Январь 2017

Individual and species survival demand that organisms find and obtain needed resources (e.g., food and shelter) and opportunities for mating despite costs and risks. Such survival-relevant natural goals act as “rewards,” i.e., they are pursued with the anticipation that their consumption (or consummation) will produce desired outcomes (i.e., will “make things better”). Behaviors with rewarding goals tend to persist strongly to a conclusion and increase over time (i.e., they are positively reinforcing) (21). Internal motivational states, such as hunger, thirst, and sexual arousal, increase the incentive value of goal-related cues and of the goal objects themselves and also increase the pleasure of consumption (e.g., food tastes better when one is hungry) (22). External cues related to rewards (incentive stimuli), such as the sight or odor of food or the odor of an estrous female, can initiate or strengthen motivational states, increasing the likelihood that complex and often difficult behavioral sequences, such as foraging or hunting for food, will be brought to a successful conclusion, even in the face of obstacles.

Мы можем здесь привести и обратный пример.  Феномен Alliesthesia  обычно иллюстрируется описанием того, как мы едим конфеты. Первую мы употребляем с большим удовольствием, каждую последующую -- с меньшим. Наконец наступает тот момент, когда мы начинаем смотреть на сладости с отвращением. Такие же примеры можно привести и с утолением жажды. Как сладок на жаре первый глоток воды и какие усилия нам предстоит делать, когда нас заставляют выпить большое количество жидкости (например, промывание желудка после отравления). Нечто похожее на врачебное назначение иногда представляет собой прием алкоголя

The evidence discussed to date suggests that opioid  peptides play a specific role in some aspect of the neural  system underlying the expression of palatability, the opioidpalatability  hypothesis. In order to evaluate fully this idea in  humans, an alternative measure of orosensory reward is  needed in order to get around the potential problems of  interpreting hedonic rating data. One approach has been to  examine in detail changes both in eating rate and the pattern  of changes in subjective appetite during meals following  manipulations of palatability alone [79]. Increasing the  rated palatability of a food increased intake and also resulted  in increases in rated hunger during the early stages of the  test meal [80].