Divided Attention Research Articles

Short-term cognitive loading deteriorates breathing pattern and gas exchange in adult patients with congenital central hypoventilation syndrome.

Human PHOX2B mutations result in life-threatening sleep-related hypoventilation (congenital central hypoventilation syndrome, CCHS). Most patients retain ventilatory activity when awake through a respiratory-related cortical network. We hypothesised that this need to mobilise cortical resources to breathe would lead to breathing-cognition interferences during cognitive loading. Seven adult CCHS patients (five women; median age 21) performed standard neuropsychological tests (paced auditory serial addition test - calculation capacity, working memory, sustained and divided attention; trail making test - visuospatial exploration capacity, cognitive processing speed, attentional flexibility; Corsi block-tapping test - visuospatial memory, short-term memory, working memory) during unassisted breathing and under ventilatory support. Ventilatory variables and transcutaneous haemoglobin oxygen saturation were recorded. Cortical connectivity changes between unassisted breathing and ventilatory support were assessed using electroencephalographic recordings (EEG). Baseline performances were lower than expected in individuals of this age. During unassisted breathing, cognitive loading coincided with increased breathing variability, and decreases in oxygen saturation inversely correlated with an increasing number of apnoeic cycles per minute (rho -0.46, 95% CI -0.76 to -0.06, p=0.01). During ventilatory support, cognitive tasks did not disrupt breathing pattern and were not associated with decreased oxygen saturation. Ventilatory support was associated with changes in EEG cortical connectivity but not with improved test performances. Acute cognitive loads induce oxygen desaturation in adult CCHS patients during unassisted breathing, but not under ventilatory support. This justifies considering the use of ventilatory support during mental tasks in CCHS patients to avoid repeated episodes of hypoxia.

Attention to attention in aphasia – elucidating impairment patterns, modality differences and neural correlates

It is increasingly acknowledged that patients with aphasia following a left-hemisphere stroke often have difficulties in other cognitive domains. One of these domains is attention, the very fundamental ability to detect, select, and react to the abundance of stimuli present in the environment. Basic and more complex attentional functions are usually distinguished, and a variety of tests has been developed to assess attentional performance at a behavioural level. Attentional performance in aphasia has been investigated previously, but often only one specific task, stimulus modality, or type of measure was considered and usually only group-level analyses or data based on experimental tasks were presented. Also, information on brain-behaviour relationships for this cognitive domain and patient group is scarce.We report detailed analyses on a comprehensive dataset including patients' performance on various subtests of two well-known, standardised neuropsychological test batteries assessing attention. These tasks allowed us to explore: 1) how many patients show impaired performance in comparison to normative data, in which tasks and on what measure; 2) how the different tasks and measures relate to each other and to patients’ language abilities; 3) the neural correlates associated with attentional performance.Up to 32 patients with varying aphasia severity were assessed with subtests from the Test of Attentional Performance (TAP) as well as the Test of Everyday Attention (TEA). Performance was compared to normative data, relationships between attention measures and other background data were explored with principal component analyses and correlations, and brain-behaviour relationships were assessed by means of voxel-based correlational methodology.Depending on the task and measure, between 3 and 53 percent of the patients showed impaired performance compared to normative data. The highest proportion of impaired performance was noted for complex attention tasks involving auditory stimuli. Patients differed in their patterns of performance and only the performance in the divided attention tests was (weakly) associated with their overall language impairment. Principal components analyses yielded four underlying factors, each being associated with distinct neural correlates.We thus extend previous research in characterizing different aspects of attentional performance within one sample of patients with chronic post stroke aphasia. Performance on a broad range of attention tasks and measures was variable and largely independent of patients’ language abilities, which underlines the importance of assessing this cognitive domain in aphasic patients. Notably, a considerable proportion of patients showed difficulties with attention allocation to auditory stimuli. The reasons for these potentially modality-specific difficulties are currently not well understood and warrant additional investigations.

Divided attention effects in visual search are caused by objects not by space.

Divided attention effects have been observed across a variety of stimuli and perceptual tasks, which have given rise to both object-based and space-based theories of divided attention. Object-based theories assert that processing information from multiple objects is limited, whereas space-based theories assert that processing information from multiple locations is limited. Extant results in the literature are collectively inconsistent with both simple object-based theories and simple space-based theories of divided attention. Using a visual search task with the extended simultaneous-sequential method to reveal capacity limitations, we found evidence of limited-capacity processing of object properties and unlimited-capacity processing of feature contrast. We found no evidence of a separate spatial limitation. A multiple pathway processing theory can account for these and a large body of previous results. According to this theory, tasks that require object processing must follow a limited-capacity pathway and therefore incur divided attention effects. Tasks that depend on only feature contrast can follow a separate unlimited-capacity processing pathway and therefore do not incur divided attention effects.

