Cognitive enhancement by drugs in health and disease

Methamphetamine-induced adaptation of learning rate dynamics depend on baseline performance

The ability to calibrate learning according to new information is a fundamental component of an organism's ability to adapt to changing conditions. Yet, the exact neural mechanisms guiding dynamic learning rate adjustments remain unclear. Catecholamines appear to play a critical role in adjusting the degree to which we use new information over time, but individuals vary widely in the manner in which they adjust to changes. Here, we studied the effects of a low dose of methamphetamine (MA), and individual differences in these effects, on probabilistic reversal learning dynamics in a within-subject, double-blind, randomized design. Participants first completed a reversal learning task during a drug-free baseline session to provide a measure of baseline performance. Then they completed the task during two sessions, one with MA (20 mg oral) and one with placebo (PL). First, we showed that, relative to PL, MA modulates the ability to dynamically adjust learning from prediction errors. Second, this effect was more pronounced in participants who performed poorly at baseline. These results present novel evidence for the involvement of catecholaminergic transmission on learning flexibility and highlights that baseline performance modulates the effect of the drug.

Adapting Ourselves, Instead of the Environment: An Inquiry into Human Enhancement for Function and Beyond

Technology enables humans not only to adapt their environment to their needs but also to modify themselves. Means of Human Enhancement - embodied technologies to improve the human body's capabilities or to create a new one - are the designated means of adapting ourselves instead of the environment. The debate about these technologies is typically fought on ethical soil. However, alarmist, utopian, and science fiction scenarios distract from the fact that Human Enhancement is a historical and pervasive phenomenon incorporated into many everyday practices. In the vein of disentangling conceptual difficulties, we claim that means of Human Enhancement are either physiologically or psychologically embodied, rendering the merging with the human user their most defining aspect. To fulfill its purpose, an enhancement must pass the test-in-the-world, i.e., assisting with effective engagement with a dynamic world. Even if failing in this regard: Human Enhancement is the fundamental and semi-targeted process of changing the users relationship with the world through the physical or psychological embodiment of a hitherto external object and/or change of one's body. This can potentially change the notion of being human. Drawing on a rich body of theoretical and empirical literature, we aim to provide a nuanced analysis of the transformative nature of this phenomenon in close proximity to human practice. Stakeholders are invited to apply the theory presented here to interrogate their perspective on technology in general and Human Enhancement in particular.

Assessment of lisdexamfetamine on executive function in rats: A translational cognitive research

Executive function, including working memory, attention and inhibitory control, is crucial for decision making, thinking and planning. Lisdexamfetamine, the prodrug of d-amphetamine, has been approved for treating attention-deficit hyperactivity disorder and binge eating disorder, but whether it improves executive function under non-disease condition, as well as the underlying pharmacokinetic and neurochemical properties, remains unclear. Here, using trial unique non-matching to location task and five-choice serial reaction time task of rats, we found lisdexamfetamine (p.o) enhanced spatial working memory and sustained attention under various cognitive load conditions, while d-amphetamine (i.p) only improved these cognitive performances under certain high cognitive load condition. Additionally, lisdexamfetamine evoked less impulsivity than d-amphetamine, indicating lower adverse effect on inhibitory control. In vivo pharmacokinetics showed lisdexamfetamine produced a relative stable and lasting release of amphetamine base both in plasma and in brain tissue, whereas d-amphetamine injection elicited rapid increase and dramatical decrease in amphetamine base levels. Microdialysis revealed lisdexamfetamine caused lasting release of dopamine within the medial prefrontal cortex (mPFC), whereas d-amphetamine produced rapid increase followed by decline to dopamine level. Moreover, lisdexamfetamine elicited more obvious efflux of noradrenaline than that of d-amphetamine. The distinct neurochemical profiles may be partly attributed to the different action of two drugs to membranous catecholamine transporters level within mPFC, detecting by Western Blotting. Taken together, due to its certain pharmacokinetic and catecholamine releasing profiles, lisdexamfetamine produced better pharmacological action to improving executive function. Our finding provided valuable evidence on the ideal pharmacokinetic and neurochemical characteristics of amphetamine-type psychostimulants in cognition enhancement.

Acetylcholine and metacognition during sleep

Acetylcholine is a neurotransmitter and neuromodulator involved in a variety of cognitive functions. Additionally, acetylcholine is involved in the regulation of REM sleep: cholinergic neurons in the brainstem and basal forebrain project to and innervate wide areas of the cerebral cortex, and reciprocally interact with other neuromodulatory systems, to produce the sleep-wake cycle and different sleep stages. Consciousness and cognition vary considerably across and within sleep stages, with metacognitive capacity being strikingly reduced even during aesthetically and emotionally rich dream experiences. A notable exception is the phenomenon of lucid dreaming-a rare state whereby waking levels of metacognitive awareness are restored during sleep-resulting in individuals becoming aware of the fact that they are dreaming. The role of neurotransmitters in these fluctuations of consciousness and cognition during sleep is still poorly understood. While recent studies using acetylcholinesterase inhibitors suggest a potential role of acetylcholine in the occurrence of lucid dreaming, the underlying mechanisms by which this effect is produced remains un-modelled and unknown; with the causal link between cholinergic mechanisms and upstream psychological states being complex and elusive. Several theories and approaches targeting the association between acetylcholine and metacognition during wakefulness and sleep are highlighted in this review, moving through microscopic, mesoscopic and macroscopic levels of analysis to detail this phenomenon at several organisational scales. Several exploratory hypotheses will be developed to guide future research towards fully articulating how metacognition is affected by activity at the acetylcholine receptor.

Phenolic Derivatives with Anti-Acetylcholinesterase Inhibitory Activities from Galeola nudifolia in Vietnam

A new phenolic derivative, galeomalate A (1), together with five known structurally related compounds (2-6), was isolated from the ethyl acetate extract of Galeola nudifolia collected in Vietnam. The structures were elucidated by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-TOF-MS, and CD data, and chemical conversion of the sugar moiety. All isolated compounds possessed acetylcholinesterase (AChE) inhibitory activities in a dose-dependent manner. Among them, compounds 2 and 3 exhibited the first and second highest inhibitory activity on AChE with IC50 values of 122.13 and 125.49 μM, respectively. Compounds 1 and 4-6 inhibited the AChE activity by mixed modes of action comprising competitive and non-competitive modes, whereas 2 and 3 exerted their inhibitory activities in a competitive manner. Molecular docking analyses suggested that the phenyl-β-D-glucopyranoside unit of 2 and 3 bound to the active site of AChE for the competitive inhibitory activities, while the mixed inhibitory activity of 4 was due to the two binding patterns in the active-site and the active-site entrance of AChE. Furthermore, the docking studies indicated that 1, 5, and 6 would inhibit AChE in a mixed inhibitory manner by adopting three distinct binding patterns of the additional phenyl-β-D-glucopyranoside unit at the active-site entrance.

Pharmacokinetics of Novel Dopamine Transporter Inhibitor CE-123 and Modafinil with a Focus on Central Nervous System Distribution

S-CE-123, a novel dopamine transporter inhibitor, has emerged as a potential candidate for cognitive enhancement. The objective of this study was to compare the tissue distribution profiles, with a specific focus on central nervous system distribution and metabolism, of S-CE-123 and R-modafinil. To address this objective, a precise liquid chromatography-high resolution mass spectrometry method was developed and partially validated. Neuropharmacokinetic parameters were assessed using the Combinatory Mapping Approach. Our findings reveal distinct differences between the two compounds. Notably, S-CE-123 demonstrates a significantly superior extent of transport across the blood-brain barrier (BBB), with an unbound brain-to-plasma concentration ratio (Kp,uu,brain) of 0.5, compared to R-modafinil's Kp,uu,brain of 0.1. A similar pattern was observed for the transport across the blood-spinal cord barrier. Concerning the drug transport across cellular membranes, we observed that S-CE-123 primarily localizes in the brain interstitial space, whereas R-modafinil distributes more evenly across both sides of the plasma membrane of the brain's parenchymal cells (Kp,uu,cell). Furthermore, our study highlights the substantial differences in hepatic metabolic stability, with S-CE-123 having a 9.3-fold faster metabolism compared to R-modafinil. In summary, the combination of improved BBB transport and higher affinity of S-CE-123 to dopamine transporters in comparison to R-modafinil makes S-CE-123 a promising candidate for further testing for the treatment of cognitive decline.

