Movement Latency Research Articles

Labels strengthen motor learning of new tools

Recent reformulations of the Sapir-Whorf hypothesis have shown how labels can guide our thinking in situations of uncertainty, facilitating the identification of objects. We examine whether the effect of labels extends beyond perceptual processes, to help us learn the motoric manipulations required to use novel tools. Exploiting immersive virtual reality, we measured behavioural movement latencies and electrophysiological activity from participants learning to use a range of labeled and unlabeled novel tools. We found that providing a tool with a label reduced the time taken to reach for it, with participants also faster and more accurate when executing the manipulations required to use it. Conversely, labels did not confer any facilitation when the tool was simply moved to another location; participants were slower to grasp a labeled tool when asked to transport it. These findings were also supported by electrophysiological recordings, showing a reduction in sensorimotor beta-band (~30 Hz) power when participants were asked to use the labeled tools, but not move them. This modulation of beta activity indicates augmented learning of motor-activity related to tool use within somatosensory regions due to the activation of its lexical representation. These results suggest an extension of the Whorfian hypothesis, such that language not only modulates our thoughts and perceptual processes, but also affects our actions with objects and tools. We propose that labels tune our somatosensory experience and help to memorize body states related to tool use by creating an invariant lexical anchor on which we can build motor learning and experience.

Long‐term behavioral repeatability in wild adult and captive juvenile turtles (Terrapene carolina): Implications for personality development

AbstractAnimal personality can be defined as conspecific individuals consistently differing in behavioral tendencies. Personality is typically identified by behavioral repeatability, which occurs when within‐individual variance is low relative to among‐individual variance in the population. Intraspecific comparisons of behavioral repeatability in juveniles and adults within and across years are rare, but would be useful for testing hypotheses related to origins of animal personality and whether individuals exhibit stable or diverging behavior with ontogeny. To examine within‐ and across‐year behavioral repeatability for eastern box turtles (Terrapene carolina), we assessed boldness (movement latency after brief confinement) of captive‐born juveniles twice within three days when eight months old. We then repeated these tests for the same individuals one year later. Juveniles exhibited repeatable boldness within and across years. Although increasing body temperature was slightly associated with decreased movement latency, test year (1 or 2), or housing experience (being raised in an enriched or unenriched condition) had no effects on boldness. We also assessed across‐year repeatability of boldness (head emergence from the shell after brief confinement) for wild adults at 1–3 year intervals. Adults also exhibited repeatable across‐year boldness that was of similar magnitude to juveniles. We found no indication that sex class or whether adults had been radio‐tracked influenced boldness. Our results suggest eastern box turtles demonstrate consistent individuality in boldness from an early age that is largely unaffected by temporal or environmental variation, and these behavioral differences can be maintained for multiple years in captivity and the wild, contrasting with theoretical expectations for personality development. These findings add to recent accumulating evidence demonstrating juvenile and adult box turtles exhibit multiple repeatable behaviors over the short‐ and long‐term. We suggest this species is quickly gaining traction as a model organism for studying the proximate and ultimate causes of personality development within long‐lived animals.

Wpływ miękkich multifokalnych soczewek kontaktowych z wysokimi addycjami na koordynację wzrokowo-ruchową

The aim of the present study was to assess whether soft multifocal contact lens (SMFCLs) with high addition powers, designed for myopia control, may have an impact on eye movements and eye–hand coordination. A total of 24 young adults used SMFCLs (Relax, SwissLens) with high additions: +2D (Add2) and +4D (Add4). Single vision (Add0) contact lenses were used as controls (Orbis, SwissLens). In the eye–hand coordination task, the study participants were asked to point out the small circle displayed on a touch screen. Reaction time and accuracy of pointing, as well as latency of eye movements were measured. Results showed that SMFCLs had no significant impact on the latency of eye movements (135, 136, 139 ms, for Add0, Add2 and Add4, p = 0.171), reaction time (732, 730, 727 ms for Add0, Add2 and Add4, p = 0.932) or percent error (17%, 13%, 18% for Add0, Add2 and Add4, p = 0.386).

