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1.
Working memory associated with anti-suicidal ideation effect of repeated-dose intravenous ketamine in depressed patients.
Chen, X, Wang, M, Hu, Y, Zhan, Y, Zhou, Y, Zheng, W, Liu, W, Wang, C, Zhong, X, Li, H, et al
European archives of psychiatry and clinical neuroscience. 2021;(3):431-438
Abstract
Suicide is a tremendous threat to global public health, and a large number of people who committed suicide suffered the pain of mental diseases, especially major depressive disorder (MDD). Previous study showed that ketamine could reduce suicidal ideation (SI), potentially by improving the impaired working memory (WM). The objective of current study was to illuminate the relationship between WM and SI in MDD with repeated ketamine treatment. MDD patients with SI (n = 59) and without SI (n = 37) completed six intravenous infusions of ketamine (0.5 mg/kg over 40 min) over 12 days (Day 1, 3, 5, 8, 10 and 12). The severity of depressive symptoms, SI and WM were assessed at baseline, day 13 and day 26. We found that WM was significantly improved after 6 ketamine infusions (F = 161.284, p = 0.009) in a linear mixed model. Correlation analysis showed that the improvement of depressive symptom was significantly associated with WM at baseline (r = - 0.265, p = 0.042) and the reduction in SSI-part I was related to the change of WM (r = 0.276, p = 0.034) in the MDD patients with SI. Furthermore, Logistic regression analysis showed that improvement in WM might predict the anti-SI response of ketamine. Our findings suggest that the improvement of working memory may partly account for the anti-SI effect of ketamine, and intervention of improving working memory function may be capable of reducing suicidal ideation.
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2.
Altered event-related potentials and theta oscillations index auditory working memory deficits in healthy aging.
Nowak, K, Costa-Faidella, J, Dacewicz, A, Escera, C, Szelag, E
Neurobiology of aging. 2021;:1-15
Abstract
Speech comprehension deficits constitute a major issue for an increasingly aged population, as they may lead older individuals to social isolation. Since conversation requires constant monitoring, updating and selecting information, auditory working memory decline, rather than impoverished hearing acuity, has been suggested a core factor. However, in stark contrast to the visual domain, the neurophysiological mechanisms underlying auditory working memory deficits in healthy aging remain poorly understood, especially those related to on-the-fly information processing under increasing load. Therefore, we investigated the behavioral costs and electrophysiological differences associated with healthy aging and working memory load during continuous auditory processing. We recorded EEG activity from 27 younger (∼25 years) and 29 older (∼70 years) participants during their performance on an auditory version of the n-back task with speech syllables and 2 workload levels (1-back; 2-back). Behavioral measures were analyzed as indices of function; event-related potentials as proxies for sensory and cognitive processes; and theta oscillatory power as a reflection of memory and central executive function. Our results show age-related differences in auditory information processing within a latency range that is consistent with a series of impaired functions, from sensory gating to cognitive resource allocation during constant information updating, especially under high load.
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3.
Acute hyperglycaemia leads to altered frontal lobe brain activity and reduced working memory in type 2 diabetes.
Backeström, A, Papadopoulos, K, Eriksson, S, Olsson, T, Andersson, M, Blennow, K, Zetterberg, H, Nyberg, L, Rolandsson, O
PloS one. 2021;(3):e0247753
Abstract
How acute hyperglycaemia affects memory functions and functional brain responses in individuals with and without type 2 diabetes is unclear. Our aim was to study the association between acute hyperglycaemia and working, semantic, and episodic memory in participants with type 2 diabetes compared to a sex- and age-matched control group. We also assessed the effect of hyperglycaemia on working memory-related brain activity. A total of 36 participants with type 2 diabetes and 34 controls (mean age, 66 years) underwent hyperglycaemic clamp or placebo clamp in a blinded and randomised order. Working, episodic, and semantic memory were tested. Overall, the control group had higher working memory (mean z-score 33.15 ± 0.45) than the group with type 2 diabetes (mean z-score 31.8 ± 0.44, p = 0.042) considering both the placebo and hyperglycaemic clamps. Acute hyperglycaemia did not influence episodic, semantic, or working memory performance in either group. Twenty-two of the participants (10 cases, 12 controls, mean age 69 years) were randomly invited to undergo the same clamp procedures to challenge working memory, using 1-, 2-, and 3-back, while monitoring brain activity by blood oxygen level-dependent functional magnetic resonance imaging (fMRI). The participants with type 2 diabetes had reduced working memory during the 1- and 2-back tests. fMRI during placebo clamp revealed increased BOLD signal in the left lateral frontal cortex and the anterior cingulate cortex as a function of working memory load in both groups (3>2>1). During hyperglycaemia, controls showed a similar load-dependent fMRI response, whereas the type 2 diabetes group showed decreased BOLD response from 2- to 3-back. These results suggest that impaired glucose metabolism in the brain affects working memory, possibly by reducing activity in important frontal brain areas in persons with type 2 diabetes.
