Downs as well as ups spice life, but need to be in balance. In the calculus of the heart, it is the ratio of positive to negative emotions that determines the sense of well-being.
— Daniel Goleman, Emotional Intelligence

Emotion: that aspect of “consciousness” devoted to affect or feeling; a strong feeling, aroused mental state, or intense state of drive or unrest directed toward a definite object, with physiological, somatic, and behavioral components. (NCIt) A complex psychological state that involves subjective experience, a physiological response, and a behavioral or expressive response. (Hockenbury, 326) A state characterized by physiological “arousal,” changes in facial expression, “gestures,” posture, and subjective feelings. (Coon, 409)

Emotion leads us to seek out pleasure and avoid pain. (Rose, Episode 4 Eric Kandel) (Dr. Jaak Panksepp has) argued that there is evidence for seven primary emotional processes. (Campbell, BSP91) The most universal emotion we have is the desire to engage with the world, enthusiastically; to look for resources. This was discovered in 1954 … and called the 'reward' system’ - because animals would press levers to activate this system, and reward was a big-ticket concept. This system participates in every other emotion. And we have a ‘fear system’ that allows us to automatically pull away from a situation. The third system means … you're going to at some point compete for resources—even fight for resources. And a terrific way, if someone takes your stuff away, is to get angry. Well, the brain has a ‘rage system.’ Then, if we're mammals, we have to pass on our genes into the next generation, and you have to have a ‘lust system.’ If you have a successful ‘lust system,’ that means that you've had children. Mothers, of course, are committed to the baby. That maternal devotion has a special system that we call a ‘care system.’ A little child that is lost always cries (in need for its mother). We call this the ‘panic system,’ because this is an “anxiety” feeling that is different than the one that emerges from fear. There is one more great system and that’s the ‘play system.’ (Panksepp, BSP91)

Actor Experiments: a reading experiment. Each actor told a tragic story to a group of listeners. When the first actor’s face showed an appropriate sadness, the listeners “amygdala” and related "circuits" for sadness activated. When the second actor’s face was smiling, activation in the listeners occurred in a brain region specializing in vigilance for social threats or conflicting information. In this case, the listeners disliked the person telling the story. (Goleman, 22) Actors, who can make you laugh or cry, are very good at reading the felt states of their own bodies and transmitting those feelings via “mirror” system communication. (Blakeslee, 166)

Apathy: lack of emotion or emotional expression; a disorder of motivation that persists over time. (MeSH)

Boredom: a psychological state resulting from any activity that lacks motivation, or from enforced continuance in an uninteresting situation. (MeSH)

Blended Emotions: two or more “primary emotions” experienced at the same time. For instance, Melinda feels fear and anger when her daughter is not home after curfew. (McCornack, 122)

Deactivation: preventing unwanted emotions by systematically desensitizing yourself to emotional experience. For example, Josh insulates himself with numbness after his wife’s death. (McCornack, 131)

Emotion Appraisal: evaluating the personal meaning of a stimulus or situation. (Coon, 421)

Emotion Contagion: the rapid spreading of emotion from person to person, such as anger running through a mob. (McCornack, 118)

Emotion Support: expressions of concern, empathy, and positive regard. (Hockenbury, 495)

Emotion Wildfire: (emotions) out of control, acquiring a momentum of their own, not subsiding with time, as they usually do, but instead intensifying. One acts to intensify whatever emotion is felt, turning fear into terror, anger into fury, disgust into revulsion, distress into anguish. Consumes whatever it confronts - objects, strangers, loved ones, the self - until it is spent. (Ekman, 172)

Feelings: emotional sensations. (NCIt) Short-term emotional reactions to events that generate only limited arousal, such as the fleeting nostalgia you experience hearing a familiar song. (McCornack, 119) Those … states which can be experienced and have arousing and motivational properties. (MeSH) Feelings come in many different categories, one could say. There are “sensory” feelings like taste and cold. There are bodily feelings—homeostatic feelings—like hunger and thirst. And then the greatest mystery is the internal feelings of the brain, which are emotional feelings of anger, fear, loneliness. Those emotional feelings do not have a clear pathway from the body or the periphery - the external senses. Those can modulate it and trigger things, but the actual feeling emotional state is built into the brain in some way. (Panksepp, BSP65)

Frazzled: a neural state in which emotional upsurges hamper the workings of the executive center. (Goleman, 267)

Mood: the temporary state of mind or feelings of a person or group. (Oxford) A low-intensity, long-lasting emotional state. (Coon, 411) Low-intensity states of mind that are not caused by particular events and typically last longer than emotions. For example: boredom, contentment, grouchiness, serenity. (McCornack, 119) Though we typically know what has triggered an outright emotion, we often find ourselves in a specific mood without knowing it. When you’re 'feeling blue,' you’re more likely to recall negative or unpleasant memories.  (Goleman, 18) Also referred to as ‘affect.’

Mood Triggers: examples include Muzak in an elevator, a sour tone in someone’s voice, a picture of a happy face, the friendly tone of a taped voice on a telephone, or a happy voice reading material. (Goleman, 17-18)

Moral Emotions: a grouping including moral indignation, compassion, embarrassment, and shame. The ventral "prefrontal cortex" is an important structure for triggering these emotions. (Rose, Episode 4 Antonio Damasio)

Somatic Marker Hypothesis: the theory that emotion derives in large part from body states and plays an important, largely under-appreciated role in rational thought and decision making. (Blakeslee, 214)