Distinct effects of orexin receptor antagonist and GABAA agonist on sleep and physical/cognitive functions after forced awakening

The majority of patients with insomnia are treated with hypnotic agents. In the present study, we evaluated the side-effect profile of an orexin receptor antagonist and γ-aminobutyric acid A (GABAA) receptor agonist on physical/cognitive functions upon forced awakening. This double-blind, randomized, placebo-controlled, cross-over study was conducted on 30 healthy male subjects. Fifteen minutes before bedtime, the subjects took a pill of suvorexant (20 mg), brotizolam (0.25 mg), or placebo and were forced awake 90 min thereafter. Physical- and cognitive-function tests were performed before taking the pill, after forced awakening, and the next morning. Polysomnographic recordings revealed that the efficacies of the hypnotic agents in prolonging total sleep time (∼30 min) and increasing sleep efficiency (∼6%) were comparable. When the subjects were allowed to go back to sleep after the forced awakening, the sleep latency was shorter under the influence of hypnotic agents (∼2 min) compared to the placebo trial (24 min), and the rapid eye movement latency was significantly shorter under suvorexant (98.8, 81.7, and 48.8 min for placebo, brotizolam, and suvorexant, respectively). Although brotizolam significantly impaired the overall physical/cognitive performance (sum of z score) compared with placebo upon forced awakening, there was no significant difference in the total z score of performance between suvorexant and placebo. Notably, the score for static balance with the eyes open was higher under suvorexant compared to brotizolam administration. The energy expenditure was lower under suvorexant and brotizolam compared with the placebo. The effect size of brotizolam (d = 0.24) to reduce the energy expenditure was larger than that of suvorexant (d < 0.01).

Sleep stage dynamics in young patients with sleep bruxism.

We hypothesized that sleep stage dynamics are different in patients with sleep bruxism (SB) and that these changes are associated with the occurrence of rhythmic masticatory muscle activity (RMMA). Fifteen healthy controls and 15 patients with SB underwent overnight polysomnography. Sleep variables and survival curves of continuous runs of each sleep stage were compared between the groups. Stage transition dynamics and the probability of stage fragmentation were analyzed for three epochs before and after the epoch with RMMA. Survival curves of continuous runs of each sleep stage, terminated with or without RMMA, were also compared. There were no significant differences in sleep variables between the groups, except for shorter sleep latency, shorter rapid eye movement (REM) latency, and longer total N1 duration in SB patients than in controls. REM sleep and N2 were significantly less continuous in SB patients than in controls. In the SB group, stage fragmentation probability was significantly increased for the epoch with RMMA compared with the baseline for all stages. Meanwhile, the occurrence of RMMA did not affect the continuity of N2 or REM; however, the occurrence of RMMA was preceded by more continuous N3 runs. Sleep stage dynamics differed between SB patients and controls. RMMA does not result in sleep disruption but is likely associated with dissipation of sleep pressure. Less continuity of REM sleep in SB may provide insights into the underlying pathophysiological mechanisms of SB, which may be related to REM sleep processes such as cortical desynchronized states or brainstem activation.

Dysfunctional attentional bias and inhibitory control during anti-saccade task in patients with internet gaming disorder: An eye tracking study

BackgroundAlthough internet gaming disorder (IGD) is considered an addictive disorder, evidence of the neurobiological underpinnings of IGD as an addictive disorder is currently lacking. We investigated whether attentional bias toward game-related stimuli was altered in IGD patients using an eye-tracking method during an anti-saccade task. MethodsTwenty-three IGD patients and 27 healthy control (HC) subjects participated in the anti-saccade task with game-related, neutral, and scrambled images during eye tracking. Participants rated subjective scores of valence, arousal, and craving for each image stimulus after finishing eye tracking. Mixed design analysis of variance was performed to compare the differences between eye movement latency and error rate in the pro-saccade and anti-saccade conditions according to image type across the IGD and HC groups. ResultsIn the anti-saccade task, the IGD group exhibited higher error rates in the case of game-related images than in neutral or scrambled images. However, ratings on valence, arousal, and craving did not vary among image types. The error rates of the HCs did not vary across image types, but higher arousal/craving and lower valence were reported with respect to the game-related images. ConclusionsIncreased error rate during anti-saccade tasks with game-related stimuli in IGD may be due to disabilities in goal-directed behavior or inhibitory control, as observed in other addictive disorders. These findings suggest that attentional bias toward game-related stimuli can be a sensitive biological marker of IGD as an addictive disorder.

