Comparing implementation intention interventions in relation to young adults’ intake of fruit and vegetables

This study tests whether the effectiveness of implementation intention-based interventions to increase fruit and vegetable intake in a young adult population can be enhanced using additional pre-intervention instructions and alternative formats; namely, an ‘if-then’ implementation intention versus a more general, ‘global’ plan that does not explicitly link a situational cue with a goal-directed response. Participants (N?=?557) completed pre-test measures of planning, motivation and behaviour with respect to increasing their fruit and vegetable intake before being randomised to a 3 (intervention format: control vs. ‘if-then’ vs. ‘global’ implementation intentions)?×?2 (pre-intervention instruction vs. no pre-intervention instruction) between-participants design. Results revealed a significant intervention format by time interaction, such that intake significantly increased by 0.50 portions in the if-then format condition compared with 0.31 in the global format and 0.01 in the control condition. These results suggest that ‘if-then’ manipulations are superior in promoting behaviour change in an applied setting. The use of pre-intervention instructions had no additional effect on behaviour, providing evidence for the efficacy of implementation intentions even when experimenter demand is reduced. Evidence is also presented to suggest that reported increases in intake are not related to demand characteristics.     

肥胖成因的解释——基于食物奖赏研究的视角

肥胖的形成和发展受生物、心理和社会因素的共同作用,其中食物奖赏对肥胖的产生有重要的作用。食物是一种自然奖赏,它指机体天生对食物的渴望和依赖。食物奖赏包括"wanting"、"liking"以及"learningreinforcement"三个成分,每个成分由相应的神经通路表征。食物奖赏调控机体的摄食行为并以此调控体重变化。目前,关于肥胖与食物奖赏关系的理论模型主要有刺激—敏感化理论、奖赏过度理论以及奖赏不足理论。采用横断面设计、前瞻研究设计和纵向被试内重复测量设计,使用食物图片线索和直接给予美味奶昔的技术方法,人类脑成像研究从不同侧面为以上三个理论模型提供了证据。除此之外,食物奖赏还受基因的调控。目前,研究者关注较多的是多巴胺D2受体基因Taq IA rs1800497的多态性和FTO基因rs9939609的多态性对食物奖赏及体重改变的调控。     

Commitment, choice and self-control

When offered a choice (Choice Y) between a small immediate reward (2-sec exposure to grain) and a large reward (4-sec exposure to grain) delayed by 4 sec, pigeons invariably preferred the small, immediate reward. However, when offered a choice (Choice X) between a delay of T seconds followed by Choice Y and a delay of T seconds followed by restriction to the large delayed reward only, the pigeon's choice depended on T. When T was small, the pigeons chose the alternative leading to Choice Y (and then chose the small, immediate reward). When T was large, the pigeons chose the alternative leading to the large delayed reward only. The reversal of preference as T increases is predicted by several recent models for choice between various amounts and delays of reward. The preference for the large delayed alternative with long durations of T parallels everyday instances of advance commitment to a given course of action. Such commitment may be seen as a prototype for self-control.     

Can you eat it? A link between categorization difficulty and food likability

In the present study we examined whether categorization difficulty regarding a food is related to its likability. For this purpose, we produced stimulus images by morphing photographs of a tomato and a strawberry. Subjects categorized these images as either a tomato or a strawberry and in separate sessions evaluated the food's eatability or the subject's willingness to eat (Experiments 1 and 2) and the likeliness of existence of each food (Experiment 2). The lowest score for ca- tegorization confidence coincided with the lowest scores for eatability, willingness to eat, and likeliness of existence. In Experiment 3, we found that food neophobia, a trait of ingestion avoidance of novel foods, modulated food likability but not categorization confidence. These findings suggest that a high categorization difficulty generally co-occurs with a decrease in food likability and that food neophobia modulates likability. This avoidance of difficult-to-categorize foods seems ecologically valid because before eating we have little information regarding whether a food is potentially harmful.     

Transfer between contextual conditional discriminations: an examination of how stimulus conjuctions are represented

In 2 experiments, when rats were placed in 1 pair of contexts, A and B, 2 relationships were in force (X --> food and Y --> no food), and when they were placed in another pair of contexts, C and D, the complementary relationships were operative (Y --> food and X --> no food). In Experiment 1, rats then received a 2nd discrimination that was either contextually congruent (in A and B, Y --> food and X --> no food; in C and D, X --> food and Y --> no food) or contextually incongruent (in A and D, Y --> food and X --> no food; in C and B, X --> food and Y --> no food) with the 1st discrimination. In Experiment 2, the 1st discrimination, involving X and Y, was interleaved with a 2nd discrimination, involving V and W, that was again either congruent (in A and B, V --> food and W --> no food) or incongruent (in A and D, V --> food and W --> no food) with the 1st discrimination. The congruent discriminations were acquired more readily than were the incongruent discriminations.     

