Auditory Verbal Learning Task Research Articles

Brain mGlu5 Is Linked to Cognition and Cigarette Smoking but Does Not Differ From Control in Early Abstinence From Chronic Methamphetamine Use.

The group-I metabotropic glutamate receptor subtype 5 (mGlu5) has been implicated in methamphetamine exposure in animals and in human cognition. Because people with methamphetamine use disorder (MUD) exhibit cognitive deficits, we evaluated mGlu5 in people with MUD and controls and tested its association with cognitive performance. Positron emission tomography was performed to measure the total VT of [18F]FPEB, a radiotracer for mGlu5, in brains of participants with MUD (abstinent from methamphetamine for at least 2 weeks, N = 14) and a control group (N = 14). Drug use history questionnaires and tests of verbal learning, spatial working memory, and executive function were administered. Associations of VT with methamphetamine use, tobacco use, and cognitive performance were tested. MUD participants did not differ from controls in global or regional VT, and measures of methamphetamine use were not correlated with VT. VT was significantly higher globally in nonsmoking vs smoking participants (main effect, P = .0041). MUD participants showed nonsignificant weakness on the Rey Auditory Verbal Learning Task and the Stroop test vs controls (P = .08 and P = .13, respectively) with moderate to large effect sizes, and significantly underperformed controls on the Spatial Capacity Delayed Response Test (P = .015). Across groups, Rey Auditory Verbal Learning Task performance correlated with VT in the dorsolateral prefrontal cortex and superior frontal gyrus. Abstinent MUD patients show no evidence of mGlu5 downregulation in brain, but association of VT in dorsolateral prefrontal cortex with verbal learning suggests that medications that target mGlu5 may improve cognitive performance.

Verbal fluency patterns associated with the amnestic conversion from mild cognitive impairment to dementia

Patients with amnestic mild cognitive impairment (aMCI) are at a higher risk of converting to Alzheimer's disease. The aim of this study was to examine the potential use of Verbal Fluency (VF) measures as markers for predicting the conversion to dementia. At baseline, 61 aMCI, aged 65 to 80 years, underwent a comprehensive neuropsychological assessment, including phonemic (PVF) and semantic verbal fluency (SVF) tasks. After 18 months, 14 individuals with aMCI had progressed to a diagnosis of dementia. The findings revealed that aMCI-converter group had lower Mini Mental State Examination and Rey Auditory Verbal Learning Task scores than aMCI-no converter and produced fewer clusters in both VF tasks and a lower number of switches in PVF at baseline (p < 0.05). According to receiver operating characteristic curve analysis, the number of clusters in PVF had the highest predictive value (AUC = 0.80) with a threshold of 5.510 for identifying aMCI-converter at baseline. Additionally, participants with higher levels of education exhibited more clusters and switches in VF tasks (p < 0.05). These results suggest that qualitative measures of VF could serve as neuropsychological markers for predicting cognitive decline in individuals with aMCI. Furthermore, the study highlights the potential influence of the education level on cognitive performance in neuropsychological tasks.

The Effects of Cognitive Ability, Mental Health, and Self-Quarantining on Functional Ability of Older Adults During the COVID-19 Pandemic: Results From the Canadian Longitudinal Study on Aging.

Determine whether levels of anxiety and depression, cognitive ability, and self-quarantining during and prior to the pandemic predict decreases in perceived functional ability. Longitudinal data collected from the Canadian Longitudinal Study on Aging (CLSA) COVID-19 Questionnaire Study (2020) and core CLSA study (Follow-Up 1; 2014-2018). 17541 CLSA participants. Self-quarantining behaviours from questionnaires administered at Baseline (April 2020), Monthly, and Exit (December 2020) time points of the CLSA COVID-19 Questionnaire Study, levels of anxiety and depression at Baseline, perceived change in functional ability at Exit, and performance on neuropsychological tests (Rey Auditory Verbal Learning Task, Mental Alternation Task, Animal Fluency Test) and functional ability (Older Americans Resources and Services [OARS] Multidimensional Assessment Questionnaire) from the core CLSA study. Greater cognitive ability pre-pandemic (B = -.003, P < .01), higher levels of anxiety (B = -.024, P < .01) and depressive symptoms (B = -.110, P < .01) at Baseline, and higher frequency of engaging in self-quarantining throughout the COVID-19 survey period (B = -.098, P < .01) were associated with perceived loss in functional ability at Exit. Self-quarantining behaviour was associated with perceived loss in functional ability only at average and high levels of depressive symptoms (B = -.013, P < .01). Older adults with higher cognitive and lower functional ability prior to the pandemic were at greater risk of decreased perceived functional ability during the first year of the pandemic, as were those who experienced greater levels of anxiety and depressive symptoms during the pandemic. Strategies/interventions to preserve functional ability in older adults with cognitive independence prior to future pandemics are warranted.

