O córtex orbitofrontal é apontado como uma estrutura fundamental para a tomada de decisão baseada em valor. Acredita-se que sua função envolva a valoração de recompensas a partir da integração de informações sensoriais e memória, a fim de comparar custos e benefícios. Resultados conflitantes sobre os efeitos da lesão do córtex orbitofrontal em tarefas de escolha intertemporal geram questionamentos sobre o nível de especialização de sua função. O presente estudo almeja testar a hipótese de que a participação do córtex orbitofrontal no desempenho de tarefa de escolha intertemporal depende da experiência dos animais com a tarefa em relação ao momento da lesão. Para isto foi utilizada uma tarefa de escolha intertemporal em que os animais deveriam escolher entre dois reforços distintos, um deles menor e entregue imediatamente após a resposta, e o outro maior porém entregue após um determinado tempo de espera após a resposta. Foram incluídos quatro grupos, dois experimentais envolvendo lesão neurotóxica do córtex orbitofrontal e dois controle-operados submetidos a procedimentos idênticos, exceto pela indução de lesão (os grupos controle foram, posteriormente a análises dos resultados comportamentais e constatada ausência de diferença, fundidos num único grupo controle). Um grupo experimental e um correspondente grupo controle foram submetidos a neurocirurgia antes da exposição a 15 sessões de treino na tarefa. Um outro grupo experimental e seu correspondente controle foram submetidos a treinamento similar, porém, depois da neurocirurgia. Posteriormente, todos os animais foram submetidos a 10 sessões adicionais de treino na mesma tarefa e, a seguir, a outras 10 sessões de treino de reversão, em que os locais previamente associados aos esquemas de reforço foram invertidos. Os resultados revelaram que todos os grupos se comportaram de maneira semelhante nas diferentes fases experimentais, independente do momento de realização da lesão ou mesmo da própria lesão, indicando que o córtex orbitofrontal intacto não é necessário para a aquisição e o desempenho da tarefa de escolha intertemporal. Esses resultados levam a conclusão de que danos seletivos do córtex orbitofrontal não geram prejuízos no desempenho de escolhas intertemporais / The orbifrontal cortex is pointed out as a fundamental structure for value-based decision making. It is believed that its function involves the valuation of rewards from the integration of sensory information and memory in order to compare costs and benefits. Conflicting results on the effects of the orbifrontal cortex lesion on tasks of intertemporal choice bring about questions on the level of specialization of its function. The purpose of the present study is to test the hypothesis that the participation of the orbifrontal cortex in the task performance of intertemporal choice depends on the experience of the animal with the task in relation to the moment of injury. For this, an intertemporal choice task was used in which the animals had to choose between two distinct reinforcements, one smaller and delivered immediately after the response and the other larger but delivered after a certain waiting time after the response. Four groups were included, two experimental groups involving neurotoxic injury and two control groups, submitted to identical procedures, except for the induction of lesion (the control groups were, after an analysis of behavioral results and found no difference, merged into a single group control) an experimental group and a corresponding control group underwent neurosurgery before being exposed to 15 training tasks sessions. Another experimental group and its corresponding control underwent similar training, yet, after neurosurgery. Afterward, all the animals were submitted to 10 additional training sessions on the same task and later to another 10 reversal sessions, in which the sites previously associated to the reinforcement schemes were inverted. The results revelead that all groups behaved similarly in the different experimental phases regardless the time of injury or even the lesion itself, showing that the intact orbifrontal cortex is not necessary for the acquisition and performance of the task of intertemporal choice. These results lead to the conclusion that selective orbifrontal cortex damages do not generate losses in the performance of intertemporal choices

The thesis analyzes the measure of academic procrastination among students and the measure of general procrastination among working population with a university degree. The thesis includes 3 studies. In study 1 an experiment was conducted on 33 students of the University of Economics in Prague. The results show, that students achieve better academic results given external, evenly distributed deadlines compared to when they are allowed to set the deadlines themselves. The second study analyses long-term data about 1909 students of the University of Economics and their academic results. The results show that procrastination can influence as much as 8% of the final grade. Study 3 analyzes information about 2487 subjects and their tax-return forms. It puts into context the dates of submission of the tax returns and personal characteristics of the submitters. The results show that procrastination declines with age. Methods on how to fight procrastination are suggested at the end of the thesis.

