Cognitive Enhancement and Neuroprotective Abilities of Plants

Extensive research suggests that a number of plant-derived chemicals and traditional Oriental herbal remedies possess cognition-enhancing properties. Widely used current treatments for dementia include extracts of Ginkgo biloba and several alkaloidal, and therefore toxic, plant-derived cholinergic agents. Several non-toxic, European herbal species have pan-cultural traditions as treatments for cognitive deficits, including those associated with aging. Acute administration has also been found to reliably improve mnemonic performance in healthy young and elderly cohorts, whilst a chronic regime has been shown to attenuate cognitive declines in sufferers from Alzheimer's disease. The present chapter looks at the ethnobotanical and pharmacological importance of various plants cognitive enhancing and other neuroprotective abilities.

‘Cognitive enhancers’: A qualitative exploration of university students’ experiences with prescription medicines for academic purposes

Qualitative work with students who use prescription medicines for academic purposes is limited. Thus, a more nuanced understanding of tertiary students’ experiences is urgently needed. Our study – which draws on five semi-structured interviews with New Zealand university students, complemented with information from local newspapers, blog entries and discussion forums – reveals students’ motivations and perceived effects, their risk perceptions and provides insights into the circumstances enabling the engagement with prescription medicines for academic purposes. Students were influenced by peers and social norms; and ideas about identity, morality and fairness also played a role for engaging with cognitive enhancers. Students used high levels of stress and workload to justify their use but took individual responsibility for their practices. By taking responsibility in this way, rather than considering it as a product of their environment, they buy into the neoliberal university discourse. Unexpectedly, some participants were already receiving medically justified psychopharmacological treatment but extended and supplemented this with nonmedical use. Others considered their use as being for academic emergencies, and that their low level of use helped manage risks. Overall, students viewed pharmacological cognitive enhancement for improving academic performance as cautious, safe, and morally acceptable. We argue in this paper that a local understanding of students’ motivations, justifications and perceptions of pharmacological cognitive enhancement is required, to tailor policies and support systems better to their needs and behaviours.

Radical Enhancement, Knowledge, and Autonomous Belief

Epistemic autonomy is necessary for knowledge in ways that epistemologists have not yet fully appreciated. This chapter uses a series of thought experiments featuring (radical) forms of cognitive enhancement in order to show why; in particular, and with reference to a series of tweaks on Lehrer’s ‘TrueTemp’ case, I motivate an autonomous belief condition on propositional knowledge, a condition the satisfaction of which—it will be shown—is neither entailed by, nor entails, the satisfaction of either a belief condition or, importantly, an epistemic justification condition. This transition from a ‘JTB+X’ to a ‘JTAB+X’ template marks an important and needed update to the received thinking about what knowing involves. (Of course, the question of whether knowledge is analysable is contentious; an appendix for knowledge-firsters explains the relevance of the necessity of epistemic autonomy for knowledge for knowledge-first projects).

A Preclinical Model of Computerized Cognitive Training: Touchscreen Cognitive Testing Enhances Cognition and Hippocampal Cellular Plasticity in Wildtype and Alzheimer’s Disease Mice

With the growing popularity of touchscreen cognitive testing in rodents, it is imperative to understand the fundamental effects exposure to this paradigm can have on the animals involved. In this study, we set out to assess hippocampal-dependant learning in the APP/PS1 mouse model of Alzheimer’s disease (AD) on two highly translatable touchscreen tasks – the Paired Associate Learning (PAL) task and the Trial Unique Non-Matching to Location (TUNL) task. Both of these tests are based on human tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and are sensitive to deficits in both mild cognitive impairment (MCI) and AD. Mice were assessed for deficits in PAL at 9–12 months of age, then on TUNL at 8–11 and 13–16 months. No cognitive deficits were evident in APP/PS1 mice at any age, contrary to previous reports using maze-based learning and memory tasks. We hypothesized that daily and long-term touchscreen training may have inadvertently acted as a cognitive enhancer. When touchscreen-tested mice were assessed on the Morris water maze, they showed improved task acquisition compared to naïve APP/PS1 mice and wild-type (WT) littermate controls. In addition, we show that touchscreen-trained WT and APP/PS1 mice show increased cell proliferation and immature neuron numbers in the dentate gyrus compared to behaviorally naïve WT and APP/PS1 mice. This result indicates that the touchscreen testing paradigm could improve cognitive performance, and/or mask an impairment, in experimental mouse models. This touchscreen-induced cognitive enhancement may involve increased neurogenesis, and possibly other forms of cellular plasticity. This is the first study to show increased numbers of proliferating cells and immature neurons in the hippocampus following touchscreen testing, and that touchscreen training can improve cognitive performance in maze-based spatial navigation tasks. This potential for touchscreen testing to induce cognitive enhancement, or other phenotypic shifts, in preclinical models should be considered in study design. Furthermore, touchscreen-mediated cognitive enhancement could have therapeutic implications for cognitive disorders.