Gray Matter Atrophy to Explain Subclinical Oculomotor Deficit in Multiple Sclerosis.

Eye movement deficits are frequently noted in multiple sclerosis during bedside clinical examination, but subtle dysfunction may remain undetected and might only be identified with advanced approaches. While classical neurology provides insight into the complex functional anatomy of oculomotor functions, little is known about the structural background of this dysfunction in MS. Thirty four clinically stable, treated relapsing-remitting MS patients with mild disability and 34 healthy controls were included in our study. Group difference and correlation with clinical parameters were analyzed in case of the latency, peak-velocity, gain, dysconjugacy index, and performance during a saccade and anti-saccade task. High-resolution T1 weighted, T2 FLAIR, and double inversion recovery images were acquired on 3T to evaluate the correlation between behavioral and MRI parameters, such as T2 lesion and T1 black-hole burden, global brain, gray, and white matter atrophy. VBM style analysis was used to identify the focal gray matter atrophy responsible for oculomotor dysfunction. Significantly increased latency in the prosaccade task and significantly worse performance in the anti-saccade task were found in MS patients. The detailed examination of conjugated eye movements revealed five subclinical internuclear ophthalmoparesis cases. The peak velocity and latency of the anti-saccade movement correlated with the number of black holes, but none of the eye movement parameters were associated with the T2 lesion burden or location. Global gray matter volume correlated with saccade and anti-saccade latency, whereas white matter and total brain volume did not. Local gray matter atrophy in the left inferio-parietal lobule and temporo-occipital junction correlated with anti-saccade peak velocity. Our results show that neurodegeneration-like features of the MRI (black-hole, gray matter atrophy) are the best predictors of eye movement deficit in MS. Concurring with the clinico-radiological paradox, T2 lesion burden cannot explain the behavioral results. Importantly, anti-saccade peak velocity correlates with gray matter atrophy in the left parietal regions, which are frequently implicated in attention tasks.

Aerobic exercise modulates cytokine profile and sleep quality in elderly.

Sleep disturbance is a major problem for older adults which can be exacerbated by increased inflammation as aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. There is a need to develop alternative medicine techniques to help improve sleep quality in the elderly. To investigate the effects of aerobic exercise training on the sleep quality and inflammatory cytokines in elderly subjects. Forty previously sedentary elderly subjects participated in this study, their age ranged from 61- 67 years. All subjects were randomly assigned to supervised aerobic exercise intervention group (group A, n=25) or control group (group B, n=25). Polysomnographic recordings for sleep quality assessment, interleukin- 6 (IL-6), tumor necrosis factor- alpha (TNF-α) and interleukin-10 (IL-10) were measured before and after 6 months at the end of the study. There was a significant increase in total sleep duration, sleep efficiency and sleep onset latency in group(A) after 6 months of aerobic exercise training, while, wake time after sleep onset and rapid eye movement (REM) latency significantly reduced after 6 months of aerobic training compared with values obtained prior to aerobic exercise training. Also, the mean values of TNF- α and IL-6 decreased significantly and the mean value of IL-10 significantly increased in group (A) after the aerobic exercise training, however the results of the control group were not significant. Moreover, there were significant differences between both groups at the end of the study. Exercise training can be considered as a non-pharmacological modality for modifying sleep quality and inflammation among elderly.

Joint Attention in Infancy and the Emergence of Autism

BackgroundIn typical infant development, parents and their children jointly contribute to establishing frequent episodes of joint attention that boost language acquisition and shape social cognition. Here we used novel live eye-tracking technology to evaluate the degree to which autism spectrum disorder (ASD) is related to reduced responding to others’ joint attention bids in infancy (RJA) and to a reduced tendency to initiate joint attention episodes (IJA). Because young infants use their gaze for both RJA and IJA, this approach allowed us to quantify these elusive processes early in life. MethodsThe final sample consisted of 112 infants (54 boys and 58 girls), of whom 81 were at familial risk for ASD and 31 were typically developing low-risk infants. At follow-up (36 months of age), 22 children in the high-risk group were diagnosed with ASD. ResultsAt 10 months of age, rates of IJA were lower in infants later diagnosed with ASD than in the comparison groups (effect sizes d = 0.78–0.95) and followed an atypical developmental trajectory from 10 to 18 months (p < .002). RJA distinguished infants based on familial ASD risk, albeit not ASD diagnosis. The differences in IJA could not be explained by overall looking time, social preference, eye movement latencies, or number of fixations. ConclusionsThis live eye-tracking study suggests that during an important period for the development of social cognition (10–18 months of age), infants later diagnosed with ASD show marked atypicalities in IJA but not in RJA. The results indicate that IJA is an important target for future prodromal intervention trials.

