Reaction Time Variability Research Articles

Reduction of polyketone membranes prepared by thermally induced phase separation with solvent co-extrusion for enhanced fouling resistance

This study utilized solvent co-extrusion technology and NaBH4 reduction to fabricate polyketone (PK) hollow fiber membranes with high water permeance and fouling resistance. Variations in reduction reaction time were explored to assess their impact on chemical composition, morphology, and properties. The results showed that the reduction reaction leads to the conversion of carbonyl groups on the membrane surface to hydroxyl groups, and with prolonged reaction time, the amount of hydroxyl groups on the membrane surface increases to a certain extent. The change in membrane chemical composition enhanced the hydrophilicity, while leaving the membrane morphology, mechanical properties, and separation performance largely unaffected. Static adsorption tests with bovine serum albumin (BSA) and E. coli exhibited distinct fouling behavior. While pristine PK membranes displayed significant BSA adsorption, PK reduction significantly reduced it. Both pristine and reduced PK membranes showed minimal E. coli attachment, likely due to weak interactions. Dynamic filtration tests demonstrated excellent flux recovery for reduced PK membranes, especially after 10 min of reduction, indicating superior fouling resistance with high flux recovery and low irreversible fouling, regardless of foulant type. These findings highlight a straightforward and efficient approach for producing high-performance membranes with exceptional fouling resistance suitable for practical applications.

From attentional fluctuations to intentional fluctuations? Monitoring behavior and intraindividual variability in time-based prospective memory.

In sharp contrast to event-based prospective memory (PM), dynamics of (re)allocation of attention between the ongoing and PM tasks have been much less investigated in time-based PM tasks. We propose an in-depth examination of attention allocation in a time-based PM task by jointly analyzing multiple indicators of time-monitoring behavior, net and time-structured intraindividual variability (IIV) in ongoing-task reaction times (OT RTs), and task performance. Results from dynamic structural equation modeling in a lifespan sample of 198 adults (19-86 years) revealed that larger fluctuations in OT RTs (net IIV) predicted poorer OT performance, but fostered a more efficient pattern of time-monitoring behavior (i.e., checking a clock more frequently and strategically, and slowing OT RTs during the PM response window) that, in turn, enhanced PM. Conversely, greater inertia in OT RTs (time-structured IIV) led to fewer clock-checks and poorer PM performance. Focusing attention on time monitoring to enhance PM performance did not detrimentally affect OT accuracy. Instead, participants showed a speed-accuracy tradeoff to optimize both OT and PM accuracies by slowing their OT RTs during the PM response window. This study therefore shows that two concomitant aspects of IIV (net and time-structured IIV) not only predicted time-monitoring behavior, but also OT and PM accuracies differentially, hence advocating for the necessity to consider both aspects of IIV and time monitoring together to better understand attention allocation policies in time-based PM tasks. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The effect of individual and paired Brailletonik exercises on balance and reaction time in children with intellectual disability

Backgroundchildren with Intellectual Disabilities (ID) are less proficient in motor skills compared to normally developing children, which means they need more time for learning skills. In this context, the purpose of this research is to investigate the effect of the Brailletonik physical activity program (BPAM) on the balance and reaction time of children with ID.MethodsThe statistical sample is consisted of 30 children aged 8 to 12 (21 boys, 9 girls) with ID with an average age of 9.8 ± 1.39, who were selected through convenience sampling. Participants were divided into two groups of individual BPAM, and pair BPAM. Training sessions were held for 21 sessions (seven weeks) and each session included 30 min of training. To measure static balance and reaction time, Stork Stand test and Simple Reaction Time Software were used respectively. The analysis of covariance (ANCOVA) and Bonferroni’s post hoc test were used to analyze the data. Data analysis was performed using SPSS software version 26 at a significance level of p ≤ 0.05.ResultsThe results showed that individual and paired exercise groups had significant progress from pre-test to post-test in both variables of balance and reaction time (p = 0.001). Also, the comparison of the performance of the groups in the post-test showed that the average performance of the paired exercise group was significantly better than the individual exercise group in the balance variable (p = 0.03) and in the reaction time variable (p = 0.01).ConclusionAccordingly, it can be concluded that BPAM in paired groups has a greater effect on the balance and reaction time of children with ID.