Acetylcholine and noradrenaline enhance foraging optimality in humans

Foraging theory prescribes when optimal foragers should leave the current option for more rewarding alternatives. Actual foragers often exploit options longer than prescribed by the theory, but it is unclear how this foraging suboptimality arises. We investigated whether the upregulation of cholinergic, noradrenergic, and dopaminergic systems increases foraging optimality. In a double-blind, between-subject design, participants (N = 160) received placebo, the nicotinic acetylcholine receptor agonist nicotine, a noradrenaline reuptake inhibitor reboxetine, or a preferential dopamine reuptake inhibitor methylphenidate, and played the role of a farmer who collected milk from patches with different yield. Across all groups, participants on average overharvested. While methylphenidate had no effects on this bias, nicotine, and to some extent also reboxetine, significantly reduced deviation from foraging optimality, which resulted in better performance compared to placebo. Concurring with amplified goal-directedness and excluding heuristic explanations, nicotine independently also improved trial initiation and time perception. Our findings elucidate the neurochemical basis of behavioral flexibility and decision optimality and open unique perspectives on psychiatric disorders affecting these functions.

On pharmacological neuroenhancement as part of the new neurorights' pioneering legislation in Chile: a perspective

The so-called neurorights are emerging human rights, or rather reconfigurations of already existing human rights, seeking to address the impact of the possible misuse of neurotechnologies, which have the potential to become more invasive and harmful in the future if not regulated. The aim of specifying neurorights is to protect the dignity and autonomy of the individual in the face of neurotechnological advances. Recently, Chile proposed a Constitutional reform inspired by the neurorights, opening a debate. One of the proposed neurorights is fair and equitable access to cognitive enhancement, which will be the specific object of this perspective article. Starting from the legal proposal, we analyse and discuss some perspectives on cognitive enhancement, or "neuroenhancement", which could be considered as part of enhancement neurotechnologies, pointing out that pharmacological enhancers, or "smart drugs", might be considered as part of these enhancers. We present a classification of the different types of cognitive enhancements as it has been proposed in the literature, into which pharmacological cognitive enhancement can be included, concluding that there is currently no agreement amongst scholars and lawyers about the ethical consideration of pharmacological cognitive enhancement. We therefore argue that it is necessary for the legislator to explicitly address the issue in the proposed regulations, in order to take a clear position on the topic, as it has been done in the United Kingdom, where the pharmacological neuroenhancers have been explicitly excluded from the regulation. If pharmacological neuroenhancers are going to be considered neurotechnologies, then new law proposals should seek harmonization with the already existing legislation regulating pharmacological health and consumer rights (both globally, taking into account international drug laws, and locally, according to each country's internal regulations) and of course, with the whole system of fundamental rights. Finally, we briefly discuss the ethical problem of equitable access to this new type of neurotechnologies (as part of the neurorights) and leave the debate open for new insights from the scientific community on the possible consequences of including (or not) pharmacological neuroenhancers as neurotechnologies for cognitive enhancement in the framework of the ethical and legal debate.

Turning the Spotlight to Cholinergic Pharmacotherapy of the Human Language System

Even though language is essential in human communication, research on pharmacological therapies for language deficits in highly prevalent neurodegenerative and vascular brain diseases has received little attention. Emerging scientific evidence suggests that disruption of the cholinergic system may play an essential role in language deficits associated with Alzheimer's disease and vascular cognitive impairment, including post-stroke aphasia. Therefore, current models of cognitive processing are beginning to appraise the implications of the brain modulator acetylcholine in human language functions. Future work should be directed further to analyze the interplay between the cholinergic system and language, focusing on identifying brain regions receiving cholinergic innervation susceptible to modulation with pharmacotherapy to improve affected language domains. The evaluation of language deficits in pharmacological cholinergic trials for Alzheimer's disease and vascular cognitive impairment has thus far been limited to coarse-grained methods. More precise, fine-grained language testing is needed to refine patient selection for pharmacotherapy to detect subtle deficits in the initial phases of cognitive decline. Additionally, noninvasive biomarkers can help identify cholinergic depletion. However, despite the investigation of cholinergic treatment for language deficits in Alzheimer's disease and vascular cognitive impairment, data on its effectiveness are insufficient and controversial. In the case of post-stroke aphasia, cholinergic agents are showing promise, particularly when combined with speech-language therapy to promote trained-dependent neural plasticity. Future research should explore the potential benefits of cholinergic pharmacotherapy in language deficits and investigate optimal strategies for combining these agents with other therapeutic approaches.

The costs and benefits of psychedelics on cognition and mood

Anecdotal evidence has indicated that psychedelic substances may acutely enhance creative task performance, although empirical support for this claim is mixed at best. Clinical research has shown that psychedelics might have enduring effects on mood and well-being. However, there is no neurocognitive framework that ties acute changes in cognition to long-term effects in mood. In this review, we operationalize creativity within an emerging cognitive control framework and assess the current empirical evidence of the effects of psychedelics on creativity. Next, we leverage insights about the mechanisms and computations by which other psychoactive drugs act to enhance versus impair cognition, in particular to those that act on catecholamines, the neurophysiological consequences of which are relatively well understood. Finally, we use the same framework to link the suggested psychedelic-induced improvements in creativity with enduring psychedelic-induced improvements in mood.

Evaluating the Effects of Rivastigmine on Decision-Making in Patients with Mild Cognitive Impairment by Cambridge Neuropsychological Test Automated Battery (CANTAB); A Randomized, Double-Blind, Placebo-Controlled Trial

Background

Decision-making is a complex process, and most studies showed that patients with mild cognitive impairment (MCI) make worse decisions than healthy people.

Objectives

This study aims to evaluate the effect of rivastigmine on the decision-making of MCI patients using the Cambridge Neuropsychological Test Automated Battery (CANTAB) tests.

Methods

The study was conducted at the Roozbeh Hospital neurology clinic, and 30 patients with mild cognitive impairment over 40 years old were randomly recruited to receive rivastigmine or placebo twice daily for 12 weeks. The initial dose of rivastigmine or placebo was 1.5 mg twice daily and was increased to 3 mg twice daily per patient compliance. A CANTAB test was conducted before and following the intervention.

Results

The mean age of patients in the rivastigmine group was 58.93 ± 10.88, and in the placebo group was 59.33 ± 10.34. The median MMSE (Mini-Mental State Examination) was 26 (IQR = 25 - 26) in both groups. Patients in the rivastigmine group showed significant differences in all subgroup tests of CGT, IST, and SST except in risk adjustment in the CGT test, discrimination in the IST test, and median correct RT on the go trial and SSRT in the SST test. The most commonly reported adverse effects were gastrointestinal complications.

Conclusions

According to the results, rivastigmine significantly improved the primary decision-making outcomes in comparison with placebo.

