Temporal division of the decision-making process: An EEG study.

Decision-making is a process that allows individuals to choose an option or alternative in order to maximize a subjective gain or achieve a set goal by evaluating and establishing a preference based on contextual and internal information. Ernst and Paulus proposed a three-stage temporal division of this process: 1) the assessment and formation of preferences among possible options; 2) the selection and execution of an action; and 3) the experience or evaluation of an outcome. Each stage involves the participation of several brain regions, including the prefrontal, parietal, and temporal cortices. There are reports of distinct functionalities of these cortices for each stage of decision-making, but those studies focus on individual stages and do not provide any direct comparisons among them. Therefore, using a task that allows the clear temporal separation of the three stages of decision-making, we characterized the electroencephalographic activity (EEG) of those cortices in 30 healthy right-handed men during preference changes that occurred while performing a decision-making task. As the trials progressed, the preference for the stimulus shifted towards maximizing gains on the task. Forty trials sufficed to maintain these behavioral changes. Specific EEG patterns for each stage of decision-making were obtained, and it was possible to associate them with the cognitive processes involved in each one. These EEG data support the temporal division of the decision-making process proposed by Ernest and Paulus and show that the task designed could be a useful tool for determining behavioral and cerebral changes associated with stimuli preference during decision-making.