Visual Information Processing Task Research Articles

Structural brain correlates of sustained attention in healthy ageing: Cross-sectional findings from the LEISURE study

Sustained attention is important for maintaining cognitive function and autonomy during ageing, yet older people often show reductions in this domain. The role of the underlying neurobiology is not yet well understood, with most neuroimaging studies primarily focused on fMRI. Here, we utilise sMRI to investigate the relationships between age, structural brain volumes and sustained attention performance. Eighty-nine healthy older adults (50–84 years, Mage 65.5 (SD=8.4) years, 74 f) underwent MRI brain scanning and completed two sustained attention tasks: a rapid visual information processing (RVP) task and sustained attention to response task (SART). Independent hierarchical linear regressions demonstrated that greater volumes of white matter hyperintensities (WMH) were associated with worse RVP_A’ performance, whereas greater grey matter volumes were associated with better RVP_A’ performance. Further, greater cerebral white matter volumes were associated with better SART_d’ performance. Importantly, mediation analyses revealed that both grey and white matter volumes completely mediated the relationship between ageing and sustained attention. These results explain disparate attentional findings in older adults, highlighting the intervening role of brain structure.

Dual low-rank structure embedding for robust visual information processing

The low-rank (LR) property is widely applied to capture the global as well as intrinsic structure of the given data in different visual information processing tasks. Actually, there are three key information to determine the performance and generalization low-rank property based methods: (1) visual intrinsic structural information, (2) visual representation structural information, (3) visual robust information. To achieve these jointly in a unified framework, in this paper, we propose Dual Low-rank Structure Embedding (DLSE) that embeds structural and robust information. We additionally proposed the Joint Matrix-based Linear Representation (JMLR) and theoretically proved it can realize DLSE. The proposed method was validated on 6 datasets (from 1,440 samples to 70,000 samples in size) and showed a promising performance in visual recognition (14.32% improvement compared with the deep features). In addition, we performed multiple analysis on robustness, representation, and its parameters to show the effectiveness of DLSE from different aspects.

Chronic supplementation of a multi-ingredient herbal supplement increases speed of cognitive task performance alongside changes in the urinary metabolism of dopamine and the gut microbiome in cognitively intact older adults experiencing subjective memory decline: a randomized, placebo controlled, parallel groups investigation.

The effects of herbs on brain function are often investigated in isolation, yet herbal preparations are often complex combinations of phytochemicals, designed to target widespread mechanisms. To assess the effects of chronic, 12 weeks, supplementation of a multi-ingredient herbal supplement (containing Bacopa monnieri, Gotu kola leaf, Turmeric whole powder, Reishi full spectrum, Rosemary, Cardamom, Holy Basil, Turmeric Wholistic™ extract, Green Tea & Seagreens) on cognitive function in older adults with subjective memory decline. Secondly, to investigate whether effects are underpinned by shifts in microbial composition and/or metabolism of the herbs. Male and female participants (N = 128) aged between 55-75 years completed lab-based cognitive assessments, and provided stool and urine samples, at baseline and then following 90 days of multi-ingredient herb, or placebo, supplementation. Deficits in memory were observed in response to 90 days of multi-ingredient herbal supplement supplementation but the positive effects were all focused on speed of cognitive task performance, with an additional improvement in the false alarm rate on the rapid visual information processing task. These improvements coincided with an increased presence of tyrosine in the urinary metabolome and this may implicate the role of dopamine in these processing and/or motor speed increases. Finally, multi-ingredient herbal supplementation significantly reduced levels of 3 bacterial species in the gut microbiome and one of these, Sutterella, coincides with lower levels of constipation reported in the multi-ingredient herbal supplement condition. A multi-ingredient herbal supplement increases speed of cognitive task performance and increased metabolism of tyrosine suggests that this is modulated by increased dopaminergic activity. Reduced levels of Sutterella in the gut is associated with improved bowel movements of participants. Interpretation of the negative effects on memory are, however, stymied by an unequal randomization of participants into treatment groups pre- and post-COVID 19.Clinical trial registration: identifier NCT05504668.

Attentional problems occur across multiple psychiatric disorders and are not specific for ADHD.

