Beata Y. Silber

Examining the nootropic effects of a special extract of Bacopa monniera on human cognitive functioning: 90 day double-blind placebo-controlled randomized trial.

While Ayurvedic medicine has touted the cognitive enhancing effects of Bacopa monniera for centuries, there is a need for double‐blind placebo‐controlled investigations. One hundred and seven healthy participants were recruited for this double‐blind placebo‐controlled independent group design investigation. Sixty‐two participants completed the study with 80% treatment compliance. Neuropsychological testing using the Cognitive Drug Research cognitive assessment system was conducted at baseline and after 90 days of treatment with a special extract of Bacopa monniera (2 × 150 mg KeenMind) or placebo. The Bacopa monniera product significantly improved performance on the ‘Working Memory’ factor, more specifically spatial working memory accuracy. The number of false‐positives recorded in the Rapid visual information processing task was also reduced for the Bacopa monniera group following the treatment period. The current study provides support for the two other published studies reporting cognitive enhancing effects in healthy humans after a 90 day administration of the Bacopa monniera extract. Further studies are required to ascertain the effective dosage range, the time required to attain therapeutic levels and the effects over a longer term of administration. Copyright

The effects of 90-day supplementation with the omega-3 essential fatty acid docosahexaenoic acid (DHA) on cognitive function and visual acuity in a healthy aging population.

The omega-3 fatty acid docosahexaenoic acid (DHA) is essential for nervous system and retinal development and there is evidence to suggest that DHA deficiencies increase with normal aging. A triple-blind placebo-controlled randomized repeated-measures trial was conducted with 74 healthy participants, aged 45-77 years. Cognitive and visual acuity measures and plasma levels of DHA were determined at baseline and after 90 days of administration of either HiDHA(®) (Clover Corp., Sydney, NSW, Australia: 1000 mg of tuna oil; comprising 252 mg DHA, 60 mg EPA and 10 mg vitamin E) or placebo (1000 mg soybean oil). Ninety days of DHA supplementation was found to significantly raise both plasma DHA and total ω-3 plasma levels in the treatment group, as well as significantly lower total ω-6 levels. However, no significant effects of DHA supplementation on cognitive functioning were found. For participants with corrected vision, the group receiving DHA were found to have significantly better right eye visual acuity posttreatment in comparison with the placebo group (F(1,22) = 7.651; p = 0.011; partial η(2) = 0.258).

The effects of dexamphetamine on simulated driving performance

RationaleThe number of road fatalities related to the presence of amphetamines in drivers has been relatively constant over the past 10 years. However, there remains uncertainty as to the extent that these drugs induce driving impairment, and whether any such impairments translate to an increase in road fatalities.ObjectivesTo examine the acute effects of 0.42 mg/kg dexamphetamine on simulated driving performance, and to establish which, if any, simulated driving abilities become impaired following dexamphetamine administration.MethodsA repeated-measures, counter-balanced, double-blind, placebo-controlled design was employed. Twenty healthy volunteers completed two treatment conditions—0.42 mg/kg dexamphetamine and placebo. Performance was assessed using a driving simulator task. Blood and saliva samples were obtained prior to the driving tasks and immediately after task completion (120 min and 170 min post-drug administration, respectively).ResultsMean dexamphetamine blood concentrations were 83 ng/ml and 98 ng/ml at 120 min and 170 min, respectively. Results indicated a decrease in overall simulated driving ability following dexamphetamine administration during the day-time but not the night-time scenario tasks. Contributing to this performance reduction, “incorrect signalling”, “failing to stop at a red traffic light” and “slow reaction times” were the behaviours most strongly affected by dexamphetamine.ConclusionsThe decrease in simulated driving ability observed during the day-time driving tasks are consistent with the perceptual narrowing or tunnel vision that is associated with dexamphetamine consumption.

Does coffee enriched with chlorogenic acids improve mood and cognition after acute administration in healthy elderly? A pilot study

RationaleCaffeine exerts positive effects on cognitive and behavioral processes, especially in sub-optimal conditions when arousal is low. Apart from caffeine, coffee contains other compounds including the phenolic compounds ferulic acid, caffeic acid, and the chlorogenic acids, which have purported antioxidant properties. The chlorogenic acids are the most abundant family of compounds found in coffee, yet their effects on cognition and mood have not been investigated.ObjectivesThis study aims to ascertain whether a coffee rich in chlorogenic acid modulates brain function.MethodsThe present pilot study examined the acute effects of decaffeinated coffee with regular chlorogenic acid content and decaffeinated coffee with high chlorogenic acid content on mood and cognitive processes, as measured by behavioral tasks and event-related potentials (ERPs). Performance and ERP responses to a battery of cognitive tasks were recorded at baseline and following the equivalent of three cups of coffee in a randomized, double-blind, crossover study of 39 healthy older participants.ResultsCompared with the decaffeinated coffee with regular chlorogenic acid and placebo, caffeinated coffee showed a robust positive effect on higher-level mood and attention processes. To a lesser extent, the decaffeinated coffee high in chlorogenic acid also improved some mood and behavioral measures, relative to regular decaffeinated coffee.ConclusionsOur pilot results suggest that non-caffeine compounds in coffee such as the chlorogenic acids may be capable of exerting some acute behavioral effects, thus warranting further investigation.

Effects of 2G and 3G mobile phones on performance and electrophysiology in adolescents, young adults and older adults.

