A metacontrast masking paradigm was employed to provide evidence for the richness and diversity of our visual experience. Square-and diamond-shaped targets were followed by square-and diamond-shaped masks at varying stimulus onset asynchronies (SOAs), resulting in shape-congruent and shape-incongruent trials. In Experiment 1, participants reported in each trial how they perceived target and mask. After extended training, seven different aspects of the target could be distinguished as specific percepts in this metacontrast masking paradigm. These percepts encompass aspects including the temporal distance between both stimuli, the perceived contrast of the target, and motion percepts resulting from the interplay between the target and mask. Participants spontaneously reported each of these percepts, and the frequency of reports varied systematically with SOA and the congruency between target and mask. In Experiment 2, we trained a new group of participants to distinguish each of these target percepts. Again, the frequency of reports of the specific percepts varied with SOA and congruency, just as in Experiment 1. In a last session, we measured objective discrimination performance yielding the typical individually different masking functions across SOAs. An examination of the relation between the frequencies of reports of subjective percepts and objective discrimination performance revealed multiple dissociations between these measures. Results suggest a multidimensional pattern of subjective experiences under metacontrast, which is reflected in dissociated subjective and objective measures of visual awareness. As a consequence, awareness cannot be assessed exhaustively by a single measure, thus challenging the use of simple one-dimensional subjective or objective measures in visual masking.

Tag der mündlichen Prüfung: 13.03.2019 II Acknowledgements My sincere thanks go to all my colleagues for the very nice cooperation over the past years. Passionate discussions and a good portion of humor have made working very pleasant. I am very grateful for the fruitful cooperation that and I will miss you. Especially my supervisors, Uwe Mattler, Hannes Rakoczy and Thorsten Albrecht helped me a lot to advance my work with constructive criticism, emotional support and inspiration. I have always found an open ear and the willingness to support me with problems. Thank you very much for your support over the last three years. Of course, I would never have been able to work without the support of the student assistants who accompanied me during my doctorate: Alexander Kraut, Judith Diele, Charlotte Fink, Selin Altiok und Katja Lorenz. Thank you very much for your great cooperation.My thanks also go to my family and friends, who cheered me up in difficult times and without whom life would be half as beautiful. In particular I would like to thank my husband, who is always there for me with help and advice, who believes in me and supports me. I would like to dedicate the last thought to my daughter who made it possible to finish my work in spite of her presence. I am very happy that you are with us.