Attentional problems are common and have been associated with multiple psychiatric disorders. This study examined problems of sustained attention across a range of psychiatric disorders using a validated computerized trans-diagnostic attentional paradigm (a continuous performance task). We hypothesized that multiple psychiatric disorders, particularly attention deficit hyperactivity disorder (ADHD), would be associated with pronounced attentional problems. Totally, 576 non-treatment seeking participants (aged 18-29years) were enrolled from general community settings, provided demographic variables, and underwent clinical assessments to detect mental health disorders. Each participant underwent the rapid visual information processing task, a validated computerized test measuring sustained attention. The two measures of sustained attention were the sensitivity index and target detection (proportion of targets detected). The profile of attentional deficits was examined across different disorders using z-scores relative to controls. Participants with social phobia, obsessive-compulsive disorder (OCD), bulimia nervosa, and intermittent explosive disorder showed the greater impairment in target sensitivity, all with effect sizes of at least 0.8. Target detection was impaired across multiple disorders, with OCD and binge eating disorder exhibiting the most pronounced impairment. Post-traumatic stress disorder (PTSD) and compulsive sexual behavior were associated with particularly spared performance on both measures. These data indicate that impaired attention is non-specific for ADHD and in fact several other disorders are associated with markedly larger deficits. Instead of clinicians assuming sustained attention problems are due to ADHD, a variety of disorders should be screened for when people report attentional problems. Future work should examine the contribution of comorbidities and psychoactive substances (prescribed or illicit) to the profiles identified.

Neural correlates of expectations-induced effects of caffeine intake on executive functions

Placebo effects are defined as the beneficial subjective or behavioral outcomes of an intervention that are not attributable to its inherent properties; Placebo effects thus follow from individuals’ expectations about the effects of the intervention. The present study aimed at examining how expectations influence neurocognitive processes.We addressed this question by contrasting three double-blinded within-subjects experimental conditions in which participants were given decaffeinated coffee, while being told they had received caffeinated (condition i) or decaffeinated coffee (ii), and given caffeinated coffee while being told they had received decaffeinated coffee (iii).After each of these three interventions, performance and electroencephalogram was recorded at rest as well as during sustained attention Rapid Visual Information Processing task (RVIP) and a Go/NoGo motor inhibitory control task.We first aimed to confirm previous findings for caffeine-induced enhancement on these executive components and on their associated electrophysiological indexes (The Attention-P3 component, response conflict NoGo-N2 and inhibition NoGo-P3 components (ii vs iii contrast); and then to test the hypotheses that expectations also induce these effects (i vs ii), although with a weaker amplitude (i vs iii).We did not confirm any of our hypotheses for caffeine-induced behavioral improvements and thus did not test the effect of caffeine-related expectations. At the electrophysiological level, however, we confirmed that caffeine increased the Attention-P3 and NoGo-P3 components amplitude but did not confirm an effect on the response-conflict N2 component. We did not confirm that expectations influence any of the investigated electrophysiological indices, but we confirmed that the Attention-P3 Global Field Power values were larger for the caffeine compared to the expectations conditions.We conclude that previously identified behavioral effect size of caffeine and of the related expectations for sustained attention and inhibitory control may have been overestimated, and that caffeine primarily influences the cognitive processes and brain areas supporting attention allocation. Finally, we confirm that caffeine-related expectations induce smaller effects than the substance itself.

Association of Lithium and Second-Generation Antipsychotics with Neurocognition in Youth with Bipolar Disorder.