Hippo-released WWC1 facilitates AMPA receptor regulatory complexes for hippocampal learning

Learning and memory rely on changes in postsynaptic glutamergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type receptor (AMPAR) number, spatial organization, and function. The Hippo pathway component WW and C2 domain-containing protein 1 (WWC1) regulates AMPAR surface expression and impacts on memory performance. However, synaptic binding partners of WWC1 and its hierarchical position in AMPAR complexes are largely unclear. Using cell-surface proteomics in hippocampal tissue of Wwc1-deficient mice and by generating a hippocampus-specific interactome, we show that WWC1 is a major regulatory platform in AMPAR signaling networks. Under basal conditions, the Hippo pathway members WWC1 and large tumor-suppressor kinase (LATS) are associated, which might prevent WWC1 effects on synaptic proteins. Reduction of WWC1/LATS binding through a point mutation at WWC1 elevates the abundance of WWC1 in AMPAR complexes and improves hippocampal-dependent learning and memory. Thus, uncoupling of WWC1 from the Hippo pathway to AMPAR-regulatory complexes provides an innovative strategy to enhance synaptic transmission.

Assessment of knowledge, perception, attitude, and use of performance-enhancing substances among students of Faculty of Medicine, Alexandria University, Egypt: a pilot study

Background

The market for performance enhancement substances (PESs) is currently one of the fastest expanding sectors. Most studies have always concentrated on athletes in terms of PESs’ misuse, ignoring a critical segment of the community: the future health-care workers. Thus, the aim of the study was to probe the knowledge, perception, and attitude of medical students regarding the misuse of PESs in sports and medical academic study. A cross-sectional study was conducted among students of Alexandria Faculty of Medicine, Egypt. Data were collected via self-administered electronic survey from 208 students of both sexes (aged from 18 to 26 years old). Analysis of factors affecting the consumption of PESs like gender differences, and their prior knowledge and perception was performed using logistic regression models.

Results

More than half of the participants have no idea about law concerning the use of doping substances. There were no significant disparities in knowledge and perception between males and females. Female students, on the other hand, consistently reported having a better understanding of the negative impacts of PESs’ misuse. Surprisingly, females are more prone to consume PESs for cognitive enhancement rather than the physical performance.

Conclusions

The study is the first to explore the awareness of the medical students, their attitude, and perception towards different ethical scenarios confronted in the daily practice. This finding pinpoints that the common trend of striving for fitness and an ideal body shape and weight has produced a shift in the prevalence of the PESs use according to gender in Egypt. Moreover, females in medicine academics are more prone to use PESs to improve the cognitive functions albeit it is nonsignificant statistically. Therefore, efforts should be directed to raise the awareness of medical practitioners of diverse categories of these substances, health hazards, laws, and penalties. More importantly, policy measures for their production, marketing, and misuse among university students should be reconsidered by the government.

Autonomy, procedural and substantive: a discussion of the ethics of cognitive enhancement

As cognitive enhancement research advances, important ethical questions regarding individual autonomy and freedom are raised. Advocates of cognitive enhancement frequently adopt a procedural approach to autonomy, arguing that enhancers improve an individual's reasoning capabilities, which are quintessential to being an autonomous agent. On the other hand, critics adopt a more nuanced approach by considering matters of authenticity and self-identity, which go beyond the mere assessment of one's reasoning capacities. Both positions, nevertheless, require further philosophical scrutiny. In this paper, we investigate the ethics of cognitive enhancement through the lenses of political and philosophical arguments about autonomy and freedom. In so doing, we contend that a substantive, relational account of individual autonomy offers a more holistic understanding of the ethical concerns of cognitive enhancement.

Pharmacological targeting of cognitive impairment in depression: recent developments and challenges in human clinical research

Impaired cognition is often overlooked in the clinical management of depression, despite its association with poor psychosocial functioning and reduced clinical engagement. There is an outstanding need for new treatments to address this unmet clinical need, highlighted by our consultations with individuals with lived experience of depression. Here we consider the evidence to support different pharmacological approaches for the treatment of impaired cognition in individuals with depression, including treatments that influence primary neurotransmission directly as well as novel targets such as neurosteroid modulation. We also consider potential methodological challenges in establishing a strong evidence base in this area, including the need to disentangle direct effects of treatment on cognition from more generalised symptomatic improvement and the identification of sensitive, reliable and objective measures of cognition.

Striatal dopamine dissociates methylphenidate effects on value-based versus surprise-based reversal learning

Psychostimulants such as methylphenidate are widely used for their cognitive enhancing effects, but there is large variability in the direction and extent of these effects. We tested the hypothesis that methylphenidate enhances or impairs reward/punishment-based reversal learning depending on baseline striatal dopamine levels and corticostriatal gating of reward/punishment-related representations in stimulus-specific sensory cortex. Young healthy adults (N = 100) were scanned with functional magnetic resonance imaging during a reward/punishment reversal learning task, after intake of methylphenidate or the selective D_2/3-receptor antagonist sulpiride. Striatal dopamine synthesis capacity was indexed with [¹⁸F]DOPA positron emission tomography. Methylphenidate improved and sulpiride decreased overall accuracy and response speed. Both drugs boosted reward versus punishment learning signals to a greater degree in participants with higher dopamine synthesis capacity. By contrast, striatal and stimulus-specific sensory surprise signals were boosted in participants with lower dopamine synthesis. These results unravel the mechanisms by which methylphenidate gates both attention and reward learning.

The mechanisms underpinning the variability in methylphenidate’s effects on cognition remain unclear. Here, the authors show that such effects reflect changes in striatal dopamine-related output gating of task-relevant cortical signals, and that these changes depend on baseline dopamine synthesis capacity.

Neuroprotective Effect of Morin Hydrate against Attention-Deficit/Hyperactivity Disorder (ADHD) Induced by MSG and/or Protein Malnutrition in Rat Pups: Effect on Oxidative/Monoamines/Inflammatory Balance and Apoptosis

Monosodium glutamate (MSG) is one of the most widely used food additives. However, it has been linked to protein malnutrition (PM) and various forms of toxicities such as metabolic disorders and neurotoxic effects. The current study is the first to explore the association between MSG, PM, and induced brain injury similar to attention-deficit/hyperactivity disorder (ADHD). Moreover, we determined the underlying mechanistic protective pathways of morin hydrate (MH)―a natural flavonoid with reported multiple therapeutic properties. PM was induced by feeding animals with a low protein diet and confirmed by low serum albumin measurement. Subsequently, rat pups were randomized into seven groups of 10 rats each. Group I, III, and VI were normally fed (NF) and groups II, IV, V, and VII were PM fed. Group I served as normal control NF while Group II served as PM control animals. Group III received NF + 0.4 g/kg MSG, Group IV: PM + 0.4 g/kg MSG, Group V: PM + 60 mg/kg MH, Group VI: NF + 0.4 kg/g MSG + 60 mg/kg MH and Group VII: PM + 0.4 kg/kg MSG + 60 mg/kg MH. At the end of the experimental period, animals were subjected to behavioral and biochemical tests. Our results showed that treatment of rats with a combination of MSG + PM-fed exhibited inferior outcomes as evidenced by deteriorated effects on behavioral, neurochemical, and histopathological analyses when compared to rats who had received MSG or PM alone. Interestingly, MH improved animals’ behavior, increased brain monoamines, brain-derived neuroprotective factor (BDNF), antioxidant status and protein expression of Nrf2/HO-1. This also was accompanied by a significant decrease in brain MDA, inflammatory markers (NF-kB, TNF-α and IL1β), and suppression of TLR4/NLRP3/caspase-1 axis. Taken together, MSG and/or PM are associated with neuronal dysfunction. Our findings suggest MH as a potential neuroprotective agent against brain insults via targeting Nrf2/HO-1 and hindering TLR4/NLRP3 inflammasome signaling pathways.

Cognitive and neuropsychiatric effects of noradrenergic treatment in Alzheimer's disease: systematic review and meta-analysis

BACKGROUND

Dysfunction of the locus coeruleus-noradrenergic system occurs early in Alzheimer's disease, contributing to cognitive and neuropsychiatric symptoms in some patients. This system offers a potential therapeutic target, although noradrenergic treatments are not currently used in clinical practice.

