Humans and other animals systematically discount the value of future rewards as a function of their delay, and individual differences in the steepness of this ``delay discounting'' are predictive of a range of important real-world outcomes. Episodic future thinking, the mental simulation of episodes in the personal future, is one means by which to curb delay discounting. This thesis seeks to contribute to our understanding of how this effect occurs. The account that predominates in the literature is that episodic future thinking simulates the experience of future rewards, enabling their undiscounted value to be appreciated in the present. This thesis takes this account as a starting point, formalizing it in a mathematical model and carrying out several experimental studies to test its predictions. We find that key predictions are not borne out and develop an alternative account in which simulated experience plays a less central role. / Thesis / Doctor of Philosophy (PhD) / Pursuing our goals for the future usually means sacrificing immediate gratification, yet we often make decisions that are not in our best interest over the long term. This is because we assign lower subjective value to future rewards the further they are from the present. Individuals differ in how much they devalue future rewards, and these differences are related to many real-world outcomes. Our tendency to devalue future rewards is reduced when we vividly imagine the future in a process called ``episodic future thinking,'' and this thesis seeks to understand how this effect occurs. The most obvious explanation would seem to be that episodic future thinking ``simulates'' the experience of future rewards and allows us to recognize their value in the present. However, using results from several experimental studies, I argue that this may not be the best explanation after all, and I develop an alternative.

A normative experimental study was undertaken to establish whether engaging in positive, negative, and neutral mental imagery affected the reaction rate of participants to positive, negative, and neutral word stimuli. The sample consisted of computer literate, English speaking participants with no history of clinical disorders. A total of 80 participants took part in the study, with 40 participants from either gender. The results of a factorial ANOVA indicated that the type of mental imagery engaged in had a significant effect on the rate at which participants responded to stimuli (p=.00023, F=8.4057), whilst the emotional valence of the stimuli did not have a significant effect (p=.30503, F=1.1877). However, the interaction between the type of mental imagery and the emotional valence of the stimuli was highly significant (p=.00794, F=3.4576), thereby indicating that engaging in positive or negative mental imagery did bias participants towards a faster reaction rate to positive or negative stimuli respectively. / M.A. (Psychology) / Psychology

