Processing Speed In Individuals Research Articles

Ab. No. 85 Effectiveness of Practice of Stroop Test on Selective Attention and Processing Speed in Individuals With Stroke

Introduction: To identify the effectiveness of practice of Stroop test on selective attention and processing speed in the individuals diagnosed with stroke. To determine the significance of the Stroop test in cognitive rehabilitation for stroke survivors. Methods: Survivors of unilateral stroke with their first stroke episode between time frame of 3-18 months and age ranged between 30- 65 years were included in the study. Methods: Twenty-five participants were randomly assigned into two groups using computerized randomization list. Experimental group participants intervened with 30 minutes session of practicing of the Stroop test along with conventional physiotherapy for consecutive 10 days and control group participants received conventional physiotherapy for consecutive 10 days. Mann Whitney U test and independent sample t test were used for inter-group analysis. Wilcoxon test and dependent sample t test were used for pre-test and post-test group analysis. Results: Experimental group showed significant improvement in Stroop Test Card A (p= 0.03), Stroop Test Card B (p= 0.00), Stroop Test Card C (p= 0.00), Trail Making Test A (p= 0.00) and Trail Making Test B (p= 0.00) when compared pre and post intervention and significant difference was observed in Stroop Test Card A (p= 0.05), Stroop Test Card B (p= 0.00), Stroop Test Card C (p= 0.00), Trail Making Test A (p= 0.00) and Trail Making Test B (p= 0.00) when compared to the control group. Conclusion: Stroop test practicing was found to be efficient in improving selective attention and processing speed in individuals with stroke. Implications: Stroop test practicing can be a simple, convenient way of improving the parameters of the cognitive functions and thus could be added with regular treatment protocols of stroke survivors.

88 Social Cognition and Information Processing Speed in Individuals with Multiple Sclerosis and Co-Morbid Diabetes: An Interim Analysis

Objective:Multiple sclerosis (MS) is associated with cognitive and social cognitive deficits. Social cognition impairments may include difficulty with facial expression and emotion recognition. People with MS (PwMS) may also not be aware of their cognitive challenges as demonstrated through discrepant objective and subjective assessments. Research recently conducted in demyelinated mouse models demonstrated that metformin, a drug typically used to treat type II diabetes mellitus (DMII), promotes remyelination and reverses existent social cognition impairment by repressing the monoacylglycerol lipase (MgII) enzyme in the brain. We aim to translate this basic science research and are conducting a pilot study to determine if metformin improves social cognition in PwMS. This project will compare social cognition in those with MS and comorbid DMII who are treated with metformin and those who are not. For the purposes of this interim data analysis, we collapse across both MS groups who are, and who are not, treated with metformin. The current objective is to evaluate the relationship between subjective (i.e., perceived empathy), objective social cognition and information processing speed (IPS) in PwMS and co-morbid diabetes.Participants and Methods:Preliminary data on 15 PwMS are included. Participants completed a demographic questionnaire, a cognitive assessment battery, an objective social cognition assessment and self-report questionnaires. These questionnaires assessed subjective social cognition, fatigue, mood, and disability level.Results:Preliminary results showed that IPS was positively correlated with the affective empathy domain of social cognition, r = .53, p = .04. Additionally, IPS was positively correlated with objective social cognition, r = .71, p = 003. Follow-up regression analyses demonstrated that IPS predicted objective social cognition, R2 = .71, SE = 3.04, F(1,13) = 13.36, p = .003 and subjective social cognition, R2 = .53, SE = 5.39, F(1,13) = 4.97, p = .04. However, subjective and objective measures of social cognition were not correlated, p > .05 and remained uncorrelated when IPS was controlled for, p > .05.Conclusions:A majority of the variance in social perception is explained by IPS, suggesting that how quickly one can think may be a fundamental cognitive process to allow optimal functioning in social situations. While the reason for the relationship between IPS and subjective social cognition is perhaps less apparent, it may reflect a more global cognitive compromise that impacts both cognitive and social processes. This lends support to the Relative Consequence Model that suggests IPS deficits are a fundamental cognitive deficit underlying other more complex cognitive processes. The lack of correlation between subjective perception of empathy and objective social cognition requires further exploration and could potentially be related to some individuals with MS having a diminished ability to judge their own social proficiency. Further analyses with a larger sample will be conducted to assess group differences in social cognitive outcomes and MgII levels between metformin and non-metformin groups. If PwMS who take metformin have better social cognition compared to PwMS who do not take metformin, Mgll levels can be used as a biomarker to guide metformin treatment with the goal of improving social cognition.