Optimization of biomass durian peel as a heterogeneous catalyst in biodiesel production using microwave irradiation

Abstract The present study investigated biodiesel production from the transesterification of palm oil with methanol using calcined biomass durian peel (BDP) as a heterogeneous catalyst assisted by microwave irradiation. Characterization of the calcined BDP showed that K2O is the main compound with a concentration of 86.15 wt%. The effect of three independent variables of catalyst weight (3–12 wt%), reaction time (1–10 min), and power of microwave (180–900 W) was used to determine the optimum condition on biodiesel production using the response surface method-based on the Box–Behnken design experiment. The optimum biodiesel conversion of 97.3% was achieved under experimental parameters of catalyst concentration of 12 wt%, reaction time of 9 min, and microwave power of 180 W. The catalyst concentration and reaction time have significant effects on biodiesel conversion.

Combination of addition and activation of lipase enzyme in peanut seed (Arachis hypogaea L.) for direct fatty acid production

Fatty acids are oleochemical products that are widely used as raw materials in various industries. Fatty acids are obtained from various plants and animals, one of which is peanuts. Peanuts contain 76% - 82% unsaturated fatty acids and the rest is saturated fatty acids. The purpose of this study is to produce fatty acids by turning on the peanut seed’s lipase enzyme. In this study, the addition of immobilized lipase enzyme as much as 0.1% of the sample mass was also carried out. This research method was carried out by grinding peanut seeds using a chopper with variations in the addition of water and variations in reaction time at 35 °C and 30 °C. The mixture of peanut seeds and water is then separated using a hand press, then heated to evaporate the water content. Furthermore, the resulting peanut oil was tested for fatty acid content, density, viscosity, and pH. From this study, the highest fatty acid content was obtained at 10.73% which was achieved at 35 °C and at a reaction time of 6 hours with the addition of enzymes and the addition of 40% water, while the result obtained without the addition of enzymes at the same conditions was 4.51%.

Looper, an updated closed loop feature detection platform for automated neonate cardio-respiratory measurements and data analysis

Facemask pneumotachography is a common, precise experimental approach for measuring respiratory outcomes in neonate rodents (P7-8), particularly in autoresuscitation experiments that inform upon Sudden Infant Death Syndrome where failure of autoresuscitation is hypothesized to be a common endpoint. However, current approaches rely on direct, real-time waveform inspection by an observer and their highly variable reaction times to execute responsive changes in assay gas exposures. Looper, represents a novel and significant improvement on typical observer-based interpretation of live data to initiate challenge and recovery gas applications to uncover nuanced features in neonate cardiorespiratory physiology. Leveraging our previously published Breathe Easy software, we have expanded the analytical capabilities of the software to analyze key features within a typical autoresuscitation cycle. Utilizing the software output, we have further developed machine learning approaches that enable real-time prediction of cardio-respiratory failure based distinct waveform features more than 10min in advance, setting the stage for novel experiments to identify critical interventional windows for enhancing resuscitation. R01HL161142 R01HL130249. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Impacts of synthesis variables on spectroscopics evaluation of biobased fatty amide as alkylammonium salt’s precursor for perovskite

