Panksepp၊ Jaak (2005)။ Affective neuroscience: the foundations of human and animal emotions ([Reprint] ed.)။ Oxford [u.a.]: Oxford Univ. Press။ p.9။ ISBN978-0195096736။ Our emotional feelings reflect our ability to subjectively experience certain states of the nervous system. Although conscious feeling states are universally accepted as major distinguishing characteristics of human emotions, in animal research the issue of whether other organisms feel emotions is little more than a conceptual embarrassment
Ekman၊ Paul; Davidson၊ Richard J. (1994)။ The Nature of emotion: fundamental questions။ New York: Oxford University Press။ pp.291–293။ ISBN978-0195089448။ Emotional processing, but not emotions, can occur unconsciously.
Cabanac, Michel(2002)."What is emotion?". Behavioural Processes60: 69–83. doi:10.1016/S0376-6357(02)00078-5. PMID 12426062.“There is no consensus in the literature on a definition of emotion. The term is taken for granted in itself and, most often, emotion is defined with reference to a list: anger, disgust, fear, joy, sadness, and surprise. [...] I propose here that emotion is any mental experience with high intensity and high hedonic content (pleasure/displeasure).”