5 Combining Neurophysiology and Behavioral Measures to Identify Biomarkers of Clinical and Preclinical Hippocampus-Dependent Memory Dysfunction

Objective:Memory is a critical piece of the human experience and impairments in neural memory networks can have devastating consequences for the affected person. A subtype of memory, episodic memory generates context for the present based on past experience and allows us to make predictions about the future. Episodic memories become stable fixtures through long-term memory consolidation. It is believed that consolidation of episodic memory requires a dynamic interplay between connected hippocampal-cortical networks, mainly during sleep. Sleep oscillations, slow oscillations and thalamocortical spindles, coupled with hippocampal sharp wave ripples (SWR) is proposed to be mechanistically involved in establishing the crucial cortical-subcortical dialog. The current study aimed to determine alterations in typical sleep oscillations and oscillation coupling in patients with and without structural hippocampal damage and correlate them with neuropsychological measures believed to be sensitive to hippocampal dysfunction, i.e., Rey Auditory Verbal Learning Task (RAVLT) and Verbal Paired Associates (VPA-II).Participants and Methods:We used intracranial electroencephalography (iEEG) in 14 patients with epilepsy to directly record hippocampal and neocortical oscillations and neuropsychological measures obtained prior to implantation. Half of the participants were diagnosed with mesial temporal sclerosis (MTS) in the left hippocampus and healthy tissue in the right hippocampus. The other half did not have MTS and had either mesial temporal epilepsy without MTS or extra-temporal seizures. We analyzed hippocampal SWR output from both hippocampi and characterized neocortical slow oscillations and spindles and their coupling for each participant. We correlated electrophysiological data with behavioral results of neuropsychological testing in order to characterize the clinical relevance.Results:SWR analysis revealed significant differences in the frequency, t(7639) = 15.52, p&gt;.001, p &gt; .001), amplitude, t(7664) = -23.93, p &gt; .001, and waveforms (p &gt; .001) of SWR in the sclerotic versus healthy hippocampi. Patients with a sclerotic hippocampus but relatively preserved verbal memory scores (RAVLT, VPA-II) showed increased SWR amplitudes in the contralateral hippocampus compared to patients with low verbal memory scores. Additionally, we found differences between hemispheres in phase amplitude coupling of SWRs to spindles and SOs (p &gt; 0.001). Results of our correlational analysis were variable and dependent upon additional factors, such as age of onset and diagnosis duration.Conclusions:Results from this work will aid in establishing a criterion for characterizing a relationship between subcortical and cortical oscillations as they relate to memory performance. Besides aiding our understanding of the neural mechanisms underpinning memory consolidation this will ideally help with developing neurophysiological biomarkers that may predict possible memory decline in resective or ablative neurosurgery absent of structural lesion. In addition, this work may potentially provide first evidence of a neurophysiological biomarker directly recorded from the human hippocampus to support possible reorganization of memory functioning in the non-sclerotic hippocampus.