The Limitations of Reward Effects on Saccade Latencies: An Exploration of Task-Specificity and Strength.

Saccadic eye movements are simple, visually guided actions. Operant conditioning of specific saccade directions can reduce the latency of eye movements in the conditioned direction. However, it is not clear to what extent this learning transfers from the conditioned task to novel tasks. The purpose of this study was to investigate whether the effects of operant conditioning of prosaccades to specific spatial locations would transfer to more complex oculomotor behaviours, specifically, prosaccades made in the presence of a distractor (Experiment 1) and antisaccades (Experiment 2). In part 1 of each experiment, participants were rewarded for making a saccade to one hemifield. In both experiments, the reward produced a significant facilitation of saccadic latency for prosaccades directed to the rewarded hemifield. In part 2, rewards were withdrawn, and the participant made a prosaccade to targets that were accompanied by a contralateral distractor (Experiment 1) or an antisaccade (Experiment 2). There were no hemifield-specific effects of the reward on saccade latency on the remote distractor effect or antisaccades, although the reward was associated with an overall slowing of saccade latency in Experiment 1. These data indicate that operant conditioning of saccadic eye movements does not transfer to similar but untrained tasks. We conclude that rewarding specific spatial locations is unlikely to induce long-term, systemic changes to the human oculomotor system.

Analysis of sleep structure and related factors in children with severe obstructive sleep apnea-hypopnea syndrome

Objective: To investigate the sleep structure and related factors in children with severe obstructive sleep apnea-hypopnea syndrome(OSAHS). Method: We summarized the characteristics of 250 children withsevere OSAHS diagnosed by polysomnography（PSG）in our hospital from January 1, 2017 to December 31, 2017. According to AHI, the patients were divided into three groups, 159 in group A with 20 < AHI≤0, 57 in group B with 40 < AHI≤60, and 34 in group C with AHI > 60. We collected the basic data, sleep parameters (sleep efficiency, latency, sleep stage, sleep index, etc.), preoperative arterial blood gas test results (awake and postsleep state), echocardiographic findings of the three groups. Statistical comparisons between groups were performed with SPSS19.0. Result: BMI, AHI, OAHI, LSaO₂ was significantly different with among the three groups (all P<0.01), and there was a linear correlation between BMI and AHI (r=0.251). There was significant differences in sleep efficiency (SE), sleep latency (SO), and rapid eye movement (REM) latency among the three groups. Compared with group A, the proportion of sleep in stage 1 increased by 38%, the proportion of sleep in stage 3+4 was decreased by 19%, and the proportion of REM was decreased by 14% in group C. There was no significant difference between group A and B. There was a significant linear correlation between AHI and ODI in NREM and REM, respectively (r¹=0.663, r₂=0.499, P< 0.001), and the ODI in REM (63.8±35.0) was significantly higher than that in NREM (29.7±36.0), accounting for 68% of the sleep. Sixty-five children had received preoperative arterial blood gas test (awake and post-sleep state). There was a significant negative correlation between AHI and SaO₂ after sleep (r=-0.444, P=0.000), and no significant correlation in awake state. Forty-four patients underwent preoperative echocardiographic examination. There was significant differences between group A and C in interventricular septum thickness, left ventricular diameter, and main pulmonary artery diameter (P<0.05). There was no significant difference between group A and B. There were no significant differences in aortic annulus diameter, left atrial diameter, left ventricular end diastolic dimension (LVEDD), ejection fraction(EF), and right ventricular anteroposterior diameter among the groups (P>0.05). Conclusion: Obesity is an important factor affecting the severity of OSAHS. As the severity of disease increased, the proportion of awakening time and stage 1 of sleep increased, but stage 3, 4 and REM decreased significantly. The SE, SO, and REM latency were significantly associated with the severity of OSAHS. The severity of hypoxemia is significantly related to AHI, and mainly occur in REM stage. Severe OSAHS is risk factor for cardiovascular complications.

