I. Introduction
Autonomous Agents (AAs) are software entities that carry out operations on behalf of users or other programs with certain degree of independence and autonomy. In doing so, AAs make use of knowledge about the environment and representations of desires and goals [1]. This type of intelligent system has been crucial for the advance of fields such as software engineering, human-computer interaction and artificial intelligence. In these fields, AAs have been designed to carry out tasks that require the imitation of human cognitive functions, including decision making, planning, and reasoning [2]–[4]. Moreover, evidence shows that emotions influence cognitive functions [5], [6]. The emotional significance of perceived stimuli influences the normal operation of processes such as attention, perception, and decision making. According to fields such as psychology and neuroscience, emotions result from the interaction of several cognitive and affective processes, including memory, perception, motivations, and attention [7]–[9].