Ammonium salts are widely used in chemical industries as additives in cement industries, phase change materials in thermal cooling, ionic materials in electrochromic window and multifunction medium/precursor/catalyst in solar cells to improve the efficiency and stability. This work introduces a procedural enhancement by incorporating a liquid-liquid extraction purification process, resulting in a high-purity biobased fatty amide (FA) with tri-substitution and high-purity biobased tetraalkylammonium ammonium salt (TAS). Biobased FA derived from renewable sources was synthesized via an amidation reaction between fatty acids from vegetable oil with tris(3-aminopropyl)amine under reflux conditions, producing a precursor for TAS used in perovskite solar cell (PSC). This study aimed to optimize and determine the reaction condition of biobased FA at various key synthesis variables by investigating the effects of solvent selection, reaction and crystallization, temperature, catalyst, mole ratio, and dehydrating agent on synthesis yield. A multiple liquid-liquid extraction process was employed to enhance the purity of biobased FA by tunning the selection of solvent based on its relative polarity of the reactant and products. Response surface methodology (RSM) and central composite design (CCD) were utilized to optimize the total yield and the three key variables (reaction time, crystallization time, catalyst amount) respectively. The experimental model developed in this study demonstrated a high degree of fitness with the experimental data (F-value = 27.34), p-value < 0.05) and nonsignificant lack of fit. The model predicted a maximum synthesis yield percentage of 52.62 % under optimal conditions (reaction and crystallization time of 12 and 28 hours), respectively with 4.47 % catalyst). The coefficient of determination of R2 = 0.98 shows a high correlation with the predicted values and in good agreement with the experimental values. Physicochemical properties analysis using spectroscopies techniques, confirmed improved purity with 100% abundance yield of tri-substitution biobased FA and enhanced TAS’s purity up to 60%. The optimization study sheds light on the impact of key synthesis variables on the synthesis yield and percentage abundance (purity), advancing the development of more efficient and tailored sustainable construction materials. These findings highlight the potential of using biobased FA as a sustainable source for TAS production, contributing to a more environmentally friendly approach in PSC development.

Nanofiber membranes immobilized with in-situ grown nanoparticles for enhanced wetting resistance in direct contact membrane distillation

Immobilizing nanoparticles (NPs) onto the hydrophobic nanofiber membrane surface is an effective method to enhance its resistance to pore wetting in membrane distillation (MD) due to construction of a hierarchical structure. However, loading NPs onto the fabricated membrane through post-treatment techniques (e.g., electrospray, physical vapor deposition etc.) results in agglomeration of NPs and their weak attachment with membrane surface. To address this issue, we utilize precipitation and crystallization methods to achieve in-situ growth of zinc oxide (ZnO) NPs onto nanofiber surface for intensifying their interaction. Morphological characterization demonstrated that the size and amount of in-situ grown ZnO NPs could be controlled by varying reaction time and concentration of precipitation agent. Furthermore, the resultant nanofiber membrane with higher contact angles (163°) showed stable water flux and effective salt rejection in presence of surfactant and oil. Finally, the kinetics of wetting progression monitored by ultrasonic time-domain reflectometry (UTDR) further confirmed that the early partial wetting induced by surfactants was significantly restrained owing to the hierarchical structure generated by the in-situ grown ZnO NPs. This study suggested the modified nanofiber membrane presented outstanding wetting resistance to low-surface-tension foulants and promise for desalination in MD.

Nitrate removal study of synthesized nano γ-alumina and magnetite-alumina nanocomposite adsorbents prepared by various methods and precursors.

The challenges in water treatment include the need for efficient removal of pollutants like nitrate, which poses significant environmental and health risks. Alumina's significance lies in its proven effectiveness as an adsorbent for nitrate removal due to its high surface area and affinity for nitrate ions. This study delves into the synthesis of differen nano-sized γ-alumina (γA1-5) employing diverse precursors and methods, including nepheline syenite, lime, aluminum hydroxide, precipitation, and hydrothermal processes at varying reaction times. Simultaneously, magnetite (Fe3O4) nanoparticles and magnetite/γ-alumina nanocomposites (Fn/γA5) were synthesized using the co-precipitation method with varying weight ratios (n). Our primary objective was to optimize γ-alumina synthesis by comparing multiple methods, shedding light on the influence of different precursors and sources. Hence, a comprehensive adsorption study was conducted to assess the materials' efficacy in nitrate removal. This study fills gaps in the literature, providing a novel perspective through the simultaneous assessment of magnetite/alumina nanocomposites and pure alumina performance. Structural and morphological properties were studied employing XRD, FT-IR, FESEM, EDX, XRD, and VSM techniques. The conducted experiments for γA5, F5/γA5, and F10/γA5 nanocomposites showcased the optimum pH of 5 and contact time of 45min for all samples. The influence of nitrate's initial concentration on the removal percentage was investigated with initial concentrations of 10ppm, 50ppm, and 100ppm. γA5, F5/γA5 and F10/γA5 nanocomposites had 17.3%, 55%, and 70% at 10 ppm, 18%, 55.16%, and 74% at 50 ppm, and 8.6%, 53.1%, and 63%, respectively. The results highlighted that F10/γA5 can be used as a remarkable adsorbent for wastewater treatment purposes.

