Group processes in food choices: The role of ethnic identity and perceived ethnic norms upon intentions to purchase ethnical food products

A study tested an extended Theory of Planned Behaviour (TPB) model, inclusive of measures of ethnical identification and perceived ethnic group norms, in the ethnical food purchasing domain. One hundred and thirty‐five Jamaicans, living in the Brixton neighbourhood, London, were administered a self‐reported questionnaire measuring the classical TPB components (attitudes, subjective norms, perceived behavioural control, behavioural intentions) plus three additional components: identification with the Jamaican group, perceived norms of the Jamaican group and past behaviour. Results of hierarchical multiple regressions showed that past behaviour, ethnical identification and perceived group norms explain an additional proportion of variance in intentions, independently of attitudes, subjective norms and perceived control. A two‐way interaction, between ethnical identification and perceived group norms, was detected. A stronger relation between group norms and intentions emerged among high ethnical identifiers. Theoretical and practical implications are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Local Food Environments: They’re All Stocked Differently

The obesity epidemic has widened the aims of prevention research to include the influence of local food environments on health outcomes. This mixed methods study extends existing research focused on local food environments by examining whether community members’ find food accessible. Data from food store audits and one-on-one interviews were analyzed. Results reveal that most of the food stores surrounding the three research sites were convenience stores and non-chain grocery stores; interviewees did not perceive these stores to be “real” food stores. Tobacco and alcohol products were more prevalent in the food stores than all varieties of milk, fresh fruits, or fresh vegetables. Food access varied by site in a manner that was designed to appeal to customers’ race, class, gender, or environment. Findings reveal that local food environments are reflections of social hierarchies. Unraveling the politics of space ought to be a part of broader efforts to promote the public’s health.     

Withholding Hydration and Nutrition in Newborns

In the twenty-first century, decisions to withhold or withdraw life-supporting measures commonly precede death in the neonatal intensive care unit without major ethical controversy. However, caregivers often feel much greater turmoil with regard to stopping medical hydration and nutrition than they do when considering discontinuation of mechanical ventilation or circulatory support. Nevertheless, forgoing medical fluids and food represents a morally acceptable option as part of a carefully developed palliative care plan considering the infant’s prognosis and the burdens of continued treatment. Decisions to stop any form of life support should focus on the clinical circumstances, not the means used to sustain life.     

Organization of sex-typical patterns of defense during food protection in the rat: The role of the opponent's sex

Feeding rats defend a food item from an approaching conspecific by turning away, laterally, about 180°. Females and males use a different composition of movements and stepping patterns to perform these defensive dodges. This study was designed to examine the role of the robber's sex on the execution of sex-typical patterns of dodging. All subjects were tested with a partner of each sex. During dodging, females used the female-typical pattern of pivoting around the pelvis, and males used the male-typical midbody pivot, irrespective of the robber's sex. These findings show that the sex-typical patterns of dodging are not determined by the sex of the partner. Females and males however, differed in how they were oriented towards a same sex robber at the end of the dodge. This suggests that while male and female robbers must pose different defensive problems, these differences are dealt with by modifying the sex-typical pattern of dodging rather than by switching to the dodge pattern of the opposite sex. This further suggests that the differences in the composition of the dodge pattern in males and females are not due to extrinsic contingencies, but rather, are due to intrinsic differences in the sex-typical organization of defensive motor patterns. Aggr. Behav. 23:197–214, 1997.© 1997 Wiley-Liss, Inc.     

Seasonal variation in pigeon body weight and delayed matching-to-sample performance

The weights of 5 pigeons with free access to food, monitored over 3 calendar years in the laboratory, were found to fluctuate with season. All pigeons were at their heaviest in the winter and were lightest in the summer. Five different pigeons performed a standard delayed matching-to-sample task for 44 weeks from January to November. Their weights were held at 85% of their summer free-feeding weights, making their predicted deprivation level higher in the winter relative to predicted winter free-feeding weights. Slopes of forgetting functions fit to weekly response totals for each pigeon were shallower in winter, showing an improvement in accuracy with longer delays. Thus, delayed matching-to-sample performance may have been affected by the practice of maintaining the pigeons at a constant body weight throughout the calendar year.     