Making choices in anticipation of similar future choices can increase self-control

Two experiments tested the efficacy of linking a current choice with similar future choices as a means of increasing self-control. Participants were offered choices between smaller and sooner vs. larger and later amounts of money (Experiment 1, n = 60) or food (Experiment 2, n = 34). After a small-large pair for which the participant preferred the smaller reward was found, a choice between the same pair was offered as the 1st of 5 such choices to be offered over a period of weeks. The majority of participants in both experiments who chose between all 5 smaller and all 5 larger rewards chose the larger rewards. One third of participants in Experiment 1 who could choose independently on each pair in the series reversed their previous preference and chose the larger reward in the context of the series. These results suggest that self-control can be enhanced by viewing one's current choice as predictive of future choices.     

Acquired equivalence and distinctiveness of cues: I. Exploring a neural network approach

Rats were placed in 4 contexts (A, B, C, D) where they received 2 auditory stimuli (X, Y); in A and B, presentations of X were paired with food and those of Y were not, and in C and D, Y was paired with food and X was not. Rats then received combinations of contexts that had provided congruent (AB, CD) or incongruent (AD, CB) information about X and Y's relationship to food. Responding was more variable during congruent than incongruent trials (Experiment 1) and was systematically increased and decreased during congruent (relative to incongruent) trials by the presentation of food or no food, respectively (Experiment 2). These results support a connectionist approach to acquired changes in stimulus distinctiveness.     

AGENCY AND AWARENESS

I focus on the idea that if, as a result of lacking any conscious goal related to X‐ing and any conscious anticipation or awareness of X‐ing, one could sincerely reply to the question ‘Why are you X‐ing?’ with ‘I didn't realize I was doing that,’ then one's X‐ing is not intentional. My interest is in the idea interpreted as philosophically substantial (rather than merely stipulative) and as linked to the familiar view that there is a major difference, relative to the exercise of agential control, between acting on a conscious goal (even one the agent is not actively thinking about) and acting on a non‐conscious goal (about which the sincerely ‘clueless’ response ‘I didn't realize I was doing that’ could be provided). After raising some doubts about the target idea, I consider the two most promising lines of defence. I argue that neither is convincing, and that we should reject the suggestion that the idea is properly accepted as a matter of common sense. Even absent any conscious goal related to X‐ing and any conscious anticipation or awareness of X‐ing, there is room for counting X‐ing as intentional if X‐ing is, or is appropriately related to, a non‐conscious goal.     

Social comparison mediates chimpanzees’ responses to loss,not frustration

Why do chimpanzees react when their partner gets a better deal than them? Do they note the inequity or do their responses reflect frustration in response to unattainable rewards? To tease apart inequity and contrast, we tested chimpanzees in a series of conditions that created loss through individual contrast, through inequity, or by both. Chimpanzees were tested in four social and two individual conditions in which they received food rewards in return for exchanging tokens with an experimenter. In conditions designed to create individual contrast, after completing an exchange, the chimpanzees were given a relatively less-preferred reward than the one they were previously shown. The chimpanzees’ willingness to accept the less-preferred rewards was independent of previously offered foods in both the social and individual conditions. In conditions that created frustration through inequity, subjects were given a less-preferred reward than the one received by their partner, but not in relation to the reward they were previously offered. In a social context, females were more likely to refuse to participate when they received a less-preferred reward than their partner (disadvantageous inequity), than when they received a more-preferred reward (advantageous inequity). Specifically, the females’ refusals were typified by refusals to exchange tokens rather than refusals to accept food rewards. Males showed no difference in their responses to inequity or individual contrast. These results support previous evidence that some chimpanzees’ responses to inequity are mediated more strongly by what others receive than by frustration effects.     

Pigeons are attracted to a perceived gain without an actual gain

Reference dependence refers to the reduced value of a reward that is less than expected, or the added value of a reward that is greater than expected. There is evidence that when pigeons are offered an alternative that has 1 pellet versus an alternative that has 2 pellets, but one of the two pellets offered will be removed, the pigeons prefer the originally presented 1 pellet (loss aversion). In the present research, we tested for the opposite effect (gain attraction). In Experiments 1 and 2, pigeons could choose between 2 pellets, each one on a distinctive background. If they chose the optimal alternative, they received a second pellet. In Experiment 2, the second pellet obtained was the one not initially chosen (a task sometimes referred to as the ephemeral reward task). Pigeons learned to choose optimally in both experiments. In Experiment 3, we tested the pigeons for reference dependence. Pigeons were given an alternative that offered them one pellet or two pellets, if they chose the one-pellet alternative, they received an additional pellet, and if they chose the two-pellet alternative, they received the two pellets. In keeping with the reference dependence hypothesis, the pigeons preferred the 1-pellet alternative that gave them an extra pellet. These effects are related to similar findings with humans, including the endowment effect.