OBJECTIVE This study examined sensory and cognitive processing in adolescents, young adults and older adults, when exposed to 2nd (2G) and 3rd (3G) generation mobile phone signals. METHODS Tests employed were the auditory 3-stimulus oddball and the N-back. Forty-one 13-15 year olds, forty-two 19-40 year olds and twenty 55-70 year olds were tested using a double-blind cross-over design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days. RESULTS 3-Stimulus oddball task: Behavioural: accuracy and reaction time of responses to targets were not affected by exposure. Electrophysiological: augmented N1 was found in the 2G condition (independent of age group). N-back task: Behavioural: the combined groups performed less accurately during the 3G exposure (compared to Sham), with post hoc tests finding this effect separately in the adolescents only. Electrophysiological: delayed ERD/ERS responses of the alpha power were found in both 3G and 2G conditions (compared to Sham; independent of age group). CONCLUSION Employing tasks tailored to each individuals ability level, this study provides support for an effect of acute 2G and 3G exposure on human cognitive function. SIGNIFICANCE The subtlety of mobile phone effect on cognition in our study suggests that it is important to account for individual differences in future mobile phone research.

A randomised placebo-controlled trial to differentiate the acute cognitive and mood effects of chlorogenic acid from decaffeinated coffee

In the current study, sixty healthy older adults aged 50 years or older, and who were light to moderate coffee drinkers, were administered 6g of a decaffeinated green coffee blend (NESCAFÉ Green Blend coffee; GB) or 540mg pure chlorogenic acids (CGA) or placebo in a double-blind acute cross-over design, with cognitive and mood assessments pre-dose, 40-mins and 120-mins post-dose. The primary outcome measure was accuracy in Rapid Visual Information Processing (RVIP). Secondary cognitive outcome measures included RVIP reaction time as well as Inspection time (IT), Jensen Box decision/reaction times, serial subtraction and N-Back working memory. Secondary mood measures included Bond-Lader and caffeine Research visual analogue scales (VAS). No significant treatment effects were found for the primary outcome measure, although significant effects were found amongst secondary measures. Overall, CGA in isolation was not found to significantly improve cognitive function relative to placebo whereas the GB was found to improve sustained attention as measured by the N-Back task in comparison to placebo overall (t=2.45,p=.05), as well as decision time on a 2-choice reaction time task (Jensen box) in comparison to placebo at 40 minutes post-dose (t=2.45,p=.05). Similarly, GB was found to improve alertness on both the Bond-Lader at 120 minutes relative to CGA (t=2.86, p=0.02) and the caffeine Research VAS relative to CGA (t=3.09, p=0.009) and placebo (t=2.75,p=0.02) at 120 minutes post-dose. Both the GB and CGA were also found to significantly improve symptoms of headache at 120 minutes relative to placebo (t=2.51,p=0.03 and t=2.43,p=.04 respectively), whilst there was a trend towards a reduction in jitteriness with GB and CGA in comparison to placebo at 40 minutes post-dose (t=2.24,p=0.06 and t=2.20,p=0.06 respectively). These findings suggest that the improvements in mood observed with GB, but not the improvements in cognitive function, are likely to some extent to be attributable to CGAs. Trial Registration: Australia New Zealand Clinical Trials Registry ACTRN12611000067976 www.anzctr.org.au

The effect of d-methamphetamine on simulated driving performance

Methamphetamine is considered to be one of the most popularly abused drugs by drivers; however, its exact effect on driving and driving behaviour has yet to be thoroughly investigated. This being despite methamphetamines increased prevalence in injured and deceased drivers.

Effects of a single, oral 60 mg caffeine dose on attention in healthy adult subjects

Caffeine induces positive effects on sustained attention, although studies assessing the acute effects of low caffeine dose (<75 mg) on sustained attention are limited and use short-term tests. Therefore, we investigated the acute effects of a 60 mg dose of caffeine on sustained attention in tests lasting up to 45 minutes using 82 low or non-caffeine-consuming healthy male (n=41) and female (n=41) adults aged between 40 and 60 years. Vigilance was measured using Mackworth Clock test, Rapid Visual Information Processing Test, adaptive tracking test, saccadic eye movement and attention switch test. Effects on mood and fatigue were analysed using Bond and Lader and Caffeine Research visual analogue scales, and Samn–Perelli questionnaire. Saliva sampling was performed for both compliance and caffeine pharmacokinetic analysis. Administration of a 60 mg caffeine dose resulted in a significant improvement in sustained attention compared with the placebo. Also a significantly improved peak saccadic velocity and reaction time performance was found, and decreased error rate. Significantly increased feelings of alertness, contentment and overall mood after caffeine treatment compared with placebo were observed. This study demonstrated that in healthy adult subjects oral administration of a single 60 mg caffeine dose elicited a clear enhancement of sustained attention and alertness, measured both in multiple objective performances and in subjective scales.

The acute effects of d-amphetamine and d-methamphetamine on ERP components in humans

While a number of behavioural studies have been conducted to investigate the acute effects of amphetamines on tasks of attention and information processing, there is currently a scarcity of research concerning their electrophysiological effects in healthy adults. It is also unclear as to whether amphetamines exert effects on stimulus evaluation or response selection. In two studies, independent groups of twenty healthy illicit stimulant users aged between 21 and 32 years were administered 0.42 mg/kg d-amphetamine versus placebo, and 0.42 mg/kg d-methamphetamine versus placebo respectively, and completed an auditory oddball task on two separate testing days. A 62-channel EEG was recorded during the completion of the task, and the effects of amphetamines on N200 and P300 ERP components were analysed. d-amphetamine significantly decreased reaction time, improved accuracy, and reduced the latency of the P300 component relative to placebo, while having no effect on the N200 component. d-methamphetamine had no effect on reaction time, accuracy or the P300 component, but reduced the amplitude of the N200 component, relative to placebo. It was concluded that there is tentative support to suggest that d-amphetamine at a dose of 0.42 mg/kg may enhance speed of information processing while d-methamphetamine at a dose of 0.42 mg/kg may reflect changes to stimulus evaluation.