There is a substantial body of philosophical and psychological work on this topic and “emotion” is an over-used word when linked with brands. A reasonable definition with scientific research behind it, and one that lends itself to the area of brands and measurement comes from Phelps.
Following an event, emotions come first. They may trigger feelings, or an evaluated response and these may be altered or modified (appraised) before they become encoded into memory.
Emotion, evaluation and appraisal can be defined in these terms:
Emotion: The discrete, unevaluated response to an external or internal event that entails a range of synchronised features, including subjective experience, expression, bodily response, and action tendencies.
They are generally non-conscious responses. (Facial coding is an example of where we can measure unevaluated response.)
Evaluation: The primary function of emotion is to highlight the significance or importance of events so that these events receive priority in further processing through the limbic system*. Evaluation does not necessarily require conscious processing. We know and can define these feelings as anger, surprise or tenderness in response to a stimulus.
Appraisal: Awareness and the cognitive interpretation of the meaning of an event can both initiate and/or alter an emotional response. The appraisal of an event elicits and modifies all the features of emotion – it is the subjective experience of emotion. This is where our past experiences and memories may intercede between our emotional response and the ultimate attitudes or behaviours that result. Survey data inevitably includes appraisal, although the framing of questions can enable us to interpret the degree to which heuristics or biases have been active. It is also helpful to understand this chain of events, since the appraised meaning may well be the de facto response encoded to memory.
These definitions are consistent with other writing and the view that emotions are processed automatically and sub-consciously, with or without subsequent conscious evaluation (Damasio).
* The Limbic System is a set of brain structures located on top of the brain stem and buried under the cortex. Limbic system structures are involved in many of our emotions and motivations, particularly those that are related to survival.