The sime sense through which a Sime discerns his placement in the universe. It is connected to the sime's internal clock which measures selyn consumption and the hours of life left. This sense seems to have evolved to assist a Sime in hunting Gens. Orientation can be disrupted by moving an unconscious Sime without expert selyn field management.
Psychospacial Orientation is the single real contribution, other than selyn-powered starships, that humans contribute to galactic civilization. Humans are the astrogators of this galaxy and all the rest of their foibles are endured for that sake alone.