A Thesis Submitted for the Degree of PhD at the University of Warwick Permanent WRAP URL: http://wrap.warwick.ac.uk/104800/ Copyright and reuse: This thesis is made available online and is protected by original copyright. Please scroll down to view the document itself. Please refer to the repository record for this item for information to help you to cite it. Our policy information is available from the repository home page. For more information, please contact the WRAP Team at: [email protected] warwick.ac.uk/lib-publications The Impact of Digital Change on Memory and Cognition by Sophie Jane Nightingale A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology University of Warwick, Department of Psychology September 2017 Table of Contents Table of Contents ............................................................................................................ 2 List of Tables ................................................................................................................... 8 List of Figures .................................................................................................................. 9 Acknowledgements ........................................................................................................ 12 Declaration ..................................................................................................................... 13 Inclusion of Published Work ....................................................................................... 13 Abstract .......................................................................................................................... 14 Chapter 1 : Introduction .............................................................................................. 15 A brief history of photography .................................................................................... 15 Drawing with light ................................................................................................ 15 The chemical effects of light ................................................................................ 16 From chemicals to bits—the digitalisation of light .............................................. 16 A picture is worth a thousand words, or is it? ...................................................... 17 The effects of photos on memory and cognition ......................................................... 20 The constructive nature of memory ...................................................................... 20 Photos and childhood memories ........................................................................... 22 Can photos affect recent memories? ..................................................................... 23 Photos and judgements ......................................................................................... 25 Summary ..................................................................................................................... 26 Chapter 2 : Real-World Implications of Photo Manipulation in the Digital Age ... 27 Consequences of digitally manipulating images ......................................................... 27 Photo evidence on trial ......................................................................................... 27 Digital photo manipulation and well-being .......................................................... 31 Consequences of taking so many photos ..................................................................... 34 Thesis aims and outline ............................................................................................... 35 Part One ......................................................................................................................... 37 Chapter 3 : Can people identify original and manipulated photos of real-world scenes .............................................................................................................................. 37 Introduction ................................................................................................................. 37 2 Experiment 1 ............................................................................................................... 43 Method .................................................................................................................. 43 Subjects and design ........................................................................................... 43 Stimuli ............................................................................................................... 43 Procedure .......................................................................................................... 46 Results and discussion .......................................................................................... 47 Overall accuracy on the detection task and the location task ........................... 47 Ability to detect and locate by manipulation type ............................................ 49 Image metrics and accuracy .............................................................................. 51 Individual factors in detecting and locating manipulations .............................. 55 Experiment 2 ............................................................................................................... 59 Method .................................................................................................................. 59 Subjects and design ........................................................................................... 59 Stimuli ............................................................................................................... 59 Procedure .......................................................................................................... 59 Results and discussion .......................................................................................... 60 Overall accuracy on the detection task and the location task ........................... 60 Ability to detect and locate by manipulation type ............................................ 63 Image metrics and accuracy .............................................................................. 65 Individual factors in detecting and locating manipulations .............................. 70 Conclusion ................................................................................................................... 72 Chapter 4 : Can people identify geometric inconsistencies in cast shadows? ......... 77 Introduction ................................................................................................................. 77 Experiment 1a .............................................................................................................. 83 Method .................................................................................................................. 83 Subjects and Design .......................................................................................... 83 Stimuli ............................................................................................................... 83 Procedure .......................................................................................................... 86 Results and Discussion ......................................................................................... 86 Overall accuracy on the shadow task ................................................................ 86 Individual factors and image metrics ................................................................ 87 Experiment 1b ............................................................................................................. 89 3 Method .................................................................................................................. 89 Subjects and Design .......................................................................................... 89 Stimuli and Procedure ....................................................................................... 89 Results and Discussion ......................................................................................... 89 Overall accuracy on the shadow task ................................................................ 90 Individual factors and image metrics ................................................................ 90 Experiment 2a .............................................................................................................. 93 Method .................................................................................................................. 93 Subjects and Design .......................................................................................... 93 Stimuli ............................................................................................................... 93 Procedure .......................................................................................................... 94 Results and Discussion ......................................................................................... 94 Overall accuracy on the shadow task ................................................................ 94 Preference for shadows to the left or right ........................................................ 96 Experiment 2b ............................................................................................................. 98 Method .................................................................................................................