Interaction between apolipoprotein E genotypes, excessive daytime sleepiness, and cognitive function in obstructive sleep apnea patients.

Some studies show an association between the apolipoprotein E ε4 allele (ApoEε4) and obstructive sleep apnea syndrome (OSAS), and other studies, an association between ApoEε4 and excessive daytime sleepiness (EDS), but there are no data in the literature on the interaction between EDS, cognitive function, and ApoEε4 in patients with OSA. To examine the cognitive function of adults with and without EDS and with and without ApoEε4. A total of 21 male and female patients aged between 33 and 79 years, underwent a clinical interview, ApoE genotyping, neuropsychological evaluation, polysomnography, and the application of the Epworth Sleepiness Scale. Excessive daytime sleepiness was associated with lower intelligence quotient (IQ; total performance) and worse immediate visual memory, regardless of the ApoE genotype. Patients carrying the ApoEε3/ε4 genotype had a worse performance in divided attention, constructional praxis, perceptual organization, and cognitive flexibility. A combination of the ε4 allele and EDS potentiates the negative effect on cognition, except for immediate visual memory. In this case, patients had a worse performance in terms of processing speed, selective attention, and visuomotor coordination. Excessive daytime sleepiness and the ApoEε3/ε4 genotype are associated with worse cognitive performance in OSA patients. The combination of EDS and ε4 allele potentiates cognitive impairment.

Cognitive Science of PowerPoint Part II: The Power of Attention

The most common pedagogical visual tool used in engineering classrooms are slides, such as those generated by Google Slides, Keynote, Prezi or PowerPoint. Unfortunately, when viewed through the lens of current models describing human information processing, many slides are poorly designed. That is, they either contain too much, poorly organized, or distracting information. Given the complexity of engineering content, it is essential that slides be used to help the student focus on key elements to increase learning, rather than simply act as a data dump or cue card. The paper will first provide an overview of human attention processes and how these impact working memory and learning. Then, the paper will provide an overview of selected theories from cognitive psychology, including top-down vs. bottom-up processing, focused vs. divided attention, and salience models (e.g. perception, gaze, and motion). Finally, using an authentic example of an engineering classroom slide, this paper will demonstrate how the practical application of these cognitive theories of attention can increase focus on (and thus retention) of the relevant content. This paper aims to be a “why-to” as well as a “how-to” guide for improving visual aids, specifically slides, in the engineering classroom. Note, this paper builds on our previous paper that focused on the cognitive load with respect to slide design.

Exploring the sustained and divided attention of novice versus experienced drivers

Purpose of the researchDriving is a complex task that requires appropriate engagement in, and regulation of, sustained attention and divided attention. This study explored the sustained- and divided-attention function of novice young adult drivers and experienced adult drivers. MethodsFifteen novice young adult drivers (mean age = 20.07) and 18 experienced adult drivers (mean age = 41.33) participated in the study. The participants’ sustained and divided attention were assessed using a computerised fixed Sustained Attention-to-Response Task (SART) and a modified version with low cognitive-load and high cognitive-load conditions. Their attention was also assessed using the Color Trails Test (CTT) and Digit Span Test (DST). The participants’ cognitive resources that were available during the assessments were monitored using the Rating Scale Mental Effort (RSME). ResultsThe main results of this study showed that the experienced drivers had significantly higher performance in terms of accuracy in both sustained attention (p = 0.011) and divided attention (p = 0.008 and 0.006 in low and high cognitive-load conditions, respectively) components of the SART. No significant differences in the CTT and DST were found between the two groups. The results of the RSME also indicated that both groups had comparable cognitive resources available throughout the assessments. ConclusionsThis study suggests that experienced adult drivers have a higher developed ability to engage in and maintain sustained and divided attention appropriately. These results provide insight related to attention function, which might affect novice young adult drivers compared with experienced drivers.

The role of working memory in speech recognition by hearing-impaired older listeners: does the task matter?