4 Misinterpreting cognitive change over multiple timepoints: When practice effects meet age-related decline

Objective:Practice effects (PE) on cognitive testing impede our ability to accurately assess change. In particular, they hamper the detection of mild cognitive impairment (MCI) and progression to dementia by delaying the point at which test scores fall below diagnostic impairment cutoffs. When decline over time is expected, as with older adults or progressive diseases, failure to adequately address PEs may lead to inaccurate conclusions because PEs artificially boost scores while pathology-related or age-related decline reduces scores. The participant-replacement method accounts for PEs by comparing performance of demographically-matched replacement participants to returnees who have been tested previously. Unlike most methods, the participant-replacement method can separate pathology- or age-related decline from PEs; however, this method has only been used across two timepoints. Neuropsychologists tend to think that PEs level out after the first follow-up, but this issue has not been evaluated in models that allow PEs in the presence of overall decline. Including more than two timepoints makes it possible to determine if PEs level out after the first follow-up, but it is analytically challenging because individuals may not be assessed at every timepoint.Participants and Methods:We examined 1190 older adults in the Alzheimer’s Disease Neuroimaging Initiative who were cognitively unimpaired (n=809) or had MCI (n=381) at baseline. Participants completed six neuropsychological measures (Trails A, Trials B, Boston Naming Test, Category Fluency, Logical Memory, Rey Auditory Verbal Learning Task) at three timepoints (baseline, 12-month, 24-month). We implemented the participant-replacement method using generalized estimating equations in comparisons of matched returnees and replacements to calculate PEs. Propensity scores matched individuals on age, education, sex, and an estimate of premorbid functioning. Generalized estimating equations modeled PEs and age-related decline separately for each cognitive measure.Results:We observed significant PEs for 5 of the 6 measures in the cognitively unimpaired group and 4 measures in the baseline MCI group. PEs did not uniformly decrease across time; some—specifically on episodic memory measures—continued to increase beyond the first follow-up for both groups of participants. Without accounting for PEs, cognitive function appeared to improve or stay the same. In contrast, when PEs were included in the models, cognitive function appeared to decline or stay the same across time.Conclusions:The replacement method of PE adjustment revealed significant PEs across two follow-ups. PEs for episodic memory, in particular, did not level out, but actually increased after the first follow-up, two years after baseline. As expected in these older adults, accounting for PEs revealed cognitive decline, in some cases, even when PE-unadjusted scores improved. This method of assessing PEs, in turn, means earlier detection of cognitive deficits, including progression to MCI, and more accurate characterization of longitudinal change.

Sex-specific impulsivity, but not other facets of executive function, predicts fat and sugar intake two-years later amongst adolescents with a healthy weight: Findings from the ABCD study

During adolescence, processes that control food intake (executive functions [EF]) undergo extensive refinement; underlying differences in EF may explain the inability to resist overeating unhealthy foods. Yet, overeating fat and sugar also causes changes to EF and cognition but disentangling these relationships has been difficult, as previous studies included youth with obesity. Here, amongst youth initially of a healthy weight, we evaluate whether 1) sex-specific underlying variation in EF/cognition at 9/10-years-old predict fat/sugar two-years later (Y2) and 2) if these relationships are moderated by body mass index (BMI), using linear mixed effects models (controlled for puberty, caregiver education; random effect: study site). Data were leveraged from Adolescent Brain Cognitive Development Study (n = 2987; 50.4% male; 15.4% Latino/a/x; 100% healthy weight at baseline; 12.4% overweight/obese by Y2, data release 4.0). EF and cognition (e.g., inhibition, cognition, motor, memory, impulsivity) were assessed with the NIH toolbox, Rey Auditory Verbal Learning Task, Little Man Task, the BIS/BAS, and UPPS-P. A saturated fat/added sugar (kcals) composite score was extracted from the validated Kids Food Block Screener. For males, greater baseline impulsivity (e.g., Positive Urgency, Lack of Planning and Perseverance) and reward (e.g., Fun seeking, Drive) was related to greater Y2 intake. For both sexes, greater baseline Negative Urgency and higher BMI was related to greater Y2 intake. No other relationships were observed. Our findings highlight a phenotype that may be more at risk for weight gain due to overconsumption of fat/sugar. Thus, prevention efforts may wish to focus on impulsive tendencies for these foods.

Language MEG predicts postoperative verbal memory change in left mesial temporal lobe epilepsy

ObjectiveTo clarify whether preoperative language magnetoencephalography (MEG) predicts postoperative verbal memory (VM) changes in left mesial temporal lobe epilepsy (LMTLE). MethodsWe reviewed 18 right-handed patients with LMTLE who underwent anterior temporal lobectomy or selective amygdala hippocampectomy, 12 with (HS+) and 6 without hippocampal sclerosis (HS−). Patients underwent neuropsychological assessment before and after surgery. MEG was measured with an auditory verbal learning task in patients preoperatively and in 15 right-handed controls. Dynamic statistical parametric mapping (dSPM) was used for source imaging of task-related activity. Language laterality index (LI) was calculated by z-score of dSPM in language-related regions. LI in the region of HS+ and HS− was compared to controls. The correlation between LI and postoperative VM change was assessed in HS+ and HS−. ResultsPreoperative LI in supramarginal gyrus showed greater right-shifted lateralization in both HS+ and HS− than in controls. Right-shifted LI in supramarginal gyrus was correlated with postoperative VM increase in HS+ (p = 0.019), but not in HS−. ConclusionsRight-shifted language lateralization in dSPM of MEG signals may predict favorable VM outcome in HS+ of LMTLE. SignificanceFindings warrant further investigation of the relation between regional language laterality index and postoperative verbal memory changes.