Objective: Numerous studies have examined the association of antimanic medications with neurocognition in adults with bipolar disorder (BD). However, few studies have examined this topic in youth. Thus, we aimed to examine the association of lithium and second-generation antipsychotics (SGAs), the first-line antimanic medications for youth with BD, with neurocognition in a relatively large sample of youth with BD.Methods: Participants included 91 youth with BD-I, -II, or -Not Otherwise Specified, aged 13–20 years (n = 14 current lithium use, n = 51 current SGA use). We examined four tests from the Cambridge Neuropsychological Test Automated Battery: Intra/Extra Dimensional Set-Shifting Task (IED), Rapid Visual Information Processing Task (RVP), Stockings of Cambridge Test (SOC), and Affective Go/No-Go (AGN). Within-sample Z-scores were computed, and a global neurocognitive composite score and g factor derived from these tests comprised the primary outcomes. Multivariable analyses controlled for age, sex, and IQ.Results: Current lithium use was significantly associated with poorer cognitive flexibility/set-shifting (IED). After further controlling for lifetime comorbid attention-deficit/hyperactivity disorder and current depression symptoms in sensitivity analyses, the lithium finding was no longer significant. Current SGA use was significantly associated with greater affective processing bias (AGN). No significant findings survived correction for multiple comparisons. All other cognitive outcomes were not significantly associated with current lithium use, current SGA use, or total number of current medications.Conclusions: Treatment with lithium or SGAs was associated with minimal neurocognitive impairments, with small effect sizes in primary multivariable analyses. This study adds to the limited body of literature examining medication use in relation to neurocognition in youth with BD. While the current study cannot rule out associations of smaller effect size, present findings suggest that leading mood-stabilizing medications are not associated with frank neurocognitive impairments in youth with BD.

Acute cognitive performance and mood effects of coffee berry and apple extracts: A randomised, double blind, placebo controlled crossover study in healthy humans

ABSTRACT Background: Polyphenols from coffee berry (chlorogenic acid) and apple (flavanol) have been shown to improve mood and increase cerebral blood flow in healthy humans. These effects may underpin the cognitive effects of polyphenols seen previously. Objective: The aim of the present paper was to extend previous research by investigating the effects of coffee berry at high and low doses when combined with apple extract on cognitive performance and mood. Design: This randomised, double-blind, placebo controlled, crossover trial included 46 healthy males and females,18–49 years of age (mean age 23 years),consuming: 1100 mg coffee berry extract, 1100 mg coffee berry extract plus 275 mg apple extract, 100 mg coffee berry extract plus 275 mg apple extract or placebo on 4 separate occasions, completing cognitive and mood assessments pre-dose and then again at 1-, 3- and 6 hrs post-dose. Results: Analysis revealed a consistent pattern of alerting effects following 1100 mg coffee berry extract. Limited effects on cognitive function were observed. Specifically, faster peg and ball performance (executive function) was observed following 1100 mg coffee berry plus apple extract and accuracy on the Rapid Visual Information Processing (RVIP) task increased on the third of four repetitions following 1100 mg coffee berry alone. Interestingly, more false alarms on RVIP were observed following the same intervention. Conclusions: In line with previous findings, 1100 mg coffee berry engendered increased arousal. The absence of effects on mood when an apple extract was added, and the potential for the low dose of caffeine within the coffee berry to act synergistically with polyphenols, raise interesting future avenues of research. Abbreviations: Cognitive demand battery (CDB), Profile Of Mood States (POMS), Visual Analogue Scale (VAS), Rapid Visual Information Processing (RVIP)

Classification of Eye Tracking Data in Visual Information Processing Tasks Using Convolutional Neural Networks and Feature Engineering

Eye tracking technology has been adopted in numerous studies in the field of human–computer interaction (HCI) to understand visual and display-based information processing as well as the underlying cognitive processes employed by users when navigating a computer interface. Analyzing eye tracking data can also help identify interaction patterns with regard to salient regions of an information display. Deep learning technology is increasingly being used in the analysis of eye tracking data by allowing for the classification of large amounts of eye tracking results. In this paper, eye tracking data and convolutional neural networks (CNNs) were used to perform a classification task to predict three types of information presentation methods. As a first step, a number of data preprocessing and feature engineering approaches were applied to eye tracking data collected through a controlled visual information processing experiment. The resulting data were used as input for the comparison of four CNN models with different architectures. In this experiment, two CNN models were effective in classifying the information presentations with overall accuracy greater than 80%.

Effect of Distractors on Sustained Attention and Hyperactivity in Youth With Attention Deficit Hyperactivity Disorder Using a Mobile Virtual Reality School Program

Objective: This study examined whether distractors in virtual reality (VR) environment affected the attention and hyperactivity in children and adolescents with ADHD. Method: A total of 40 students (21 ADHD, 19 controls) aged between 9 and 17 years participated in this study. A rapid visual information processing task utilizing VR (VR-RVP) was performed under two conditions (no-distractor and distractor condition). Task performance and head movement during each condition were compared, and additional analyses were conducted after grouping participants into two developmental stages. Results: Children with ADHD performed comparably to the controls under the distractor condition, but had poorer performance under the no-distractor condition. They displayed more head movement under the distractor condition than in the no-distractor condition. Conclusion: VR is possibly a useful tool for investigating the effect of distractors on individuals with ADHD, and children with ADHD are more vulnerable to a low-level stimulation situation than normal children in VR.

