“…Other works centered around student emotional state detection analyze and process signals from Electroencephalogram (EEG), Electromyogram (EMG), Electrocardiography (ECG), Electrodermal activity (EDA), heart rate variability, skin temperature, blood volume pulse, respiration, or Electrodermography (EDG)/galvanic skin response (GSR) [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Researchers [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] report the use of deep learning and machine learning (ML) techniques for emotion classification. Finally, other techniques rely on emotion recognition via computer vision [ 22 , 41 , 48 , 49 , 50 ], linguistic semantic approaches [ 51 ], and biological features [ 52 ].…”