Research progress of interaction between epilepsy and sleep in children

Epilepsy is a chronic brain lesion caused by a variety of pathological factors. It is characterized by repeatability, transient and seizure, and is one of the common neurological systemic diseases in children. Seizures can induce structural changes of sleep and cause sleep disorders, and sleep disorders call induce interictal epileptiform discharges and seizures. The abnormal sleep structure of children with epilepsy is characterized by decreased total sleep time, prolonged sleep latency, prolonged latency of rapid eye movement (REM), and decreased proportion of sleep fragments and shortened sleep cycle time. Epilepsy and sleep are closely related and complex. Controlling seizures can help improve the quality of sleep. The normalization of sleep structure in children with epilepsy can help control seizures, thus improving overall quality of life and long-term prognosis. Key words: Children; Epilepsy; Sleep disorders

Association between inflammatory potential of the diet and sleep parameters in sleep apnea patients.

The aim of this study was to analyze the association between the inflammatory potential of diet and sleep parameters in individuals with obstructive sleep apnea (OSA) and to evaluate the sensitivity and specificity of the dietary inflammatory index (DII) at predicting sleep pattern. Patients diagnosed with mild to severe OSA were included in the study (N = 296). Sleep pattern was analyzed by polysomnography and subjective sleep parameters. DII scores were calculated from a validated food frequency questionnaire. Receiver operating characteristic curve analysis and generalized linear models were conducted. DII scores were efficient at predicting apnea severity (P < 0.05) and daytime sleepiness (P = 0.02) in age stratification and predicting rapid eye movement latency in obese individuals (P = 0.03). No significant associations were found between DII scores and the majority of sleep parameters. The DII was only associated with daytime sleepiness; patients with a more proinflammatory diet (quintile 4) showed more subjective sleepiness than the group with a more anti-inflammatory diet (quintile 1; P < 0.05). Findings from this study indicated that the DII could be sensitive and specific for predicting apnea severity in individuals commonly associated with OSA. Although the DII was not associated with most of the sleep parameters, the few associations found demonstrated the need for more studies that evaluate whether DII is associated with the risk for OSA symptoms.

Modeling and Analysis of Optical Modulators Based on Free-Carrier Plasma Dispersion Effect

Silicon photonic networks are revolutionizing computing systems by improving the energy efficiency, bandwidth, and latency of data movements. Optical modulators, such as microresonators (MRs) and Mach–Zehnder interferometers (MZIs), are the basic building blocks of silicon photonic networks. This paper proposes a SPICE-compatible electro-optical co-simulation model, basic optical switch integration model (BOSIM), to systematically study optical modulators using PN, PIN, and metal–insulator–silicon (MIS) capacitor device technologies. BOSIM holistically models both transient and steady state properties, such as switching speed, power, transmission spectrum, area, and carrier distribution. BOSIM is validated by the measured data from eight research groups and companies. Compared to MRs, BOSIM shows MZIs are fast, with a high extinction ratio and large bandwidth but in the sacrifice of loss, energy, and area. Using a PIN diode over a PN diode can save area, but retain the loss and energy, while an MIS capacitor has the shock response of carrier distribution in a narrow range and is marginalized gradually. For instance, an MZI can achieve a $2.5 {\times }$ bit rate, $6.06{\times }$ extinction ratio, $71.04 {\times }\,\,3$ -dB bandwidth, but costs at least $1.93 {\times }$ passing loss, $1.46 {\times }$ energy consumption, and $16.67 {\times }$ area, compared with MR.