Vitamin D is associated with visual memory in young northern adolescents

ABSTRACT Background Vitamin D status has been linked to visual memory in adults. We hypothesized a similar association in young adolescents. Methods Participants were 9–13 years. The Rey-Osterrieth Complex Figure Task (ROCF), Rey Auditory Verbal Learning Task (RAVLT), Digit Span (Forward, Backward), and verbal fluency task assessed visual and verbal learning/memory, attention/working memory, and executive functioning/language, respectively. An at-home, mail-in blood spot test assessed 25(OH)D levels. Results Participants (N = 56) were 10.7 ± 1.3 years, 61% females, 25(OH)D levels 84.2 ± 25 nmol/L(39.9 - 167.2 nmol/L) and 41% had insufficient vitamin D status (<75 nmol/L). Only measures of visual memory (ROCF-Recall, -%Recall of Copy) were significantly correlated with 25(OH)D, r = .34, p < .01 and r = .33, p < .01, respectively, and 25(OH)D remained a significant independent predictor on multiple regression analyses, which included age and sex.(ROCF-Recall overall model: Adj R2 = .24, p < .001; for 25(OH)D: p = .009; ROCF-%Recall of Copy overall model: Adj R2 = .20 p < .002; for 25(OH)D: p = .01). Individuals with sufficient vitamin D performed significantly better only on these measures (t-tests; ROCF-Recall, p = .016, d = 0.68; ROCF-%Recall of Copy, p = .022, d = 0.64). Despite moderate effect sizes (d = 0.4–0.5) in the Younger Age Group (9–10 years), only in the Older Age Group (11–13 years) was 25(OH)D significantly correlated with ROCF-Recall, r = .64, p = .0001 and ROCF-%Recall of Copy, r = .64, p = .0001, as well as working memory (Digit Span-Backward), Spearman’s r = .46, p = .013. Similarly, those in the Older Age Group with sufficient vitamin D performed significantly better on ROCF-Recall, p = .01, d = 1.07; and ROCF-%Recall of Copy, p = .009, d = 1.08. Conclusions Vitamin D insufficiency was common in young adolescents. Similar to adults, visual memory was better among participants with higher 25(OH)D and those with sufficient levels. This effect was especially pronounced among older participants, suggesting possible time- and/or age-related implications of vitamin D status on cognition.

Wild blueberry (poly)phenols can improve vascular function and cognitive performance in healthy older individuals: a double-blind randomized controlled trial

BackgroundEvidence suggests that the intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown. MethodsA double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65–80 y. Participants received either 26 g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome, and blood parameters were measured at baseline and 12 wk following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using microelution solid-phase extraction coupled with liquid chromatography–mass spectrometry. ResultsA significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared with the placebo group (0.86%; 95% CI: 0.56, 1.17, P < 0.001; −3.59 mmHg; 95% CI: −6.95, −0.23, P = 0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task was also found following WBB treatment compared with placebo (P < 0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared with placebo. No changes in the CBF or gut microbiota composition were found. ConclusionsDaily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function and decreases 24 h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future CVD risk in an older population and may improve episodic memory processes and executive functioning in older adults at risk for cognitive decline.Clinical Trial Registration number in clinicaltrials.gov: NCT04084457.