食物线索注意偏向及其神经机制

与其他类型的刺激相比, 个体会优先注意食物相关刺激, 即对食物刺激的注意偏向。对影响食物线索注意偏向个体因素研究的分析发现：(1)在状态因素中, 饥饿以及与自我威胁有关的、唤起强度大的负性情绪对食物线索注意偏向有增强作用, 这在注意加工的早期和晚期都有体现; (2)在特质因素中, 行为研究发现, 相比于体重正常个体和非限制性饮食者, 超重/肥胖个体以及唤起节食目标的成功限制性饮食者没有更强的注意偏向, 但是, ERP研究发现, 在注意加工的早期阶段, 就出现了特质因素对食物线索注意偏向的影响; (3) fMRI研究发现, 对食物线索的注意过程伴随着脑岛、眶额叶皮层等与奖励相关的脑区及视觉注意网络的激活。未来研究需要：(1)从动态角度研究注意偏向, 进一步提高测量的信度; (2)使用专门的范式探究个体因素影响注意偏向的神经机制; (3)严格分离不同状态因素; (4)对被试进行严谨筛选和划分, 做好被试间的对比研究。     

女性食物选择的演化视角：基于性选择过程的理论探讨

性选择在人类心理、行为等表型的演化过程中扮演了重要角色,但其对女性食物选择的影响却相对较少被关注。性选择塑造了男女不同的择偶策略,男性择偶时对女性外在吸引力的关注使得女性更加重视身材等外在吸引力信息。而女性身材与饮食的密切联系,进一步提示性选择过程应该会对女性的食物选择产生影响。以之为基础,梳理求偶动机激活可能引发的女性食物选择的变化,以及女性生理期不同阶段在食物选择上的变异,有助于了解性选择过程对女性食物选择的影响。未来研究中,进一步从行为、激素、脑等不同层面剖析对应影响及涉及机制,对该领域的长远发展有重要意义。     

THE COSTS OF EATING: A BEHAVIORAL ECONOMIC ANALYSIS OF FOOD REFUSAL

Behavioral economic concepts were applied to the analysis and treatment of pediatric feeding disorders in a clinical setting. In Experiment 1, children who chronically refused food were presented with varying amounts of food on a spoon (empty, dipped, quarter, half, and level). Each child exhibited a different but orderly demand function of response (acceptance, expulsion, and mouth clean) by cost (increasing spoon volume) for a constant pay-off of toys and social interaction. In Experiment 2, physical guidance or nonremoval of the spoon for food refusal was initiated at the smallest spoon volume with low levels of acceptance, and was subsequently introduced at the largest spoon volume with moderate levels of acceptance. Treatment was effective in increasing acceptance, and these effects generalized hierarchically across untargeted spoon volumes. The results of both studies provide preliminary support that increasing spoon volume can be equated conceptually with increasing response effort, and that the change from differential reinforcement to physical guidance or nonremoval of the spoon appears to have altered the elasticity of each child's demand function.     

Cocaine's effects on food-reinforced pecking in pigeons depend on food-deprivation level.

Four pigeons deprived to 80% of their laboratory free-feeding weights pecked keys under a multiple fixed-ratio 30 fixed-interval 5-min schedule of food presentation. Components alternated strictly with 15-s timeouts separating them; each was presented six times. When rates of pecking were stable, 2 pigeons' weights were reduced to 70%, and the other 2 pigeons' weights were increased to 82.5% to 85% of free-feeding levels. Cocaine (1.0, 3.0, 5.6, and 10.0 mg/kg and saline) was administered 5 min prior to sessions. When each dose had been tested twice, pigeons' weights were adjusted to the level that they had not yet experienced, and cocaine was tested again. Cocaine reduced response rates in a dose-dependent manner under the fixed-ratio schedule and under the fixed-interval schedule at high doses, and increased rates under the fixed-interval schedule at low low doses. Reductions in pecking rates occurred at lower doses under both schedules in 3 of 4 pigeons when they were less food deprived compared to when they were more food deprived. Low doses of cocaine increased low baseline rates of pecking in the initial portions of the fixed-interval schedules by a greater magnitude when pigeons were more food deprived. Thus, food-deprivation levels altered both the rate-decreasing and rate-increasing effects of cocaine. The implications of these results for the mechanisms by which food deprivation increases cocaine self-administration and for the dependence of cocaine's effects on the baseline strength of operant behavior are discussed.