OBJECTIVE

To assess the efficacy of drugs with principally noradrenergic action in improving cognitive and neuropsychiatric symptoms in Alzheimer's disease.

METHODS

The MEDLINE, Embase and ClinicalTrials.gov databases were searched from 1980 to December 2021. We generated pooled estimates using random effects meta-analyses.

RESULTS

We included 19 randomised controlled trials (1811 patients), of which six were judged as 'good' quality, seven as 'fair' and six 'poor'. Meta-analysis of 10 of these studies (1300 patients) showed a significant small positive effect of noradrenergic drugs on global cognition, measured using the Mini-Mental State Examination or Alzheimer's Disease Assessment Scale-Cognitive Subscale (standardised mean difference (SMD): 0.14, 95% CI: 0.03 to 0.25, p=0.01; I2=0%). No significant effect was seen on measures of attention (SMD: 0.01, 95% CI: -0.17 to 0.19, p=0.91; I2=0). The apathy meta-analysis included eight trials (425 patients) and detected a large positive effect of noradrenergic drugs (SMD: 0.45, 95% CI: 0.16 to 0.73, p=0.002; I2=58%). This positive effect was still present following removal of outliers to account for heterogeneity across studies.

DISCUSSION

Repurposing of established noradrenergic drugs is most likely to offer effective treatment in Alzheimer's disease for general cognition and apathy. However, several factors should be considered before designing future clinical trials. These include targeting of appropriate patient subgroups and understanding the dose effects of individual drugs and their interactions with other treatments to minimise risks and maximise therapeutic effects.

PROSPERO REGISTERATION NUMBER

CRD42021277500.

Intelligenzsteigerung durch Neuroenhancement?

Zusammenfassung. Die menschliche Intelligenz gehört zu den bestuntersuchten psychologischen Merkmalen, in denen interindividuelle Differenzen bestehen. Die mehr als 100jährige Forschungsgeschichte hat einen hoch belastbaren Wissensstand hervorgebracht; dieser umfasst die Definition, die Psychometrie, die (ontogenetische) Entwicklung, die Struktur, die Vorhersagekraft für real-life-Variablen, das Wissen über elementar-kognitive, verhaltensgenetische und neurobiologische Grundlagen der Intelligenz, u.v.m. Jüngst steht zudem die Frage des ‚enhancements‘ der Intelligenz im Fokus, eine Frage, die nicht zuletzt durch die aktuelle philosophische Strömung des Transhumanismus stark an Bedeutung gewinnt. Der Transhumanismus nimmt eine substanzielle Erhöhung (enhancement) von Fähigkeiten und anderen (auch) psychologischen Eigenschaften des Menschen ins Zentrum und postuliert, dass ein soziokultureller Fortschritt – und letztlich das Überlegen des Homo Sapiens und unseres Planeten – erst durch technologischen Fortschritt ermöglicht werde. Viele Transhumanisten stellen eine substanzielle Steigerung der Intelligenz in den Vordergrund, die primär durch (neuro–)‌technologische und pharmakologische Maßnahmen zu bewerkstelligen seien. Diese Debatten sind jedoch oft gekennzeichnet durch übertrieben optimistische Annahmen der Möglichkeiten moderner neurowissenschaftlicher Methoden bei gleichzeitiger Vernachlässigung der potenziellen negativen Folgen für das Individuum, für die Gesellschaften und insgesamt für unsere Spezies. Im gegenständlichen Überblicksbeitrag werden behaviorale, neuroelektrische und pharmakologische Methoden im Hinblick auf ihr aktuelles Potenzial einer Steigerung der individuellen Intelligenz analysiert. Die zwischenzeitlich zu diesen Fragen vorliegenden experimentellen Studien, sowie verfügbare Metaanalysen lassen allerdings den Schluss zu, dass bislang keine der gegenwärtig verfügbaren Methoden das Potenzial haben, die individuelle Intelligenz substanziell zu steigern. Und selbst falls solche möglicherweise in absehbarer Zeit zur Verfügung stünden, müssen zuvor sowohl individuelle als auch gesellschaftliche (negative) Konsequenzen einer kritischen Analyse unterzogen werden. Diese sind Gegenstand einer abschließenden Diskussion.

Meta-analysis: Dose-Dependent Effects of Methylphenidate on Neurocognitive Functioning in Children With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Neurocognitive deficits are at the heart of explanatory models of attention-deficit/hyperactivity disorder (ADHD), and lead to significant impairments in daily life. Determining the dosing effects of methylphenidate (MPH) on a broad range of neurocognitive functions and investigating possible impairing effects of high doses is therefore important.

METHOD

Placebo-controlled trials were included that investigated MPH dosing effects on neurocognitive functions in children and adolescents (aged 5-18 years) diagnosed with ADHD. Effect sizes (standardized mean differences [SMDs]) were calculated for different neurocognitive functions (baseline speed, variability in responding, nonexecutive memory and executive memory, inhibitory control, and cognitive flexibility) and, if available, for ADHD symptoms. Meta-regression analysis were used to investigate linear effects of dose (mg/kg/dose), and separate meta-analyses compared SMDs for 3 MPH dose ranges: low (0.10-0.30 mg/kg/dose), medium (0.31-0.60 mg/kg/dose), and high (0.61-1.00 mg/kg/dose).

RESULTS

A total of 31 studies fulfilled inclusion criteria, comprising 804 children with ADHD. Methylphenidate had beneficial effects on all neurocognitive functions (d = 0.20-0.73). Significant linear dosing effects were found for ADHD symptoms and lower-order neurocognitive functions (baseline speed, variability in responding, nonexecutive memory), with greater enhancement of functioning with increasing dose. No dosing effects were found for higher-order neurocognitive functions (executive memory, inhibitory control, and cognitive flexibility). No detrimental effects of MPH were found on any of the investigated functions.

CONCLUSION

Methylphenidate was superior to placebo in improving ADHD symptoms and a broad range of neurocognitive functions; however, effects sizes regarding the effects of dose vary substantially between functions. Our data highlight the importance of considering both neurocognitive and symptomatic aspects of ADHD in clinical practice.

Cholinergic neurotransmitter system: a potential marker for post-stroke cognitive recovery

This scientific commentary refers to ‘Cholinergic and hippocampal systems facilitate cross-domain cognitive recovery after stroke’ by O’Sullivan et al. (https://doi.org/10.1093/brain/awac070).

New approaches for the quantification and targeting of noradrenergic dysfunction in Alzheimer's disease

There is clear, early noradrenergic dysfunction in Alzheimer's disease. This is likely secondary to pathological tau deposition in the locus coeruleus, the pontine nucleus that produces and releases noradrenaline, prior to involvement of cortical brain regions. Disruption of noradrenergic pathways affects cognition, especially attention, impacting memory and broader functioning. Additionally, it leads to autonomic and neuropsychiatric symptoms. Despite the strong evidence of noradrenergic involvement in Alzheimer's, there are no clear trial data supporting the clinical use of any noradrenergic treatments. Several approaches have been tried, including proof-of-principle studies and (mostly small scale) randomised controlled trials. Treatments have included pharmacotherapies as well as stimulation. The lack of clear positive findings is likely secondary to limitations in gauging locus coeruleus integrity and dysfunction at an individual level. However, the recent development of several novel biomarkers holds potential and should allow quantification of dysfunction. This may then inform inclusion criteria and stratification for future trials. Imaging approaches have improved greatly following the development of neuromelanin-sensitive sequences, enabling the use of structural MRI to estimate locus coeruleus integrity. Additionally, functional MRI scanning has the potential to quantify network dysfunction. As well as neuroimaging, EEG, fluid biomarkers and pupillometry techniques may prove useful in assessing noradrenergic tone. Here, we review the development of these biomarkers and how they might augment clinical studies, particularly randomised trials, through identification of patients most likely to benefit from treatment. We outline the biomarkers with most potential, and how they may transform symptomatic therapy for people living with Alzheimer's disease.