The influence of Apolipoprotein E ε4 carrier status on posterior cingulate cortex thickness and learning

AbstractBackgroundThinning of the posterior cingulate cortex (PCC) is implicated in Alzheimer’s disease (AD). Though some evidence suggests ApolipoproteinE (APOE) ε4 carriers (ε4+) have thinner PCCs than non‐carriers (ε4‐), the evidence is conflicting and lacks association with learning outcomes relevant to AD.MethodA subset from an ongoing clinical trial (NIH/NIA: R01AG058919) was used for analyses and included 26 ε4+ (73% female, Agemean=55.81±5.53) and 42 ε4‐ (88% female, Agemean= 57.54±5.10), who were all cognitively normal, sedentary, and had a family history of AD. Genetic sampling was completed via passive drool. Structural MRI was completed to assess PCC cortical thickness, and the Rey Auditory Verbal Learning Task (AVLT) was used to assess learning. Brain segmentation was completed with Freesurfer’s automated pipeline, and left and right PCC cortical thickness was extracted for analysis. A learning over trials (LOT) composite score from the AVLT was calculated to represent learning. An analysis of covariance was completed to assess the effect of carrier status on left/right PCC thickness, controlling for age and sex. Linear regressions were completed to assess main effects and interaction of carrier status and left/right PCC thickness in predicting LOT when controlling for age and sex.Resultε4+ had less cortical thickness in the left PCC (F(1,64)=5.07, p=.03), but not the right PCC (p=.33), relative to ε4‐. Carrier status predicted LOT (Left: F(1,62)=10.37, p&lt;.01; Right: F(1,62)=10.66, p&lt;.01), however this was superseded by significant interactions between carrier status and PCC thickness predicting LOT (Left: F(1,62)=10.72, p&lt;.01; Right: F(1, 62)=11.10, p&lt;.01), with post‐hoc analyses demonstrating PCC thickness predicts LOT for ε4+ (Left:β=‐21.07, p=.04; Right:β=‐24.33, p&lt;.01), but not ε4‐ (p’s&gt;.09).ConclusionIn cognitively normal sedentary adults with a family history of AD, carrying the APOE ε4 allele was associated with a thinner left PCC. Further, thinner bilateral PCCs in ε4+ were associated with greater learning during the AVLT task. This suggests that ε4+ may have compensatory neural pathways to account for losses in the PCC, which temporarily bolster learning to delay the onset of AD. However, additional research is needed to continue understanding the neural mechanisms affected by carrying the APOE ε4 allele.

The effects of physical activity timing and complexity on episodic memory: A randomized controlled trial

The role of two types of acute physical activity (PA) bouts were assessed on young adults’ free-recall and recognition memory in two experiments, which differed in the temporal relation of PA and word encoding. Before or following training on the Rey Auditory Verbal Learning Task, participants performed a simple two-step dance, a complex four-step dance, or remained seated. Hypotheses proposed that PA prior to encoding and complex PA would enhance PA’s mnemonic benefits. Memory assessed post-PA, 24 h, and 7 days after training indicated that timing and complexity of PA did not impact free-recall or recognition memory. Findings differ from a previous study showing complex PA benefited motor learning more than simple PA (Tomporowski & Pendleton, 2018). The inconsistency may be due to different working memory processes underlying consolidation and retrieval of procedural or episodic information. Theory-based explanations regarding memory storage and retrieval are proposed to elucidate this selective process.

Verbal Learning and Longitudinal Hippocampal Network Connectivity in Temporal Lobe Epilepsy Surgery.

IntroductionLearning new verbal information can be impaired in 20–40% of patients after mesial temporal lobe resection. In recent years, understanding epilepsy as a brain network disease, and investigating the relationship between large-scale resting networks and cognition has led to several advances. Aligned studies suggest that it is the integrity of the hippocampal connectivity with these large-scale networks what is relevant for cognition, with evidence showing a functional and structural heterogeneity along the long axis hippocampus bilaterally.ObjectiveOur aim is to examine whether pre-operative resting-state connectivity along the long hippocampal axis is associated with verbal learning decline after anterior temporal lobe resection.MethodsThirty-one patients with epilepsy who underwent an anterior temporal lobe resection were pre-surgically scanned at 3-tesla, and pre/post-surgery evaluated for learning deficits using the Rey Auditory Verbal Learning Task (RAVLT). Eighteen controls matched by age, gender and handedness were also scanned and evaluated with the RAVLT. We studied the functional connectivity along the (anterior/posterior) long axis hippocampal subregions and resting-state functionally-defined brain networks involved in learning [executive (EXE), dorsal attention (DAN) and default-mode (DMN) networks]. Functional connectivity differences between the two groups of patients (learning intact or with learning decline) and controls were investigated with MANOVA and discriminant analysis.ResultsThere were significant differences in the pattern of hippocampal connectivity among the groups. Regarding the anterior connectivity hippocampal pattern, our data showed an increase of connectivity in the pathological side with the DAN (p = 0.011) and the EXE (p = 0.008) when comparing learning-decline vs. learning-intact patients. Moreover, the non-pathological side showed an increase in the anterior connectivity pattern with the DAN (p = 0.027) between learning-decline vs. learning-intact patients. In contrast, the posterior hippocampus showed a reduction of connectivity in the learning-decline patients with the DMN, both in the pathological (p = 0.004) and the non-pathological sides (p = 0.036). Finally, the discriminant analysis based on the pre-operative connectivity pattern significantly differentiated the learning-decline patients from the other groups (p = 0.019).ConclusionOur findings reveal bilateral connectivity disruptions along the longitudinal axis of the hippocampi with resting-state networks, which could be key to identify those patients at risk of verbal learning decline after epilepsy surgery.