The trial-by-trial fluctuations in primary motor cortex excitability during attentional bias among smokers: A transcranial magnetic stimulation study

BackgroundA relatively new computational approach called trial-level bias score (TL-BS) has shown that attentional bias to smoking-related stimuli in smokers fluctuates temporally, trial by trial, during attention tasks. Here, we investigated the reliability of using TL-BS values to assess attentional bias and the electrophysiology mechanisms undergirding fluctuations in attentional bias among smokers. MethodIn total, 26 male smokers and 26 male non-smokers performed a dot-probe task in Experiment 1. In Experiment 2, an additional 23 male smokers and 23 male non-smokers performed the same task while undergoing single-pulse transcranial magnetic stimulation, which was used to investigate corticospinal excitability. ResultsIt showed that assessing TL-BS parameters for reaction time (RT) was more reliable than calculating the traditional mean attentional bias score; however, this superior reliability was no longer apparent after controlling for general RT variability. There was a significant difference between smokers and non-smokers in TL-BS parameters calculated for both RT and motor-evoked potential (MEP) amplitude. However, TL-BS parameters for RT and MEP amplitude were strongly correlated with general RT variability and general MEP variability, respectively. ConclusionsOur findings indicated that TL-BS parameters may not be ideal for measuring attentional bias at either the behavioral or electrophysiology level; however, larger general RT and MEP amplitude variabilities in non-smokers may indicate dysregulation of cognitive processing in smokers.

Exploring the associations of demographics and scale measures with cognitive driving behavior among older drivers in China

Age-related changes and frailty are reasons for the high proportion of older drivers in certain types of crashes, such as giving right of way at intersections and turning left. The identified crash causes include the driver’s demographics, driving style, cognitive function, and mental workload. This study aimed to explore the associations of demographics and scale measures with cognitive driving behavior. Thirty-nine drivers, consisting of twenty younger drivers (18–60 years old) and nineteen older drivers (above 60 years old), participated in driving simulation experiments after completing scale tests. The selected scale measures included the demographic questionnaire, Multidimensional Driving Style Inventory (MDSI-C), Mini-Mental State Examination (MMSE), Trail Making Test Part A (TMT-A) and Part B (TMT-B), and the National Aeronautics and Space Administration Task Load Index (NASA-TLX) for obtaining subjective information from drivers. Driving scenarios were developed based on the driving characteristics of older adults to investigate age-related driving ability. The driving behavior parameters included reaction time, lateral stability, and driving speed, corresponding to reaction, perception, and execution. Three stepwise regression models showed that NASA-TLX, the interaction between age and driving experience, and the interaction between age and TMT-A significantly explained 53.3 % of reaction time variance; TMT-A, risk driving style, anxiety driving style, and gender significantly explained 53.5 % of lateral stability variance; TMT-A, NASA-TLX, and MMSE significantly explained 60.6 % of driving speed variance. Subsequently, the impact of four age-related predictor variables on driving behavior was further discussed. It is worth noting that a rich driving experience may compensate for driving performance. However cognitive impairment impairs this compensation. Driving behavior is influenced by a combination of various factors. Age, as a physiological indicator, is not sufficient to be a strong predictive factor for lateral stability and driving speed. The results provide a reference for traffic safety management departments to streamline driving suitability test procedures and propose targeted training methods for older drivers.

