Comparison of risky and intertemporal choice processes

in Simplified Chinese: 风险与跨期决策对人类生存发展至关重要。两类决策在理论、行为和过程上具有多重相似性, 但已有研究缺乏对两类决策过程的系统性直接比较, 且忽略了概率与时间的等量关系问题及其中的个体差异。本研究设计了自适应设计优化的概率−时间等量转换任务新范式, 基于个体层面测量其概率和时间的等量转换值, 据此在个性化的单结果(研究1)和双结果(研究2)风险和跨期决策眼动实验中, 针对两类模型检验的核心规则(补偿性/非补偿性、基于选项/基于维度), 基于多层次指标(行为、局部和整体过程特征、认知建模), 全面比较两类决策的异同。结果表明: 自适应设计优化的概率与时间等量转换范式有效, 个体可对概率与时间进行有效等量转换; 两类决策均更遵循非补偿性和基于维度的规则, 但二者在行为、过程及机制层面均存在特异性。该结果为未来两类决策的比较研究提供了可靠有效的工具, 有助于构建和发展普适性决策模型, 并为该模型提供了精细化参数及基于心理学解释的基础证据。 Abstract in English: Risky choice (RC) and intertemporal choice (IC) are two fundamental decision-making categories essential to people’s daily life. The former involves selecting among outcomes with varying probabilities, whereas the latter requires making decisions across different time points. These domains share similarities regarding theoretical developments, behavioral effects, and neural bases. A critical challenge persists because, although previous studies have revealed that RC and IC involve similar cognitive processes, findings remain inconsistent regarding their precise underlying mechanisms. Examining the similarities and differences between RC and IC from a decision process perspective contributes to the development of a generalized decision-making framework and clarifies the boundaries of its applicability. However, existing studies lack direct comparisons and converging process evidence between these two decision types. Given that probability and time parameters influence decision preferences and processes, ensuring their comparability is essential when comparing RC and IC. Previous research has often used fixed parameters, neglecting the conversion between probability and time, as well as individual differences; such an approach potentially introduces biases in experimental results due to parameter effects and individual variability. To address these limitations, the present study initially developed a novel paradigm that subjectively equates probability to time and generates a unique set of parameters for each participant. Then, by incorporating eye-tracking technology, the research systematically investigated the cognitive mechanisms underlying RC and IC during single-outcome (Study 1) and dual-outcome (Study 2) tasks. Each study consisted of two phases. In Study 1 (N = 41, Mage = 27.14), each participant first generated pairs of approximately equivalent RC and IC options. Following the adaptive design optimization method, participants made choices between an RC and IC option possessing similar payoffs. The IC option was fixed, whereas the probability of the RC option was adjusted according to user responses until reaching an indifference point. Second, the study used these equivalent options to construct single-outcome RC and IC tasks and examined their underlying processes via eye-tracking technology. In Study 2 (N = 37, Mage = 26.31), the equivalent conversion paradigm operated in the opposite manner. That is, the RC option remained fixed, whereas the time parameter of the IC option was adjusted. The research then extended these findings by constructing dual-outcome options, focusing on compensatory versus noncompensatory and alternative-based versus attribute-basedrules. By integrating eye-tracking and hierarchical Bayesian modeling, the analysis examined local and holistic decision processes. The entire set of analyses aimed to (1) determine whether the decision processes of RC and IC are similar and (2) identify the computational model most suitable for both decisions. Regarding the first aim, results indicated that RC and IC share equivalent conversion points and comparable local decision processes, which reflect noncompensatoryand attribute-based rules. However, RC and IC differ in holistic process characteristics, as IC undergoes a relatively more deliberate and deeper fashion than RC. Furthermore, as task complexity increased from single-outcome to dual-outcome scenarios, the process similarity between RC and IC increased, suggesting the adoption of more parallelized and simplified decision strategies. Regarding the second aim, computational modeling of process characteristics suggests that both types of decisions are consistent with nondiscounting models. Altogether, these results reveal that participants more likely follow the noncompensatory, attribute-based rules rather than the compensatory, alternative-basedrules when deciding for RC and IC. To conclude, the present study demonstrates several key findings. (1) The equivalent conversion paradigm confirmed the existence of subjective equivalent options between probability and time. (2) After equivalent conversion, despite process-level differences, RC and IC exhibited consistency in core cognitive mechanisms. In both decision types, and contrary to classic discounting models, individuals seem not to follow compensatory, alternative-based rules, which undergo a “weighting and summing” or “time discounting” process. Instead, they more likely use simple heuristic rules hypothesized by nondiscounting models. (3) RC and IC demonstrated distinct behavioral preferences, process characteristics, and underlying mechanisms, such as differences in processing complexity and overall eye-movement dynamics. Overall, the research provides new perspectives on theoretical and methodological comparisons across different decision-making tasks and offers empirical support for the development of a more unified decision-making theory.

Equivalence (formal languages) · Expected utility hypothesis · Intertemporal choice · Logical equivalence · Utility theory · Decision-Making and Behavioral Economics · Economic and Environmental Valuation · Risk Perception and Management