Transcranial Brain Stimulation Improves Cognition in Older Adults With Depression and Anxiety

Older adults admitted to hospital for rehabilitation often have some degree of concomitant cognitive impairment, which may be a barrier to optimizing rehabilitation approaches. Transcranial direct current stimulation (tDCS), a type of non-invasive brain stimulation, delivers a low electrical current across the brain. The neuromodulatory effects of tDCS can be of therapeutic benefit and has been shown to augment cognitive functions in both healthy and clinical populations. This study investigated the effects of tDCS on cognition in older adult inpatients with depression or anxiety. It was hypothesized that anodal tDCS over the left dorsolateral prefrontal cortex would increase cognitive performance compared to a placebo group. Twenty adults between 65 to 86 years of age admitted to the Glenrose Rehabilitation Hospital with underlying depression or anxiety were recruited. Anodal (n=10) or sham (n=10) tDCS stimulation was administered at 1.5mA over 20 minutes, for 10-15 sessions based on participant availability. Cognitive assessments were administered before and after the tDCS protocol. Anodal tDCS stimulation resulted in significant gains on the Symbol Digit Modality Test, Trail Making Test Part A, and Forward Digit Span. This study demonstrated a tDCS-invoked cognitive enhancement in the domains of attention, information processing speed, and short-term memory processes. With the rapidly ageing population, tDCS may be a potential therapeutic option for cognitive enhancement and may be beneficial in ageing-related cognitive-disorders including mild cognitive impairment and dementia.

The Case Against Cognitive Enhancement: Responding to the Reversal Test

<p>In this thesis I argue against the use of genetic technologies to enhance human cognitive capacities. More specifically, I respond to Nick Bostrom and Toby Ord's "Reversal Test", which they use to argue in favour of genetic cognitive enhancement. The Reversal Test is a burden of proof challenge designed to diagnose status quo bias in arguments against enhancement. By noting that most of those who oppose raisingintelligence would also oppose lowering intelligence, the Reversal Test puts the onuson opponents of enhancement to explain why both increases and decreases in our cognitive capacity would be worse than the status quo (our current level of intelligence). Bostrom and Ord claim that if no good reasons can be provided, this indicates that the opposition to enhancement is influenced by status quo bias. Since cognitive biases cannot provide a moral reason against enhancement, opposition to genetic cognitive enhancement shown to be affected by status quo bias canaccordingly be discounted. The aim of my thesis, then, is to overcome the Reversal Test' s burden of proof challenge by showing that my reasons for opposing cognitive enhancement are notinfluenced by status quo bias. However, I do not argue that enhanced intelligence could not be beneficial to the individual. Instead, I claim that the probable unequal distribution of enhancements between the best- and worst-off would be likely to cause serious injustices to those who are unable to afford them.</p>

The Case Against Cognitive Enhancement: Responding to the Reversal Test

<p>In this thesis I argue against the use of genetic technologies to enhance human cognitive capacities. More specifically, I respond to Nick Bostrom and Toby Ord's "Reversal Test", which they use to argue in favour of genetic cognitive enhancement. The Reversal Test is a burden of proof challenge designed to diagnose status quo bias in arguments against enhancement. By noting that most of those who oppose raisingintelligence would also oppose lowering intelligence, the Reversal Test puts the onuson opponents of enhancement to explain why both increases and decreases in our cognitive capacity would be worse than the status quo (our current level of intelligence). Bostrom and Ord claim that if no good reasons can be provided, this indicates that the opposition to enhancement is influenced by status quo bias. Since cognitive biases cannot provide a moral reason against enhancement, opposition to genetic cognitive enhancement shown to be affected by status quo bias canaccordingly be discounted. The aim of my thesis, then, is to overcome the Reversal Test' s burden of proof challenge by showing that my reasons for opposing cognitive enhancement are notinfluenced by status quo bias. However, I do not argue that enhanced intelligence could not be beneficial to the individual. Instead, I claim that the probable unequal distribution of enhancements between the best- and worst-off would be likely to cause serious injustices to those who are unable to afford them.</p>