Sleep Disorders in Egyptian MS Patients: Clinical and Polysomnography Study

Background: multiple sclerosis (MS) is an inflammatory disorder of the brain, spinal cord, and optic nerves. MS affects more than two million people worldwide; sleep disorders are very common in the general population; their high prevalence rate suggests that MS patients will certainly be suffering from comorbid sleep disorders. Objective: study the prevalence of sleep disorders among MS patients by clinical and Polysomnography (PSG) studies. Patients and Methods: twenty-five MS patients and 12 healthy controls were examined by expanded disability status scale (EDSS) for functional disability, Pittsburg sleep quality index (PSQI) for sleep quality, Epworth sleepiness scale (ESS) for excessive daytime sleepiness, international restless leg syndrome scale (IRLSS) for restless led syndrome (RLS). PSG studies were done for all subjects for assessment of quality of sleep and sleep parameters. Magnetic Resonance Imaging (MRI) Brain was done for MS patients g to subtype it according to McDonald criteria 2010. Results: seventy six percent of MS patients had poor sleep quality according to PSQI (8.6 ±3.7). While 44% had excessive daytime sleepiness according to ESS (12.2±3.6) and 40% had RLS according to IRLSS. Patients with progressive MS (PMS) either primary (PPMS) or secondary (SPMS) subtypes had poorer sleep quality index and excessive daytime sleepiness compared to relapsing remitting MS (RRMS) subtype. PSG study showed decreased total sleep time (TST) and sleep efficiency index in MS patients with prolonged sleep latency and decreased rapid eye movement (REM) latency and higher total arousal index and periodic limb movement (PLM) index than control. EDSS of MS patients had positive correlation with PSQI and ESS. Also EDSS had inverse correlation with TST and sleep efficiency index on PSG. Conclusion: sleep disorders are prevalent among MS patients. PPMS and SPMS patients showed more prevalence of sleep disorder than RRMS with poorer sleep parameters on PSG.

Sleep Disorders in Egyptian MS Patients: Clinical and Polysomnography Study

Background: multiple sclerosis (MS) is an inflammatory disorder of the brain, spinal cord, and optic nerves. MS affects more than two million people worldwide; sleep disorders are very common in the general population; their high prevalence rate suggests that MS patients will certainly be suffering from comorbid sleep disorders. Objective: study the prevalence of sleep disorders among MS patients by clinical and Polysomnography (PSG) studies. Patients and Methods: twenty-five MS patients and 12 healthy controls were examined by expanded disability status scale (EDSS) for functional disability, Pittsburg sleep quality index (PSQI) for sleep quality, Epworth sleepiness scale (ESS) for excessive daytime sleepiness, international restless leg syndrome scale (IRLSS) for restless led syndrome (RLS). PSG studies were done for all subjects for assessment of quality of sleep and sleep parameters. Magnetic Resonance Imaging (MRI) Brain was done for MS patients g to subtype it according to McDonald criteria 2010. Results: seventy six percent of MS patients had poor sleep quality according to PSQI (8.6 ±3.7). While 44% had excessive daytime sleepiness according to ESS (12.2±3.6) and 40% had RLS according to IRLSS. Patients with progressive MS (PMS) either primary (PPMS) or secondary (SPMS) subtypes had poorer sleep quality index and excessive daytime sleepiness compared to relapsing remitting MS (RRMS) subtype. PSG study showed decreased total sleep time (TST) and sleep efficiency index in MS patients with prolonged sleep latency and decreased rapid eye movement (REM) latency and higher total arousal index and periodic limb movement (PLM) index than control. EDSS of MS patients had positive correlation with PSQI and ESS. Also EDSS had inverse correlation with TST and sleep efficiency index on PSG. Conclusion: sleep disorders are prevalent among MS patients. PPMS and SPMS patients showed more prevalence of sleep disorder than RRMS with poorer sleep parameters on PSG.

Visual Disengagement: Genetic Architecture and Relation to Autistic Traits in the General Population

Visual disengagement has been hypothesized as an endophenotype for autism. In this study we used twin modelling to assess the role of genetics in basic measures of visual disengagement, and tested their putative association to autistic traits in the general population. We used the Gap Overlap task in a sample of 492 twins. Results showed that most of the covariance among eye movement latencies across conditions was shared and primarily genetic. Further, there were unique genetic contributions to the Gap condition, but not to the Overlap condition—i.e. the one theorized to capture visual disengagement. We found no phenotypic association between autistic traits and disengagement, thus not supporting the hypothesis of visual disengagement as an endophenotype for autistic traits.