Elevated serum Neurofilament Light chain (NfL) as a potential biomarker of neurological involvement in Myotonic Dystrophy type 1 (DM1)

BackgroundCognitive and behavioural symptoms due to involvement of the central nervous system (CNS) are among the main clinical manifestations of Myotonic Dystrophy type 1 (DM1). Such symptoms affect patients’ quality of life and disease awareness, impacting on disease prognosis by reducing compliance to medical treatments. Therefore, CNS is a key therapeutic target in DM1. Deeper knowledge of DM1 pathogenesis is prompting development of potential disease-modifying therapies: as DM1 is a rare, multisystem and slowly progressive disease, there is need of sensitive, tissue-specific prognostic and monitoring biomarkers in view of forthcoming clinical trials. Circulating Neurofilament light chain (NfL) levels have been recognized as a sensitive prognostic and monitoring biomarker of neuroaxonal damage in various CNS disorders.MethodsWe performed a cross-sectional study in a cohort of 40 adult DM1 patients, testing if serum NfL might be a potential biomarker of CNS involvement also in DM1. Moreover, we collected cognitive data, brain MRI, and other DM1-related diagnostic findings for correlation studies.ResultsMean serum NfL levels resulted significantly higher in DM1 (25.32 ± 28.12 pg/ml) vs 22 age-matched healthy controls (6.235 ± 0.4809 pg/ml). Their levels positively correlated with age, and with one cognitive test (Rey’s Auditory Verbal learning task). No correlations were found either with other cognitive data, or diagnostic parameters in the DM1 cohort.ConclusionsOur findings support serum NfL as a potential biomarker of CNS damage in DM1, which deserves further evaluation on larger cross-sectional and longitudinal studies to test its ability in assessing brain disease severity and/or progression.

Sex differences in the acute effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC).

Cannabis is the most common illicit drug used in the USA and its use has been rising over the past decade, while the historical gap in rates of use between men and women has been decreasing. Sex differences in the effects of cannabinoids have been reported in animal models, but human studies are sparse and inconsistent. We investigated the sex differences in the acute subjective, psychotomimetic, cognitive, and physiological effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis. Healthy male and female individuals, with limited exposure to cannabis, participated in a double blind, placebo-controlled study of intravenous (IV) placebo or THC at two doses (0.015mg/kg and 0.03mg/kg). Visual analog scale (VAS) was used to measure subjective effects, Psychotomimetic States Inventory (PSI) and the Clinician-Administered Dissociative Symptoms Scale (CADSS) were used to assess the psychotomimetic effects and perceptual alterations, respectively, and Rey Auditory Verbal Learning Task (RAVLT) was used to evaluate cognitive effects. Outcome variables were represented as the peak change from baseline for each variable, except RAVLT which was used only once per the test day after the subjective effects. A total of 42 individuals participated in this study. There were no significant differences between male and female participants in background characteristics. There was a significant main effect of sex on the VAS scores for THC-induced "High" (F1,38 = 4.27, p < 0.05) and a significant dose × sex interaction (F2,77 = 3.38, p < 0.05) with female participants having greater "High" scores than male participants at the lower THC dose (0.015mg/kg). No other sex differences were observed in acute subjective, psychotomimetic, cognitive, or physiological effects of THC. There were significant sex differences in subjective effects of feeling "High" at a lower dose of THC. However, there were no other sex-related differences in the subjective, physiological, or cognitive effects of THC.