A comparative study of simple reaction time in PCOS and non-PCOS patients and its relation with BMI

Introduction and Aim: Polycystic ovarian syndrome (PCOS) is a hormonal disorder of the female reproductive system causing infertility, an irregular menstrual cycle, and hormonal imbalance characterized by hyperandrogenism. Reaction to any stimulus is a voluntary response that measures the speed of response of a person. There is gender variation in reaction time, hence there is a need for evaluation of reaction time in PCOS. Thus, auditory and visual reaction time may be affected in the women with polycystic ovaries. The aim of the study was to compare ART and VRT in PCOS and non-PCOS Individuals and to correlate ART and VRT with BMI in PCOS individuals. Materials and Methods: Age-matched 25 normal and 25 PCOS were subjected to ART and VRT and recordings were obtained. The anthropological parameters like height, weight, and BMI were computed. The results were analyzed using a t-test and Pearson’s correlation test using SPSS software. Results: The auditory reaction time showed significant (p&lt;0.001) increase in PCOS 0.318±0.0388 than non-PCOS individuals 0.239±0.0629. There was positive correlation(r=0.491, p&lt;0.05) of BMI with visual reaction time in PCOS individuals. Conclusion: Since there is an increase in reaction time and a positive relation with BMI we can say that there is a decline in cognition in PCOS individuals probably due to hormonal changes and obesity.

Quadratic associations between cardiovascular stress reactivity and development of cool and hot executive functions in adolescents.

Stress affects executive functions and exploring the association between stress-induced physiological reactivity and executive functions could highlight the potential mechanism of the stress-cognitive function link. Our study examined the linear and nonlinear associations between cardiovascular stress reactivity and cool and hot executive functions among adolescents. In November 2021 (T1), 273 Chinese adolescents between 11 and 14 (Mage = 12.93, SDage = 0.79) underwent a speech task during which their cardiovascular data were recorded, and they completed a Flanker task and an Emotional Stroop task. In May 2023 (T2), 253 adolescents again completed the Flanker and Emotional Stroop tasks. Cool and hot executive functions were assessed using the intra-individual reaction time variability of the Flanker task and Emotional Stroop task, respectively. Results showed that cardiovascular stress reactivity was positively linearly associated with cool executive functions at T1 and quadratically (inverted U-shaped) associated with cool executive functions at T1 and hot executive functions at T1 and T2. These findings suggest that compared to very high and very low cardiovascular reactivity, moderate to high cardiovascular reactivity to a structured social challenge is associated with better cool and hot executive functions.

CaO@ZrO2@g-C3N4 nanosorbent for superior malachite green dye selectivity and adsorption from contaminated water

The steady rise in the volume of waste produced by the forestry, lumber, and paper sectors has necessitated the exploration of methods to convert these waste products into commercially advantageous resources for human use. The present study presents the synthesis and utilization of CaO@ZrO2@g-C3N4 (CZCN) as an innovative adsorbent for eliminating malachite green (MG) from aqueous solutions. The CZCN nanosorbent was subjected to characterization using various analytical techniques, including XRD, EDX, TEM, BET, FTIR, and XPS. The examination of characterizations indicated that the CZCN exhibited a limited range of particle sizes and possessed a significant surface area. The findings from the adsorption experiments demonstrated a correlation between the efficiency of MG dye removal and variations in solution pH, starting concentration, and reaction time. The adsorption equilibrium isotherm demonstrated that the adsorption of MG adhered to the Langmuir isotherm model, exhibiting a maximum adsorption capacity of 1140 mg/g. A pseudo-second-order kinetic model best described the experimental data. The CZCN nanosorbent exhibits promising adsorption capabilities, suggesting potential for future investigation and utilization in treating wastewater containing dyes.