Emotional Information Processing and Assessment of Cognitive Functions in Social Anxiety Disorder: An Event-Related Potential Study.

The aim of our study was to determine deficits in cognitive areas, including social cognition such as emotion recognition capacity, theory of mind, and electrophysiological alterations in patients with social anxiety disorder (SAD) and to identify their effects on clinical severity of SAD. Enrolled in our study were 26 patients diagnosed with SAD and 26 healthy volunteers. They were administered the Liebowitz Social Anxiety Scale (LSAS), Reading Mind in the Eyes Test (RMET), and Cambridge Neuropsychological Test Automated Battery. EEG monitoring was performed for electrophsiologic investigation. In the patient group, total reading the mind scores were lower (P = .027) while P300 latencies and emotion recognition latency during the Emotion Recognition Task (ERT) were longer (P = .038 and P = .012, respectively). The false alarm scores in the Rapid Visual Information Processing Task (RVP) were higher in the patient group (P = .038). In a model created using multivariate linear regression analysis, an effect of ERT and RVP scores on LSAS scores was found. Results of our study confirm that particularly impairment of cognitive functions such as sustained attention and emotion recognition may seriously affect the clinical presentation negatively. P300 latency in the parietal region may has the potential to be a biological marker that can be used in monitoring treatment.

6 Hz transcranial alternating current stimulation of mPFC improves sustained attention and modulates alpha phase synchronization and power in dorsal attention network

ABSTRACT Transcranial alternating current stimulation (tACS) is a noninvasive brain stimulation tool appropriate to modulate cortical oscillations and activity via the application of weak currents. The major goal of this study was to investigate the effects of medial Prefrontal Cortex (mPFC) stimulation on sustained attention task performance measured by Rapid Visual Information Processing (RVIP) task and the brain networks assumed to be critical to sustained attention. mPFC has been shown to be involved in sustained attention performance and as a main hub in default mode network (DMN). mPFC activity modulation via theta tACS was implemented in this study. This was a single blind study with 21 participants receiving active and sham stimulation with the electrodes on FPz and the Inion. tACS was able to impact different RVIP measures (total hits, A’ (sensitivity to target), total correct rejection, etc.). Relative power spectrum density (PSD) analysis yielded significant increases in theta frequency mostly in the fronto-central regions after active tACS and current source density (CSD) analysis yielded significant power modulations in theta frequency band in post-central gyrus. Furthermore, phase locking value (PLV) analysis showed that there were significant changes in cortical connections in the Dorsal Attention Network (DAN) in alpha frequency band. This study showed that theta frequency tACS over mPFC, was able to produce significant modulations in an RVIP task and its associated brain networks in healthy participants.

A specific dietary fibre supplementation improves cognitive performance-an exploratory randomised, placebo-controlled, crossover study.

The impact of the microbiota on the gut-brain axis is increasingly appreciated. A growing body of literature demonstrates that use of dietary fibre and prebiotics can manipulate the microbiota and affect host health. However, the influence on cognition and acute stress response is less well understood. The objective of this study was to investigate the efficacy of a dietary fibre, polydextrose (PDX), in improving cognitive performance and acute stress responses through manipulation of the gut microbiota in a healthy population. In this double-blind, randomised, placebo-controlled, crossover design study, 18 healthy female participants received 12.5 g Litesse®Ultra (> 90% PDX polymer) or maltodextrin for 4 weeks. Cognitive performance, mood, acute stress responses, microbiota composition, and inflammatory markers were assessed pre- and post-intervention. PDX improved cognitive flexibility as evidenced by the decrease in the number of errors made in the Intra-Extra Dimensional Set Shift (IED) task. A better performance in sustained attention was observed through higher number of correct responses and rejections in the Rapid Visual Information Processing (RVP) task. Although there was no change in microbial diversity, abundance of Ruminiclostridium 5 significantly increased after PDX supplementation compared with placebo. PDX supplementation attenuated the increase of adhesion receptor CD62L on classical monocytes observed in the placebo group. Supplementation with the PDX resulted in a modest improvement in cognitive performance. The results indicate that PDX could benefit gut-to-brain communication and modulate behavioural responses.