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

L’imagerie musicale involontaire (IMIN) est un phénomène mental extrêmement commun. Il peut être défini en tant que type d’imagerie mentale musicale qui devient consciente sans effort ou intentionnalité et qui n’est pas pathologique. La forme la plus connue d’IMIN est le « ver d’oreille », qui se présente généralement comme un court extrait musical tournant en boucle en tête et dont on se débarrasse difficilement. L’objectif principal de la présente thèse est d’investiguer les mécanismes cognitifs sous-tendant le phénomène puisque, malgré l’intérêt répandu dans les médias populaires, son étude expérimentale est récente et un modèle intégré n’a pas encore été proposé. Dans la première étude, l’induction expérimentale a été tentée et les caractéristiques des images mentales d’épisodes d’IMIN ont été investiguées. Dans le laboratoire, des chansons accrocheuses (versus des proverbes) ont été présentées répétitivement aux participants qui devaient ensuite les chanter le plus fidèlement possible. Ils ont par après quitté le laboratoire, une enregistreuse numérique en mains, avec la consigne d’enregistrer une reproduction vocale la plus fidèle possible de ce qu’ils avaient en tête lors de tous leurs épisodes d’IMIN sur une période de quatre jours, ainsi que de décrire leur timbre. L’expérience a été répétée deux semaines plus tard. Douze des dix-huit participants du groupe expérimental ont rapporté des pièces induites comme épisodes d’IMIN, ce qui confirme l’efficacité de la procédure d’induction. La tonalité et le tempo des productions ont ensuite été analysés et comparés à ceux des pièces originales. Similairement pour les épisodes d’IMIN induits et les autres, les tempi produits et, dans une moindre mesure pour les non-musiciens, les tonalités étaient proches des originaux. Le timbre décrit était généralement une version simplifiée de l’original (un instrument et/ou une voix). Trois études se sont ensuite intéressées au lien entre le potentiel d’IMIN et la mémorabilité. Dans une étude préliminaire, 150 chansons du palmarès francophone radiophonique ont été évaluées en ligne par 164 participants, sur leur niveau de familiarité, d’appréciation et de potentiel d’IMIN. Les pièces ont ensuite été divisées en groupes de stimuli à faible et à fort potentiel d’IMIN, qui ont été utilisés dans une tâche typique de rappel libre/reconnaissance, premièrement avec des francophones (pour qui les pièces étaient familières) et ensuite avec des non-francophones (pour qui les pièces étaient non-familières). Globalement, les pièces à fort potentiel d’IMIN étaient mieux rappelées et reconnues que les pièces à faible potentiel. Une dernière étude a investigué l’impact de la variabilité inter-stimulus du timbre sur les résultats précédents, en demandant à une chanteuse d’enregistrer les lignes vocales des pièces et en répétant l’expérience avec ces nouveaux stimuli. La différence précédemment observée entre les stimuli à fort et à faible potentiel d’IMIN dans la tâche de reconnaissance a ainsi disparu, ce qui suggère que le timbre est une caractéristique importante pour le potentiel d’IMIN. En guise de conclusion, nous suggérons que les phénomènes mentaux et les mécanismes cognitifs jouant un rôle dans les autres types de souvenirs involontaires peuvent aussi s’appliquer à l’IMIN. Dépendamment du contexte, la récupération mnésique des pièces peut résulter de la répétition en mémoire à court terme, de l’amorçage à court et long terme ou de l’indiçage provenant de stimuli dans l’environnement ou les pensées. Une des plus importantes différences observables entre l’IMIN et les autres souvenirs involontaires est la répétition. Nous proposons que la nature même de la musique, qui est définie par la répétition à un niveau micro- et macro-structurel en est responsable. / Involuntary Musical Imagery (INMI) is a widely prevalent musical phenomenon. It can be defined as a type of musical mental imagery that becomes accessible to consciousness without any effort or intent and that is not pathological. The best known form of INMI is the “earworm”, which usually presents as a short excerpt of music running repetitively through one’s mind and which is difficult to get rid of. The goal of the present thesis is to build a better understanding of the cognitive mechanisms at play, because, although the phenomenon is discussed abundantly in the popular literature and media, the scientific inquiries are recent and an integrated model has yet to be proposed. In the first study, experimental induction was attempted and the characteristics of INMI episodes’ mental images were assessed. In the laboratory, catchy songs (versus proverbs) were presented repeatedly to participants who had to sing them back (or reproduce the proverbs’ prosody) as accurately as possible. Participants then left for four days with a recording device, singing their INMI episodes as similarly as possible to their mental imagery and describing their timbre. The experiment was repeated two weeks later. Twelve out of the eighteen participants in the experimental group reported INMI episodes of the induced songs, which confirms the effectiveness of the induction procedure. The sung productions were then analyzed for key and tempo and were compared to the original versions. Produced tempi and, to a smaller extent in the case of non-musicians, keys were close to the originals, for both the induced and other INMI episodes. Described timbre was generally a simplified version of the original (one instrument and/or voice). Three studies then addressed the link between INMI potential and memorability. In a preliminary study, 150 francophone hit songs were evaluated online by 164 participants, as to their familiarity, liking and INMI potential. They were then divided into high and low INMI potential song groups and were used as stimuli in a typical free recall/recognition task, first with Francophones (for whom the songs were familiar) and then with non-Francophones (for whom the songs were unfamiliar). Globally, high INMI potential songs were better recalled and recognized than low INMI potential songs. A final study investigated the impact on the previous results of the timbre variability between songs, by asking a single female singer to make vocal recordings of the stimuli and repeating the experiment. The previously observed difference between high and low INMI potential songs on the recognition task disappeared, suggesting that timbre plays an important role in INMI potential. In conclusion, we suggest that mental phenomena and cognitive mechanisms applying to other involuntary thoughts and memories can also apply to INMI. Depending on the context, memory retrieval of the songs can happen as the result of short-term memory rehearsal, short and long-term priming or cuing from stimuli in the environment or thoughts. The biggest difference between INMI and other types of involuntary memories is repetition. We suggest that the nature of music, which is defined by repetition at a micro- and macro-structural level, explains this discrepancy.