     

When leader–member exchange differentiation improves work group functioning: The combined roles of differentiation bases and reward interdependence

Drawing on social hierarchy theory, we develop a contingency model of leader–member exchange (LMX) differentiation in which LMX differentiation is positively and negatively related to group cooperation and group social undermining, respectively, when it is based on the group members’ performance, but the relations are reversed (i.e., negative and positive, respectively) when it stems from a leader's personal liking of the members. In addition, we propose that the moderating effects of the performance and personal liking bases of LMX differentiation are magnified by the levels of reward interdependence. Specifically, under a high (vs. low) level of reward interdependence, LMX differentiation based on performance more strongly relates to high group cooperation and low group social undermining, whereas LMX differentiation with a personal liking basis is more likely to decrease group cooperation and increase group social undermining. Group cooperation and social undermining are then hypothesized to convey the three‐way interactive effects of LMX differentiation, its two bases, and reward interdependence on subsequent group performance. Analyses of data from 328 sales groups of a large retailer support the core part of our contingency model of LMX differentiation.     

Identifying good opportunities to act: Implementation intentions and cue discrimination

Forming an implementation intention (‘If I encounter situation X, then I'll perform behaviour Y!’) is thought to increase the likelihood that the person will detect a good opportunity to act. Experiment 1 found support for this hypothesis in a novel context where detection of the specified cue was very difficult. Experiments 2 and 3 extended existing paradigms to test whether this improved cue detection has costs in terms of increased false positives and/or slower responses to ambiguous stimuli. This hypothesis was not supported. Forming an implementation intention led to more accurate (Experiment 2) and faster (Experiment 3) responses to the specified cue without compromising responses to non‐relevant, or ambiguous, stimuli. Overall, the findings suggest that forming an implementation intention is an effective self‐regulatory tool because the specified cues are discriminated swiftly and with precision. Copyright © 2004 John Wiley & Sons, Ltd.     

Specific Food Aversion Acquired During Restricted Environmental Stimulation

Two studies, one conducted in Australia and one in Canada, tested the effects of the Restricted Environmental Stimulation Technique (REST) on food preferences. Subjects undergoing 24 hours of darkness and silence were either permitted to take some of their favorite high-caloric foods to eat during the session or were given standard laboratory liquid diet food. In the second study, a social isolation condition (without sensory reduction) and a nonconfined control condition were also used. The results reliably indicate that preferred foods taken into the chamber were significantly less favorably rated after REST, while the same experience led to increased liking of previously less preferred foods. Some originally liked items were completely eliminated from the subject's diet after the experiment, while others were eaten significantly less frequently than before. REST has previously been useful in a weight reduction program; its effect in decreasing the attractiveness of highly liked problem foods may add to its impact in this context.     

Young Children's Reports of When Events Occurred: Do Event Type and Assessment Method Matter?

Studying young children's reporting about when various events occurred informs about the development of episodic memory and metacognition. In two experiments, 55 3‐ to 5‐year‐old children participated in two activity sessions, a week apart. During the activity sessions, they learned novel animal facts and body movements, and they coloured animal pictures and posed for body movement photos. Immediately after the second activity session, children were interviewed about when they experienced the various events. Overall, children were as accurate about learning events as physical events, but they were more accurate when asked temporal distance (e.g. ‘Which did you learn a longer time ago, “X” or “Y”?’) than temporal location questions (e.g. ‘Which did you learn before today, “X” or “Y”?’). The results suggest that young children's apparent difficulty recognizing new learning is not due to a rapid ‘remember‐to‐know shift’. Rather, the way we ask young children about when they experienced various events determines their accuracy. Copyright © 2016 John Wiley & Sons, Ltd.     

Diachronic Dutch Books and Evidential Import

A handful of well‐known arguments (the ‘diachronic Dutch book arguments’) rely upon theorems establishing that, in certain circumstances, you are immune from sure monetary loss (you are not ‘diachronically Dutch book‐able’) if and only if you adopt the strategy of conditionalizing (or Jeffrey conditionalizing) on whatever evidence you happen to receive. These theorems require non‐trivial assumptions about which evidence you might acquire—in the case of conditionalization, the assumption is that, if you might learn that e, then it is not the case that you might learn something else that is consistent with e. These assumptions may not be relaxed. When they are, not only will non‐(Jeffrey) conditionalizers be immune from diachronic Dutch bookability, but (Jeffrey) conditionalizers will themselves be diachronically Dutch bookable. I argue: 1) that there are epistemic situations in which these assumptions are violated; 2) that this reveals a conflict between the premise that susceptibility to sure monetary loss is irrational, on the one hand, and the view that rational belief revision is a function of your prior beliefs and the acquired evidence alone, on the other; and 3) that this inconsistency demonstrates that diachronic Dutch book arguments for (Jeffrey) conditionalization are invalid.     

