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Several recent clinical trials have shown that docosahexaenoic acid (DHA) supplements have a significant effect on cognition in cognitively impaired older adults. This randomised controlled trial aimed to investigate the cognitive effects of a DHA fish oil supplement in older adults with mild cognitive impairment, and to examine the moderating effect of the apolipoprotein E (APOE) ɛ4 allele on cognition and well-being.Seventy-two older adults between the ages of 60 and 90 from New Zealand were given a DHA supplement equivalent to 1491 mg DHA + 351 mg eicosapentaenoic acid per day or a placebo for a period of 12 months. Outcome measures included cognition, wellbeing and self-rated quality of life as well as height, weight, blood pressure and APOE genotyping.The final analysis (n = 60) found no evidence of a treatment effect on cognitive measures, although did find a treatment effect on systolic blood pressure (p = 0.03, ƞDespite no effect on cognition, the positive result in APOE ɛ4 carriers on depression and anxiety scores and on systolic blood pressure justifies further DHA trials. It may be a prudent step going forward for more studies to replicate the design elements (dose, duration and cognitive measures) of previous DHA trials to help understand why not all older adults appear to benefit from taking a fish oil supplement.

Kiwifruit (KF) effects on the human glycaemic response to co-ingested wheat cereal were determined. Participants (n = 20) consumed four meals in random order, all being made to 40 g of the same available carbohydrate, by adding kiwifruit sugars (KF sug; glucose, fructose, sucrose 2:2:1) to meals not containing KF. The meals were flaked wheat biscuit (WB)+KFsug, WB+KF, WB+guar gum+KFsug, WB+guar gum+KF, that was ingested after fasting overnight. Blood glucose was monitored 3 h and hunger measured at 180 min post-meal using a visual analogue scale. KF and guar reduced postprandial blood glucose response amplitude, and prevented subsequent hypoglycaemia that occurred with WB+KFsug. The area between the blood glucose response curve and baseline from 0 to 180 min was not significantly different between meals, 0-120 min areas were significantly reduced by KF and/or guar. Area from 120 to 180 min was positive for KF, guar, and KF+guar, while the area for the WB meal was negative. Hunger at 180 min was significantly reduced by KF and/or guar when compared with WB. We conclude that KF components other than available carbohydrate may improve the glycaemic response profile to co-ingested cereal food.

Background: Docosahexaenoic acid (DHA) is important for brain function, and its status is dependent on dietary intakes. Therefore, individuals who consume diets low in omega-3 (n23) polyunsaturated fatty acids may cognitively benefit from DHA supplementation. Sex and apolipoprotein E genotype (APOE) affect cognition and may modulate the response to DHA supplementation. Objectives: We investigated whether a DHA supplement improves cognitive performance in healthy young adults and whether sex and APOE modulate the response. Design: Healthy adults (n = 176; age range: 18‐45 y; nonsmoking and with a low intake of DHA) completed a 6-mo randomized, placebo-controlled, double-blind intervention in which they consumed 1.16 g DHA/d or a placebo. Cognitive performance was assessed by using a computerized cognitive test battery. For all tests, z scores were calculated and clustered into cognitive domains as follows: episodic and working memory, attention, reaction time (RT) of episodic and working memory, and attention and processing speed. ANCOVAwas conducted with sex and APOE as independent variables. Results: RTs of episodic and working memory improved with DHA

Recent research has suggested that fear of driving is common in the general population. People may have various concerns when driving, and instruments for the assessment of these concerns are lacking. The present paper describes the development and preliminary evaluation of the Driving Cognitions Questionnaire (DCQ). The DCQ is a 20-item scale that measures three areas of driving-related concerns--panic-related, accident-related, and social concerns. In three separate samples from different countries (n=69, 100, and 78), the scale showed good internal consistency and substantial correlations with measures of the severity of driving fear. It discriminated well between people with and without driving phobia. It also showed convergent validity with other measures. The questionnaire shows promise for use in research and clinical practice.

The authors review the literature on the 2 main models of the placebo effect: expectancy theory and classical conditioning. A path is suggested to dissolving the theoretical impasse that has long plagued this issue. The key is to make a clear distinction between 2 questions: What factors shape placebo effects? and What learning mediates the placebo effect? The reviewed literature suggests that classical conditioning procedures are one shaping factor but that verbal information can also shape placebo effects. The literature also suggests that conditioning procedures and other sources of information sometimes shape conscious expectancies and that these expectancies mediate some placebo effects; however, in other cases conditioning procedures appear to shape placebo effects that are not mediated by conscious cognition. The placebo effect is a topic of interest to psychologists and health practitioners in a wide variety of areas, and the question of the mechanisms underlying this effect is gaining increasing attention. In this article, we review the literature related to the two main approaches to the placebo phenomenon: expectancy theory and classical conditioning. According to expectancy theory, placebo effects are mediated by explicit (consciously accessible) expectancies. In contrast, according to the classical conditioning approach, they are conditioned responses (CRs). We begin with the problematic issue of defining placebos and placebo effects, and we then turn to the question of whether these effects actually exist. Having established that they do, we shift the focus to the main task of the article: determining the roles of expectancy and conditioning in the placebo effect. This task is divided into two parts. The first has the aim of clearing up the confusion that exists in the placebo literature concerning the relationship between conditioning and expectancy. These approaches are often pitted against one another, under the assumption that either expectancy theory or classical conditioning accounts for the placebo effect. We reject this view, arguing that the two approaches are compatible. One stumbling block is the assumption that classical conditioning is a particular form of learning, necessarily distinct from expectancy learning. However, conditioning is defined in terms of stimulus inputs and their subsequent effects. Specifically, an organism has been classically conditioned when exposure to a contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US) results in a relevant change in the organism’s state or behavior. This leaves open the question of what mechanisms mediate conditioning. In some cases, conditioning procedures lead to nonconscious learning, and the effects of conditioning are not cognitively mediated. In other cases, though, conditioning effects are mediated by conscious expectancies. Thus, expectancy theory provides an explanation for some examples of classical conditioning. Furthermore, expectancies are not shaped only by conditioning procedures, but also by factors such

