Driving and Satisfying Emotions
Emotions in a natural agent are either pleasant or unpleasant, but never neutral, (Nesse, 1990). We can understand emotions as being either positive or negative, (Zhang & Lee, 2009). This may be useful when describing emotions from a personal perspective, but this description carries connotations and an implicit judgment on their utility. We need to differentiate between the experience of an emotion and its effect. For example, it may be argued that anger is a negative emotion because it is unpleasant to experience. An equally valid argument is that anger has positive motivational benefits. Nesse gives an example of the rationality of anger. In a long term, committed social partnership where one party is tempted to defect, the threat of an irrational and spiteful retaliation because of the betrayed partner’s anger decreases the likelihood of a defection continuing or even taking place at all.
We could also think of emotions as being either attractive or repulsive. This may be useful when describing emotions within the context of a dynamical system but it is less applicable when describing animal or human behavior. For example sadness and fear are repulsive emotions that we normally seek to minimize but people deliberately invoke sadness by watching soap operas and other melodramas. They deliberately invoke fear when reading or watching thrillers or by participating in fun-fair rides or extreme sports. In the latter case, people engage in these activities because they are also exciting and fun. Emotions can be simultaneously attractive and repulsive.
Rolls (2005, p. 118) describes emotions in terms of rewards and punishments. An animal will work for a reward, but will work to escape or avoid a punishment.
Emotions are proposed as being states elicited by rewards and punishers and changes in reward and punishment (Rolls, 1999, p. 60). Contentment can be considered a rewarding emotional state for example, but how is this different from the emotion of joy? Rolls uses the concept of positive and negative reinforcers and punishers as determined by whether the reinforcer or punisher increases the probability of a response by the agent.
These terms may be useful when describing observations of animal behavior but they are less descriptive when referring to emotional experiences or an appreciation of why rewards and punishers have the effect that they do. Animals experience reward and punishment. From the perspective of the animal, reward and punishment is more than mere habituation and conditioning.
It can be seen that the utility and limitations of the descriptions that we use partially depend upon the context in which they are employed. Can we decide on terms that are unambiguous regardless of whether we are referring to the experience of emotions or observations of animal behavior? It is proposed here that emotions can be thought of as being either driving or satisfying. These terms describe both the experience and behavioral effect of being in an emotional state and are also neutral as to its utility. This is more than a mere linguistic exercise; there is a theoretical basis behind these terms.
Rolls (2005, p. 128), discusses how taxes orient an organism toward or away from stimuli in its environment. Phototaxis bends a plant toward a light source for example. An organism may move toward sources of nutrients or away from materials with physical properties detrimental to its health.
Animals need to maintain homeostasis. Various bodily processes need to be kept relatively constant. Critical resources must be kept replete regardless of the environment that the agent may inhabit. Examples of these resources include levels of food, water and oxygen. Internal physiological variables must also be kept within a certain range. For example, natural agents will seek warmth when it is too cold and try to cool down when it is too hot.
Panksepp (1998) describes how sensations generate pleasure or displeasure depending on the homeostatic equilibrium of the body. For example, food tastes better when we are hungry (p. 164). Panksepp also discusses the idea of emotional attractors in the brain as reflected by repetitive patterns of electrical activities that are triggered by specific environmental stimuli (p. 94).
When discussing homeostasis we can think of driving emotions occurring when the organism needs to reassert the internal equilibrium of its physiological processes. Satisfying emotions would ensue when equilibrium is reasserted or maintained. Although successful adaptation to an environment is more than a matter of maintaining homeostasis, the concepts apply equally well to neutral actions and behaviors that have no intrinsic value to the maintenance of the body. For example, animals may be driven to seek out others to breed and socially bond with, and can be satisfied and settle down when they do.
So far we have only judged emotions as being driving or satisfying. If these terms are to be non-ambiguous then we need to be able to determine their classification through quantifiable measurements rather than via interpretation.