Fast and Stable Responses during Decision Making Require Strong Inhibitory Processes in Soccer Players.

Quick decision making is a vital factor for a successful pass in soccer games. Many previous studies of decision making in soccer focused on motor execution, but inhibitory processing has remained unclear. This study aimed to clarify the differences in motor execution and inhibitory among Japanese collegiate soccer players with different skill levels. We evaluated the behavioral data and event-related potentials in the high-skilled, low-skilled, and novice groups during the Go/No-go and pass choice reaction tasks. The reaction time (RT) was significantly shorter in the high group than in the novice group, and RT variability was small in the high group. The amplitude of the N2 component was significantly larger in the high group than in the low and novice groups, and the latency of the P3 component was significantly shorter in the high and low groups than in the novice group during the pass choice reaction task. The subtracted No-go N2 amplitude was also significantly larger in the high and low groups than in the novice group, and correlations existed between the RT, RT variability, and the subtracted No-go N2 amplitude during these tasks. These data indicate that soccer players' behavioral responses and inhibition processing decision-making activities are associated with skill levels.

Carbonaceous catalysts (biochar and activated carbon) from agricultural residues and their application in production of biodiesel: A review

Carbonaceous catalysts obtained from agricultural residue could have potential in the production of biofuels such as biodiesel. This review paper discusses the preparation conditions (temperature, heating rate, hold time, inert gas flow rate, etc play key roles in development of textural characteristics of the catalysts) and functionalization methods of biochar and activated carbon derived from agricultural residues and their application to produce biodiesel. Research works reported in achieving maximum yield of biodiesel in terms of variable precursors, alcohol-to-oil ratio, reaction time and temperatures have been profoundly tabulated. Effect of textural properties of the biochar and activated carbon (such as surface area, total pore volume, average pore size, and functional group attached with the catalyst) on the biodiesel yield are examined. Studies on Regeneration and reusing of the spent catalysts are carefully inspected. The economic evaluation studies for the biochar and activated carbon and the applications of these for biodiesel production are scrutinized. Finally, the strategies to increase biomass and catalyst productivity, future prospect and research directions to enhance biofuel/biodiesel production and for the development of biochar and activated carbon from agricultural residues for sustainable biodiesel production is suggested.

On the nonlinearity of the foreperiod effect

One of the frequently employed tasks within the implicit timing paradigm is the foreperiod task. The foreperiod is the time interval spanning from the presentation of a warning signal to the appearance of a target stimulus, during which reaction time trajectory follows time uncertainty. While the typical approach in analyzing foreperiod effects is based on linear approximations, the uncertainty in the estimation of time, expressed by the Weber fraction, implies a nonlinear trend. In the present study, we analyzed the variable foreperiod reaction times from a relatively large sample (n = 109). We found that the linear regression on reaction times and log-transformed reaction times poorly fitted the foreperiod data. However, a nonlinear regression based on an exponential decay function with three distinctive parameters provided the best fit. We discussed the inferential hazards of a simplistic linear approach and demonstrated how a nonlinear formulation can create new opportunities for studies in implicit timing research, which were previously impossible.

Increased intraindividual variability in reaction time performance is associated with emerging cognitive decline in cognitively unimpaired adults.

