Twelve healthy subjects, six young and six elderly, of either sex, took part in this two-period crossover study. In each session, a dose of trial drug--either 200 mg caffeine or a matching placebo--was given orally at 0900 hours. A battery of psychomotor tests and visual analogue scales was administered before treatment and at 1, 2 and 3 h post-treatment. The objective tests showed a significant increase in tapping rate in the young, while the elderly showed improved attention, faster choice-reaction time, and greater body sway on caffeine. The visual analogue scales showed that the young subjects felt more alert, calmer, more interested, and steadier on caffeine, while no significant changes were seen in the elderly. These results show that caffeine produces changes predominantly in the direction of improved performance and feeling of well-being, and suggest that the elderly are more sensitive to the objective effects of the drug, while reporting less subjective effect than the young.

The use of pen-based electronic questionnaires and conventional paper questionnaires was compared in a randomized crossover study. Forty-six patients, aged 17-81 years, suffering from gastro-intestinal disorders, initially filled in a paper quality of life questionnaire for familiarization purposes, then on two subsequent visits completed electronic and paper questionnaires in randomized order. At the last visit they completed a preference survey. The results showed a high degree of acceptability of the electronic questionnaire, with 57% of patient preferring electronic and 13% preferring paper, while the remaining 30% expressed no preference. Neither age, gender nor familiarity with technology showed any marked association with patients' preferences. All patients found both paper and electronic questionnaires easy to use. Data were more complete on the electronic questionnaire (100%) than on the paper (99.1%). Data handling procedures were greatly simplified. These results show that major benefits in completeness of data, speed of data flow, and data handling workload can be obtained from the use of pen-based electronic questionnaires.

We propose a set of requirements for designing handheld computer systems for electronic collection of patient diary and questionnaire data in clinical trials: (1) the system should be suitable for use by all types of patient to be included in the clinical trial programme; (2) patients must be capable of using the system and be comfortable with it after a short period of training; (3) responses should always result from an action by the user--defaults should not be taken as data; (4) all information necessary to a given question should be simultaneously available on the screen. This applies to both the questions and the response options. We present guidelines as to how these requirements may be met in practice, so that bias may be avoided both in patient selection and in the responses made; so that electronic data collection may be as effective as possible, and so that study procedures are convenient and unobtrusive for the patients.

The results here do not suggest that supplementation with these doses of DHA for 8 weeks has any beneficial effect on brain function in cognitively intact children.

RationaleDeficient inhibitory control is predictive of increased alcohol consumption in the laboratory; however, little is known about this relationship in naturalistic, real-world settings.ObjectivesIn the present study, we implemented ecological momentary assessment methods to investigate the relationship between inhibitory control and alcohol consumption in the real world.MethodsHeavy drinkers who were motivated to reduce their alcohol consumption (N = 100) were loaned a smartphone which administered a stop signal task twice per day at random intervals between 10 a.m. and 6 p.m. for 2 weeks. Each day, participants also recorded their planned and actual alcohol consumption and their subjective craving and mood. We hypothesised that day-to-day fluctuations in inhibitory control (stop signal reaction time) would predict alcohol consumption, over and above planned consumption and craving.ResultsMultilevel modelling demonstrated that daily alcohol consumption was predicted by planned consumption (β = .816; 95% CI .762–.870) and craving (β = .022; 95% CI .013–.031), but inhibitory control did not predict any additional variance in alcohol consumption. However, secondary analyses demonstrated that the magnitude of deterioration in inhibitory control across the day was a significant predictor of increased alcohol consumption on that day (β = .007; 95% CI .004–.011), after controlling for planned consumption and craving.ConclusionsThese findings demonstrate that short-term fluctuations in inhibitory control predict alcohol consumption, which suggests that transient fluctuations in inhibition may be a risk factor for heavy drinking episodes.Electronic supplementary materialThe online version of this article (10.1007/s00213-018-4860-5) contains supplementary material, which is available to authorized users.

Adequate levels of vitamins and minerals are essential for optimal neural functioning. A high proportion of individuals, including children, suffer from deficiencies in one or more vitamins or minerals. This study investigated whether daily supplementation with vitamins/minerals could modulate cognitive performance and mood in healthy children. In this randomised, double-blind, placebo-controlled, parallel groups investigation, eighty-one healthy children aged from 8 to 14 years underwent laboratory assessments of their cognitive performance and mood pre-dose and at 1 and 3 h post-dose on the first and last days of 12 weeks' supplementation with a commercially available vitamins/mineral product (Pharmaton Kiddie). Interim assessments were also completed at home after 4 and 8 weeks at 3 h post-dose. Each assessment comprised completion of a cognitive battery, delivered over the Internet, which included tasks assessing mood and the speed and accuracy of attention and aspects of memory (secondary, semantic and spatial working memory). The vitamin/mineral group performed more accurately on two attention tasks: 'Arrows' choice reaction time task at 4 and 8 weeks; 'Arrow Flankers' choice reaction time task at 4, 8 and 12 weeks. A single task outcome (Picture Recognition errors) evinced significant decrements at 12 weeks. Mood was not modulated in any interpretable manner. Whilst it is possible that the significant improvements following treatment were due to non-significant numerical differences in performance at baseline, these results would seem to suggest that vitamin/mineral supplementation has the potential to improve brain function in healthy children. This proposition requires further investigation. Adequate levels of vitamins and minerals are essential for the optimal performance of a host of physiological processes that have both direct and indirect effects on brain function, including neurotransmitter synthesis, receptor binding, membrane ion pump function, energy metabolism and cerebral blood flow (1,2) . It is therefore unsurprising that a relationship has been shown to exist, in cross-sectional and prospective studies, between dietary consumption of vitamins and cognitive performance. Much of this research has focused on elderly populations, where positive relationships exist between cognitive performance and either dietary intake, or endogenous levels, of B vitamins (3 -5) and vitamins C and E (6 -8)

We found that mobile phones allowed practical research on cognitive performance in an everyday life setting. Alcohol impaired function in both laboratory and everyday life settings at relevant doses of alcohol.

This study compared administration of performance tests and visual analogue scales (VAS) using a newly developed pen computer (PenC) battery with established tests using either pencil-and-paper (PP) or conventional computer. The performance of 47 subjects (23 male, age 18-45 years, weight 51-112 kg) was compared on the two systems after a dose of ethanol (0.8 g/kg up to a maximum of 60 g for males, 50 g for females) or placebo in a double-blind two-period randomized crossover study. Mean (SD) blood ethanol concentrations (breathalyser) were 94.5 mg/100 ml (21.9) at the start of the test battery (30 min post-drink) and 80.2 (13.0) at the end of the battery (75 min post-drink). Ethanol effects were found in all tests, with most outcome measures showing significant slowing or loss of accuracy. Results from the Rapid Visual Information Processing, Sentence Verification and Continuous Attention tasks show that the ethanol-placebo difference and the statistical significance of this difference are in close correspondence for the two modes of administration. The pen computer versions of these tasks may therefore be used as direct replacements for the previous versions. Digit-Symbol and maze tasks did not correspond so closely both showing differences in the speed-accuracy trade-off between the two modes. These tests, however, are sensitive to the effects of ethanol, and may be useful in their own right. Principal component analysis suggested that VAS may be grouped into two factors: (1) 'functional integrity', including measures of alertness and perceived proficiency, and (2) 'mood', including happiness and sociability. Factor 1 showed substantial effects of ethanol, while factor 2 was unchanged. There was close agreement between the results from PP and PenC for both factors as well as for the Sober-Drunk scale, which showed the expected effects of ethanol. Thus pen computer VAS perform in a similar way to the PP versions.