Objective Working memory refers to a cognitive system that holds a limited amount of information in a temporarily heightened state of availability, for use in ongoing cognitive tasks. Research suggests a link between working memory and speech recognition. In this study, we investigated this relationship using two working memory tests that differed in regard to the operationalisation of the link between working memory and attention: the auditory visual divided attention test (AVDAT) and the widely used reading span test. Design The relationship between speech-in-noise recognition and working memory was examined for two different working memory tests that varied in methodological and theoretical aspects, using a within-subject design. Study sample Nineteen hearing-impaired older listeners participated. Results We found a strong link between the reading span test and speech-in-noise recognition and a less robust link between the AVDAT and speech-in-noise recognition. There was evidence for the role of selective attention in speech-in-noise recognition, shown via the new AVDAT measure. Conclusion Our findings suggest that the strength of the relationship between speech-in-noise recognition and working memory may be influenced by the match between the demands and the stimuli of the speech-in-noise task and those of the working memory test.

Pre-frail older adults show improved cognition with StayFitLonger computerized home–based training: a randomized controlled trial

Multidomain interventions have shown tremendous potential for improving cognition in older adults. It is unclear if multidomain interventions can be delivered remotely and whether remote intervention is beneficial for older adults who are vulnerable or at risk of cognitive decline. In a 26-week multi-site, home-based, double-blind, randomized controlled trial, 120 cognitively healthy older adults (75 robust, 45 pre-frail; age range = 60–94) recruited from Switzerland, Canada, and Belgium were randomized to receive either the StayFitLonger (SFL) computerized multidomain training program or an active control intervention. Delivered on tablets, the SFL intervention combined adapted physical exercises (strength, balance, and mobility), cognitive training (divided attention, problem solving, and memory), opportunities for social and contributive interactions, and psychoeducation. The active control intervention provided basic mobilization exercises and access to video games. Cognitive outcomes were global cognition (Z-scores of attention, verbal fluency, and episodic memory for nondemented older adults; ZAVEN), memory, executive function, and processing speed. Linear mixed model analyses indicated improved performance on the ZAVEN global cognition score in the SFL group but not in the active control group. Stratified analyses by frailty status revealed improved ZAVEN global cognition and processing speed scores following SFL in the pre-frail group but not in the robust group. Overall, the study indicates that a computerized program providing a multidomain intervention at home can improve cognition in older adults. Importantly, pre-frail individuals, who are at higher risk of cognitive decline, seem to benefit more from the intervention. Trial registration: ClinicalTrials.gov, NCT037519 Registered on January 22, 2020—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04237519.

Developing multiple shortened forms of virtual reality-based color trails test

The Color Trails Test (CTT) is a pencil-and-paper (P&P) neuropsychological test. The CTT is divided into two parts that assess sustained visual attention (Trails A) and divided attention (Trails B). The CTT can also be performed in a virtual reality setting (VR-CTT) introducing a wider spatial range of targets. In cases of multiple assessments, repeating the same CTT configuration can bias the results due to fatigue and learning effects. The aim of this study is to create five different short versions of the VR-CTT. The different forms were created by rotating or flipping the original targets spatial layout on one of the axes and by ending it at ball #13. Healthy young participants (N = 15) performed the shortened VR-CTT forms (in a counterbalanced order), the P&P CTT and the original VR-CTT. We found no difference between the completion times of the five forms (p > 0.2), and a significant difference between Trails A and B across all forms (p < 0.04). Additionally, there was no evidence of a learning effect between trials (p > 0.4). Moreover, the shortened VR-CTT forms showed correlations with the P&P CTT (p < 0.05) and with the original VR-CTT (p < 0.06). These findings suggest that all five forms have an equal level of difficulty and that the different forms managed to mitigate the learning effects reported for repeated testing of the same spatial layout. This opens the possibility of applying the shortened VR-CTT forms for research settings and sets the basis for developing it into a clinical diagnostics tool.

Hypertension Status Moderated the Relationship between the Hippocampal Subregion of the Left GC-ML-DG and Cognitive Performance in Subjective Cognitive Decline

Background To investigate the relationship between hypertension status, hippocampus/hippocampal subregion structural alteration, and cognitive performance in subjective cognitive decline (SCD). Methods All participants were divided into two groups according to blood pressure status: SCD without hypertension and SCD with hypertension. The cognitive assessments and T1-MPRAGE brain MRI were performed to measure the cognitive function and the volume of the hippocampus and hippocampal subregions. Association and mediating/moderating effects were analyzed between the volume of hippocampus/hippocampal subregions and cognitive scores. Results Compared to the SCD without hypertension, we found (1) increased reaction time (RT) of the Go/No go test, compatible test, and divided attention visual task and (2) decreased volume of the left whole hippocampal/left subiculum/left CA1/left presubiculum/left parasubiculum/left molecular layer HP/left GC-ML-DG/left HATA in SCD with hypertension. There was a significant negative association between the volume of the left GC-ML-DG and Go/No go test RT in SCD without hypertension. A significant moderating effect of hypertension status on the relationship between the volume of the left GC-ML-DG and Go/No go test RT was found. Conclusion The results suggested that hypertension status affects inhibitory control function and visual divided attention which may be related to the reduction of hippocampus/hippocampal subregion volume in SCD. Limitations. The study has several limitations. First, this study does not include a healthy control group. In further studies, healthy controls may need to assess the interaction between hypertension status and disease status on cognitive function. Second, we defined the hypertension status using with or without hypertension disease. More detailed parameters of hypertension status need to be further studied. Third, our study was a small number of participants/single-center and cross-sectional study, which may hinder its generalization. A large-sample/multicenter, longitudinal study is helpful to comprehensively understand the relationship between hypertension status and cognitive function in SCD patients.

The Assessment of Different Types of Attention in Children Using a Computerized Test Battery

We designed a computerized test battery that was used to assess sustained, selective and divided attention in children aged 8 vs. 9 years. A group of children aged 8.34 ± 0.48 years (n = 30, 14 male, 16 female) and a group of children aged 9.33 ± 0.51 years (n = 42, 21 male, 21 female) participated in the study. The test battery included one simple reaction time task, two divided attention tasks, two sustained attention tasks, and one selective attention task. The analysis of task performance revealed age-related difference in the efficiency of sustained attention: the reactions of 9-year-old children to target stimuli were significantly faster than the reactions of 8-year-old children. The computerized battery showed sensitivity to different aspects of attention and might become a useful tool for the neuropsychological assessment of attention in children with and without developmental disorders.

Involvement of the cerebellum in the regulation of executive functions in children-Preliminary analysis based on a neuropsychological study of children after cerebellar tumour surgery.

AimPreliminary assessment of executive functions in children with cerebellar lesions, description of their emotional-social functioning and selection of sensitive neuropsychological tools to detect the cerebellar cognitive affective syndrome (CCAS).Materials and methodsThe study group consisted of 10 children after cerebellar tumour surgery. The control group consisted of 10 healthy children, matched for age and sex: The IDS-2 executive functions battery, the Conners 3 ADHD questionnaire, the Autism Spectrum Rating Scales (ASRS) and the International Cooperative Ataxia Rating Scale (ICARS) were used.ResultsStatistical analysis showed statistically significant differences between the experimental and control groups in terms of two dimensions of executive functioning. Children from experimental group was characterised by worse planning and divided attention than healthy controls. Moreover children with cerebellar lesions were characterised by significantly higher levels of some behaviours similar to that observed in autism spectrum disorders, namely difficulties in social relationships, self-regulation of emotions, attention, and greater behavioural rigidity. Test power analysis and estimation of the effect size by the Cohen’s d coefficient indicated that with a slight increase in the size of the experimental group, the probability of detecting statistically significant difference in the executive functions total measure score as well as in several ASRS subscales increased, but not in Conners 3 subscales.ConclusionsCerebellar damage may pose a risk for dysexecutive syndrome and social-emotional problems in children. The IDS-2 executive functions battery and the ASRS test are sufficiently sensitive tools to assess elements of the CCAS in children.

Odor identification testing is inferior compared to neurocognitive testing in predicting conversion to Alzheimer's Disease

IntroductionAlzheimer’s disease (AD) is a neurodegenerative disorder that affects memory, thinking, attention, and emotion or AD. Smelling problems are frequent symptoms of dementia. The aim of this study was to evaluate whether it is possible to predict if someone with anosmia or hyposmia has a higher risk of getting dementia or even AD.MethodsThis study was a retrospective longitudinal study, and the data used were part of a larger research project, the Vienna Conversion to Dementia Study. The 173 participants were divided into four groups based on cognitive features such as healthy control (HC), subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI). Olfactory assessment and neurocognitive assessment were administered.ResultsWe found that 30.5% of aMCI patients converted into AD after an average of about two years. The corresponding ROC analyses for olfactory testing showed that Sniffin’ Sticks revealed significant results regarding the conversion to AD, whereas the Assessment of Self-Reported Olfactory Functioning and olfaction-related quality of life (ASOF) inventory using the Subjective Olfactory Capability (SOC) subscale, the Smell-Related Problems (SRP) subscale, and the Olfaction-Related Quality of life (ORQ) did not. A logistic regression showed that among the olfactory test procedures, only the Sniffin’ Sticks enabled a relevant prognosis. Including neurocognitive measures in the model, only VSRT and the Trail Making Test-B. The other predictors did not contribute to the prediction of conversion to AD.ConclusionUnlike self-reporting of olfactory functioning, olfactory testing using standardized tests may have potential for predicting dementia, especially AD. However, olfactory tests have lower predictive power than neurocognitive tests such as verbal memory and divided attention tests.ImplicationsDiagnostic tools for predicting dementia as accurately and early as possible are important. Olfactory assessment, compared to neurocognitive tests for verbal memory and divided attention, is inferior in predicting the prognosis of AD.

A Novel Method Based on ERP and Brain Graph for the Simultaneous Assessment of Various Types of Attention.

Assessment of attention is of great importance as one of human cognitive abilities. Although neuropsychological tests have been developed and used to evaluate the ability to pay attention, their validity and reliability have been reduced due to some limitations such as the presence of intervention factors, including human factors, limited range of languages, and cultural influences. Therefore, direct outputs of the brain system, represented by event-related potentials (ERPs), and the analysis of its function in cognitive activities have become very important as a complementary tool to assess various types of attention. This research tries to assess 4 types of attention including sustained, alternative, selective, and divided, using an integrated visual-auditory test and brain signals simultaneously. Thus, the electroencephalogram (EEG) data were recorded using 19 channels, and the integrated visual and auditory (IVA-AE) test was simultaneously performed on twenty-eight healthy volunteers including 22 male and 6 female subjects with the average age of 27 ± 5.3 years. Then ERPs related to auditory and visual stimuli with synchronous averaging technique were extracted. A topographic brain mapping (topo-map) was plotted for each frame of stimulation. Next, an optical flow method was implemented on different topo-maps to obtain motion vectors from one map to another. After obtaining the overall brain graph of an individual, some features were extracted and used as measures of local and global connectivity. The extracted features were consequently evaluated along with the parameters of the IVA test by support vector machine regression (SVM-R). The volume of attention was then quantified by combining the IVA parameters. Ultimately, estimation accuracy of each type of attention including focused attention (86.1%), sustained attention (83.4%), selective attention (80.9%), and divided attention (79.9%) was obtained. According to the present study, there is a significant relationship between response control and attention indicators of the IVA test as well as ERP brain signals.

Association between descending pain modulatory system and cognitive impairment in fibromyalgia: A cross-sectional exploratory study.

BackgroundThe successful regulation of sensory input to the central nervous system depends on the descending pain modulatory system (DPMS). For the effective regulation of sensory input to the central nervous system and behavioral responses to pain, the DPMS is required. Its connection to fibromyalgia (FM)-related cognitive dysfunction has not yet been investigated. Therefore, this study tested whether measures of verbal fluency, sustained attention, and short-term and working memory could distinguish FM patients from healthy controls (HC). Additionally, it investigated, using a standardized paradigm, the link between cognitive ability and the function of the DPMS in responders and non-responders to the conditioned pain modulation test (CPM-test).Materials and methodsWe enrolled 21 HC women and 69 FM patients, all of whom ranged in age from 30 to 65. We employed scores from the Trail Making Test (TMTB-A) (sustained and divided attention), the Controlled Oral Word Association Test (COWAT) (orthographic and semantic fluency), and the Digits subtest of the Wechsler Adult Intelligence Scale (WAIS-III) as dependent variables.ResultsA generalized linear model (GLM) adjusted by educational level revealed significantly lower scores in FM than HC on the Span digits forward, COWAT-orthographic, and TMTB-A. For FM patients, multilevel MANCOVA revealed that the cognitive performance of non-responders compared to responders to CPM-test showed lower adjusted scores in Span digits forward (Partial-η2 = 0.358, P = 0.001), Span digits backward (Partial-η2 = 0.358, P = 0.001), COWAT-orthographic (Partial-η2 = 0.551, P = 0.001), COWAR-semantic (Partial-η2 = 0.355, P = 0.001), and TMTB-A (Partial-η2 = 0.360, P = 0.001). The association between the cognitive tests and the DPMS is moderated by the serum level of brain-derived neurotrophic factor (BDNF). Additionally, these cognitive assessments had a positive correlation with antidepressant use and pain threshold. The cognitive assessments, on the other hand, were conversely associated with a life of quality.ConclusionBased on these findings, it can be shown that HC performed substantially better on cognitive exams than FM did. They demonstrated a link between clinical complaints about attention and memory and decreased DPMS effectiveness. Additionally, they demonstrated that the BDNF is a moderating element in a potential relationship between the severity of cognitive impairment and DPMS dysfunction.