Ziel der vorliegenden Studie war die Überprüfung der Wirksamkeit von Imaginationsübungen bei klimakterischen Beschwerden (IKB) im Sinne einer Linderung menopausaler Symptome sowie einer Besserung des psychischen Befindens und der Lebensqualität bei Mammakarzinompatientinnen. Das Mammakarzinom ist das häufigste Krebsleiden der Frau in Deutschland. Öfter als bei gesunden Frauen treten bei Brustkrebspatientinnen klimakterische Beschwerden auf, die in Frequenz und Schwere meist stärker ausgeprägt sind. Als Therapiemöglichkeit wurden die IKB in Anlehnung an das Autogene Training (AT) sowie die Simonton-Methode entwickelt. Über eine Entspannungssequenz und folgende Imagination sollen sich Hitzewallungen lindern lassen und das Wohlbefinden sowie die Lebensqualität gesteigert werden. Mittels Kopplung der Imagination an eine Geste soll der Effekt auch im Alltag provozierbar sein. Als Studiendesign wurde eine prospektive kontrollierte Interventionsstudie mit monatsabhängiger Blockrandomisierung durchgeführt, in deren Rahmen die Interventionsgruppe, die IKB erhielt, mit einer Kontrollgruppe verglichen wurde, die am AT teilnahm. Von August 2008 bis Mai 2011 wurden 121 Patientinnen in die Studie involviert, von diesen konnten 94 in die Datenauswertung einbezogen werden. Die Erhebung der nötigen Parameter erfolgte mittels Fragebögen zu drei Erhebungszeitpunkten: am Anfang und am Ende des Klinikaufenthalts sowie drei Monate nach der Entlassung aus der Klinik. Die Auswertung ergab in beiden Kollektiven eine signifikante Linderung von Hitzewallungen und anderen klimakterischen Beschwerden sowie eine Verbesserung des psychischen Befindens und der Lebensqualität, die sich überwiegend nach drei Monaten im häuslichen Umfeld beständig zeigten. Der Nachweis einer signifikanten Überlegenheit des IKBs gegenüber dem AT gelang nicht, allerdings zeigte sich in der IKB-Gruppe überzufällig häufig eine bessere Entwicklung als in der Kontrollgruppe. Zum Nachweis eines signifikanten Gruppeneffekts sowie zur Kontrolle möglicher Konfounder wie der Spontanremission bzw. Effekten der Rehabilitationsbehandlung sind weitere Studien mit einer größeren Power, im ambulanten Setting und gegen treatment as usual zu empfehlen.

O debate da imagética mental consiste de uma controvérsia iniciada nos anos 1970 a respeito da forma das representações mentais, e foi travada principalmente entre Stephen Kosslyn, que propunha uma forma imagética, e Zenon Pylyshyn, que propunha um formato simbólico-estrutural, além de apontar falhas conceituais na teoria da afiguração implícita no modelo pictorialista. Nesta dissertação, apresenta-se um balanço filosófico deste debate, levando em conta também críticas adicionais de Daniel Dennett aos pressupostos da abordagem pictorialista. / The mental imagery debate is a controversy that began in the 1970s concerning the form of mental representation, and was carried out mainly by Stephen Kosslyn, who defended a picture-like representation, and Zenon Pylyshyn, who proposed a symbolic-structural format. The latter also pointed out conceptual problems of the pictorialist model. This thesis presents a philosophical discussion of the debate, also taking into account additional criticisms by Daniel Dennett to the presuppositions of the pictorialist approach.