Assessing prevalence, knowledge and use of cognitive enhancers among university students in the United Arab Emirates: A quantitative study

BACKGROUND

Cognitive enhancers (CE) are often used to improve memory, alertness and cognitive capacity. These products are commercially and pharmaceutically available. Due to high academic pressure, university students are at risk of CE misuse. However, data regarding this issue are limited, especially in the United Arab Emirates (UAE).

AIMS

To assess the prevalence of CE intake; evaluate students' knowledge of these substances; and identify student characteristics associated with CE usage.

METHOD

A cross sectional study based on a validated online survey that was distributed using university-licensed software (Qualtrics) as a direct web link via email and social media to all Medical, Pharmacy, Dentistry, Nursing and Engineering students enrolled in six UAE universities. Associations between student characteristics and CE use were investigated using the chi-squared test and multiple logistic regression. Reasons for CE use, temporal patterns of use, details regarding purchase and types of CE used were compared by gender.

RESULTS

One quarter of students had used CEs. There was a clear difference between users and non-users in terms of gender (p<0.001). CE users were disproportionately represented by students from either UAE or other Arab countries (p<0.001), and by students of Medicine, followed by Pharmacy, Dentistry, and Engineering (p<0.001). CE use increased with year of study, reaching the highest level in the fourth year (p<0.001), which for most programmes is the final year. Modafinil was self-administered, especially in males, for concentration and alertness; B12 was typically taken by female students for academic performance and concentration; and high-dosage caffeine compounds were ingested to improve alertness levels. Use of the internet for both obtaining information and purchasing CEs was frequently reported. Multiple logistic regression analysis showed that gender, nationality, and year of study were associated with CE use among UAE university students.

CONCLUSIONS

Universities need to address the prevalence of CE use amongst their students by providing effective support programs.

Effects of Lisdexamfetamine, a Prodrug of D-Amphetamine, on Locomotion, Spatial Cognitive Processing and Neurochemical Profiles in Rats: A Comparison With Immediate-Release Amphetamine

D-amphetamine has been used to enhance cognitive performance over the last few decades. Due to the rapid absorption after administration, d-amphetamine shows narrow effective window and severe abuse potential. Lisdexamfetamine, a prodrug of d-amphetamine, reduces the magnitude of plasma d-amphetamine concentration and prolongs the action duration when compared with immediate-release d-amphetamine at equimolar doses. However, the differences of these two drugs, which produce distinct pharmacokinetic characteristics, in cognition improvement still unclear. In present study, we compared the effects of d-amphetamine (i.p) and lisdexamfetamine (p.o) at equimolar doses (0.2, 0.5, 1.5, 4.5, and 13.5 mg/kg of d-amphetamine base) on locomotion, spatial working memory and recognition memory in rats. Given the crucial involvement of dopamine neurotransmitter system within the medial prefrontal cortex (mPFC) in cognitive processing, microdialysis was conducted to profile the difference in neurochemical characteristics between the two drugs. In our results, d-amphetamine ranges from 0.5 to 1.5 mg/kg significantly increased locomotor activity. However, d-amphetamine ranges from 0.2 to 13.5 mg/kg failed to improve spatial working memory and recognition memory in Y-maze-based spontaneous alternation and two-trial delayed alternation tasks of rats, respectively. In contrast, lisdexamfetamine with 4.5 mg/kg significantly increased the locomotion and improved both spatial working and recognition memory. Further, microdialysis showed that lisdexamfetamine induced lower magnitude and longer duration of extracellular dopamine increase than that of d-amphetamine. These results suggest that lisdexamfetamine was more effective than d-amphetamine in improving spatial cognitive performance, which was attributed to the steady and lasting dopamine release pattern within the mPFC.

Commercial Brain Training: Efficacy, Transfer Effects, and the Influence of Personality Traits: A Study Conducted on Healthy Young Adults

In the present study, we investigated the effects of a four-week working memory (WM) and attention training program using commercial brain training (Synaptikon GmbH, Berlin). Sixty young healthy adults were assigned to the experimental and active control training programs. The training was conducted in a naturalistic home-based setting, while the pre- and post-examinations were conducted in a controlled laboratory setting. Transfer effects to an untrained WM task and to an untrained episodic memory task were examined. Furthermore, possible influences of personality, i.e., the five-factor model (FFM) traits and need for cognition (NFC), on training outcomes were examined. Additionally, the direct relationship between improvement in single trained tasks and improvement in the transfer tasks was investigated. Our results showed that both training groups significantly increased performance in the WM task, but only the WM training group increased their performance in the episodic memory transfer task. One of the training tasks, a visuospatial WM task, was particularly associated with improvement in the episodic memory task. Neuroticism and conscientiousness showed differential effects on the improvement in training and transfer tasks. It needs to be further examined whether these effects represent training effects or, for example, retest/practice or motivation effects.

Stimulant Usage by Medical Students for Cognitive Enhancement: A Systematic Review

Stimulants have been used throughout human history for a variety of reasons. High levels of stress and the demanding nature of medical school make their usage among medical students particularly common. The most prevalent stimulant used by students is coffee, followed by tea and other forms of caffeine like sugary energy drinks. In addition, amphetamine-based medications for treating attention deficit hyperactivity disorder (ADHD) have been increasing in popularity, which many students take illicitly. Students report taking various forms of stimulants to promote cognitive enhancement, prolong wakefulness and retain focus for long periods of time. Moderate doses of caffeine and amphetamines would lead to enhanced alertness and concentration. However, large increases in dosage or frequency would lead to an increased risk of toxicity and adverse effects. The positive outcomes from stimulant consumption are often overshadowed by the negative side effects and incorrect dosage. Thus, it appears that usage of stimulants should be limited, in favor of a more sustainable approach to cognitive enhancement. This review analyzes the use of stimulants among the medical student community, consequences of misuse and discussed the healthy and organic approaches to lessen the stress and improve academic performance. This article also discusses the mechanisms of action, acceptable doses, additives, ingredients of stimulants commonly used by medical students for cognitive enhancement and the implications of long-term use as the stress of practicing medicine extends well beyond the medical school years.

Cognition in the Chronic Pain Experience: Preclinical Insights

Acutely, pain is protective. It promotes escape from, and future avoidance of, noxious stimuli through strong and often lifetime associative memories. However, with persistent acute pain or when pain becomes chronic, these memories can promote negative emotions and poor decisions often associated with deleterious behaviors. In this review, we discuss how preclinical studies can provide insights into the relationship between cognition and chronic pain. We also discuss the concept of pain as a cognitive disorder and new strategies for treating chronic pain that emphasize inhibiting the formation of pain memories or promoting 'forgetting' of established pain memories.

The Use and Impact of Cognitive Enhancers among University Students: A Systematic Review

INTRODUCTION

Cognitive enhancers (CEs), also known as "smart drugs", "study aids" or "nootropics" are a cause of concern. Recent research studies investigated the use of CEs being taken as study aids by university students. This manuscript provides an overview of popular CEs, focusing on a range of drugs/substances (e.g., prescription CEs including amphetamine salt mixtures, methylphenidate, modafinil and piracetam; and non-prescription CEs including caffeine, cobalamin (vitamin B12), guarana, pyridoxine (vitamin B6) and vinpocetine) that have emerged as being misused. The diverted non-prescription use of these molecules and the related potential for dependence and/or addiction is being reported. It has been demonstrated that healthy students (i.e., those without any diagnosed mental disorders) are increasingly using drugs such as methylphenidate, a mixture of dextroamphetamine/amphetamine, and modafinil, for the purpose of increasing their alertness, concentration or memory.

AIM

To investigate the level of knowledge, perception and impact of the use of a range of CEs within Higher Education Institutions.

METHODOLOGY

A systematic review was conducted in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Whilst 1400 studies were identified within this study through a variety of electronic databases (e.g., 520 through PubMed, 490 through Science Direct and 390 through Scopus), 48 papers were deemed relevant and were included in this review.

RESULTS

The most popular molecules identified here included the stimulant CEs, e.g., methylphenidate, modafinil, amphetamine salt mixtures and caffeine-related compounds; stimulant CEs' intake was more prevalent among males than females; drugs were largely obtained from friends and family, as well as via the Internet. It is therefore suggested that CEs are increasingly being used among healthy individuals, mainly students without any diagnosed cognitive disorders, to increase their alertness, concentration, or memory, in the belief that these CEs will improve their performance during examinations or when studying. The impact of stimulant CEs may include tolerance, dependence and/or somatic (e.g., cardiovascular; neurological) complications.

DISCUSSION

The availability of CEs for non-medical indications in different countries is influenced by a range of factors including legal, social and ethical factors. Considering the risk factors and motivations that encourage university students to use CE drugs, it is essential to raise awareness about CE-related harms, counteract myths regarding "safe" CE use and address cognitive enhancement in an early stage during education as a preventative public health measure.

Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives

Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, β-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.

Adjunctive Approaches to Aphasia Rehabilitation: A Review on Efficacy and Safety

Aphasia is one of the most socially disabling post-stroke deficits. Although traditional therapies have been shown to induce adequate clinical improvement, aphasic symptoms often persist. Therefore, unconventional rehabilitation techniques which act as a substitute or as an adjunct to traditional approaches are urgently needed. The present review provides an overview of the efficacy and safety of the principal approaches which have been proposed over the last twenty years. First, we examined the effectiveness of the pharmacological approach, principally used as an adjunct to language therapy, reporting the mechanism of action of each single drug for the recovery of aphasia. Results are conflicting but promising. Secondly, we discussed the application of Virtual Reality (VR) which has been proven to be useful since it potentiates the ecological validity of the language therapy by using virtual contexts which simulate real-life everyday contexts. Finally, we focused on the use of Transcranial Direct Current Stimulation (tDCS), both discussing its applications at the cortical level and highlighting a new perspective, which considers the possibility to extend the use of tDCS over the motor regions. Although the review reveals an extraordinary variability among the different studies, substantial agreement has been reached on some general principles, such as the necessity to consider tDCS only as an adjunct to traditional language therapy.

A role for 5-HT4 receptors in human learning and memory

BACKGROUND

5-HT4 receptor stimulation has pro-cognitive and antidepressant-like effects in animal experimental studies; however, this pharmacological approach has not yet been tested in humans. Here we used the 5-HT4 receptor partial agonist prucalopride to assess the translatability of these effects and characterise, for the first time, the consequences of 5-HT4 receptor activation on human cognition and emotion.

METHODS

Forty one healthy volunteers were randomised, double-blind, to a single dose of prucalopride (1 mg) or placebo in a parallel group design. They completed a battery of cognitive tests measuring learning and memory, emotional processing and reward sensitivity.

RESULTS

Prucalopride increased recall of words in a verbal learning task, increased the accuracy of recall and recognition of words in an incidental emotional memory task and increased the probability of choosing a symbol associated with a high likelihood of reward or absence of loss in a probabilistic instrumental learning task. Thus acute prucalopride produced pro-cognitive effects in healthy volunteers across three separate tasks.

CONCLUSIONS

These findings are a translation of the memory enhancing effects of 5-HT4 receptor agonism seen in animal studies, and lend weight to the idea that the 5-HT4 receptor could be an innovative target for the treatment of cognitive deficits associated with depression and other neuropsychiatric disorders. Contrary to the effects reported in animal models, prucalopride did not reveal an antidepressant profile in human measures of emotional processing.

Methylphenidate boosts choices of mental labor over leisure depending on striatal dopamine synthesis capacity

The cognitive enhancing effects of methylphenidate are well established, but the mechanisms remain unclear. We recently demonstrated that methylphenidate boosts cognitive motivation by enhancing the weight on the benefits of a cognitive task in a manner that depended on striatal dopamine. Here, we considered the complementary hypothesis that methylphenidate might also act by changing the weight on the opportunity cost of a cognitive task, that is, the cost of foregoing alternative opportunity. To this end, 50 healthy participants (25 women) completed a novel cognitive effort-discounting task that required choices between task and leisure. They were tested on methylphenidate, placebo, as well as the selective D2-receptor agent sulpiride, the latter to strengthen inference about dopamine receptor selectivity of methylphenidate's effects. Furthermore, they also underwent an [18F]DOPA PET scan to quantify striatal dopamine synthesis capacity. Methylphenidate boosted choices of cognitive effort over leisure across the group, and this effect was greatest in participants with more striatal dopamine synthesis capacity. The effects of sulpiride did not reach significance. This study strengthens the motivational account of methylphenidate's effects on cognition, and suggests that methylphenidate reduces the cost of mental labor by increasing striatal dopamine.

The Dark Triad of personality and attitudes toward cognitive enhancement

Background

Cognitive enhancement (CE) refers to the voluntary improvement of human cognitive capabilities. Few studies have examined the general attitude of the public towards CE. Such studies have suggested that the use of CE is considered largely unacceptable by the public. In parallel, past research indicates that individuals scoring high on the Dark Triad of personality (Machiavellianism, narcissism, and psychopathy) and competitiveness have atypical views of ethical questions. In this study, we examined (a) whether attitudes towards CE are associated with individual differences in the Dark Triad of personality as well as in trait and contextual competitiveness and (b) whether the Dark Triad moderates the effect of trait and contextual competitiveness on attitudes towards CE.

Method

US employees (N = 326) were recruited using Mechanical Turk. Participants completed a web survey. Data were analyzed by means of (robust) hierarchical regression and (robust) ANCOVAs.

Results

The Dark Triad of personality and one of its subscales, Machiavellianism, predicted positive attitudes towards CE. Neither trait competitiveness nor contextual competitiveness were linked to general attitudes towards CE, but the DT was a positive moderator of the association between contextual competitiveness and positive attitudes.

Conclusion

Our findings extend the incipient knowledge about the factors relating to favourable views of CE by highlighting the role of dark personality traits in shaping such views. Our study further shows contextual factors can play a differentiated role with respect to such attitudes depending upon dark personality traits. Implications for policy-making are discussed.

Neuro-enhancement among German junior physicians: Prevalence, reasons and associations to mental health outcomes and quality of life

BACKGROUND

Previous research studies have demonstrated that neuro-enhancement, the use of legal or illegal drugs by healthy individuals to improve their job performance, is practiced among employees. Researchers discussed possible reasons for employees to consider the use of substances for neuro-enhancement.

OBJECTIVE

The aim of this study was to identify the prevalence of usage and motives for practicing neuro-enhancement among a sample of German junior physicians. The secondary objective was to determine associations between neuro-enhancement, mental health outcomes and quality of life.

METHODS

This cross-sectional study included an online survey to analyze junior physicians' neuro-enhancement stimulant use and their motives for usage (n = 873). Second, mental health outcomes and quality of life were assessed. Descriptive and analytic (Kruskal Wallis test, logistic regression) statistics were obtained.

RESULTS

Of the 873 junior physicians, 18% reported having used stimulants for neuro- enhancement. 8% of the physicians have taken prescription stimulants (e.g. modafinil) or illicit drugs (e.g. cannabis) at least once in their lifetime. The most common reasons for taking stimulants were to enhance concentration, to relax and to increase alertness. Neuro-enhancement was associated with emotional exhaustion (p < 0.01), lower quality of life (p < 0.05) and work-related stress (p < 0.01).

CONCLUSIONS

Our study results give an overview on the actual situation regarding frequency and motives for taking performance-enhancing substances. The prevalence rate was low in comparison to current public debates. Decreasing the prevalence of neuro-enhancement among physicians requires the implementation of strategies targeting stress reduction and workload management.

Is Methylphenidate Beneficial and Safe in Pharmacological Cognitive Enhancement?

Nootropics are drugs used to either treat or benefit cognition deficits. Among this class, methylphenidate is a popular agent, which acts through indirect dopaminergic and noradrenergic agonism and, therefore, is proposed to enhance performance in catecholamine-dependent cognitive domains such as attention, memory and prefrontal cortex-dependent executive functions. However, investigation into the efficacy of methylphenidate as a cognitive enhancer has yielded variable results across all domains, leading to debate within the scientific community surrounding its off-label use in healthy individuals seeking scholaristic benefit or increased productivity. Through analysis of experimental data and methodological evaluation, it is apparent that there are dose-, task- and domain-dependent considerations surrounding the use of methylphenidate in healthy individuals, whereby tailored dose administration is likely to provide benefit on an individual basis dependent on the domain of cognition in which benefit is required. Additionally, it is apparent that there are subjective effects of methylphenidate, which may increase user productivity irrespective of cognitive benefit. Whilst there is not extensive study in healthy older adults, it is plausible that there are dose-dependent benefits to methylphenidate in older adults in selective cognitive domains that might improve quality of life and reduce fall risk. Methylphenidate appears to produce dose-dependent benefits to individuals with attention-deficit/hyperactivity disorder, but the evidence for benefit in Parkinson's disease and schizophrenia is inconclusive. As with any off-label use of pharmacological agents, and especially regarding drugs with neuromodulatory effects, there are inherent safety concerns; epidemiological and experimental evidence suggests there are sympathomimetic, cardiovascular and addictive considerations, which might further restrict their use within certain demographics.

A Novel Feed-Forward Modeling System Leads to Sustained Improvements in Attention and Academic Performance

Objective: This study tested a novel feed-forward modeling (FFM) system as a nonpharmacological intervention for the treatment of ADHD children and the training of cognitive skills that improve academic performance. Method: This study implemented a randomized, controlled, parallel design comparing this FFM with a nonpharmacological community care intervention. Improvements were measured on parent- and clinician-rated scales of ADHD symptomatology and on academic performance tests completed by the participant. Participants were followed for 3 months after training. Results: Participants in the FFM training group showed significant improvements in ADHD symptomatology and academic performance, while the control group did not. Improvements from FFM were sustained 3 months later. Conclusion: The FFM appeared to be an effective intervention for the treatment of ADHD and improving academic performance. This FFM training intervention shows promise as a first-line treatment for ADHD while improving academic performance.

The Downsides of Cognitive Enhancement

Cognitive enhancement is becoming progressively popular as a subject of scientific investigation and by the public, although possible adverse effects are not sufficiently understood. We call for cognitive enhancement to build on more specific, mechanistic theories given that a-theoretical approaches to cognitive enhancement are both a cause and a consequence of a strong, if not exclusive focus on the benefits of procedures suited to enhance human cognition. We focus on downsides of cognitive enhancement and suggest that every attempt to enhance human cognition needs to deal with two basic principles: the neuro-competition principle and the nonlinearity principle. We discuss the possibility of both principles in light of recent attempts to improve human cognition by means of transcranial direct current stimulation, a well-established brain stimulation method, and clinically relevant nootropic drugs. We propose that much stronger emphasis on mechanistic theorizing is necessary in guiding future research on both the upsides and the downsides of cognitive enhancement.

Una aproximación bioética a la mejora cognitiva en individuos sanos

La discusión sobre el human enhancement es uno de los temas que ha tomado más relevancia dentro de los debates bioéticos actuales. En este artículo realizaremos un abordaje sobre este concepto, específicamente en relación al tema de la mejora cognitiva. Con la idea de crear un marco ético reflexivo, abordaremos el tema desde varias vertientes. En primer lugar, cómo se entiende la mejora cognitiva, a partir de dos aspectos distintos: la finalidad de la mejora y la acción mejoradora en sí misma. Posteriormente, se enfocarán los alcances de la mejora cognitiva desde la óptica de las investigaciones científicas sobre el tema. En la segunda parte del texto, analizaremos (a partir del meta-análisis de una selección de investigaciones científico-empíricas) el tema de si realmente se presenta una mejora y, de ser así, de qué clase de mejora se trata. Para finalizar, realizaremos una reflexión en torno a los problemas morales que presenta la mejora cognitiva, para concluir brevemente que este tipo de mejora solo se presenta en un sentido muy limitado, al tiempo que se encuentra justificada por un marco reduccionista de la cognición y, por lo tanto, del ser humano mismo.

Cognitive Enhancing Drugs in Sport: Current and Future Concerns

Sporting authorities and policy makers have warned of a radical increase in the availability and use of so-called 'smart' drugs, which putatively deliver cognitive enhancements in the form of improved focus, concentration, alertness, and rapid decision-making. Although the potential for health risks is well documented when it comes to performance enhancing drugs in sport, the health implications of cognitive enhancing drugs (CEDs) remain unclear. Objectives: This article aims to provide a foundational understanding about CEDs and their application in sport. It considers what little is known about the types, nature, impact, and implications of their use for athletes and sport policy. Method: A narrative literature review was undertaken to ascertain the emerging role of CEDs beyond their clinical use to treat prescribed disorders, including the limited studies in the sporting domain. This review also considered literature pertinent to the impact of CEDs in sport and the challenges for sport policy. Results: Given the prospects of negative health impacts, policy-makers interested in preventing and controlling the use of CEDs, as well as reducing harm to athletes at all levels of performance, need guidance. This article highlights multi-faceted concerns and shines a spotlight on key issues for sporting bodies to consider regarding the critical impact that widespread use and adoption of these substances might entail. Conclusion: While the World Anti-Doping Agency (WADA) is seemingly awake to the threat posed, actions to circumvent the spread of CEDs throughout sport are nascent and require greater understanding and attention.

The effect of curcumin on cognition in Alzheimer's disease and healthy aging: A systematic review of pre-clinical and clinical studies

Alzheimer's disease constitutes a growing cause of cognitive impairment in aging population. Given that current treatments do not produce the desired therapeutic effects, the need for finding alternative biological and pharmacological approaches is critical. Accumulating evidence suggests inflammatory and oxidative stress responses as potential causal factors of cognitive impairments in Alzheimer's disease and healthy aging. Curcumin has received increased interest due to its unique molecular structure that targets inflammatory and antioxidant pathways as well as (directly) amyloid aggregation; one of the major hallmarks of Alzheimer's disease. Therefore, this review summarizes preclinical and clinical findings on curcumin as a potential cognitive enhancer in Alzheimer's disease and normal aging. Databases used for literature searches include PubMed, EMBASE and Web of Science; in addition, clinicaltrials.gov was used to search for clinical studies. Overall, animal research has shown very promising results in potentiating cognition, both physiologically and behaviourally. However, human studies are limited and results are less consistent, complicating their interpretation. These inconsistencies may be related to differences in methodology and the included population. Taking into account measurements of important inflammatory and antioxidant biomarkers, optimal dosages of curcumin, food interactions, and duration of treatment would increase our understanding on curcumin's promising effects on cognition. In addition, increasing curcumin's bioavailability could benefit future research.

Neurofeedback training with a low-priced EEG device leads to faster alpha enhancement but shows no effect on cognitive performance: A single-blind, sham-feedback study

INTRODUCTION

Findings of recent studies indicate that it is possible to enhance cognitive capacities of healthy individuals by means of individual upper alpha neurofeedback training (NFT). Although these results are promising, most of this research was conducted based on high-priced EEG systems developed for clinical and research purposes. This study addresses the question whether such effects can also be shown with an easy to use and comparably low-priced Emotiv Epoc EEG headset available for the average consumer. In addition, critical voices were raised regarding the control group designs of studies addressing the link between neurofeedback training and cognitive performance. Based on an extensive literature review revealing considerable methodological issues in an important part of the existing research, the present study addressed the question whether individual upper alpha neurofeedback has a positive effect on alpha amplitudes (i.e. increases alpha amplitudes) and short-term memory performance focussing on a methodologically sound, single-blinded, sham controlled design.

