A decision process can be conceptually separated into a perceptual process and a decision strategy. The former includes all the different mechanisms that contribute to accumulate information relevant to the decision, whereas the decision strategy determines when enough information has been accumulated and a decision can be taken. Although perceptual processes have been extensively investigated in the last decades, decision strategies have received comparatively little attention. The main aim of this work is to fill this gap by analysing four decision strategies with two different experimental paradigms. We also focus on ancillary decision-making topics, such as the effect of stimulus intensity, foreperiod duration, payoff manipulation, and the response distributions in the rate domain. We initially performed a qualitative analysis of decision strategies by using a classic reaction time tasks on human participants while assuming the Drift Diffusion Model, one of the many models used for simple and fast decisions, as the perceptual process. We found that increasing the time of the trial does not have a relevant effect on the response, which is in contrast with some of the decision rules considered here. However, this approach is limited by the implicit assumption of a perceptual model that would result in different prediction for the decision strategies. We suggest the use of a different experimental design, called the EXACT Paradigm, which allows us to analyse decision strategies without having to assume any perceptual process. We tested the feasibility of such approach and applied it to several experimental studies, including a direct comparison with a classic reaction time task. Overall, two of the four decision strategies (modified Reward Rate and Reward/Accuracy) appeared to model the data satisfactorily. We discuss several ways in which the EXACT Paradigm can be used for expanding our knowledge in the field of decision-making.

La prise de décision est un processus computationnel fondamental dans de nombreux aspects du comportement animal. Le modèle le plus souvent rencontré dans les études portant sur la prise de décision est appelé modèle de diffusion. Depuis longtemps, il explique une grande variété de données comportementales et neurophysiologiques dans ce domaine. Cependant, un autre modèle, le modèle d’urgence, explique tout aussi bien ces mêmes données et ce de façon parcimonieuse et davantage encrée sur la théorie. Dans ce travail, nous aborderons tout d’abord les origines et le développement du modèle de diffusion et nous verrons comment il a été établi en tant que cadre de travail pour l’interprétation de la plupart des données expérimentales liées à la prise de décision. Ce faisant, nous relèveront ses points forts afin de le comparer ensuite de manière objective et rigoureuse à des modèles alternatifs. Nous réexaminerons un nombre d’assomptions implicites et explicites faites par ce modèle et nous mettrons alors l’accent sur certains de ses défauts. Cette analyse servira de cadre à notre introduction et notre discussion du modèle d’urgence. Enfin, nous présenterons une expérience dont la méthodologie permet de dissocier les deux modèles, et dont les résultats illustrent les limites empiriques et théoriques du modèle de diffusion et démontrent en revanche clairement la validité du modèle d'urgence. Nous terminerons en discutant l'apport potentiel du modèle d'urgence pour l'étude de certaines pathologies cérébrales, en mettant l'accent sur de nouvelles perspectives de recherche. / Decision‐making is a computational process of fundamental importance to many aspects of animal behavior. The prevailing model in the experimental study of decision‐making is the drift‐diffusion model, which has a long history and accounts for a broad range of behavioral and neurophysiological data. However, an alternative model – called the urgency‐gating model – has been offered which can account equally well for much of the same data in a more parsimonious and theoretically‐sound manner. In what follows, we will first trace the origins and development of the DDM, as well as give a brief overview of the manner in which it has supplied an explanatory framework for a large number of behavioral and physiological studies in the domain of decision‐making. In so doing, we will attempt to build a strong and clear case for its strengths so that it can be fairly and rigorously compared to potential alternative models. We will then re‐examine a number of the implicit and explicit theoretical assumptions made by the drift‐diffusion model, as well as highlight some of its empirical shortcomings. This analysis will serve as the contextual backdrop for our introduction and discussion of the urgency‐gating model. Finally, we present a novel experiment, the methodological design of which uniquely affords a decisive empirical dissociation of the models, the results of which illustrate the empirical and theoretical shortcomings of the drift‐diffusion model and instead offer clear support for the urgency‐gating model. We finish by discussing the potential for the urgency gating model to shed light on a number of clinical disorders, highlighting a number of future directions for research.

現行有關逃漏稅研究的國內外文獻，無論在理論推導或實證分析上，多集 中於非法的租稅逃漏（tax evasion）上，而忽略了另一種合法的減少稅 負的方法：租稅規避（tax avoidance）。本文乃將 Falkinger & Walther (1991) 獎懲並行的制度與傳統的租稅逃避（tax aversion）理 論相結合，而以較嚴謹的方式分析聯合的個人租稅逃漏與租稅規避的選擇 行為，即所謂的租稅逃避行為。本文共分為四章十節，略述如下：第一章 為緒論，分為三節，分別說明研究動機與目的、研究範圍與方法及章節安 排。第二章為文獻回顧，分為三節，以國、內外文獻為探討單元，分別依 時間順序及研究範圍與方法，針對租稅逃漏、租稅規避與租稅逃避聯合決 策行為等三個領域的文獻作假設分析與結論整理，最後則做一小結。第三 章為獎懲並行的租稅逃避理論（ A Mixed Penalty- Reward Tax Aversion Theory ），分為三節，第一節介紹獎懲並行的租稅逃避理論， 主要分成基本假設、模型設立、比較靜態分析和加入獎勵因素後的影響四 部份來討論。第二節乃以獎懲並行的租稅逃避模型與前章中所述較具代表 性的逃、避稅理論模型加以比較。最後則作一小結。第四章為結論，僅一 節。由於另一租稅減少途徑──租稅規避──的存在改變了許多僅討論租 稅逃漏文獻的結論。本文主要的結論是，除了查獲率和邊際懲罰率的變動 對申報所得和避稅所得佔總逃避所得的份額有明確的正向影響外，其他相 關變數如總所得、邊際稅率和邊際避稅成本的變動所造成的影響均不明確 ；而邊際獎勵率的變動對申報所得的影響亦無法確定，然其對避稅所得佔 總逃避稅所得的份額卻造成（反直觀的）負面的效果。此外，提高獎勵率 是否提高或降低其他變數變動的效果，其答案亦無法肯定。這些發現表 示 Falkinger & Walther (1991) 對於採用獎勵制度的優點似乎有誇大之 嫌。