A normative experimental study was undertaken to establish whether engaging in positive, negative, and neutral mental imagery affected the reaction rate of participants to positive, negative, and neutral word stimuli. The sample consisted of computer literate, English speaking participants with no history of clinical disorders. A total of 80 participants took part in the study, with 40 participants from either gender. The results of a factorial ANOVA indicated that the type of mental imagery engaged in had a significant effect on the rate at which participants responded to stimuli (p=.00023, F=8.4057), whilst the emotional valence of the stimuli did not have a significant effect (p=.30503, F=1.1877). However, the interaction between the type of mental imagery and the emotional valence of the stimuli was highly significant (p=.00794, F=3.4576), thereby indicating that engaging in positive or negative mental imagery did bias participants towards a faster reaction rate to positive or negative stimuli respectively. / M. A. (Psychology) / Psychology

This thesis investigates the acceptability and efficacy of Functional Imagery Training (FIT), a motivational intervention for weight-management. FIT is based on Elaborated Intrusion Theory, delivered in the style of Motivational interviewing (MI), and designed to promote sustained behaviour change and address cravings. It trains the habitual use of affective, goal-directed mental imagery of personal incentives, using imagery to plan behaviours, anticipate obstacles, and mentally try out solutions from previous successes. Participants are taught to update their imagery from their experience, and to generalise their imagery skills to new goals. In study 1, focus groups explored problems and wishes in regards to weight-management, including reactions to Functional Imagery Training (FIT) as a possible intervention. The issue of waning motivation and the desire for motivational app support was expressed in all groups. Participants were positive about FIT. Study 2 was an uncontrolled pilot trial of FIT. Eleven out of 17 participants (65%) lost 5% body weight or more by three months. Participants continued to lose weight during an unsupported 12-month period and experienced mean weight loss of 6kg (SD= 5.7; d=1.06) and mean waistline reduction of 11.5 cm (SD= 7.4; d=1.56) at 15 months. Study 3 compared the impact of FIT with MI on motivation and self-efficacy, over the first month of a randomised controlled trial (RCT) for weight-loss. Structured elicitation and training in goal-related imagery, i.e., FIT, increased motivation and self-efficacy for weight-loss relative to MI. Study 4 was the RCT for weight-loss, comparing FIT and MI over an intervention-supported six-month period, followed by six months unsupported. The FIT group achieved clinically meaningful weight-loss at 6 months (M kg-loss=4.11) and continued weight-loss at 12 months (M kg-loss=6.44); the MI group stabilised by 12 months (M kg-loss=.67), after minimal weight loss at 6 months (M kg-loss=.74). Study 5 qualitatively explored experiences of MI and FIT RCT participants, upon completing the 6-month intervention phase. MI participants wished for continued therapist- support and feared relapse. FIT participants described a mind-set-change and were confident they could maintain changes and overcome challenges using imagery techniques. Given the demonstrated benefit of motivational imagery in weight-control, FIT should be considered and further tested as an intervention for health behaviour change.

Background Research has shown that people need to be pre-informed about the ambiguity in order to perceive both interpretations (reverse) of an ambiguous figure. Children younger than 4 years mostly do not experience reversal even when informed. This suggests that the processes involved in reversal develop at this age. Aim The aim of the studies reported here was to disentangle the cognitive processes (metarepresentation, executive function, mental imagery) and the role of eye-movements involved in reversal. Method Four studies (7 experiments), each involving around sixty 3-, 4- and 5-year-old children, using multiple tasks, were conducted. The primary tasks used were the Ambiguous Figures Production and Reversal tasks. The secondary tasks used were metacognitive, executive function and mental imagery tasks. New tasks were also implemented in order to assess reversal abilities. Results Between the ages of 3 and 4 children develop the basic conceptual understanding for reversal (Study 1), that an ambiguous figure can have two interpretations. This is associated with the understanding of false belief, synonymy and homonymy. Between the ages of 4 and 5 children develop inhibitory (Study 3) and image generation abilities (Study 4). These are key cognitive processes necessary for reversal. Contrary to previous research, when task demands were changed (Reversal Task Revised) children’s reversal is at ceiling by the age of 5 (Studies 3 and 4). Eye-tracking data suggests that appropriate eye-movements, focusing on particular parts of the ambiguous figure, are not a primary causal factor in the development of reversal abilities (Study 4). Conclusion The ability to reverse develops in two stages. During stage 1 (between 3 and 4 years) children develop the necessary conceptual understanding that an ambiguous figure can have two interpretations (top-down knowledge). During stage 2 (between 4 and 5 years) children develop the necessary cognitive processes for reversal to occur (inhibition and image generation).

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal