-
1.
A systematic review of research investigating the physiological and psychological effects of combining Ginkgo biloba and Panax ginseng into a single treatment in humans: Implications for research design and analysis.
Reay, JL, van Schaik, P, Wilson, CJ
Brain and behavior. 2019;(3):e01217
Abstract
BACKGROUND AND PURPOSE The traditional herbal supplements Panax ginseng and Ginkgo biloba are self-medicated by members of the general public and prescribed by healthcare professionals in some EU countries for numerous health complaints. Clinical evidence is mixed and mechanisms of action are not fully understood. There is clinical interest into the synergistic effects of combining both herbs. METHODS We systematically review the literature investigating the effects of combination treatments on physiological and psychological outcomes in humans. We identified all studies meeting inclusion criteria: (a) written in English; (b) peer-reviewed; (c) conducted in humans; (d) including either a proprietary Panax ginseng/Ginkgo biloba treatment or a study preparation containing both; (e) placebo-controlled; (f) utilizing standardized extracts. We critically discuss each trial; calculate standardized effect sizes where possible and provide recommendations for research design and analysis. RESULTS Eight studies were identified and all investigated a proprietary combination treatment, Gincosan® . Studies are of high quality and robust; however, practice effects, choice of statistical model, and reliance upon null-hypothesis significance testing hinder generalized estimates of effect. The most consistent results are benefits to aspects of the circulatory/cardiovascular system in patient populations and "secondary memory" performance in patient and healthy populations. Two studies demonstrate synergy in healthy populations following a single dose; however, synergy in patient populations and following repeated dosing has not yet been directly tested. CONCLUSIONS A Panax ginseng and Ginkgo biloba combination treatment can improve aspects of physiological and cognitive function in humans; however, evidence for synergy requires further investigation and future research should directly investigate synergy following repeated dosing.
-
2.
Can Slow-Wave Sleep Enhancement Improve Memory? A Review of Current Approaches and Cognitive Outcomes.
Zhang, Y, Gruber, R
The Yale journal of biology and medicine. 2019;(1):63-80
Abstract
Slow-wave sleep (SWS) is involved in the overnight consolidation of declarative memories. Recent efforts using auditory stimulation, slow-oscillatory transcranial direct current stimulation (so-tDCS), and pharmacological agents have targeted sleep slow-waves as a method for enhancing cognitive performance. However, no studies thus far have integrated current evidence to provide a preliminary review of the effects of SWS enhancement on memory and other cognitive outcomes. The objective of this review was to synthesize the results of recent experimental studies that have used auditory stimulation, electrical, and pharmacological methods to boost both SWS and cognitive performance. A systematic review was done to identify and consolidate all currently existing empirical studies in this area. We found that each stimulation method could enhance slow-wave power and/or SWS duration in human subjects. Closed-loop, in-phase auditory stimulation enhanced verbal declarative memory in healthy adults. Electrical stimulation using so-tDCS showed some efficacy in promoting verbal declarative memory, picture recognition memory, and location memory. Interleukin-6 and sodium oxybate enhanced declarative verbal memory, while tiagabine and sodium oxybate improved some non-memory measures of cognitive performance. There is some evidence that so-tDCS can also improve certain cognitive outcomes in clinical populations. Overall, future studies should recruit larger sample sizes drawn from more diverse populations, and determine clinical significance and effect sizes of each enhancement methodology.
-
3.
Higher CSF Tau Levels Are Related to Hippocampal Hyperactivity and Object Mnemonic Discrimination in Older Adults.
Berron, D, Cardenas-Blanco, A, Bittner, D, Metzger, CD, Spottke, A, Heneka, MT, Fliessbach, K, Schneider, A, Teipel, SJ, Wagner, M, et al
The Journal of neuroscience : the official journal of the Society for Neuroscience. 2019;(44):8788-8797
Abstract
Mnemonic discrimination, the ability to distinguish similar events in memory, relies on subregions in the human medial temporal lobes (MTLs). Tau pathology is frequently found within the MTL of older adults and therefore likely to affect mnemonic discrimination, even in healthy older individuals. The MTL subregions that are known to be affected early by tau pathology, the perirhinal-transentorhinal region (area 35) and the anterior-lateral entorhinal cortex (alEC), have recently been implicated in the mnemonic discrimination of objects rather than scenes. Here we used an object-scene mnemonic discrimination task in combination with fMRI recordings and analyzed the relationship between subregional MTL activity, memory performance, and levels of total and phosphorylated tau as well as Aβ42/40 ratio in CSF. We show that activity in alEC was associated with mnemonic discrimination of similar objects but not scenes in male and female cognitively unimpaired older adults. Importantly, CSF tau levels were associated with increased fMRI activity in the hippocampus, and both increased hippocampal activity as well as tau levels were associated with mnemonic discrimination of objects, but again not scenes. This suggests that dysfunction of the alEC-hippocampus object mnemonic discrimination network might be a marker for tau-related cognitive decline.SIGNIFICANCE STATEMENT Subregions in the human medial temporal lobe are critically involved in episodic memory and, at the same time, affected by tau pathology. Impaired object mnemonic discrimination performance as well as aberrant activity within the entorhinal-hippocampal circuitry have been reported in earlier studies involving older individuals, but it has thus far remained elusive whether and how tau pathology is implicated in this specific impairment. Using task-related fMRI in combination with measures of tau pathology in CSF, we show that measures of tau pathology are associated with increased hippocampal activity and reduced mnemonic discrimination of similar objects but not scenes. This suggests that object mnemonic discrimination tasks could be promising markers for tau-related cognitive decline.
