Relationship between food habituation and reinforcing efficacy of food

Reinforcing value and habituation are two processes that have been used to study eating behaviors, but no research has examined their relationship, how they relate to energy intake, and whether they respond in a similar manner to food deprivation. Twenty-two female subjects were randomized to food deprived or non-deprived conditions, and assessed for food reinforcement, habituation to food and ad libitum eating. Results showed food reinforcement and habituation are correlated (r = 0.62, p = 0.002) and both independently predict energy intake. Hierarchical regression showed that the rate of habituation accounted for 30 percent of the variance in eating (p = 0.008), and adding food reinforcement increased the amount of variance accounted for up to 57.5 percent (p < 0.05). This suggests that both processes may influence energy intake in a meal.     

Observing stimulus sources that signal food or no food

Pigeons were given a choice between observing a stimulus source that was uncorrelated with food or one that was informative. The informative source was either positive, in which a stimulus change signalled food, or negative, in which change signalled no food. If observing is supported by the reduction of uncertainty, the negative as well as the positive source should be preferred to the uncorrelated source. On the other hand, if observing requires support by conditioned reinforcement, the negative source should not be preferred to the uncorrelated source. Two keys served as stimulus sources in a discrete trial procedure. The keys were lighted together, remained on for a variable length of time, and went off together. A key could change color 1 sec before going off. In the uncorrelated source, the change occurred equally often on trials ending with or without food. In the positive information source, the change occurred only on food trials, whereas in the negative information source, it occurred only on no-food trials. All stimulus changes and food delivery were response independent. As measured by orientation and autoshaped pecking, the positive information source was preferred to the uncorrelated source. However, the uncorrelated source was preferred to the negative information source. The latter result does not support the view that observing behavior is reinforced by the reduction of uncertainty. The positive and negative information sources reduced uncertainty equally but only the positive source provided a signal that could act as a conditioned reinforcer by virtue of its relation to food.     

Defective food concepts

Our aim in this paper is to employ conceptual negotiation to inform a method of rethinking defective food concepts, that is concepts that fail to suitably represent a certain food-related domain or that offer representations that run counter to the interests of their users. We begin by sorting out four dimensions of a food concept: (i) the data upon which it rests and the methodology by which those data are gathered; (ii) the ontology that sustains it; (iii) the social acts that serve to negotiate and establish the concept; (iv) and the aims and values that it fosters. We then discuss the conditions that make a food concept defective, pointing out four types of defects—fragility, polarization, incoherence, and schizophrenia—which we illustrate by means of two specific examples: local food and healthy food.

     

From world hunger to food sovereignty: food ethics and human development

The role of Amartya Sen's early work on famine notwithstanding, food security is generally seen as but one capability among many for scholars writing in development ethics. The early literature on the ethics of hunger is summarized to show how Sen's Poverty and Famines was written in response to debates of past decades, and a brief discussion of food security as a capability follows. However, Sen's characterization of smallholder food security also supports the development of agency in both a political and an economic sense. Economic agency is discussed and tied to longstanding literatures on the moral significance of farming within political economy. Finally, while the newly emergent literature on food sovereignty includes many themes, it is shown to be re-articulating arguments that stress smallholder's economic agency as a development goal. This pattern of argument thus provides a way to reconcile at least some of the claims being advanced under the banner of food sovereignty with the human development approach, while also restoring food ethics to a more central place in the overall discourse of development ethics.     

Using food redistribution to reduce packing in children with severe food refusal

Positive- and negative-reinforcement-based procedures typically have targeted acceptance for children with severe food refusal; however, these procedures do not always result in successful swallowing. Once acceptance is achieved, some children expel the food repeatedly or pack (hold or pocket) it in their mouths for extended periods of time. This study evaluated the effects of using food redistribution with a bristled massaging toothbrush to reduce packing and increase consumption in 4 children with severe feeding disorders. Packing was reduced for all children. In addition, latency to clean mouth (the duration of time from acceptance to food no longer being present in the child's mouth in the absence of expulsion) for 2 children decreased when the food-redistribution procedure was used. Results are discussed in terms of the potential operant functions of the food-redistribution procedure.     

Explaining unexplainable food choices

In recent years, psychologists have started to investigate the downstream consequences of nonconsciously activated behaviour (acting in an ‘explanatory vacuum’). Results have shown that when such behaviour is norm‐violating, people experience a need to confabulate reasons for this behaviour. The present paper aims to add more convincing evidence for this assumption. Study 1 addresses this question by replicating Study 2 of Adriaanse, Weijers, De Ridder, De Witt Huberts, and Evers ( 2014 ) while adding a condition in which people are post hoc provided with an explanation for their behaviour. Study 2 addresses this question by explicitly demanding an explanation for a nonconsciously steered choice. Both studies were conducted in the context of eating behaviour. Results of both studies were indicative of confabulation as a downstream consequence of nonconsciously steered eating behaviour (Study 1) or food choice (Study 2). Future research should address the potential of confabulated reasons spilling over to next occasions.     

Aversive CSs suppress lever pressing for food but not the eating of free food

Forty rats received CER acquisition, half “on the baseline” (response lever present), half “off the baseline.” During initial CER extinction, Ss received: (a) normal CER extinction (lever available), (b) free food during CSs only (no lever), (c) free food during non-CSs only (no lever), or (d) free food during both CS and non-CS periods (no lever). While normal extinction Ss were highly suppressed in the presence of the CS, all free food groups readily ate but did not differ in eating latencies. On subsequent CER extinction trials on the baseline, those Ss which received free food during the CSs were no less suppressed than other Ss. These data offer no support for Estes' (1969) reciprocal inhibition explanation of CER and punishment, nor do they support a fear interpretation of CER.     

素食与修行、健康新说

道经中的《大道延观碑》曰 :“其教以无为清静为宗 ,真常慈俭为宝 ,其戒则不色、不欲、不杀、不饮酒、不茹荤 ,以仁为心。”修道之人最讲慈悲二字 ,《太上虚皇天尊四十九章经》又云 :“慈悲之力 ,最为广大。”道经中也常说 :千善万善 ,不戒杀生不为真善。所以我们只有首先做到食素 ,才能做到不害生、不伤生、不杀生 ,才能培养起我们功德无量的慈悲之心。在大自然中 ,多数食肉类动物的性格都比较凶猛 ,如狼、狮、虎、豹。而以食素为主的羊、兔、马、鹿性格则相对比较温顺。据说有科学家做过一个试验 ,即用不同食物喂养鸽子。研究者将鸽子分成…