title: Analysis of physiological signals for recognition of boredom, pain, and surprise emotions.
abstract: BACKGROUND
  The aim of the study was to examine the differences of boredom, pain, and surprise. In addition to that, it was conducted to propose approaches for emotion recognition based on physiological signals.
  
  
  METHODS
  Three emotions, boredom, pain, and surprise, are induced through the presentation of emotional stimuli and electrocardiography (ECG), electrodermal activity (EDA), skin temperature (SKT), and photoplethysmography (PPG) as physiological signals are measured to collect a dataset from 217 participants when experiencing the emotions. Twenty-seven physiological features are extracted from the signals to classify the three emotions. The discriminant function analysis (DFA) as a statistical method, and five machine learning algorithms (linear discriminant analysis (LDA), classification and regression trees (CART), self-organizing map (SOM), Naïve Bayes algorithm, and support vector machine (SVM)) are used for classifying the emotions.
  
  
  RESULTS
  The result shows that the difference of physiological responses among emotions is significant in heart rate (HR), skin conductance level (SCL), skin conductance response (SCR), mean skin temperature (meanSKT), blood volume pulse (BVP), and pulse transit time (PTT), and the highest recognition accuracy of 84.7% is obtained by using DFA.
  
  
  CONCLUSIONS
  This study demonstrates the differences of boredom, pain, and surprise and the best emotion recognizer for the classification of the three emotions by using physiological signals.
authors.affiliation: IT Convergence Technology Research Laboratory, Electronics Telecommunication Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon, 305-705, South Korea. cleta4u@etri.re.kr.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Jang
authors.affiliation: IT Convergence Technology Research Laboratory, Electronics Telecommunication Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon, 305-705, South Korea. bj_park@etri.re.kr.
authors.forename: Byoung-Jun
authors.initials: BJ
authors.lastname: Park
authors.affiliation: Department of Psychology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea. peaceful1026@cnu.ac.kr.
authors.forename: Mi-Sook
authors.initials: MS
authors.lastname: Park
authors.affiliation: IT Convergence Technology Research Laboratory, Electronics Telecommunication Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon, 305-705, South Korea. shk1028@etri.re.kr.
authors.forename: Sang-Hyeob
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Psychology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea. jhsohn@cnu.ac.kr.
authors.forename: Jin-Hun
authors.initials: JH
authors.lastname: Sohn
mesh_terms: D000328:Adult; D001887:Boredom; D004562:Electrocardiography; D004644:Emotions / Q000145:classification* / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D008297:Male; D010146:Pain; D017156:Photoplethysmography; D012815:Signal Processing, Computer-Assisted; D012881:Skin Temperature; D060388:Support Vector Machine; D055815:Young Adult