It has been known for over 40 years that there are two fundamentally different kinds of detection tasks in the theory of signal detectability. The Type 1 task is to distinguish between events defined independently of the observer; the Type 2 task is to distinguish between one's own correct and incorrect decisions about those Type 1 events. For the Type 1 task, the behavior of the detector can be summarized by the traditional receiver operating characteristic (ROC) curve. This curve can be compared with a theoretical ROC curve, which can be generated from overlapping probability functions conditional on the Type 1 events on an appropriate decision axis. We show how to derive the probability functions underlying Type 2 decisions from those for the Type 1 task. ROC curves and the usual measures of performance are readily obtained from those Type 2 functions, and some relationships among various Type 1 and Type 2 performance measures are presented. We discuss the relationship between Type 1 and Type 2 confidence ratings and caution against the practice of presenting transformed Type 2 ratings as empirical Type 1 ratings.

Several recent studies have attempted to lay the groundwork for a simple, low level computer security system involving cognitive and word association passwords. The present research investigated the effect of three different word association formulation techniques on recall rates when participants were presented with their original cue words after a 2 week retention interval. Differences in the susceptibility of word associations to being guessed by someone the participant knew well were also examined. In the 'response only' group (n = 24), respondents were provided with a list of 20 cue words and were required to generate an associated response for each cue. In the 'cues and responses' group (n = 25), respondents generated both cues and associated responses, while in the 'theme' group (n = 24), respondents generated both cue and response words having first decided upon a theme for their word associations. The average recall and guessing rates were 66% and 8%, respectively. No statistically significant differences in recall or guessing rates were found between the three groups. The effect sizes obtained strongly suggest that insufficient statistical power was available to produce significant effects. Nevertheless, it is tentatively concluded that the formulation techniques employed have only a small effect on ease of recall. Future research on the utility of word associations as computer passwords needs to be based in a real computer security setting.

The present paper investigated the viability of cognitive passwords and word associations as techniques that might supplement conventional alphanumeric passwords. Results from 86 participants showed that fact-based cognitive items were better recalled than opinion-based items, but people socially close to the participants were able to guess many of the fact-based items. Guessing rates for the word associations were low but so also were the recall rates. It is concluded that selected cognitive items can yield acceptable recall and guessing rates while being less susceptible to forgetting than conventional passwords. Word associations require more research to isolate the best method of generating them.

Usability has become an important factor in the design of interactive software. In the quest to develop usable software, user participation in the design and evaluation process has been advocated. Four methods; logged data, questionnaires, interviews, and verbal protocol analyses have been the prominent base evaluation methods used, sometimes being combined in an attempt to provide a comprehensive evaluation. However, little is known about the strengths and weaknesses of these methods. In this study, these four methods were used to evaluate three different software types (spreadsheet, word processor, and database) with 148 subjects participating. The data obtained enabled a number of conclusions to be drawn regarding the usefulness of the methods when used individually and in combination.

The main goal of our original article (Stewart-Williams & Podd, 2004) was to resolve the debate between the two major approaches to the placebo effect: expectancy theory and classical conditioning. In his commentary on this article, Kirsch (2004) discussed the relationship between these approaches. His position is largely consistent with our own, and therefore we have little to say in response to this aspect of the commentary. Our only comment concerns Kirsch’s suggestion that classical conditioning is included as a component of expectancy theory. Although we agree that conditioning is one cause of expectancy change, we would emphasize that it cannot be wholly subsumed by expectancy theory, as there are some instances of conditioning that do not involve expectancies (as Kirsch, 2004, recognized). Aside from this small point, the main focus of our reply is the question of placebo psychotherapies. We also briefly consider the issue of nonconscious learning in the placebo effect.

In the present study, we investigated age-related decline in face recognition memory and whether this decline is moderated by the age of the target faces and by the number of faces that the participant must learn (memory load). Thirty-two participants in each of three age groups (18-39 years, 60-75 years, and 76-96 years) completed a face recognition task. Signal detection analyses confirmed that face recognition accuracy declined with age. However, this finding was qualified by an interaction between participant age and target age, which revealed that the age-related decline in face recognition accuracy occurred only for young target faces. Increased memory load was associated with comparable performance decrements across all age groups. However, memory load appears not to be the cause of these decrements. Instead, they appear to be a product of recognition load (the number of stimuli presented in the recognition phase).