Longitudinal joint modeling for assessing parallel interactive development of latent ability and processing speed using responses and response times.

To measure the parallel interactive development of latent ability and processing speed using longitudinal item response accuracy (RA) and longitudinal response time (RT) data, we proposed three longitudinal joint modeling approaches from the structural equation modeling perspective, namely unstructured-covariance-matrix-based longitudinal joint modeling, latent growth curve-based longitudinal joint modeling, and autoregressive cross-lagged longitudinal joint modeling. The proposed modeling approaches can not only provide the developmental trajectories of latent ability and processing speed individually, but also exploit the relationship between the change in latent ability and processing speed through the across-time relationships of these two constructs. The results of two empirical studies indicate that (1) all three models are practically applicable and have highly consistent conclusions in terms of the changes in ability and speed in the analysis of the same data set, and (2) additional analysis of the RT data and acquisition of individual processing speed measurements can reveal the parallel interactive development phenomena that are difficult to detect using RA data alone. Furthermore, the results of our simulation study demonstrate that the proposed Bayesian Markov chain Monte Carlo estimation algorithm can ensure accurate model parameter recovery for all three proposed longitudinal joint models. Finally, the implications of our findings are discussed from the research and practice perspectives.

The efficacy of speed of processing training for improving processing speed in individuals with multiple sclerosis: a randomized clinical trial.

The current study examines the efficacy of speed of processing training (SOPT) to improve processing speed (PS) in individuals with multiple sclerosis (MS). Outcomes included changes in the useful field of view (UFOV) and neuropsychological evaluation (NPE). This double-blind, placebo-controlled randomized clinical trial included 84 participants with clinically definite MS and impaired PS, 43 in the treatment group and 41 in the placebo control group. Participants completed a baseline NPE and a repeat NPE post-treatment. The treatment group was randomized to booster sessions or no contact. Long-term follow-up assessments were completed 6months after treatment. A significant effect of SOPT was observed on both the UFOV (large effect) and pattern comparison with a similar pattern of results noted on letter comparison, albeit at a trend level. The treatment effect was maintained 6months later. The impact of booster sessions was not significant. Correlations between degree of improvement on the UFOV and the number of levels completed within each training task were significant for both speed and divided attention indicating that completion of more levels of training correlated with greater benefit. SOPT is effective for treating PS deficits in MS with benefit documented on both the UFOV and a neuropsychological measure of PS. Less benefit was observed as the outcome measures became more distinct in cognitive demands from the treatment. Long-term maintenance was observed. The number of training levels completed within the 10-sessions exerted a significant impact on treatment benefit, with more levels completed resulting in greater benefit.

Eight-week multi-domain cognitive training does not impact large-scale resting-state brain networks in Parkinson’s disease

There is meta-analytic evidence for the efficacy of cognitive training (CT) in Parkinson’s disease (PD). We performed a randomized controlled trial where we found small positive effects of CT on executive function and processing speed in individuals with PD (ntotal = 140). In this study, we assessed the effects of CT on brain network connectivity and topology in a subsample of the full study population (nmri = 86). Participants were randomized into an online multi-domain CT and an active control condition and performed 24 sessions of either intervention in eight weeks. Resting-state functional MRI scans were acquired in addition to extensive clinical and neuropsychological assessments pre- and post-intervention. In line with our preregistered analysis plan (osf.io/3st82), we computed connectivity between ‘cognitive’ resting-state networks and computed topological outcomes at the whole-brain and sub-network level. We assessed group differences after the intervention with mixed-model analyses adjusting for baseline performance and analyzed the association between network and cognitive performance changes with repeated measures correlation analyses. The final analysis sample consisted of 71 participants (n CT = 37). After intervention there were no group differences on between-network connectivity and network topological outcomes. No associations between neural network and neuropsychological performance change were found. CT increased segregated network topology in a small sub-sample of cognitively intact participants. Post-hoc nodal analyses showed post-intervention enhanced connectivity of both the dorsal anterior cingulate cortex and dorsolateral prefrontal cortex in the CT group. The results suggest no large-scale brain network effects of eight-week computerized CT, but rather localized connectivity changes of key regions in cognitive function, that potentially reflect the specific effects of the intervention.