Effects of aging on cognitive and brain inter-network integration patterns underlying usual and dual-task gait performance.

IntroductionAging affects the interplay between cognition and gait performance. Neuroimaging studies reported associations between gait performance and structural measures; however, functional connectivity (FC) analysis of imaging data can help to identify dynamic neural mechanisms underlying optimal performance. Here, we investigated the effects on divergent cognitive and inter-network FC patterns underlying gait performance during usual (UW) and dual-task (DT) walking.MethodsA total of 115 community-dwelling, healthy participants between 20 and 80 years were enrolled. All participants underwent comprehensive cognitive and gait assessments in two conditions and resting state functional MRI (fMRI) scans. Inter-network FC from motor-related to 6 primary cognitive networks were estimated. Step-wise regression models tested the relationships between gait parameters, inter-network FC, neuropsychological scores, and demographic variables. A threshold of p < 0.05 was adopted for all statistical analyses.ResultsUW was largely associated with FC levels between motor and sustained attention networks. DT performance was associated with inter-network FC between motor and divided attention, and processing speed in the overall group. In young adults, UW was associated with inter-network FC between motor and sustained attention networks. On the other hand, DT performance was associated with cognitive performance, as well as inter-network connectivity between motor and divided attention networks (VAN and SAL). In contrast, the older age group (> 65 years) showed increased integration between motor, dorsal, and ventral attention, as well as default-mode networks, which was negatively associated with UW gait performance. Inverse associations between motor and sustained attention inter-network connectivity and DT performance were observed.ConclusionWhile UW relies on inter-network FC between motor and sustained attention networks, DT performance relies on additional cognitive capacities, increased motor, and executive control network integration. FC analyses demonstrate that the decline in cognitive performance with aging leads to the reliance on additional neural resources to maintain routine walking tasks.

Screen Time and Attention Subdomains in Children Aged 6 to 10 Years.

Using digital media has become the most popular leisure activity for children and adolescents. The effects of digital media use on the developing brain and cognitive processes of children are subject to debate. Here, we examine the effect of digital media use on attention subdomains in children aged 6 to 10 years. In total, 77 children participated in the study. Selective and divided attention as well as switching between attentional subdomains were quantified by the SwAD-task. Parents were asked to assess the screen time of their children (smartphone, laptop/PC, game console, tablet, TV). Results show no main or interaction effects of screen time on any of the attention conditions investigated. Based on the present findings as well as previous studies, we suggest a possible non-linear relationship between the amount of screen time and attention function. Furthermore, we emphasize the relevance of considering the socio-economic background of children and a need for longitudinal studies.

Neuropsychological correlates of P300 parameters in individuals with aphasia.