-
4.
Successful Memory Aging.
Nyberg, L, Pudas, S
Annual review of psychology. 2019;:219-243
Abstract
For more than 50 years, psychologists, gerontologists, and, more recently, neuroscientists have considered the possibility of successful aging. How to define successful aging remains debated, but well-preserved age-sensitive cognitive functions, like episodic memory, is an often-suggested criterion. Evidence for successful memory aging comes from cross-sectional and longitudinal studies showing that some older individuals display high and stable levels of performance. Successful memory aging may be accomplished via multiple paths. One path is through brain maintenance, or relative lack of age-related brain pathology. Through another path, successful memory aging can be accomplished despite brain pathology by means of efficient compensatory and strategic processes. Genetic, epigenetic, and lifestyle factors influence memory aging via both paths. Some of these factors can be promoted throughout the life course, which, at the individual as well as the societal level, can positively impact successful memory aging.
-
5.
Neurologic issues related to glucocorticoid use in oral surgery: memory and attention impairment in association with cannabis consumption.
Piperea-Șianu, D, Tălășman, S, Ceau, AM, Lorean, A, Piperea-Șianu, A, Levin, L
Quintessence international (Berlin, Germany : 1985). 2019;(2):126-134
Abstract
The use of hormonal anti-inflammatory drugs is a common practice in oral and dental surgery. They have proven enhanced efficacy, increasing therapeutic success when the treatment is properly chosen and managed. However, given the complexity of neurophysiologic processes, little is known regarding the consequences of administering glucocorticoids on brain function. This article aims to bring to the attention of dental health professionals the main neurophysiologic mechanisms by which glucocorticoid hormones can affect memory and attention. In addition, in the context of increasing global prevalence and incidence of cannabinoid consumption, both for medical and recreational purposes, the issue of the association of cortisone-derived drugs in the systemic context of these phytocannabinoids is addressed, in terms of memory issues and attention.
-
6.
Temporal lobe surgery and memory: Lessons, risks, and opportunities.
Bauman, K, Devinsky, O, Liu, AA
Epilepsy & behavior : E&B. 2019;(Pt A):106596
-
-
Free full text
-
Abstract
Careful study of the clinical outcomes of temporal lobe epilepsy (TLE) surgery has greatly advanced our knowledge of the neuroanatomy of human memory. After early cases resulted in profound amnesia, the critical role of the hippocampus and associated medial temporal lobe (MTL) structures to declarative memory became evident. Surgical approaches quickly changed to become unilateral and later, to be more precise, potentially reducing cognitive morbidity. Neuropsychological studies following unilateral temporal lobe resection (TLR) have challenged early models, which simplified the lateralization of verbal and visual memory function. Diagnostic tests, including intracarotid sodium amobarbital procedure (WADA), structural magnetic resonance imaging (MRI), and functional neuroimaging (functional MRI (fMRI), positron emission tomography (PET), and single-photon emission computed tomography (SPECT)), can more accurately lateralize and localize epileptogenic cortex and predict memory outcomes from surgery. Longitudinal studies have shown that memory may even improve in seizure-free patients. From 70 years of experience with epilepsy surgery, we now have a richer understanding of the clinical, neuroimaging, and surgical predictors of memory decline-and improvement-after TLR. "Special Issue: Epilepsy & Behavior's 20th Anniversary".
-
7.
Cognitive and motivational selectivity in healthy aging.