Evaluating the Spectrum of Cognitive-Motor Relationships During Dual-Task Jump Landing.

Cognitive function plays a role in understanding noncontact anterior cruciate ligament injuries, but the research into how cognitive function influences sport-specific movements is underdeveloped. The purpose of this study was to determine how various cognitive tasks influenced dual-task jump-landing performance along with how individuals' baseline cognitive ability mediated these relationships. Forty female recreational soccer and basketball players completed baseline cognitive function assessments and dual-task jump landings. The baseline cognitive assessments quantified individual processing speed, multitasking, attentional control, and primary memory ability. Dual-task conditions for the jump landing included unanticipated and anticipated jump performance, with and without concurrent working memory and captured visual attention tasks. Knee kinematics and kinetics were acquired through motion capture and ground reaction force data. Jumping conditions that directed visual attention away from the landing, whether anticipated or unanticipated, were associated with decreased peak knee flexion angle (P < .001). No interactions between cognitive function measures and jump-landing conditions were observed for any of the biomechanical variables, suggesting that injury-relevant cognitive-motor relationships may be specific to secondary task demands and movement requirements. This work provides insight into group- and subject-specific effects of established anticipatory and novel working memory dual-task paradigms on the neuromuscular control of a sport-specific movement.

Bilingualism and its Effects on Processing Speed in Individuals with Neurocognitive Disorders

Bilingualism and its Effects on Processing Speed in Individuals with Neurocognitive Disorders

Nicotine-induced activation of caudate and anterior cingulate cortex in response to errors in schizophrenia.

Nicotine improves attention and processing speed in individuals with schizophrenia. Few studies have investigated the effects of nicotine on cognitive control. Prior functional magnetic resonance imaging (fMRI) research demonstrates blunted activation of dorsal anterior cingulate cortex (dACC) and rostral anterior cingulate cortex (rACC) in response to error and decreased post-error slowing in schizophrenia. Participants with schizophrenia (n = 13) and healthy controls (n = 12) participated in a randomized, placebo-controlled, crossover study of the effects of transdermal nicotine on cognitive control. For each drug condition, participants underwent fMRI while performing the stop signal task where participants attempt to inhibit prepotent responses to "go (motor activation)" signals when an occasional "stop (motor inhibition)" signal appears. Error processing was evaluated by comparing "stop error" trials (failed response inhibition) to "go" trials. Resting-state fMRI data were collected prior to the task. Participants with schizophrenia had increased nicotine-induced activation of right caudate in response to errors compared to controls (DRUG × GROUP effect: p corrected < 0.05). Both groups had significant nicotine-induced activation of dACC and rACC in response to errors. Using right caudate activation to errors as a seed for resting-state functional connectivity analysis, relative to controls, participants with schizophrenia had significantly decreased connectivity between the right caudate and dACC/bilateral dorsolateral prefrontal cortices. In sum, we replicated prior findings of decreased post-error slowing in schizophrenia and found that nicotine was associated with more adaptive (i.e., increased) post-error reaction time (RT). This proof-of-concept pilot study suggests a role for nicotinic agents in targeting cognitive control deficits in schizophrenia.

Brain white matter structure and information processing speed in healthy older age.