Life span strategy implementation in verbal learning: size and type of cluster adoption

ABSTRACT Temporal and semantic associative processes during the acquisition of new verbal information undergo various changes across the life span. Temporal order clusters and subjective clusters were monitored during verbal learning trials using the Rey (Auditory Verbal Learning Task) for 1471 participants aged 8–91. Pairs, three-word, and four-word clusters were measured. Subjective clusters were generated at similar frequency across the whole life span. By contrast, a clear inverted-U curve across life span was indicated for temporal clusters. More words were subjectively clustered than clustered by temporal presentation order. The number of words clustered increased across trials, and cluster types showed a different increase profile across trials. The subjective cluster increment was faster and steeper than the temporal cluster increment in most of the age segments. Life span trajectory tendencies in the formation of temporal and semantic associations in recall were interpreted in relation to different frameworks of cognitive life span changes.

Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance.

Cannabis use is associated with relative cognitive weaknesses as observed by cross-sectional as well as longitudinal research. Longitudinal studies, controlling for relevant confounds, are necessary to differentiate premorbid from post-initiation contributions to these effects. We followed a sample of adolescents and young adults across ten years. Participants provided neurocognitive data and substance use information at two-year intervals. Participants who initiated cannabis and/or alcohol use were identified (n = 86) and split into alcohol-only initiators (n = 39) and infrequent (n = 29) and moderately frequent (n = 18) cannabis initiators. Participants completed the Rey Auditory Verbal Learning Task (RAVLT) and the Iowa Gambling Task (IGT). Group differences before and after substance use initiation and the extent to which alcohol, nicotine, and cannabis use frequencies contributed to cognitive functions over time were examined. After controlling for parental education, RAVLT new learning was worse in moderately frequent cannabis users prior to use initiation. RAVLT total learning and delayed recall showed significant declines from pre- to post-initiation in moderately frequent cannabis users. Regression analyses confirmed that frequencies of cannabis, but not alcohol, use contributed to post-initiation variations. Nicotine use showed an independent negative association with delayed memory. Findings for the IGT were not significant. Verbal learning and memory may be disrupted following the initiation of moderately frequent cannabis use while decreased new learning may represent a premorbid liability. Our use of a control group of alcohol-only users adds interpretive clarity to the findings and suggests that future studies should carefully control for comorbid substance use.

From Learning to Memory: A Comparison Between Verbal and Non-verbal Skills in 22q11.2 Deletion Syndrome.

Background: Previous studies on possible memory deficits in 22q11DS often focused on quantifying the information memorized, whereas learning processes have been mostly overlooked. Furthermore, methodological differences in task design have made verbal and non-verbal comparison challenging and mixed results have been observed depending on chosen stimuli.Method: 135 participants (78 with 22q11DS) completed a multi-trial memory task modeled after the Rey Auditory Verbal Learning Task, comparing verbal and non-verbal learning as well as retention over time. Performance in the 22q11DS group were compared to controls and learning curves were analyzed.Results: In 22q11DS, slower acquisition of non-verbal material and higher rates of errors in both verbal and non-verbal tasks was observed. After 30 min, free recall performance, when corrected for initial learning rate, was similar between 22q11DS and controls. Conversely, recognition performance was overall weaker for 22q11DS in both modalities (verbal and non-verbal).Conclusion: This study examined how information is acquired, retained in memory over time and how different recall modalities (free recall vs. recognition) could yield different performances. Clinical implications of the findings are discussed.

Effects of daily consumption of wild blueberry on cognition and urinary metabolites in school-aged children: a pilot study