WATER-BASED EXERCISE AND RESISTANCE TRAINING IMPROVE COGNITION IN OLDER ADULTS

ABSTRACT Introduction: Physical exercise has been associated with maintenance of physical abilities and the reduction of age-related cognitive decline, and is considered both a low-cost primary prevention strategy and a non-pharmacological treatment of cognitive dysfunction in older people. However, the contribution of each type of physical exercise to the cognitive health of the elderly population has not yet been fully investigated. Objective: This study investigated the possible influences of water-based and resistance training exercises on the cognitive performance of healthy older adults in automated tests, and investigated which test(s) would be the most effective indicator of differences in aging cognitive performance. Methods: Three groups of community-dwelling healthy older adults: water-based exercise group, resistance training group and sedentary group, were assessed using an automated set of neuropsychological tests (CANTAB) and tests to assess functional exercise capacity. Results were compared by one-way analysis of variance (ANOVA) and Pearson linear correlation. Results: The water-based exercise group had the best functional exercise capacity scores and the best performance in the reaction time evaluation (response and movement latencies). The resistance training group had less movement latency than the sedentary group. Functional mobility was positively correlated with response and movement latency. Conclusions: Taken together our findings show that physical exercise contributes to the preservation of cognitive function in healthy older adults and that water-based exercise has better results than resistance training in terms of reaction time. Moreover, the changes related to reaction time function were detected before the changes in working memory functions, sustained attention and learning in the sedentary participants, suggesting that this variable could be an early sensitive indicator of subtle cognitive changes associated with aging. Level of Evidence II; Retrospective study.

Effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy versus healthy controls – A prospective study

We aimed to evaluate the effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy and compare these with healthy individuals. We prospectively enrolled 37 adolescent and adult patients with refractory focal epilepsy (Group 1) and controlled epilepsy (Group 2) in each group. History pertaining to epilepsy and sleep were recorded, and all patients underwent overnight polysomnography. Language, memory, and executive function assessments were done using Western Aphasia Battery, Post Graduate Institute (PGI) memory scale, and battery of four executive function tests (Trail Making Test A & B, Digit symbol test, Stroop Task, and Verbal Fluency Test), respectively. Forty age- and sex-matched controls were also included in the study. Significant differences were noted in both objective and subjective sleep parameters among all the groups. On polysomnography, parameters like total sleep time, sleep efficiency, sleep latency, and rapid eye movement (REM) latency were found to be significantly worse in Group 1 as compared with Group 2. Cognitive and executive parameters were significantly impaired in Group 1. Shorter total sleep time, poorer sleep efficiency, and prolonged sleep latencies were observed to be associated with poor memory and executive function in patients with refractory epilepsy. Our study strongly suggests that sleep disturbances, mainly shorter total sleep time, poor sleep efficiency, and prolonged sleep latencies, are associated with impaired memory and executive function in patients with refractory focal epilepsy and to a lesser extent, among those with medically controlled epilepsy.

Central Disorders of Hypersomnolence in Children and Adults: A Comparative Study from South India.

Background:Narcolepsy and idiopathic hypersomnolence (IHS) are rare disorders. In Western populations, the reported prevalence of narcolepsy is 0.02%–0.05%. In Indian subcontinent, there are few reports on narcolepsy and none on IHS so far. Here, we compared the clinical and polysomnographic profile of narcolepsy/IHS among the pediatric and adult groups.Materials and Methods:The patients presenting with excessive daytime sleepiness (EDS) attending sleep clinic from January 2010 to December 2015 were included. Patients were diagnosed with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and IHS based on the International Classification for Sleep Disorders criteria. Patients with secondary causes of EDS were excluded from the study.Results:A total of 56 patients were included in the study (29 males and 27 females). The mean age of symptom onset was 29 years (males – 34 years and females – 24 years). Twelve (21%) patients had NT1, five (9%) patients had NT2, whereas 38 (68%) patients had IHS compared to narcolepsy, the IHS had an older mean age at presentation. The average time from symptom onset to diagnosis was 71 months. Classical tetrad of narcolepsy was rarely found in pediatric cohort, but they had more behavioral problems and weight gain. Pediatric cohort of IHS also reported behavioral problems. The mean sleep-onset latency was 3.1 min, while the mean rapid eye movement latency was 7.2 min.Conclusion:The pediatric narcolepsy patients tend to have less classical symptoms and more behavioral/eating problems as compared to adult cohort. There is significant delay in diagnosing narcolepsy, indicating the need to increase awareness among the physicians about this rare treatable disorder.