Cognitive decline, especially the slowing of information processing speed, is associated with normal ageing. This decline may be due to brain cortico-cortical disconnection caused by age-related white matter deterioration. We present results from a large, narrow age range cohort of generally healthy, community-dwelling subjects in their seventies who also had their cognitive ability tested in youth (age 11 years). We investigate associations between older age brain white matter structure, several measures of information processing speed and childhood cognitive ability in 581 subjects. Analysis of diffusion tensor MRI data using Tract-based Spatial Statistics (TBSS) showed that all measures of information processing speed, as well as a general speed factor composed from these tests (gspeed), were significantly associated with fractional anisotropy (FA) across the white matter skeleton rather than in specific tracts. Cognitive ability measured at age 11 years was not associated with older age white matter FA, except for the gspeed-independent components of several individual processing speed tests. These results indicate that quicker and more efficient information processing requires global connectivity in older age, and that associations between white matter FA and information processing speed (both individual test scores and gspeed), unlike some other aspects of later life brain structure, are generally not accounted for by cognitive ability measured in youth.

Variation in longevity gene KLOTHO is associated with greater cortical volumes.

ObjectiveIdentifying genetic variation associated with brain structures in aging may elucidate new biologic mechanisms underlying resilience to cognitive decline. We investigated whether carrying one copy of the protective haplotype “KL-VS” in longevity gene KLOTHO (KL) is associated with greater gray matter volume in healthy human aging compared to carrying no copies.MethodsWe performed unbiased whole-brain analysis in cognitively normal older adults from two independent cohorts to assess the relationship between KL-VS and gray matter volume using voxel-based morphometry.ResultsWe found that KL-VS heterozygosity was associated with greater volume in right dorsolateral prefrontal cortex (rDLPFC). Because rDLPFC is important for executive function, we analyzed working memory and processing speed in individuals. KL-VS heterozygosity was associated with enhanced executive function. Larger rDLPFC volume correlated with better executive function across the lifespan examined. Statistical analysis suggested that volume partially mediates the effect of genotype on cognition.InterpretationThese results suggest that variation in KL is associated with bigger brain volume and better function.

High-gamma activity in an attention network predicts individual differences in elderly adults' behavioral performance

The current study used a magnetoencephalogram to investigate the relationship between high-gamma (52–100Hz) activity within an attention network and individual differences in behavioral performance among healthy elderly adults. We analyzed brain activity in 41 elderly subjects performing a 3-stimulus visual oddball task. In addition to the average amplitude of event-related fields in the left intraparietal sulcus (IPS), high-gamma power in the left middle frontal gyrus (MFG), the strength of high-gamma imaginary coherence between the right MFG and the left MFG, and those between the right MFG and the left thalamus predicted individual differences in reaction time. In addition, high-gamma power in the left MFG was correlated with task accuracy, whereas high-gamma power in the left thalamus and left IPS was correlated with individual processing speed. The direction of correlations indicated that higher high-gamma power or coherence in an attention network was associated with better task performance and, presumably, higher cognitive function. Thus, high-gamma activity in different regions of this attention network differentially contributed to attentional processing, and such activity could be a fundamental process associated with individual differences in cognitive aging.

Systemic and cerebral hemodynamics during cognitive testing

Cognitive deficits are reported in 10-60% of individuals with SCI, the primary etiology of these deficits is believed to be concomitant traumatic brain injury (TBI). We recently documented diminished memory and marginally deficient attention and processing speed in individuals with SCI discordant for hypotension but matched for TBI. Twenty-nine individuals participated: 16 non-SCI controls, 6 paraplegic (T2-T10) and 7 tetraplegic (C4-C8). The Stroop test was used to measure cognitive function and transcranial Doppler ultrasound was used to measure cerebral blood flow (CBF) while resting (5min) and continuously during cognitive testing. Mean arterial pressure (MAP) was calculated from three brachial blood pressures and cerebral vascular resistance index was calculated as: CVRi=MAP/CBF. The paraplegia group (54±6) was marginally older than the non-SCI (42±15; p=0.06) and tetraplegic (42±11; p=0.09) groups. Compared to non-SCI group, normalized t-score on the Stroop Color (SC) task was significantly lower in the paraplegic group (p<0.05). In the tetraplegic group, MAP was significantly lower (p<0.05) than the non-SCI and paraplegic groups, and related to SC t-score (r (2)=0.873; p<0.01). In the paraplegic group, CBF was reduced (p<0.05) and CVRi increased (p<0.05) compared to the non-SCI group, and CVRi was increased compared to the tetraplegic group (p<0.05). A significant inverse relationship was noted between change in CVRi and SC t-score in the non-SCI group. Asymptomatic hypotension relates to cognitive performance in persons with tetraplegia; therefore, BP normalization should be considered. The inappropriate cerebral vascular response to cognitive testing and poor test performance should be investigated in persons with paraplegia.

