Fig. 1: Fixated feature subspaces. Dimensions of the subspace closest to all 3 participant groups' principal component spaces are shown for each stimulus category (minimum 86% of total variance). C = control subject, CIP = cannabis-induced psychosis, SCH = first-episode schizophrenic disorder of paranoid type, Rand = random fixation simulation for landscape (L'scape) scenes. For simplicity, only the first 10 of 30 dimensions are shown, reconstructed as eigenimages. The minimum angular deviation (in degrees) between each direction and group is given for each stimulus category and increases with higher dimensions, indicating greater divergence associated with diversity of features fixated. Graph inserts titrate subspace dimension (abscissas) against accumulated angular divergence (ordinates). A clear pattern emerged irrespective of the stimulus category: CIP > SCH > control. Landscapes were chosen as a control because they are commonly experienced, contain complex natural features and lack overt social relevance. Increasing separation (greater angular deviation) of random viewing from the landscape subspace with respect to control subjects indicates staring and unsystematic sampling of image content.