Despite decades of effort in developing evidence-based treatments, drug addiction remains one of the most problematic and enduring public health crises. Developing a new generation of theoretically-derived interventions constitutes an important clinical and scientific gap that, if addressed, may open innovative treatment opportunities. Based on the Reinforcer Pathology theory, altering the temporal window over which reinforcers are integrated (i.e., measured by delay discounting) would alter drug valuation and consumption. The first investigation—in 2 separate studies— test the Reinforcer Pathology theory by examining the effect of expanding and constricting the temporal window of integration using two mating narratives (long-term and short-term relationships, respectively) on cigarette valuation among cigarette smokers. The second investigation, test the Reinforcer Pathology theory by assessing the effect of remotely delivered Episodic Future Thinking (EFT) narratives (expands the temporal window) on real-world alcohol consumption among individuals with alcohol use disorder (AUD). Together, these investigations supported the Reinforcer Pathology theory and demonstrated its relevance for understanding and intervening in addiction. The current findings provide scientific justification to further investigate Reinforcer Pathology based interventions that expand the temporal window to change drug valuation and consumption. The construction of multi-component treatments that incorporate Reinforcer Pathology based interventions to systematically alter the temporal window may provide a novel intervention to reduce alcohol consumption. / Doctor of Philosophy / The following studies provide evidence that altering the temporal widow (how far in the future one can imagine and integrate into the present) would alter drug valuation. In the following studies, we used narratives describing long-term or short-term mating relationships (Study 1) and Episodic Future Thinking (EFT; represents one's capability to pre-experience the future; Study 2) to alter the valuation of cigarettes and alcohol, respectively. In the first study, cigarette smokers who read and vividly imagined long-term romance relationship narrative (expands the temporal window) valued cigarettes less than control (imagined looking for a lost key). In contrast, those who read and vividly imagined a short-term sexual encounter (shortens the temporal window) valued cigarettes more than controls. The second study employed EFT (expands the temporal window) as a strategy to reduce alcohol consumption, in real-world settings, over two weeks in individuals with alcohol use disorder. The study found that expanding the temporal window using EFT reduced alcohol consumption. Together, these two studies provide support to employing interventions that extend the temporal window to change drug valuation and consumption. The construction of multi-component treatments that incorporate interventions expanding the temporal window may reduce drug consumption.

L’objectif de cette thèse était d’étudier les processus impliqués dans la localisation temporelle des événements personnels futurs chez les sujets sains et les patients atteints de schizophrénie. Pour cela, nous avons utilisé la méthode de réflexion à voix haute dans trois études expérimentales pour analyser les stratégies utilisées pour déterminer la localisation temporelle des événements autobiographiques. Dans l’Etude 1, nous avons constaté que les participants utilisaient principalement des processus de reconstruction/d’inférence pour dater les événements. Ils s’appuyaient le plus souvent sur des connaissances autobiographiques (c.-à-d., des périodes de vie/événements étendus) et des connaissances générales pour reconstruire ou inférer le moment des événements, à la fois pour les événements passés et futurs. Dans l'Etude 2, nous avons constaté que les buts personnels influençaient le processus de localisation temporelle en augmentant l'accès direct à la date des événements futurs importants et en favorisant l'utilisation de connaissances autobiographiques pour inférer le moment des événements lorsque les dates ne sont pas directement accessibles. Dans l’Etude 3, nous avons constaté que les patients atteints de schizophrénie avaient des difficultés à s’appuyer sur des informations épisodiques pour reconstruire ou inférer la date des événements personnels, et qu’ils commettaient davantage d’erreurs que les participants témoins lorsqu’on leur demandait de classer dans l’ordre chronologique les événements précédemment datés. Sur la base de ces nouvelles découvertes, nous proposons un modèle à double processus pour la localisation temporelle des événements autobiographiques qui articule les mécanismes cognitifs engagés dans la datation des événements passés et futurs. / The aim of this thesis was to investigate the processes involved in the temporal location of personal future events in healthy individuals and in patients with schizophrenia. To do so, we used a think-aloud procedure in three experimental studies to analyse the strategies used to determine the times of autobiographical events. In Study 1, we found that participants mostly used reconstructive/inferential processes to date events. They relied most frequently on autobiographical knowledge (i.e., lifetime periods/extended events) and general knowledge to reconstruct or infer the times of events, both for past and future events. In Study 2, we found that personal goals influenced the temporal location process by increasing the direct access to the times of important future events, and by favouring the use of autobiographical knowledge to infer the times of events when dates are not directly accessible. In Study 3, we found that patients with schizophrenia had difficulties to rely on episodic information to reconstruct or infer the times of personal events, and made more errors when they were asked to temporally order the previously dated events. Based on these novel findings, we propose a dual-process model of the temporal location of autobiographical events that articulates the cognitive mechanisms engaged in the dating of past and future events