Local-global processing approaches in older autistic adults: A matched control study using RCFT and WAIS-IV

BackgroundResearch on information processing of older adults with autism spectrum disorder (ASD) is scarce, which is a caveat because findings in children may not apply to (older) autistic adults. This study examines visual local-global processing approaches in older autistic adults. MethodThe Rey-Osterrieth Complex Figure Test (RCFT) is a popular measure of visual-constructional ability, organisational strategy and memory. In this matched-control study, we explore if the qualitative and quantitative performance on the RCFT can be used as an operationalisation of central coherence in autistic older adults (n = 36; ages 50−84 years), and whether RCFT performance associates with autism-symptoms. WAIS-IV scores were also obtained to test for local-global differences in performance. ResultsNo evidence was found for deviating processing approaches on the RCFT (both quantitative and qualitative) in the ASD group, although copying the RCFT was significantly slower. The WAIS-IV showed no differences between participant-groups, except for a significantly better performance on Visual Puzzles by autistic participants. ConclusionsUsing visual local-global processing tests common to clinical practice, this study provides no evidence for a weak central coherence but some support for enhanced perceptual functioning in late-diagnosed high functioning older autistic adults. There was no evidence for altered strategic approaches during the completion of a complex visual information processing task (RCFT). Combining a quantitative and a qualitative scoring system of visual information processing tasks (such as RCFT) can elucidate the preferred visual information processing style in autistic individuals.

Sleep deprivation and compensatory cognitive effort on a visual information processing task.

Total sleep deprivation (TSD) is often associated with worse performance on tasks of attention and working memory, but some studies show no performance changes. One possibility is that greater compensatory cognitive effort is put forth to achieve similar results after TSD. We aimed to better understand the relationship between TSD, cognitive engagement, and performance outcomes following TSD. Twenty healthy adults completed cognitive testing following a night of normal sleep and again after ~55 hours of TSD. Participants detected target letters in low (3-item) and high (10-item) load visual letter displays on the span of apprehension task with concurrent pupillometry, a measure of cognitive effort. We found significantly poorer detection accuracy and marginally longer response times following TSD across both arrays. In both arrays, significantly greater preparatory pupillary responses were found just prior to array onset. There was also a significant session by array interaction for pupillary responses, such that significantly greater dilation was found for the 3-letter array after TSD, while a nonsignificant decline in dilation was found following the 10-letter array after TSD. These results suggest a complex relationship between attentional control and cognitive resource allocation following TSD. Sleep-deprived individuals may allocate more compensatory cognitive effort to easier tasks but choose to disengage from more challenging cognitive tasks that have little perceived reward or probability of success to preserve diminishing cognitive resources. More work is needed to better delineate the underlying neurological systems involved in these processing load-dependent attentional control mechanisms after TSD.

Acute Effects of a Polyphenol-Rich Leaf Extract of Mangifera indica L. (Zynamite) on Cognitive Function in Healthy Adults: A Double-Blind, Placebo-Controlled Crossover Study.

Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. In rodent models, oral mangiferin protects cognitive function and brain tissue from a number of challenges and modulates cerebro-electrical activity. Recent evidence has confirmed the latter effect in healthy humans following a mangiferin-rich mango leaf extract using quantitative electroencephalography (EEG). The current study therefore investigated the effects of a single dose of mango leaf extract, standardised to contain >60% mangiferin (Zynamite®), on cognitive function and mood. This study adopted a double-blind, placebo-controlled cross-over design in which 70 healthy young adults (18 to 45 years) received 300 mg mango leaf extract and a matched placebo, on separate occasions, separated by at least 7 days. On each occasion, cognitive/mood assessments were undertaken pre-dose and at 30 min, 3 h and 5 h post-dose using the Computerised Mental Performance Assessment System (COMPASS) assessment battery and the Profile of Mood States (POMS). The results showed that a single dose of 300 mg mango leaf extract significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an ‘Accuracy of Attention’ factor and an ‘Episodic Memory’ factor. Performance was also improved across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) that make up the Cognitive Demand Battery sub-section of the assessment. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). There were no interpretable treatment related effects on mood. These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract and add to previous research showing that polyphenols and polyphenol rich extracts can improve brain function.

