Emotion representation, analysis, and synthesis in continuous space: a survey

"Emotions are complex constructs with fuzzy boundaries and with substantial individual variations in expression and experience."

"To guarantee a more complete description of affective colouring, some resedarchers include expectation (the degree of anticipating or being taken unaware) as the fourth dimension, and intensity (how far a person is away from a state of pure, cool rationality) as the fifth dimension."

"Despite the existence of diverse affect models, search for optimal low-dimensional representation of affect, for analysis and synthesis, and for each modality or cue, remains open."

"While visual signals appear to be better for interpreting valence, audio signals seem to be better for interpreting arousal."

"There are also spin off companies emerging out of collaborative research at well-known universities (e.g., Affectiva established R. Picard and colleagues of MIT Media Lab)."