Mental time travel [Elektronische Ressource] : differences between episodic memory an episodic future thinking / by Julia Weiler

MENTAL TIME TRAVEL – DIFFERENCES BETWEEN EPISODIC
MEMORY AND EPISODIC FUTURE THINKING

by
Julia Weiler
A thesis submitted in partial fulfilment of the requirements for the degree of
Philosophiae Doctoris (PhD) in Neuroscience
from the International Graduate School of Neuroscience
Ruhr University Bochum



thSeptember 30 , 2010




This research was conducted at the Department of Neuropsychology, within the Faculty of
Psychology of the Ruhr University under the supervision of Prof. Dr. Irene Daum.
Printed with the permission of the International Graduate School of Neuroscience, Ruhr University Bochum
 Statement
I certify herewith that the dissertation at hand was completed and writ-
ten independently and without outside assistance. The "Guidelines for Good
Scientic Practice" according tox 9, Sec. 3 were adhered to. This work has
never been submitted in this or a similar form at this or any other domestic
or foreign institution of higher learning as a dissertation.
Julia Weiler
Bochum, 30.09.2010PhD Commission
Chair: Prof. Dr. Doris Koesling
st1 Internal Examiner: Prof. Dr. Irene Daum
nd2 Internal Examiner: Prof. Dr. Klaus-Peter Ho mann
External Examiner: Prof. Dr. Nicola Clayton
Non-Specialist: Prof. Dr. Motoharu Yoshida
Date of Final Examination:
PhD Grade Assigned:Contents
List of Figures VI
List of Tables VIII
List of Abbreviations IX
Abstract 1
1 General introduction 3
1.1 Components of mental time travel . . . . . . . . . . . . . . . . 4
1.1.1 Episodic memory . . . . . . . . . . . . . . . . . . . . . 4
1.1.2 Other processes . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Similarities between memory and future thinking . . . . . . . 5
1.2.1 Neuroimaging studies { the core network . . . . . . . . 5
1.2.2 Behavioral studies in children and adults . . . . . . . . 6
1.2.3 Investigations in clinical populations . . . . . . . . . . 7
1.3 Cognitive processes mediated by the core network . . . . . . . 8
1.3.1 Self-projection . . . . . . . . . . . . . . . . . . . . . . . 9
1.3.2 Scene construction . . . . . . . . . . . . . . . . . . . . 10
1.3.3 Unifying scence construction and self-projection . . . . 11
1.3.4 Associative processing . . . . . . . . . . . . . . . . . . 11
1.4 Dierences between memory and future thinking . . . . . . . . 12
1.4.1 Neuroimaging studies . . . . . . . . . . . . . . . . . . . 12
1.4.2 Behavioral studies . . . . . . . . . . . . . . . . . . . . 13
1.4.3 The asymmetry between past and future . . . . . . . . 14
1.5 Involvement of the human thalamus in mental time travel . . . 15
1.6 Basic principles of the applied methods . . . . . . . . . . . . . 16
1.6.1 Functional magnetic resonance imaging (fMRI) . . . . 16
1.6.2 Slow cortical potentials (SCPs) . . . . . . . . . . . . . 16
1.7 Aims of the thesis . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.7.1 Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
ICONTENTS
2 Study 1: Di erences in brain activation patterns for memory
and future thinking 19
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.1.1 Aims and hypotheses . . . . . . . . . . . . . . . . . . . 20
2.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.2 Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.3 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.2.4 Scanning parameters . . . . . . . . . . . . . . . . . . . 24
2.2.5 Data analysis . . . . . . . . . . . . . . . . . . . . . . . 24
2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.3.1 Behavioral data . . . . . . . . . . . . . . . . . . . . . . 26
2.3.2 Common activations for past and future events . . . . 27
2.3.3 Di erential activations for past and future events . . . 28
2.3.4 Whole-brain interaction analysis . . . . . . . . . . . . . 29
2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.1 Hippocampus . . . . . . . . . . . . . . . . . . . . . . . 33
2.4.2 Whole-brain interaction analysis . . . . . . . . . . . . . 34
2.4.3 Di erential activations . . . . . . . . . . . . . . . . . . 35
2.4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 36
3 Study 2: In uence of future event probability on brain acti-
vation 37