The Effect Of Brief Mindfulness Intervention As Adjuvant Of Fluid Intake On Athletes’ Cognitive Function

PURPOSE: The present study investigated the effect of combined fluid intake and brief mindfulness intervention (MBI) in a simulative half-time break of soccer competition on athletes’ cognitive function. METHODS: In a 3 (treatments) × 2 (times) double-blinded cross-over design, fourteen male athletes (age: 24.3±3.7 yr, height: 173.8±4.5 cm, weight: 68.3±5.1 kg, VO2max: 47.0±4.4 ml/kg/min) received three treatments (Control: non-carbohydrate (CHO) electrolyte solution + traveling introduction audio; CHO: CHO-electrolyte solution + travelling introduction audio; and CHO_M: CHO-electrolyte solution + MBI) in a simulative half-time break. Cognitive function performance (assessed by Stroop Test, Corsi Block Test, Rapid Visual Information processing task (RVIP)), mindfulness level, blood glucose and lactic, rating of perceived exertion was tested at different time points during the trial. RESULTS: Major findings include: (1) CHO_M trial obtained a better score in post Stroop colour test when compared with Control trial (CHO_M vs. Control: 17813.87 + 3706.98 vs. 22990.43 + 6665.36; p = .04); (2) a significant interactive effect was observed on the performance of Corsi block test (p = .03). Specifically, the reaction time decreased from pre-trial to post-trial in CHO_M and Control trials (pre vs. post: 826.88 + 384.67 vs. 667.49 + 331.56 ms, p < .01 for CHO_M; pre vs. post: 1085.43 + 388.51 vs. 798.36 + 253.28 ms; p < .01 for Control), but not in CHO trial (pre vs. post: 832.68 + 296.37 vs. 810.11 + 347.70 ms, p = .66); (3) CHO trial spent less time on missing numbers in post RVIP test than the other two trials (Control vs. CHO vs. CHO_M: 5939.57 + 2100.27 vs. 3316.79 + 2716.73 vs. 6201.43 + 4013.58 ms; p = .03), given that their performance in pre-test were statistically the same (p = .13). CONCLUSIONS: In conclusion, a positive effect of the combined fluid intake and brief MBI on athlete’s cognitive function was revealed, while both positive and negative effect was revealed for fluid intake only.

Alpha frequency rTMS modulates theta lagged nonlinear connectivity in dorsal attention network

Dorsolateral prefrontal cortex (DLPFC) is a key structure in dorsal attention network (DAN) that facilitates sustained attention by modulating activity in task related and unrelated regions of the brain. Alpha and theta frequency bands enhance connectivity among different parts of the attention network and these connections are facilitated by long-range nonlinear connectivity in theta and alpha frequency bands. This study is an investigation of the behavioral and electrophysiological effects of alpha and theta frequency repetitive transcranial magnetic stimulation (rTMS) over RDLPFC. 20 healthy participants were randomly assigned to two groups of theta (n = 11, f = 6 Hz) and alpha (n = 9, f = 10 Hz) rTMS. Electroencephalogram (EEG) was recorded before and after each session while resting and performing tasks. Current source density (CSD) and functional connectivity (FC) in DAN and default mode network (DMN) and their correlations with rapid visual information processing task (RVIP) scores were calculated . Alpha frequency rTMS resulted in significant changes in RVIP scores. Active theta rTMS caused an increase in CSD in Postcentral gyrus and active alpha rTMS resulted in significant CSD changes in inferior parietal lobule (IPL). Theta lagged nonlinear connectivity was mudulated by alpha rTMSand FC changes were observed in DAN and DMN. Positive correlations were observed between DAN regions and RVIP scores in the alpha rTMS group. Increased activity in theta frequency band in left aPFC and left DLPFC correlated positively with higher total hits in RVIP. This study showed for the first time that theta and alpha frequency rTMS are able to modulate FC in DAN and DMN in a way that results in better performance in a sustained attention task.

Attention-enhancing effects of propranolol and synergistic effects with nicotine.

