Abstract

Over the past half century, research on human decision making has expanded from a purely behaviorist approach that focuses on decision outcomes, to include a more cognitive approach that focuses on the decision processes that occur prior to the response. This newer approach, known as process tracing, has employed various methods, such as verbal protocols, information search displays, and eye movement monitoring, to identify and track psychological events that occur prior to the response (such as cognitive states, stages, or processes). In the present article, we review empirical studies that have employed eye movement monitoring as a process tracing method in decision making research, and we examine the potential of eye movement monitoring as a process tracing methodology. We also present an experiment that further illustrates the experimental manipulations and analysis techniques that are possible with modern eye tracking technology. In this experiment, a gaze-contingent display was used to manipulate stimulus exposure during decision making, which allowed us to test a specific hypothesis about the role of eye movements in preference decisions (the Gaze Cascade model; Shimojo, Simion, Keywords: eye movements, process tracing, decision making Early research in decision making focused on explaining and predicting decision outcomes, such as choices and judgments. This approach, known as the structural approach, produces statistical models that account for decision makers' responses (outcomes) as a function of the stimulus information and parameters of the decision (inputs). While this approach has been quite successful in probing the strategies that decision makers apply, the modeling of outcomes cannot identify different stages of the decision process, or changes in the decision strategy that might occur prior to the final response. To shed light on these aspects of decision making, researchers have sought ways to observe more directly the cognitive processes that occur prior to the final behavioral response.