Swirsky, LT, Spaniol, J
Wiley interdisciplinary reviews. Cognitive science. 2019;(6):e1512
Abstract
Normal aging is associated with a reduction in the selectivity of cognitive processes such as attention and memory. This loss of selectivity is attributed to diminished inhibition and cognitive control mechanisms in older adults, which render them more susceptible to distraction and more likely to attend to and encode irrelevant information. However, motivational selectivity appears largely preserved in aging. For example, older adults selectively avoid high-demand tasks, exhibit a positivity bias in attention and memory, and show better memory for high-value compared to low-value information. The aim of this review is to integrate these seemingly paradoxical findings of reduced and preserved selectivity in aging, discuss potential neural mechanisms, and propose questions for future research. This article is categorized under: Neuroscience > Cognition Psychology > Development and Aging.
-
8.
Primary fatty amides in plasma associated with brain amyloid burden, hippocampal volume, and memory in the European Medical Information Framework for Alzheimer's Disease biomarker discovery cohort.
Kim, M, Snowden, S, Suvitaival, T, Ali, A, Merkler, DJ, Ahmad, T, Westwood, S, Baird, A, Proitsi, P, Nevado-Holgado, A, et al
Alzheimer's & dementia : the journal of the Alzheimer's Association. 2019;(6):817-827
-
-
Free full text
-
Abstract
INTRODUCTION A critical and as-yet unmet need in Alzheimer's disease (AD) is the discovery of peripheral small molecule biomarkers. Given that brain pathology precedes clinical symptom onset, we set out to test whether metabolites in blood associated with pathology as indexed by cerebrospinal fluid (CSF) AD biomarkers. METHODS This study analyzed 593 plasma samples selected from the European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery study, of individuals who were cognitively healthy (n = 242), had mild cognitive impairment (n = 236), or had AD-type dementia (n = 115). Logistic regressions were carried out between plasma metabolites (n = 883) and CSF markers, magnetic resonance imaging, cognition, and clinical diagnosis. RESULTS Eight metabolites were associated with amyloid β and one with t-tau in CSF, these were primary fatty acid amides (PFAMs), lipokines, and amino acids. From these, PFAMs, glutamate, and aspartate also associated with hippocampal volume and memory. DISCUSSION PFAMs have been found increased and associated with amyloid β burden in CSF and clinical measures.
-
9.
Focused attention during eating enhanced memory for meal satiety but did not reduce later snack intake in men: A randomised within-subjects laboratory experiment.
Whitelock, V, Gaglione, A, Davies-Owen, J, Robinson, E
Appetite. 2019;:124-129
Abstract
Attending to food being eaten ('attentive eating') may reduce later overeating. However, evidence in support of this comes primarily from studies in women. The aims of the current study were to investigate the effect that attentive eating has on later food intake in men and examine potential underlying mechanisms. Using a within-subjects design, 34 men (BMI M = 23.73 kg/m2, SD = 2.93; age M = 29.15, SD = 11.99) consumed a fixed lunchtime meal on two study days. On one study day participants were instructed to pay attention to the sensory properties of the meal as they ate (focused attention condition), and on the other study day participants ate lunch normally. Three hours after each lunchtime session, ad libitum consumption of snack food was measured, and measures of memory for the earlier lunchtime meal were completed. Participants remembered the lunch to be significantly more satiating in the focused attention condition compared to the control condition. However, focused attention did not significantly affect later ad libitum snack intake or other measures of meal memory. Further research is needed to understand when focused attention influences subsequent food intake before this approach can be used effectively to reduce food intake.
-
10.
Effect of a Fibroin Enzymatic Hydrolysate on Memory Improvement: A Placebo-Controlled, Double-Blind Study.
Kang, YK, Lee, BY, Bucci, LR, Stohs, SJ
Nutrients. 2018;(2)
Abstract
The consumption of a specifically prepared silk fibroin protein enzymatic hydrolysate (FPEH) has been reported to improve cognitive function in healthy humans. The objective of the current study is to evaluate the dose-dependent effects of the FPEH on memory. Healthy adults with an average age of approximately 55 years were administered doses of 0, 280, 400 and 600 mg of FPEH per day in two divided doses for 3 weeks. The Rey-Kim Auditory Verbal Learning Test and the Rey-Kim Complex Figure Test of the Rey-Kim Memory Test were used to evaluate memory at baseline and after 3 weeks. The scores for each test were combined into the memory quotient score (MQ). Learning gradient, memory maintenance, retrieval efficacy, and drawing/recall scores were also compared. After 3 weeks of FPEH, dose-dependent increases were observed for the MQ, the learning gradient, the numbers of words remembered, the retrieval efficiency, and drawing/recall. The optimal dose for FPEH was 400 or 600 mg, depending on the end point measured. No adverse effects were reported. FPEH significantly improved measurements of memory in healthy adults by 3 weeks at doses over 280 mg daily, with an apparent plateau effect at 400-600 mg daily.