The Computerized Test of Information Processing (CTIP) Offers an Alternative to the PASAT for Assessing Cognitive Processing Speed in Individuals With Multiple Sclerosis

To compare the ability of the Computerized Test of Information Processing (CTIP) to detect impaired cognitive processing speed in patients with multiple sclerosis (MS) with a traditional 3.0 second Paced Auditory Serial Addition Test (PASAT) and the Adjusting-PASAT which allows for calculation of a speed score. A primary cognitive deficit in MS is an impaired ability to process information quickly. Unfortunately, relatively few clinical tests effectively measure information processing speed. Of these, the PASAT is generally acknowledged to be the most sensitive, but use of this test is constrained by several factors. All tests were administered to 30 adults with relapsing-remitting MS and 30 control participants. A series of analysis of variances revealed MS participants performed significantly worse than controls on the CTIP and the 3.0 second PASAT, whereas no significant difference was observed for the Adjusting-PASAT. The results suggest the CTIP can detect deficits in the speed at which people with MS process information. Thus, the CTIP offers an alternative means to the 3.0 second PASAT included in the Multiple Sclerosis Functional Composite for assessing such impairment.

Vascular smooth muscle function is associated with initiation and processing speed in patients with atherosclerotic vascular disease

We previously reported a relationship between forearm resistance vessel function and global neuropsychological performance in patients with atherosclerotic vascular disease (AVD). This study was conducted to determine the relationships among vascular smooth muscle function, endothelial function, and initiation and processing speed in this sample. Participants were 80 individuals with AVD. Resistance vessel function was measured before and after infusion of vasoactive agents. Neuropsychological assessment included measures of estimated premorbid cognitive function, current global cognitive function, initiation, and processing speed. Vascular smooth muscle function was significantly associated with the initiation/processing speed composite score [R-Square Change = .152; F Change (1,71) = 16.61; p < .001], above and beyond the variance accounted for by age, education, premorbid cognitive function, and endothelium-dependent vascular function. This relationship remained significant when controlling for current level of global cognitive functioning and 10 vascular risk factors. Endothelium-dependent vascular function was not significantly associated with test performance. Decreased vascular smooth muscle function in forearm resistance vessels was significantly associated with relatively poor initiation and processing speed in individuals with AVD. With additional research, measures of vascular function might become useful in the early identification of those individuals at greatest risk for vascular-related cognitive dysfunction.

Attentional processes discriminate between patients with mild Alzheimer's disease and cognitively healthy elderly

It is generally accepted that Alzheimer's disease (AD) is mainly characterized by memory disorders. Although recent studies also point to an important role of attention deficits early in the disease, this notion has not yet emerged in clinical practice. Our aim was to assess whether attention, quantified by reaction times, can discriminate between patients with mild AD and controls and therefore contribute to clinical diagnosis. In a cross-sectional study, 33 patients with mild AD were matched with cognitively healthy elderly controls for age, gender, educational level and depressive mood. Selective attention (SA), alternating attention (AA) and error-rates were measured by a modified reaction time test. Significant differences between both groups were found for all measures. Logistic regression showed that SA (corrected for individual processing speed) and error-rates could correctly classify subjects with an overall hit ratio of 81%. When attention measures were not corrected for individual processing speed, the overall hit ratio improved to 97%. SA and AA deteriorate in patients with mild AD and these measures can be used to discriminate between patients and matched controls, independently of depressive mood.