Aphasia is often accompanied by impairment of non-language cognitive functions. Assessment of cognitive capacity in people with aphasia (PWA) with standard neuropsychological methods may be problematic due to their language difficulties. Numerous experimental studies indicate that P300 may be considered as an index of cognitive capacity in both healthy and clinical samples. Accordingly, the measurement of event-related potentials enables the investigation of behaviourally non-observable mental processes underlying the cognitive functions that are assessed with neuropsychological tests. To investigate in PWA the relationship between P300 parameters and cognitive function efficiency measured with neuropsychological methods. A total of 25 PWA after left-hemispheric stroke participated in the study. Electrophysiological (EEG) signals were recorded during the performance of a visual Go-No Go task. P300 was identified on nine electrodes, which were then pooled in three lines: left (F3, C3, P3), central (Fz, Cz, Pz) and right (F4, C4, P4). The neuropsychological assessment of cognitive functions included mental speed, short-term memory, divided attention, executive functions, auditory language comprehension and expression. P300 latency correlated with indices of several cognitive functions: temporal resolution, psychomotor speed, spatial short-term memory, planning, word and sentence comprehension, as well as verbal fluency. Shorter P300 latencies were accompanied by greater efficiency of the abovementioned functions. In contrast, significant correlations between P300 amplitudes and cognitive measures were fragmentary. In PWA, P300 latency might be related to cognitive functioning, especially to measures that rely heavily on the speed of information processing. However, P300 seems to be unrelated to more complex cognitive functions. P300 latency may be used as a neurophysiological correlate of cognitive efficiency in PWA and might have potential applications in monitoring the effects of therapeutic interventions in this patient group. What is already known on the subject P300 parameters have been reported to be associated with cognitive performance in both healthy individuals and clinical groups (e.g., patients with Alzheimer's disease). Previous studies show that the presence of P300 at the early post-stroke stage may be a predictor of better recovery of comprehension in PWA. What this paper adds to existing knowledge Our results show for the first time that P300 may be used as a neurophysiological correlate of cognitive efficiency in PWA. In our study, P300 latency was associated with several languages and non-language cognitive functions, especially with those whose effectiveness depends mainly on processing speed. In PWA, shorter latency corresponded to more efficient cognitive functioning. What are the potential or actual clinical implications of this work? P300 measurement may be potentially useful in assessing the efficiency of certain cognitive functions in PWA. It may be also used to monitor the recovery process of PWA and to verify the effects of therapeutic interventions.

Comparison of Dual Task Training Versus Aerobics Training in Improving Cognition in Healthy Elderly Population.

BackgroundCognitive impairments, particularly in old age, are pervasive and occur because of both normal and pathological senescence. Engaging in some routine bodily activities combined with activities that stimulate cognitive skills appears beneficial in increasing cognitive resistance to degenerative processes of the brain. Dual-task training (DTT) by combining motor and cognitive activities causes improvement, particularly in executive function, working memory and divided attention, whereas aerobic exercise training (AET) plays an important role in improving executive function, attention, and memory. In this study, we attempted to compare the efficiency of DTT versus AT in improving cognitive function in healthy older individuals.MethodsForty healthy older adults between 60 and 70 years of age who met the inclusion criteria participated in this study. They were randomly split into two groups A and B. Group A (64.05±3.17 years) received DTT three times a week, whereas group B (65.50±3.44 years) received AT five times a week. Both training programs were conducted for six weeks. Cognitive function was assessed using Trail Making Test (TMT)-A, TMT-B, and Montreal Cognitive Assessment (MoCA). The assessment was done at baseline (first day of intervention), on completion of the third week, and again at the end of the training session i.e., the sixth week. The Chi-square test and the student's paired and unpaired t-tests were used for statistical analysis with a level of significance P<0.05.Discussion and resultBetterment in cognitive functions was evident after six weeks of DTT and AET. Post-intervention improvements were noted in TMT-A, TMT-B, and MoCA scores in both groups A and B (P>0.0001). However, the difference between the pre and post-intervention scores was greater for group A compared to group B indicative of remarkable improvements in cognitive function in group A.ConclusionThe current study demonstrated that both DTT and AET are notably efficient in improving cognitive function in a healthy elderly population. However, in comparison, DTT was significantly more effective than AET (P<0.05). This shows that six weeks of DTT is effective in improving cognitive function and slowing age-associated cognitive decline in older adults.

Pilot Study of Associations Among Functional Connectivity and Neurocognition in Survivors of Pediatric Brain Tumor and Healthy Peers.

This pilot study examined the associations among functional connectivity in the salience, central executive, and default mode networks, and neurocognition in pediatric brain tumor survivors and healthy children. Thirteen pediatric brain tumor survivors (9 boys, M = 12.76 years) and 10 healthy children (6 boys, M = 12.70 years) completed magnetic resonance imaging (MRI) and assessment of processing speed and executive function. Pediatric brain tumor survivors performed more poorly than healthy children on measures of processing speed, divided attention, and working memory; parent ratings of day-to-day executive function did not differ significantly by group, though both pediatric brain tumor survivors who underwent only surgical resection and healthy children were rated by parents as having difficulties approaching a standard deviation above the normative mean. Connectivity was lower in the salience network and greater in the default mode network in pediatric brain tumor survivors. Cross-method correlations showed that increased salience network and default mode network connectivity were associated with better task performance and parent-rated executive skills and higher central executive network connectivity with poorer parent-rated executive skills. This perhaps reflects an adaptive pattern of hyperconnectivity in pediatric brain tumor survivors.