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4.
Executive functions form a single construct and are associated with schooling: Evidence from three low- and middle- income countries.
Wray, C, Kowalski, A, Mpondo, F, Ochaeta, L, Belleza, D, DiGirolamo, A, Waford, R, Richter, L, Lee, N, Scerif, G, et al
PloS one. 2020;(11):e0242936
Abstract
Measuring executive function (EF) among adults is important, as the cognitive processes involved in EF are critical to academic achievement, job success and mental health. Current evidence on measurement and structure of EF largely come from Western, Educated, Industrialized, Rich and Democratic (WEIRD) countries. However, measuring EF in low-and-middle-income countries (LMICs) is challenging, because of the dearth of EF measures validated across LMICs, particularly measures that do not require extensive training, expensive equipment, or professional administration. This paper uses data from three LMIC cohorts to test the feasibility, validity and reliability of EF assessment in adults using three sub-tests (representing key components of EF) of the NIH Toolbox Cognitive battery. For each cohort, all three EF measures (inhibition, flexibility and working memory) loaded well onto a unidimensional latent factor of EF. Factor scores related well to measures of fluid intelligence, processing speed and schooling. All measures showed good test-retest reliability across countries. This study provides evidence for a set of sound measures of EF that could be used across different cultural, language and socio-economic backgrounds in future LMIC research. Furthermore, our findings extend conclusions on the structure of EF beyond those drawn from WEIRD countries.
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5.
LSD acutely impairs working memory, executive functions, and cognitive flexibility, but not risk-based decision-making.
Pokorny, T, Duerler, P, Seifritz, E, Vollenweider, FX, Preller, KH
Psychological medicine. 2020;(13):2255-2264
Abstract
BACKGROUND Psychiatric and neurodegenerative illnesses are characterized by cognitive impairments, in particular deficits in working memory, decision-making, and executive functions including cognitive flexibility. However, the neuropharmacology of these cognitive functions is poorly understood. The serotonin (5-HT) 2A receptor might be a promising candidate for the modulation of cognitive processes. However, pharmacological studies investigating the role of this receptor system in humans are rare. Recent evidence demonstrates that the effects of Lysergic acid diethylamide (LSD) are mediated via agonistic action at the 5-HT2A receptor. Yet, the effects of LSD on specific cognitive domains using standardized neuropsychological test have not been studied. METHODS We examined the acute effects of LSD (100 µg) alone and in combination with the 5-HT2A antagonist ketanserin (40 mg) on cognition, employing a double-blind, randomized, placebo-controlled, within-subject design in 25 healthy participants. Executive functions, cognitive flexibility, spatial working memory, and risk-based decision-making were examined by the Intra/Extra-Dimensional shift task (IED), Spatial Working Memory task (SWM), and Cambridge Gambling Task (CGT) of the Cambridge Neuropsychological Test Automated Battery. RESULTS Compared to placebo, LSD significantly impaired executive functions, cognitive flexibility, and working memory on the IED and SWM, but did not influence the quality of decision-making and risk taking on the CGT. Pretreatment with the 5-HT2A antagonist ketanserin normalized all LSD-induced cognitive deficits. CONCLUSIONS The present findings highlight the role of the 5-HT2A receptor system in executive functions and working memory and suggest that specific 5-HT2A antagonists may be relevant for improving cognitive dysfunctions in psychiatric disorders.