METHOD

Participants (N = 33) took part in four test sessions over four consecutive days of either neurofeedback training (NFT group) or sham feedback (SF group). In the NFT group, five three-minute periods of visual neurofeedback training were administered each day whereas in the SF group (control group), the same amount of sham feedback was presented. Performance on eight digit-span tests as well as participants' affective states were assessed before and after each of the daily training sessions.

RESULTS

NFT did not show an effect on individual upper alpha and cognitive performance. While performance increased in both groups over the course of time, this effect could not be explained by changes in individual upper alpha. Additional analyses however revealed that participants in the NFT group showed faster and larger increase in alpha compared to the SF group. Surprisingly, exploratory analyses showed a significant correlation between the initial alpha level and the alpha improvement during the course of the study. This finding suggests that participants with high initial alpha levels benefit more from alpha NFT interventions. In the discussion, the appearance of the alpha enhancement in the SF group and possible reasons for the absence of a connection between NFT and short-term memory are addressed.

Vigilance Decrement and Enhancement Techniques: A Review

This paper presents the first comprehensive review on vigilance enhancement using both conventional and unconventional means, and further discusses the resulting contradictory findings. It highlights the key differences observed between the research findings and argues that variations of the experimental protocol could be a significant contributing factor towards such contradictory results. Furthermore, the paper reveals the effectiveness of unconventional means of enhancement in significant reduction of vigilance decrement compared to conventional means. Meanwhile, a discussion on the challenges of enhancement techniques is presented, with several suggested recommendations and alternative strategies to maintain an adequate level of vigilance for the task at hand. Additionally, this review provides evidence in support of the use of unconventional means of enhancement on vigilance studies, regardless of their practical challenges.

Exercise modulates the interaction between cognition and anxiety in humans

Despite interest in exercise as a treatment for anxiety disorders the mechanism behind the anxiolytic effects of exercise is unclear. Two observations motivate the present work. First, engagement of attention control during increased working memory (WM) load can decrease anxiety. Second, exercise can improve attention control. Therefore, exercise could boost the anxiolytic effects of increased WM load via its strengthening of attention control. Anxiety was induced by threat of shock and was quantified with anxiety-potentiated startle (APS). Thirty-five healthy volunteers (19 male, age M = 26.11, SD  = 5.52) participated in two types of activity, exercise (biking at 60-70% of heart rate reserve) and control-activity (biking at 10-20% of heart rate reserve). After each activity, participants completed a WM task (n-back) at low- and high-load during safe and threat. Results were not consistent with the hypothesis: exercise vs. control-activity increased APS in high-load (p = .03). However, this increased APS was not accompanied with threat-induced impairment in WM performance (p = .37). Facilitation of both task-relevant stimulus processing and task-irrelevant threat processing, concurrent with prevention of threat interference on cognition, suggests that exercise increases cognitive ability. Future studies should explore how exercise affects the interplay of cognition and anxiety in patients with anxiety disorders.

DNA methylation regulates CHRNA7 transcription and can be modulated by valproate

The CHRNA7 gene encoding the α7 nicotinic acetylcholine receptor (nAChR) has repeatedly been linked with schizophrenia and the P50 sensory gating deficit. The α7 nAChR is considered a promising drug target for treatment of cognitive dysfunction in schizophrenia and improves memory and executive functions in patients and healthy individuals. However, clinical trials with pro-cognitive drugs are challenged by large inter-individual response variations and these have been linked to genotypic variations reducing CHRNA7 expression and α7 nAChR function. Genetic variants as well as environmental conditions may cause epigenetic dysregulation and it has previously been found that DNA methylation of a region surrounding the transcription start site of CHRNA7 is important for tissue specific regulation and gene silencing. In the present study we identify two additional regions involved in epigenetic regulation of the CHRNA7 promoter. In human temporal cortex we find large variations in expression of CHRNA7 and establish evidence for a significant correlation with DNA methylation levels of one region. We then establish evidence that genotypic variations can influence methylation levels of the CHRNA7 promoter. Epigenetic dysregulation can be reversed by pharmacological intervention and in HeLa cells. Valproate, a commonly used mood stabiliser, caused demethylation and increased CHRNA7 expression in HeLA cells. Similar demethylation effect and increased CHRNA7 expression was obtained in SH-SY5Y cells stimulated concomitantly with valproate and nicotine. In summary, both genetic and epigenetic information could be useful to predict treatment outcomes in patients and epigenetic modulation may serve as a mechanism for potentiating the effects of α7 nAChR agonists.

Molecular Docking and Cognitive Impairment Attenuating Effect of Phenolic Compound Rich Fraction of Trianthema portulacastrum in Scopolamine Induced Alzheimer's Disease Like Condition

Dementia is considered as the frequent cause of neurodegenerative mental disorder such as Alzheimer's disease (AD) amongst elderly people. Free radicals as well as cholinergic deficit neurons within nucleus basalis magnocellularis demonstrated to attribute with aggregation of β amyloid which further acts as an essential hallmark in AD. Various phenolic phytoconstituents exists in Trianthema portulastrum (TP) leaves have been reported as active against various neurological disorders. The current investigation was undertaken to evaluate the antiamnesic potential of butanol fraction of TP hydroethanolic extract (BFTP) by utilizing rodent models of elevated plus maze (EPM) and Hebbs William Maze (HWM) along with in vitro and in vivo antioxidant as well as acetylcholinesterase (AChE) inhibition studies. Molecular docking studies were also performed for evaluation of molecular interaction of existed phenolic compounds in BFTP. In vitro antioxidant study revealed concentration dependant strong ability of BFTP to inhibit free radicals. In vitro AChE inhibition study showed competitive type of inhibition kinetics. BFTP significantly reversed (p < 0.005 versus scopolamine) the damaging effect of scopolamine by reducing TL (Transfer Latency) and TRC (Time taken to recognize the reward chamber) in the EPM and HWM, respectively. BFTP also contributed towards increased (p < 0.005 versus scopolamine) enzymatic antioxidant as well as hippocampal acetylcholine (ACh) levels. Histological studies also supported the results as BFTP pretreated mice significantly reversed the scopolamine induced histological changes in hippocampal region. Docking studies confirmed chlorogenic acid has the most significant binding affinity towards AChE. This research finding concludes that BFTP could be a beneficial agent for management of cognition and behavioral disorders associated with AD.

Moral Attitudes Toward Pharmacological Cognitive Enhancement (PCE): Differences and Similarities Among Germans With and Without PCE Experience

Pharmacological cognitive enhancement (PCE), the use of illicit and/or prescription drugs to increase cognitive performance, has spurred controversial discussion in bioethics. In a semi-structured interview study with 60 German university students and employees, differences and similarities in moral attitudes toward PCE among 30 experienced participants (EPs) vs. 30 inexperienced participants (IPs) were investigated. Substances EPs used most often are methylphenidate, amphetamines, tetrahydrocannabinol and modafinil. Both EPs and IPs addressed topics such as autonomous decision making or issues related to fairness such as equality in test evaluation and distortion of competition. While most EPs and IPs were convinced that the decision of whether or not to use PCE is part of their individual freedom, their views varied considerably with regard to fairness. IPs considered issues related to fairness as much more critical than EPs. Thus, a person’s moral attitudes toward PCE may not only depend on moral common sense, but also on whether they have used illegal and/or prescription drugs for PCE before. This points to the importance of including the various relevant stakeholder perspectives in debates on the ethical and social implications of PCE.