Human Time Perception – Predictable visual stimuli are perceived earlier than unpredictable events Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften der Mathematisch-Naturwissenschaftlichen Fakultät und der Medizinischen Fakultät der Eberhard-Karls-Universität Tübingen vorgelegt von Barbara Wirxel aus Warendorf, Deutschland August - 2017 I Tag der mündlichen Prüfung: 30.Oktober 2017 Dekan der Math.-Nat. Fakultät: Prof. Dr. W. Rosenstiel Dekan der Medizinischen Fakultät: Prof. Dr. I. B. Autenrieth 1. Berichterstatter: PD Dr. Axel Lindner 2. Berichterstatter: Prof. Dr. Christoph Braun Prüfungskommission: PD Dr. Axel Lindner Prof. Dr. Christoph Braun Prof. Dr. Uwe Ilg PD Dr. Gregor Hardieß II Erklärung / Declaration: Ich erkläre, dass ich die zur Promotion eingereichte Arbeit mit dem Titel: “Human Time Perception – Predictable visual stimuli are perceived earlier than unpredictable events” selbständig verfasst, nur die angegebenen Quellen und Hilfsmittel benutzt und wörtlich oder inhaltlich übernommene Stellen als solche gekennzeichnet habe. Ich versichere an Eides statt, dass diese Angaben wahr sind und dass ich nichts verschwiegen habe. Mir ist bekannt, dass die falsche Abgabe einer Versicherung an Eides statt mit Freiheitsstrafe bis zu drei Jahren oder mit Geldstrafe bestraft wird. Tübingen, den ......................................... ............................................................. Datum / Date Unterschrift /Signatur III Table of contents Abstract ..................................................................................................................... 1 Abbreviations ............................................................................................................ 3 Introduction ............................................................................................................... 5 Motor Prediction ...................................................................................................... 6 Sensory Prediction .................................................................................................. 9 Flash-lag Effect ..................................................................................................... 10 Present Study ....................................................................................................... 14 Material and Methods ............................................................................................. 15 Basic Concept/Paradigm ....................................................................................... 15 Hypothetical Results ............................................................................................. 18 Eye Tracking ......................................................................................................... 21 IR-Lab Setup & MEG Setup .................................................................................. 23 Magnetoencephalography ..................................................................................... 24 Experiment Procedure .......................................................................................... 25 Pretest ............................................................................................................... 25 Main Experiment................................................................................................ 26 Exclusion and Inclusion Criteria ........................................................................ 27 Specific Experiment Designs, Results, and Implications ................................... 29 Design #01—Pilot study ........................................................................................ 29 Design #01: Concept ......................................................................................... 29 Design #01: Results and Implications ................................................................ 30 Design #02—Full Experiment ............................................................................... 38 Design #02: Concept............................................................................................. 38 Design #02: Results and Implications ................................................................ 41 Design #03—First Control ..................................................................................... 47 Design #03: Concept ......................................................................................... 47 Design #03: Results and Implications ................................................................ 48 Design #04—Second Control ................................................................................ 52 Design #04: Concept ......................................................................................... 52 Design #04: Results and Implications ................................................................ 54 Design #05—Third Control .................................................................................... 56 Design #05: Concept ......................................................................................... 56 Design #05: Results and Implications ................................................................ 57 Design #06—Ultimate Design (IR and MEG setup) .............................................. 59 Design #06: Concept for IR and MEG Design ................................................... 59 Design #06: Results and Implications of Measurements at IR setup ................. 61 Design #06: Conceptual details of MEG setup .................................................. 63 IV Design #06: Results and Implications of Measurement at MEG setup .............. 64 Design #06: MEG data ...................................................................................... 66 General Discussion ................................................................................................ 75 Findings on time perception across designs ......................................................... 75 Delimitation from other temporal distortions .......................................................... 82 Representational Momentum ............................................................................ 82 Prior entry .......................................................................................................... 83 Hazard rate of time ............................................................................................ 84 Saccadic Chronostasis ...................................................................................... 85 Temporal distortions of perceived stimulus duration.......................................... 86 Conclusion and Outlook ........................................................................................ 89 References .............................................................................................................. 91 Papers and Books ................................................................................................. 91 Online resources ................................................................................................... 94 Appendix ................................................................................................................. 95 Tabular overview of experiment designs ............................................................... 95 List of figures ....................................................................................................... 101 List of tables ........................................................................................................ 102 Visual angle ........................................................................................................ 102 Conference contribution ...................................................................................... 103 Acknowledgement ............................................................................................... 103 Declarations/ Erklärung ....................................................................................... 104 Danksagung .......................................................................................................... 106 V VI Abstract What is it that enables us to timely react to visual events despite the significant processing delays within the visual system? This delay is estimated to be already about 100ms in higher visual areas, a delay that is relevant if one needs to initiate fast reactions, such as catching a ball in flight or initiating an escape. To compensate for delays in motor behavior, the brain employs predictive mechanisms. We aimed to investigate whether predictability of a visual stimulus not only affects behavior but also the time of perceived stimulus onset in humans. Specifically, we hypothesized that predictable visual stimuli have an earlier perceived onset than non- predictable stimuli do. Our approach was the following: Subjects viewed streams of individual letters with a 1000ms standard interval between letters. This sequence of letters was either in alphabetical order, and thus predictable, or alternatively, the last letter of a sequence was chosen at random and thus not predictable. In each trial, subjects had to indicate whether or not the last letter agreed with the alphabetical order. Moreover, subjects had to estimate whether the duration of the last test interval, which was of varying length, was either longer or shorter than the standard interval. Varying the length of the last interval