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6.
Cognitive short- and long-term effects of coffee cherry extract in older adults with mild cognitive decline.
Robinson, JL, Hunter, JM, Reyes-Izquierdo, T, Argumedo, R, Brizuela-Bastien, J, Keller, R, Pietrzkowski, ZJ
Neuropsychology, development, and cognition. Section B, Aging, neuropsychology and cognition. 2020;(6):918-934
Abstract
There has been increasing interest in food- and dietary supplement-based materials that may support healthy cognition. However, few studies have quantitatively measured bioavailability, bioactivity, or cognitive short- and long-term effects of these materials against placebo. Earlier clinical studies reported ability of coffee cherry extract (CCE) to a.) reduce levels of reactive oxygen species (ROS) in human blood and b.) to increase serum and exosomal levels of brain-derived neurotrophic factor (BDNF), a neuroprotein essential for neurogenesis. Here, we examined CCE influence on cognitive performance. Seventy-one adults with mild cognitive decline completed this double blind, randomized, placebo-controlled, 28-day regimen. Participants engaged in a cognitive challenge that involved working memory processes. Our results suggest that effects of CCE were notable during the first week and persisted throughout the study period. Specifically, participants on the CCE regimens had significant reductions in reaction time compared to placebo when comparing baseline to days 7 and 28 (p = 0.040, partial η2 = 0.130). A main effect of group was not identified for accuracy; however, strong trends were noted between the placebo group and two of the three CCE groups. These results suggest CCE, when taken in the morning or twice per day, is associated with improvements in reaction times and trends toward indications of improved accuracy. Although further research is required, these observations may be indicative of underlying processes such as increased processing speed, sustained attention, and/or focus.
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7.
Further Evidence of Benefits to Mood and Working Memory from Lipidated Curcumin in Healthy Older People: A 12-Week, Double-Blind, Placebo-Controlled, Partial Replication Study.
Cox, KHM, White, DJ, Pipingas, A, Poorun, K, Scholey, A
Nutrients. 2020;(6)
Abstract
Curcumin (a flavonoid isolated from turmeric) affects several processes involved in neurocognitive aging. We have previously reported that short term (4-weeks) administration of a highly bioavailable curcumin preparation (Longvida©) improved working memory and reduced fatigue and stress reactivity in a healthy older cohort. The present trial (ACTRN12616000484448) was a partial replication study, evaluating similar effects at 4 and 12-weeks Longvida© supplementation. A double-blind, placebo-controlled, parallel-groups trial was conducted. Eighty participants aged 50-80 years (mean = 68.1, SD = 6.34) were randomised to receive Longvida© (400 mg daily containing 80 mg curcumin) or a matching placebo. Assessment took place at baseline then following 4 and 12 weeks treatment. Outcome measures included cognitive performance, mood and biomarkers. Compared with placebo, curcumin was associated with several significant effects. These included better working memory performance at 12-weeks (Serial Threes, Serial Sevens and performance on a virtual Morris Water Maze), and lower fatigue scores on the Profile of Mood States (POMS) at both 4 and 12-weeks, and of tension, anger, confusion and total mood disturbance at 4-weeks only. The curcumin group had significantly elevated blood glucose. These results confirm that Longvida© improves aspects of mood and working memory in a healthy older cohort. The pattern of results is consistent with improvements in hippocampal function and may hold promise for alleviating cognitive decline in some populations.
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8.
Water Consumption during a School Day and Children's Short-Term Cognitive Performance: The CogniDROP Randomized Intervention Trial.