PurposeAcute intervention with wild blueberry (WBB) has previously revealed positive cognitive and mood effects in typically developing children; however, it is unclear whether effects persist after daily supplementation. In addition, no data have been published exploring the metabolite profiles of children following berry consumption, to our knowledge. A study of this kind could provide insight into a mechanism of action for the cognitive and mood improvements observed previously in children. The aim of this pilot study was to assess cognitive performance and urinary metabolite concentrations in healthy 7–10-year-old children across a 4 week daily WBB drink intervention.MethodsThis pilot study examined the effects of daily WBB consumption for 4 weeks (766 mg total polyphenols; 253 mg anthocyanins; equivalent to 240 g fresh blueberries per day) on cognition and mood in 15 healthy 7–10-year-old children. Polyphenol metabolites were measured in 24 h urine before and after the 4 week intervention.ResultsChronic WBB-related benefits were seen on cognitively demanding trials on the modified attention network task, a task measuring executive functioning. Specifically, the WBB group maintained significantly higher accuracy on incongruent trials (96%; SE 0.03) compared with placebo participants (85%; SE 0.03; p = 0.038) after the 4 week intervention, suggesting WBB was of most benefit on the more difficult aspects of the task. No significant WBB-related effects were observed on the auditory verbal learning task or the child’s version of the positive and negative affect schedule. Urinary metabolite analyses indicated significant increases in different metabolites in WBB and placebo groups after 4 week consumption.ConclusionThe research demonstrates 24 h WBB bioavailability in a child cohort for the first time with increases in urinary hippuric acid excretion during 2 week daily WBB consumption. This study highlights the importance of conducting a larger study in children investigating the mechanism of action behind cognitive effects using bioavailability data.

One Hour-Post-load Plasma Glucose ≥155 mg/dl in Healthy Glucose Normotolerant Subjects Is Associated With Subcortical Brain MRI Alterations and Impaired Cognition: A Pilot Study.

Background: Glucose alterations are associated with impaired cognition. The 1-h-post-load plasma glucose ≥155 mg/dl in non-diabetic subjects confers an increased risk of cardiovascular events and diabetes. This pilot study aimed to investigate whether the 1-h-post-load plasma glucose ≥155 mg/dl negatively affects the subcortical regions of the brain and the cognitive functions.Methods: We enrolled 32 non-diabetic subjects. Patients were divided into two groups based on 1-h- post-load plasma glucose value > or < 155 mg/dl: normal glucose tolerance (NGT) 1-h-high and NGT 1-h-low subjects. All subjects underwent 3 Tesla MRI and standard neuropsychological tests.Results: NGT 1-h-high subjects showed significantly lower values of both right (4.9 ± 0.9 vs. 5.1 ± 0.9 ml) and left (4.8 ± 1.1 vs. 5.1 ± 1.1 ml) hippocampal hemisphere volume, while right hemisphere hippocampal diffusivity was lower in the NGT 1-h-high group (10.0 ± 0.6 vs. 10.6 ± 0.5 10−4 mm2s−1). NGT 1-h-high subjects also showed a poorer memory performance. In particular, for both Rey Auditory Verbal Learning Task (RAVLT)—immediate-recall and Free and Cued Selective Reminding Test (FCSRT)—delayed total recall, we found lower cognitive test scores in the NGT-1 h-high group (26.5 ± 6.3 and 10.4 ± 0.3, respectively).Conclusions: One-hour-post-load hyperglycemia is associated with morpho-functional subcortical brain alterations and poor memory performance tests.

The effectiveness of Bacopamonnieri (Linn.) Wettst. as a nootropic, neuroprotective, or antidepressant supplement: analysis of the available clinical data

Bacopamonnieri (Linn.) Wettst. has been used in traditional medicine as a drug to enhance and improve memory. In this regard, this study aims to provide B. monnieri's efficacy as a neuroprotective drug and as a nootropic against various neurological diseases. Literatures were collected, following Prisma guidelines, from databases, including Scopus, PubMed, Google Scholar, and Science Direct and were scrutinized using a quality scoring system. Means, standard deviations and ‘n’ numbers were extracted from the metrics and analyzed. Jamovi computer software for Mac was used to carry out the meta-analysis. The selected studies suggested that the plant extracts were able to show some improvements in healthy subjects which were determined in Auditory Verbal Learning Task, digit span-reverse test, inspection time task and working memory, even though it was not significant, as no two studies found statistically significant changes in the same two tests. B. monnieri was able to express modest improvements in subjects with memory loss, wherein only a few of the neuropsychological tests showed statistical significance. B. monnieri in a cocktail with other plant extracts were able to significantly reduce the effects of Alzheimer’s disease, and depression which cannot be solely credited as the effect of B. monnieri. Although in one study B. monnieri was able to potentiate the beneficial effects of citalopram; on the whole, currently, there are only limited studies to establish the memory-enhancing and neuroprotective effects of B. monnieri. More studies have to be done in the future by comparing the effect with standard drugs, in order to establish these effects clinically in the plant and corroborate the preclinical data.