Psychoprojective telepathy is the ability to create realistic and touchable images with one's mind. These images register as pure energy, similar to holograms.
Halanans have this special ability (other species capable of this are currently not known) and can create images several square meters in size. They usually have great control over their psychoprojected images and can use them in various ways. Sometimes, when under great stress, they might lose control of this ability, subconsciously creating alter egos to remedy the situation. The projection of these alter egos might be so overwhelming that they can slip into a coma and die from the experience.
- Memory Alpha, "Psychoprojective telepathy"