious personality traits.
On a visit to Deep Space 9 aboard the USS Prometheus in 2370, Nidell lost control of her psychoprojective telepathy, allowing Fenna to appear to Benjamin Sisko. (DS9: "Second Sight")