Nicotine increases the output of every major neurotransmitter. In previous studies designed to identify the secondary neurotransmitter systems mediating nicotine's attention-enhancing effects in a rat model, the β-adrenoceptor antagonist propranolol blocked these effects. The present study was designed to test whether this mechanism held true in humans, thus guiding development of novel nicotinic agonists for cognitive enhancement. Twenty-six nonsmokers completed a nicotine (7 mg/24 h transdermally) x propranolol (40 mg p.o., body weight-adjusted) interaction study. Over four test days, each participant received double-placebo, nicotine only, propranolol only, and nicotine plus propranolol in randomized sequence before cognitive testing. No drug effects were seen in a visuospatial attention task. In the Rapid Visual Information Processing Task, performed in two 15-min blocks, neither drug alone significantly affected hit rate, but both drugs combined acted synergistically to alleviate its decrement over time in the first block and displayed additive beneficial effects in the second. In a change detection task, propranolol enhanced accuracy and reduced reaction time independent of nicotine presence. Propranolol also enhanced subjective self-reports of vigor. Overall, the findings were contrary to those hypothesized. Propranolol displayed beneficial effects on cognition, especially on sustaining performance over time. β-adrenoceptor activation by nicotine-induced noradrenaline release appeared to limit performance-enhancing effects of nicotine, because they were unmasked by β-adrenoceptor antagonism. The results suggest that cognitive effects of changes in β-adrenoceptor tone are context-dependent; contrary to rodent paradigms, human cognitive paradigms require no physical orienting in space but prolonged periods of remaining stationary while sustaining predictable processing demands.

Carbohydrate mouth rinse has no effects on behavioral or neuroelectric indices of cognition

Rinsing the mouth with a carbohydrate solution has been suggested as a means to enhance aspects of both physical and cognitive performance. However, evidence in support of these assertions is relatively weak. The purpose of this study was to investigate the effects of a carbohydrate mouth rinse solution on motor speed, inhibition, and sustained attention as indexed by both behavioral and neuroelectric measures. Using a double-blind, placebo-controlled, within-subjects crossover design, 50 college-aged young adults performed a battery of cognitive tasks both before and after rinsing their mouth for 10 s with 20 mL of either a carbohydrate mouth rinse solution or a sensory-matched placebo control solution. A simple tapping task was used as a measure of motor speed, a modified Eriksen flanker task was used to index inhibition, and a rapid visual information processing task was used as a measure of sustained attention. Participants demonstrated longer reaction times in the Flanker task after rinsing their mouths with the carbohydrate mouth rinse, relative to pretest. No differences in reaction time were observed for the placebo control condition. P3 latency in the Flanker task as an index of attentional processing speed was shorter at posttest than at pretest in the placebo control – but not the carbohydrate mouth rinse – condition. These results suggest that despite claims of cognitive enhancement, carbohydrate mouth rinses do not appear to alter motor speed, inhibition, or sustained attention as compared to a placebo control in non-physically-fatigued college-aged adults.

Acute Intake of a Grape and Blueberry Polyphenol-Rich Extract Ameliorates Cognitive Performance in Healthy Young Adults During a Sustained Cognitive Effort

Despite an increasing level of evidence supporting the individual beneficial effect of polyphenols on cognitive performance, information related to the potential synergistic action of these phytonutrients on cognitive performance during a prolonged cognitive effort is currently lacking. This study investigated the acute and sustained action of a polyphenols-rich extract from grape and blueberry (PEGB), on working memory and attention in healthy students during a prolonged and intensive cognitive effort. In this randomised, cross-over, double blind study, 30 healthy students consumed 600 mg of PEGB or a placebo. Ninety minutes after product intake, cognitive functions were assessed for one hour using a cognitive demand battery including serial subtraction tasks, a rapid visual information processing (RVIP) task and a visual analogical scale. Flow-mediated dilation (FMD) and plasma flavan-3-ols metabolites quantification were also performed. A 2.5-fold increase in serial three subtraction variation net scores was observed following PEGB consumption versus placebo (p < 0.001). A trend towards significance was also observed with RVIP percentage of correct answers (p = 0.058). No treatment effect was observed on FMD. Our findings suggest that consumption of PEGB coupled with a healthy lifestyle may be a safe alternative to acutely improve working memory and attention during a sustained cognitive effort.