Narrative and the Stability of Intention

This paper addresses a problem concerning the rational stability of intention. When you form an intention to φ at some future time t, you thereby make it subjectively rational for you to follow through and φ at t, even if—hypothetically—you would abandon the intention were you to redeliberate at t. It is hard to understand how this is possible. Shouldn't the perspective of your acting self be what determines what is then subjectively rational for you? I aim to solve this problem by highlighting a role for narrative in intention. I'll argue that committing yourself to a course of action by intending to pursue it crucially involves the expectation that your acting self will be ‘swept along’ by its participation in a distinctively narrative form of self‐understanding. I'll motivate my approach by criticizing Richard Holton's and Michael Bratman's recent treatments of the stability of intention, though my account also borrows from Bratman's work. I'll likewise criticize and borrow from David Velleman's work on narrative and self‐intelligibility. When the pieces fall into place, we'll see how intending is akin to telling your future self a kind of story. My thesis is not that you address your acting self but that your acting self figures as a ‘character’ in the ‘story’ that you address to a still later self. Unlike other appeals to narrative in agency, mine will explain how as narrator you address a specifically intrapersonal audience.     

How emotions expressed by adults’ faces affect the desire to eat liked and disliked foods in children compared to adults

The aim of this study was to determine whether or not pleasure, neutrality, and disgust expressed by eaters in photographs could affect the desire to eat food products to a greater extent in children than in adults. Children of 5 and 8 years of age, as well as adults, were presented with photographs of liked and disliked foods. These foods were presented either alone or with an eater who expressed three different emotions: pleasure, neutrality, or disgust. Results showed that, compared with food presented alone, food presented with a pleasant face increased the desire to eat disliked foods, particularly in children, and increased the desire to eat liked foods only in the 5‐year‐old children. In contrast, with a disgusted face, the desire to eat the liked foods decreased in all participants, although to a greater extent in children, while it had no effect on the desire to eat the disliked foods. Finally, food presented with a neutral face also increased and decreased the desire to eat disliked and liked foods, respectively, and in each case more for the 5‐year‐olds than for the older participants. In sum, the facial expressions of others influence the desire to eat liked and disliked foods and, to a greater extent, in younger children.     

死亡凸显对自我姓名注意瞬脱对抗效应的影响

已有研究表明死亡凸显会抑制自我面孔和自我参照记忆加工的自我优势,可是死亡凸显对自我姓名的影响尚不明确,本研究采用事件相关电位技术,探索死亡凸显对自我姓名注意瞬脱对抗效应及其大脑神经活动的影响。58名被试在经历不同的启动任务后,完成自我姓名、朋友姓名和名人姓名的注意瞬脱任务。行为结果发现自我姓名识别正确率显著高于朋友姓名和名人姓名,表现出稳定的自我姓名加工的注意瞬脱对抗效应;电生理数据发现死亡启动后自我姓名诱发的P300波幅显著低于消极启动组和中性启动组,而朋友姓名和名人姓名并不受启动的影响。本研究结果与以往研究结果共同表明死亡想法凸显会使个体将抑制自我加工（自我姓名、自我面孔和自我参照记忆）作为应对远端死亡焦虑的一种手段。     

死亡凸显对自我姓名注意瞬脱对抗效应的影响

已有研究表明死亡凸显会抑制自我面孔和自我参照记忆加工的自我优势,可是死亡凸显对自我姓名的影响尚不明确,本研究采用事件相关电位技术,探索死亡凸显对自我姓名注意瞬脱对抗效应及其大脑神经活动的影响。58名被试在经历不同的启动任务后,完成自我姓名、朋友姓名和名人姓名的注意瞬脱任务。行为结果发现自我姓名识别正确率显著高于朋友姓名和名人姓名,表现出稳定的自我姓名加工的注意瞬脱对抗效应;电生理数据发现死亡启动后自我姓名诱发的P300波幅显著低于消极启动组和中性启动组,而朋友姓名和名人姓名并不受启动的影响。本研究结果与以往研究结果共同表明死亡想法凸显会使个体将抑制自我加工（自我姓名、自我面孔和自我参照记忆）作为应对远端死亡焦虑的一种手段。     

When does ‘Can’ imply ‘Ought’?

ABSTRACT

The Assistance Principle is common currency to a wide range of moral theories. Roughly, this principle states: if you can fulfil important interests, at not too high a cost, then you have a moral duty to do so. I argue that, in determining whether the ‘not too high a cost’ clause of this principle is met, we must consider three distinct costs: ‘agent-relative costs’, ‘recipient-relative costs’ and ‘ideal-relative costs’.