## 2 Methods  
The research was conducted in accordance with the PRISMA guidelines [21; 22]. The protocol began with electronic searches of studies published in English between 2014 and 2020 in the following databases: Web of Science, EBSCO, PubMed, Scopus, ProQuest and ScienceDirect. The following keywords were used to search in all the databases: emotion, affective, recognition, regulation, electroencephalography, heart rate, skin temperature, galvanic skin response, EOG and EEG. The Boolean operators AND and OR were used. Parentheses were used in ProQuest to limit search results due to the large number of studies found. The query design is detailed in Table 1.  
Pilot studies, reviews, meta-analyses, commentaries, book chapters, conference papers, master and doctoral dissertations, workshop descriptions and unpublished data were not included in this review. The eligibility criteria for paper selection are detailed hereunder, and the selection process is illustrated in Figure 1. Search within databases was carried out during the first two weeks of April 2020, and the selection process was carried out from April 2020 to July 2020. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Index**} & **Web of Science, EBSCO, PubMed and** & \multirow{2}{*}{**ProQuest**} \\  & **ScienceDirect** & \\ \hline \multirow{3}{*}{1} & emotion OR affective AND recognition & (emotion OR affective) AND \\  & OR regulation AND & (recognition OR regulation) AND \\  & electroencephalography & electroencephalography \\ \hline \multirow{3}{*}{2} & emotion OR affective AND recognition & (emotion OR affective) AND \\  & OR regulation AND sckin temperature OR & (recognition OR regulation) AND \\  & galvanic skin response & (skin temperature) OR (galvanic skin \\  & response) \\ \hline \multirow{3}{*}{4} & emotion OR affective AND recognition & (emotion OR affective) AND \\  & OR regulation AND electrooculography & (recognition OR regulation) AND \\  & electrocardiography & electrocardiography \\ \hline \multirow{3}{*}{5} & emotional intelligence AND & emotional intelligence AND \\  & electroencephalography & electroencephalography \\ \hline \multirow{3}{*}{6} & emotional intelligence AND & emotional intelligence AND \\  & electrocardiography & electrocardiography \\ \hline \multirow{3}{*}{7} & emotional intelligence AND skin & emotional intelligence AND skin \\  & temperature & temperature \\ \hline \multirow{3}{*}{8} & emotional intelligence AND galvanic & emotional intelligence AND galvanic \\  & skin response & skin response \\ \hline \multirow{3}{*}{9} & emotional intelligence AND & emotional intelligence AND \\  & electrocardiography & electrocardiography \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Query design. The main purpose of this review is to comprehend the state-of-the-art experimental methodologies that analyze different dimensions of emotional intelligence. Using this information, it is possible to propose an original methodology to assess emotional intelligence as a core. For this reason, the outcomes that were sought were:  
* Techniques for eliciting emotions: identify the strategies, materials, conditions, and environments that have been applied to evoke emotions. * Quantitative and/or Qualitative Assessments: differentiate the tests based on objective and subjective measurements and highlight the necessary parameters to study EI. * Data analysis: analyze the relation between electrophysiological signals, psychometric tests, and the evoked emotions. * Applications: detect targets and reasons for evaluating some dimensions of emotional intelligence. Data outcomes were extracted at the last stage of the selection process. Data extraction was conducted to answer the following research questions (RQ):
* RQ1: Which electrophysiological signals may index emotional processing? * RQ2: Which stimuli may be used to elicit emotions? * RQ3: How should psychometrics assess emotional experience?