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.1.1 Aims and hypotheses . . . . . . . . . . . . . . . . . . . 38
3.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . 38
3.2.2 Task and procedure . . . . . . . . . . . . . . . . . . . . 39
3.2.3 Scanning parameters . . . . . . . . . . . . . . . . . . . 39
3.2.4 Data analysis . . . . . . . . . . . . . . . . . . . . . . . 39
3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.3.1 Behavioral data . . . . . . . . . . . . . . . . . . . . . . 40
3.3.2 Parametric Modulation . . . . . . . . . . . . . . . . . . 41
3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.4.1 Hippocampus . . . . . . . . . . . . . . . . . . . . . . . 43
3.4.2 Modulations by occurrence probability outside the hip-
pocampus . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.4.3 Modulations by richness of detail and emotionality . . 45
3.4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 45
IICONTENTS
4 Study 3: Electrophysiological di erences in the temporal course
of memory and future thinking 47
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.1.1 Aims and hypotheses . . . . . . . . . . . . . . . . . . . 48
4.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.2 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.3 Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.4 Post-experimental interview . . . . . . . . . . . . . . . 51
4.2.5 EEG recording . . . . . . . . . . . . . . . . . . . . . . 51
4.2.6 Statistical analysis . . . . . . . . . . . . . . . . . . . . 52
4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
4.3.1 Behavioral data . . . . . . . . . . . . . . . . . . . . . . 53
4.3.2 EEG data . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.4.1 Di erences between memory and future thinking . . . . 61
4.4.2 Similarities between memory and future thinking . . . 62
4.4.3 Phenomenological properties . . . . . . . . . . . . . . . 63
4.4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 64
5 Study 4: Impact of thalamic lesions on mental time travel 65
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.1.1 Aims and hypotheses . . . . . . . . . . . . . . . . . . . 66
5.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
5.2.1 Participants . . . . . . . . . . . . . . . . . . . . . . . . 68
5.2.2 Event generation task . . . . . . . . . . . . . . . . . . 75
5.2.3 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.2.4 Interview analysis . . . . . . . . . . . . . . . . . . . . . 78
5.2.5 Statistical analysis . . . . . . . . . . . . . . . . . . . . 80
5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.3.1 Vivid mental imagery conditions . . . . . . . . . . . . 82
5.3.2 Public event conditions . . . . . . . . . . . . . . . . . . 90
5.3.3 Subjective ratings . . . . . . . . . . . . . . . . . . . . . 93
5.3.4 Temporal distance . . . . . . . . . . . . . . . . . . . . 95
5.3.5 Correlations . . . . . . . . . . . . . . . . . . . . . . . . 96
5.3.6 Diculty of conditions . . . . . . . . . . . . . . . . . . 96
5.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
5.4.1 Recombination de cits . . . . . . . . . . . . . . . . . . 98
5.4.2 The dierentiation of ctitious and future events . . . . 100
5.4.3 De cits in public event generation . . . . . . . . . . . . 101
5.4.4 Comparison of subjective and objective variables . . . 102
IIICONTENTS
5.4.5 Contribution of the medial dorsal nucleus to mental
time travel . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 106
6 General discussion 108
6.1 Summary of main results . . . . . . . . . . . . . . . . . . . . . 108
6.1.1 Study 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 108
6.1.2 Study 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.1.3 Study 3 . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.1.4 Study 4 . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.2 Neural substrates of the past/future dissociation . . . . . . . . 110
6.2.1 Reconciling previous controversial results . . . . . . . . 112
6.2.2 The prefrontal-thalamic-hippocampal axis . . . . . . . 113
6.3 The plausibility of imagined events . . . . . . . . . . . . . . . 115
6.4 Open questions . . . . . . . . . . . . . . . . . . . . . . . . . . 115
6.4.1 Role of medial dorsal thalamus and prefrontal cortex
f