Prior research suggests that adolescents are drawn to the temptations of immediate rewards to a greater degree than adults, particularly when making decisions in the company of their peers. Dual-systems models of adolescent decision making posit that this immediate reward bias derives from a developmentally normative imbalance in the neural dynamics characterizing the adolescent brain. At a time when the brain's "top-down" cognitive control system is still developing the processing efficiency and functional integration thought to support mature self-regulation in adulthood, changes in "bottom-up" dopaminergic functioning imbue adolescents with heightened sensitivity to environmentally salient rewards. The resulting bias toward under-controlled, reward-driven behavior may be further accentuated by the presence of peers, who are hypothesized to prime incentive processing circuitry to respond to opportunities for immediate rewards. The present study utilized functional magnetic resonance imaging (fMRI) to examine age- and context-related differences between adolescents and adults in neural activity and choice behavior corresponding to the comparative evaluation of sooner-smaller and larger-later rewards in an intertemporal choice task. Half of the participants were scanned in a standard "alone" condition, and half were scanned in a "peer" condition, wherein two same-sex, same-age peers informed the participant that they would be observing task performance from the scanner control room. Although behavioral results did not support the hypothesis that peer presence would accentuate adolescents' bias toward immediate rewards, they confirm that, even when making decisions alone, adolescents are more inclined than adults to sacrifice the added value of a larger future reward in order to receive a smaller reward immediately. Furthermore, fMRI results demonstrate at least three important differences between adolescents and adults in neural activity corresponding to the comparative evaluation of rewards. First, adolescents evince stronger activation than adults in regions implicated in incentive processing (including bilateral caudate), consistent with a bias toward reward-driven behavior. Second, adolescents show stronger functional connectivity between a region in the orbitofrontal cortex (OFC) whose activity is correlated with impulsive choice and a region in the ventromedial prefrontal cortex (vmPFC) shown by prior research to represent the value of decision options. This stronger OFC-vmPFC connectivity among adolescents is consistent with greater affective (OFC) influence on choice valuation and behavior (vmPFC). Finally, adolescents show stronger deactivation of regions implicated in cognitive control (including anterior cingulate and dorsolateral prefrontal cortex) when evaluating rewards with relatively longer delays, consistent with a failure to carefully consider the value of future rewards. Together, results suggest that neurodevelopmental theories of adolescent decision making would be improved by more explicit modeling of age differences in the neural processes underlying evaluation of the temporal properties of rewards. / Psychology

Every day to we make decisions that require us to reconcile our desire to be satisfied immediately with our desire to improve upon our current situation, which often requires waiting. People tend to devalue future rewards as a function of the time they must wait receive them, a phenomenon known as a delay discounting. Nearly all species exhibit delay discounting, yet there is a striking level of inter-individual variability in discounting severity. In humans, discounting rate predicts a wide array of outcomes such as academic achievement, drug addiction, salary, and obesity. Such correlational relationships have led some to argue that discounting is a stable trait. Contrary to this perspective, several studies have shown that discounting rates may gradually decrease with age. There is also evidence that contextual factors can more immediately alter an individual's discounting rate. One such factor is how information is presented, or "framed". The way in which options are framed-even if they are logically equivalent-can influence choice. Framing a choice as a loss often leads to avoidance that option, i.e. to loss aversion. Delay discounting and susceptibility to loss framing have thus far only been studied in isolation, yet in day to day life we regularly must consider both temporal and loss information, particularly as we become older. This study seeks to the bridge delay discounting, framing, and normative aging literatures to examine (1) whether reframing choices can reduce delay discounting; (2) what factors drive individual differences in discounting and framing susceptibility; (3) to what extent these phenomena interact with age; and (4) a potential application of these findings in the context of Social Security claiming. / Psychology

The thesis presents a formal model of intertemporal decision problem of working on a task for distant reward which depends on the number of periods the subject actually spends working, where the subject faces varying opportunity costs of working each period before the deadline. Three psychologically plausible causes of procrastination are incorporated into the model as transformations of the decision problem. In order to assess a hypothesis that procrastination is an evolved and stable habit, the third transformation renders the model dynamic in that past decisions and circumstances affect the present. The model is first explored via qualitative analysis and simulations are performed to further reveal its functionality.

Orientador: Prof. Dr. Yossi Zana / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2017.