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.

Adults can mentally relive experiences from their past and anticipate possible future events, a process called mental time travel (MTT). Recently, several theorists have argued that the ability to mentally travel through time may not emerge until 3- to 5-years of age. This proposal is based on evidence from a wide range of research, including investigations into children’s recall, planning and differentiation of the times of events in the past and the future. However, as yet there has been no dedicated effort to find out how and when MTT develops. The current series of studies brought together a wide range of resources with the aim of designing a series of novel paradigms to measure aspects of MTT development between 3- and 5-years of age. The first of these novel approaches asked children to report events that occurred to them “yesterday” and would occur to them “tomorrow”, revealing that by 4- to 5-years of age most children could accurately do so. Another series of studies examined children’s ability to anticipate a different, future situation, finding that only by 4- to 5-years did children’s behaviour reflect differences in an anticipated future environment. Subsequent studies focusing on children’s discrimination of past and future also suggested that by 4- to 5-years children could distinguish the different causal impact of past and future events on the present. Another task revealed that during the preschool years children become better at differentiating the times of events from throughout their own lifespan. These new data provide support for the claim that the ability to mentally travel into one’s own past and future emerges during the preschool years. This thesis describes the first directed investigation into the development of MTT as a whole, bringing together much of the empirical and theoretical literature for the first time. The tasks designed are new approaches to investigating MTT and represent a starting point for future research. This thesis also introduces and discusses theories for the development of MTT, aiming to stimulate discussion not just of when it emerges, but how, and what processes may underlie the transition.

Adults can mentally relive experiences from their past and anticipate possible future events, a process called mental time travel (MTT). Recently, several theorists have argued that the ability to mentally travel through time may not emerge until 3- to 5-years of age. This proposal is based on evidence from a wide range of research, including investigations into children’s recall, planning and differentiation of the times of events in the past and the future. However, as yet there has been no dedicated effort to find out how and when MTT develops. The current series of studies brought together a wide range of resources with the aim of designing a series of novel paradigms to measure aspects of MTT development between 3- and 5-years of age. The first of these novel approaches asked children to report events that occurred to them “yesterday” and would occur to them “tomorrow”, revealing that by 4- to 5-years of age most children could accurately do so. Another series of studies examined children’s ability to anticipate a different, future situation, finding that only by 4- to 5-years did children’s behaviour reflect differences in an anticipated future environment. Subsequent studies focusing on children’s discrimination of past and future also suggested that by 4- to 5-years children could distinguish the different causal impact of past and future events on the present. Another task revealed that during the preschool years children become better at differentiating the times of events from throughout their own lifespan. These new data provide support for the claim that the ability to mentally travel into one’s own past and future emerges during the preschool years. This thesis describes the first directed investigation into the development of MTT as a whole, bringing together much of the empirical and theoretical literature for the first time. The tasks designed are new approaches to investigating MTT and represent a starting point for future research. This thesis also introduces and discusses theories for the development of MTT, aiming to stimulate discussion not just of when it emerges, but how, and what processes may underlie the transition.