To investigate whether intraindividual variability (IIV) in reaction time (RT) over monthly administered cognitive tasks is increased in cognitively unimpaired older adults who are at risk for cognitive decline, and whether this is independent of mean RT performance. N = 109 cognitively unimpaired individuals (age 77.4 ± 5.0, 61.5% female, Mini-Mental State Examination 29.1 ± 1.3) from the Harvard Aging Brain Study completed the self-administered Computerized Cognitive Composite (C3) monthly at home for up to 1 year (12.7 ± 3.2 C3 assessments). Baseline C3 assessment coincided with routine in-clinic visits, including amyloid and tau positron emission tomography imaging and standardized cognitive testing, with cognitive testing repeated annually (1.6 ± 1.2 years follow-up). The C3 includes two simple RT tasks and two complex RT tasks. IIV estimates were derived by computing intraindividual standard deviations on residual RT scores after regressing out age and session order effects. Cross-sectional associations of IIV with cognition (global cognition, memory, executive functions [EF], processing speed) and amyloid and tau burden were examined using linear regression analyses correcting for demographics and mean RT. The association between IIV and cognitive decline was assessed using linear mixed models correcting for demographic factors, mean RT, and amyloid burden. After adjusting for mean RT, increased IIV on complex RT tasks was independently associated with worse EF performance (β = -0.10, 95% CI [-.16, -0.03], p = .004), greater inferior-temporal tau deposition (β = 0.18, 95% CI [0.02, 0.34], p = .024), and faster cognitive decline in those with elevated amyloid (β = -0.62, 95% CI [-1.18, -0.06], p = .033). Increased variability in monthly RT may reflect subtle EF deficits and provide unique information about short-term cognitive decline in preclinical Alzheimer's disease. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Is Visual Prediction Impaired in Adolescents with Autism spectrum Disorder? Event-Related Potentials in a Cued Visual GO/NOGO Task.

Aim: Deviant visual processing has been observed in autism spectrum disorder (ASD), manifesting as decreased P1 and P2 components of visual event-related potentials (ERPs). Alterations have been attributed to a failure of Bayesian inference, characterized by hypo-activation of top-down predictive abilities. To test this hypothesis, we measured the visual negativity (vN) as an ERP index of visual preparation hypothesized to mirror predictive brain activity. Method: ERPs in a cued visual GO/NOGO task in 63 adolescents with ASD (IQ > 70, attention-deficit hyperactivity disorder excluded) were compared with ERPs in a sex- and age-matched group of 60 typically developing (TD) controls. Results: The behavioral variables (omissions, commissions, reaction time, and reaction time variability), as well as ERP components reflecting, among other processes, cognitive control (contingent negative variation, P3 GO, P3 NOGO, N2 NOGO) did not differ between the groups. There were group differences in visually based ERPs. Besides P1 and P2 differences, the vN component differentiated the 2 groups with the highest effect size (d = 0.74).Conclusion: This ERP study lends support to the hypothesis suggesting that a Bayesian hypo-prediction could underlie unique perceptual experiences in individuals with ASD. This could lead to a predisposition to perceive the world with reduced influence and modulation from contextual cues, prior experiences, and pre-existing expectations.

Naturalistic assessment of reaction time variability in older adults at risk for Alzheimer's disease.

Maintaining attention underlies many aspects of cognition and becomes compromised early in neurodegenerative diseases like Alzheimer's disease (AD). The consistency of maintaining attention can be measured with reaction time (RT) variability. Previous work has focused on measuring such fluctuations during in-clinic testing, but recent developments in remote, smartphone-based cognitive assessments can allow one to test if these fluctuations in attention are evident in naturalistic settings and if they are sensitive to traditional clinical and cognitive markers of AD. Three hundred and seventy older adults (aged 75.8 +/- 5.8 years) completed a week of remote daily testing on the Ambulatory Research in Cognition (ARC) smartphone platform and also completed clinical, genetic, and conventional in-clinic cognitive assessments. RT variability was assessed in a brief (20-40 seconds) processing speed task using two different measures of variability, the Coefficient of Variation (CoV) and the Root Mean Squared Successive Difference (RMSSD) of RTs on correct trials. Symptomatic participants showed greater variability compared to cognitively normal participants. When restricted to cognitively normal participants, APOE ε4 carriers exhibited greater variability than noncarriers. Both CoV and RMSSD showed significant, and similar, correlations with several in-clinic cognitive composites. Finally, both RT variability measures significantly mediated the relationship between APOE ε4 status and several in-clinic cognition composites. Attentional fluctuations over 20-40 seconds assessed in daily life, are sensitive to clinical status and genetic risk for AD. RT variability appears to be an important predictor of cognitive deficits during the preclinical disease stage.