This thesis examines the relationship between price expectations and current consumption. Especially, whether the postponement of final consumption expenditure by households, as a result of their declining price expectations; which may be a deflatively-recessive spiral starter; coincides with economic theory and practice. Based on this, appropriate economic policy recommendations can be drawn. The analysis in the framework of intertemporal consumer model of two periods extended by inflation and the risk confirms this hypothesis. Price expectations positively affect current consumption through the intertemporal substitution effect of real interest rate changes. However, certain assumptions must be fulfilled. Especially, the economy must be in a fixed nominal interest rate environment, the substitution effect must not be offset by the effect of a change in the expected real disposable income or the income effect of the change in the real interest rate and the households must have a higher disposable income so that they can afford to postpone consumption. These findings coincide with the conclusions of the empirical analyzes mentioned in this thesis.

Indiana University-Purdue University Indianapolis (IUPUI) / Impulsivity, or the tendency to act prematurely without foresight, has been linked to a diverse range of pathological conditions. Foresight refers to the ability to envision future rewards and events (i.e. prospectively sample) and has been associated with decreased impulsivity. One form of impulsivity is measured by the ability to delay gratification and is often studied in the framework of Delay Discounting (DD). DD provides the means to study impulsivity in a number of pathological conditions. However, whether impulsivity precedes the development of pathological states or results from the pathological state itself is not fully understood. This necessitates an understanding of neurobiological mechanisms contributing to decision making in both non-impulsive as well as impulsive populations of individuals. Animal models allow invasive techniques to be used to dissect the neurocircuitry involved in decision making. Given that the decision-making process is an ongoing process rather than an isolated event, optogenetics provide the temporal and spatial specificity necessary for evaluating brain region specific contributions to decision making in DD. In the present study, optogenetics were used to assess the contribution of the medial Prefrontal Cortex (mPFC), a brain region involved in ‘goal-directed’ behavior, in the planning of future choices (i.e. prospective plans) and subsequent measures of impulsivity in an adjusting amount DD procedure. Optogenetic inhibition of mPFC was conducted in Wistar rats during different epochs of a DD task in order to assess how mPFC affects planning behavior in a population of rat not considered to be highly impulsive. Although no direct effects on planning behavior (e.g. consistency) were observed, inhibiting mPFC after a trial has been initiated and directly before a choice was made (Epoch 2) was observed to increase measures of impulsivity in comparison to days where no optogenetic manipulation occurred in a delay-specific manner. This suggests that mPFC differentially contributes to decision making at different delays. A pattern of associations between choice latency, impulsivity, and consistency began to emerge for inactivation occurring in Epoch 2, suggesting that mPFC contributes to some aspect of planning choices during this epoch. Moreover, these results indicate that mPFC is involved in decision making in Wistar Rats. Understanding the direct role that mPFC plays in promoting choices of delayed rewards provides a neurobiological target for treatment aimed at reducing impulsivity in the clinical population.

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.

This thesis takes three different perspectives, using theoretical and experimental techniques, on time-inconsistent preferences and how the existence of multiple selves can affect both consumer behaviour and policy design. Across domains such as retirement saving, health, and educational achievement, intertemporal choice presents a challenge for both individuals and policymakers. The first paper, 'Choosing When to Nudge: Designing Behavioural Policy around Decision-Making Costs,' considers how behavioural policy, which has proven increasingly popular with policymakers, affects welfare. I find that for present-biased consumers, behavioural policies help some consumers but can inefficiently discourage others from optimizing. Such policies therefore have an ambiguous effect on welfare, and similar to traditional policies, can impose equity-efficiency tradeoffs. Monopolies may increase welfare given their incentive to simplify consumer decisions instead of exploit switching costs. The second paper, 'Virtue and Vice with Endogenous Preferences,' considers behaviour when preferences are affected by consumer decisions. I introduce agents whose temptation to consume in the present is affected by how much they choose to save for the future. I find that differences between agents can trap them in divergent paths of self-improvement -- saving more, they value the future more, making saving optimal -- or binging -- consuming more makes them indifferent to future costs, making consumption optimal. At the extreme, it is frequently an optimum for a consumer to consume their entire wealth. The final paper, 'Bet You Can't Eat Just One: Consumption Complementarity and 'Self'-Control' considers an intrapersonal game between a moderate cold self and a hot self that wants to indulge. In equilibrium, sophisticated selves best respond to each other's behaviour: the cold self over-abstains and the hot self over-indulges to avoid inducing the other state. I test these ideas in the lab, and find that subjects on a diet who were induced to consume a piece of chocolate before the experiment indulge more in chocolate during the experiment, even when the initial indulgence was imposed by the experimenter. Eating a piece of chocolate, this suggests, can induce a period during which chocolate is more appealing.