Drozdowska, A, Falkenstein, M, Jendrusch, G, Platen, P, Luecke, T, Kersting, M, Jansen, K
Nutrients. 2020;(5)
Abstract
There is still little research examining the relationship between water consumption in school and specific cognitive performance. The aim of this cluster-randomized intervention CogniDROP trial was to investigate the short-term effects of drinking water during the morning on executive functions. The participants were from the 5th and 6th grade of a comprehensive school in Germany (14 classes, n = 250, 61.6% boys). The classes were randomly divided into an intervention group (an education on healthy drinking behavior and a promotion of water consumption) and a control group. A battery of computerized tasks (Switch Task, 2-Back Task, Corsi Block-Tapping Task and Flanker Task) was used to test executive functions. Urine color and thirst were evaluated to check the hydration level. Physical activity over the past 24 h was measured using GT3X ActiGraph. A non-linear relationship was observed between the amount of drinking water and executive performance. Consuming water up to 1000 mL (or up to 50% of Total Water Intake) had benefits during memory tasks. Urine color and number of steps on the study day correlated with water consumed. The results suggest that a water-friendly environment supports school-aged children in adequate water intake resulting in better cognitive performance, especially short-term memory.
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9.
Neural markers of category-based selective working memory in aging.
Mok, RM, O'Donoghue, MC, Myers, NE, Drazich, EHS, Nobre, AC
NeuroImage. 2019;:163-173
Abstract
Working memory (WM) is essential for normal cognitive function, but shows marked decline in aging. The importance of selective attention in guiding WM performance is increasingly recognized. Studies so far are inconclusive about the ability to use selective attention during WM in aging. To investigate the neural mechanisms supporting selective attention in WM in aging, we tested a large group of older adults using functional magnetic resonance imaging whilst they performed a category-based (faces/houses) selective-WM task. Older adults were able to use attention to encode targets and suppress distractors to reach high levels of task performance. A subsequent, surprise recognition-memory task showed strong consequences of selective attention. Attended items in the relevant category were recognized significantly better than items in the ignored category. Neural measures also showed reliable markers of selective attention during WM. Purported control regions including the dorsolateral and inferior prefrontal and anterior cingulate cortex were reliably recruited for attention to both categories. Activation levels in category-sensitive visual cortex showed reliable modulation according to attentional demands, and positively correlated with subsequent memory measures of attention and WM span. Psychophysiological interaction analyses showed that activity in category-sensitive areas were coupled with non-sensory cortex known to be involved in cognitive control and memory processing, including regions in the prefrontal cortex and hippocampus. In summary, we found that older adults were able to recruit a network of brain regions involved in top-down attention during selective WM, and individual differences in attentional control corresponded to the degree of attention-related modulation in the brain.
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10.
Attentional and working memory performance following alcohol and energy drink: A randomised, double-blind, placebo-controlled, factorial design laboratory study.
Benson, S, Tiplady, B, Scholey, A
PloS one. 2019;(1):e0209239
Abstract
Alcohol mixed with energy drinks (AMED) studies have typically not shown antagonism of acute alcohol effects by energy drink (ED), particularly over relatively short time frames. This study investigated the effects of alcohol, ED, and AMED on attentional and working memory processes over a 3 h period. Twenty-four young adults took part in a randomised, double-blind, placebo-controlled, factorial, 4-arm study. They were administered 0.6g/kg alcohol and 250 ml ED (containing 80 mg caffeine), and matching placebos alone and in combination. A battery of attentional and working memory measures was completed at baseline then 45, 90 and 180 min post-treatment. Alcohol produced a characteristic shift in speed/accuracy trade-off, having little effect on reaction times while increasing errors on all attentional measures (4-choice Reaction Time, Number Pairs and Visual Search), as well as a composite Attentional error score and one working memory task (Serial Sevens). ED alone improved two working memory measures (Memory Scanning accuracy and Digit-Symbol reaction times) and improved speed of responding on a composite Working Memory score. There was no consistent pattern of AMED vs. alcohol effects; AMED produced more errors than alcohol alone on one attentional measure (Visual Search errors) at 45 min only whereas AMED resulted in fewer errors on the Serial Sevens task at 90 min and better Digit-Symbol accuracy and reaction time at 45 min. Alcohol consumption increases error rate across several attentional and working memory processes. Mutual antagonism between alcohol and ED showed no consistent pattern and likely reflects a complex interaction between caffeine and alcohol levels, phase of the blood alcohol limb, task domain and cognitive load.