Word List Generation Performancein Alzheimer's Disease and Vascular Dementia

ABSTRACT Word list generation (WLG) was examined among clinical samples of individuals with Alzheimer's disease (AD) (n = 73) or ischemic vascular dementia (IVD) (n = 85), equivalent in age, education, current and estimated premorbid intellectual functioning, and proportion of men and women. The AD group performed significantly better than did the IVD group on lexical WLG, and a trend was observed indicating superior performance among the IVD group on categorical WLG. Within-groups, comparisons of group means, and profile analyses of individual performance patterns all indicated that persons with AD demonstrated a lexical > categorical pattern significantly more often than did IVD participants. The absolute difference in average performance between the AD and IVD groups on lexical and categorical WLG was small; the findings, however, generally support the clinical utility of the lexical > categorical WLG pattern in the differential diagnosis of AD and IVD. The patterns of performance support the presence of relative impairment in semantic processing among the individuals with AD and global deficits in retrieval and processing speed in individuals with IVD.

Speed of information processing in traumatic brain injury: modality-specific factors.

To assess speed of information processing by two serial addition tests (one visual, one auditory) in individuals with moderate-to-severe traumatic brain injuries (TBIs) and in a healthy, normal control group (NC). The tasks were designed to equate and control for accuracy of performance across the TBI and NC groups, thus allowing for quantification of information processing speed. Performance across groups and tasks were compared using 2 x 2 repeated measure analyses of variance (ANOVAs). In addition, each individual's processing speed was used to adjust rate of stimulus presentation on a subsequent "rehabilitation" trial to determine further whether this adjustment equated accuracy of performance. Rehabilitation hospital. 22 outpatients with moderate-to-severe TBI (6 women, 16 men; mean age = 34.6 years; duration of loss of consciousness = 22.6 days) and 20 age- and education-matched healthy controls. Processing speed was slower in TBI subjects, relative to controls and was significantly related to measures of executive functioning for those with TBI. Relative to controls, speed of processing in the TBI group was disproportionately slower when information was presented in the auditory, relative to the visual, modality. Speed of information processing is a major impairment in those with TBI when unconfounded by performance accuracy. The modality-specific impairment observed in the TBI group may, in part, be due to a greater within-modality interference effect created by the auditory version of the task. By manipulating information at a pace customized for an individual through compensatory strategies and environmental modifications, information-processing performance of TBI participants can be enhanced significantly.

Small cell carcinoma of the lung: An overview

The current study used a magnetoencephalogram to investigate the relationship between high-gamma (52–100 Hz) activity within an attention network and individual differences in behavioral performance among healthy elderly adults. We analyzed brain activity in 41 elderly subjects performing a 3-stimulus visual oddball task. In addition to the average amplitude of event-related fields in the left intraparietal sulcus (IPS), high-gamma power in the left middle frontal gyrus (MFG), the strength of high-gamma imaginary coherence between the right MFG and the left MFG, and those between the right MFG and the left thalamus predicted individual differences in reaction time. In addition, high-gamma power in the left MFG was correlated with task accuracy, whereas high-gamma power in the left thalamus and left IPS was correlated with individual processing speed. The direction of correlations indicated that higher high-gamma power or coherence in an attention network was associated with better task performance and, presumably, higher cognitive function. Thus, high-gamma activity in different regions of this attention network differentially contributed to attentional processing, and such activity could be a fundamental process associated with individual differences in cognitive aging.

Utilization of a lambda (Λ)‐shaped transistor for a hardware neuron model

AbstractInformation processing in a biological system is more redundant than in a computer system, realizing real‐time processing, eventhough the individual processing speed is low. This paper discusses a neuron electronic model; it is considered the core of biological information processing that has application to engineering problems. The circuit is based on the element which uses a Λ‐shaped transistor, a three‐terminal voltage‐controlled negative‐resistance device, to realize both negative resistance and inductance. It is shown that a hardware neuron model can be constructed by a simple circuit. The existence of a threshold and the generation of action potential are discussed, together with other characteristics of the model. It is then shown that, by improving the Λ‐shaped transistor, a hardware neuron model can be constructed with the self‐organizing function with adjustable threshold. The model is compared with BVP and HH models. A hardware neuron model with K‐conductance characteristics of H‐H model is constructed, followed by the discussion of characteristics such as those for constant‐current stimulation. Through this analysis, it is demonstrated that the proposed model can well simulate the biological neuron, and has the potential to be applied to engineering problems.