Recovery Of Cognitive Performance Research Articles

Recovery of Cognitive Performance Following Multi-Stressor Military Training.

This project aimed to assess the impact of an 8-day military training exercise on cognitive performance, and track its recovery in periods of reduced training load and partially restored sleep. Military personnel often work in challenging multi-stressor environments, where sleep loss is inevitable. Sleep loss can impair multiple cognitive domains, which can have disastrous consequences in military contexts. A total of 57 male and female soldiers undergoing the Australian Army combat engineer Initial Employment Training course were recruited and tracked over a 16-day study period which included an 8-day field-based military training exercise. Cognitive performance was assessed via a computerised battery at seven time points across four sequential study periods; 1) baseline (PRE), 2) military field training exercise which included total sleep deprivation (EX-FIELD), 3) training exercise at simulated base with restricted sleep opportunities (EX-BASE), and 4) a 3-day recovery period (REC). Subjective load, fatigue, and sleep were evaluated continuously via questionnaire and actigraphy. Psychomotor speed, reaction time, visual tracking and vigilance were impaired following the EX-FIELD period (p < 0.05). The majority of affected measures recovered 2days following EX-FIELD, being no different in EX-BASE compared to PRE. The sensitivity of the cognitive tests to sleep restriction, and recovery, indicates they can help assess operational readiness in military personnel. Future studies should explore other indicators of, and strategies to preserve, operational readiness in military personnel. This study highlights the impact of work-induced fatigue on cognitive performance, and would interest authorities seeking to preserve operational readiness.

Involuntary, forced or voluntary exercise can ameliorate the cognitive deficits by enhancing levels of hippocampal NMDAR1, pAMPAR1 and pCaMKII in a model of vascular dementia

ABSTRACT Objectives: To investigate the effect on vascular dementia of involuntary exercise induced by functional electrical stimulation and of forced and voluntary exercise, focusing on the recovery of cognitive function and using a rat model of dementia. Methods: A demential model was created in Wistar rats who were then given forced exercise, allowed voluntary exercise (wheel running) or had exercise induced through functional electrical stimulation. Their responses were quantified using a Morris water maze and by measuring long-term potentiation in the hippocampus. Immunohistochemical staining was used to evaluate neurogenesis in the hippocampus and Nissl staining was applied to visualize viable neuron loss in the DG sector. In addition, the levels of NMDAR1, AMPAR1, pAMPAR1, pCaMKII, CaMKII, Bcl-2 and Bax in the hippocampus were assessed by western blotting. Results: All of the exercise groups showed a recovery of cognitive performance and improved long-term potentiation. The three modes of exercise all increased the number of DCX immunopositive cells and reduced losses of intact-appearing neurons in the hippocampal DG zones roughly equally. All proved about equally effective in increasing the levels of NMDAR1, pAMPAR1 and pCaMKII and increasing the Bcl-2/Bax ratio to protect neurons from apoptosis. Conclusion: Exercise induced by electrical stimulation has beneficial effects comparable to those of other types of exercise for alleviating the cognitive deficits of vascular dementia.

Functional Connectivity Is Altered in Concussed Adolescent Athletes Despite Medical Clearance to Return to Play: A Preliminary Report

Recovery following sports-related concussion (SRC) is slower and often more complicated in young adolescent athletes than in collegiate players. Further, the clinical decision to return to play is currently based on symptoms and cognitive performance without direct knowledge of brain function. We tested the hypothesis that brain functional connectivity (FC) would be aberrant in recently concussed, asymptomatic athletes who had been cleared to return to play. A seed-based FC analysis measured the FC of the default mode network (DMN) (seeds = anterior cingulate cortex, posterior cingulate cortex (PCC), right lateral parietal cortex, and left lateral parietal cortex) 30 days after SRC in asymptomatic high school athletes cleared to return to play (n = 13) and was compared to the FC of high school athletes with orthopedic injury (OI) (n = 13). The SRC group demonstrated greater FC than the OI group between the PCC and the ventral lateral prefrontal cortex, as well as between the right lateral parietal cortex and lateral temporal cortex (with regions both outside of and within the DMN). Additionally, the OI group demonstrated greater FC than the SRC group between right lateral parietal cortex and supramarginal gyrus. When relating the FC results to verbal memory performance approximately 1 week and 1 month after injury, significantly different between-group relations were found for the posterior cingulate and right lateral parietal cortex seeds. However, the groups did not differ in verbal memory at 1 month. We suggest that changes in FC are apparent 1-month post-SRC despite resolution of post-concussion symptoms and recovery of cognitive performance in adolescent athletes cleared to return to play.

Cognitive function recovery rate in early postoperative period: comparison of propofol, sevoflurane and isoflurane anesthesia

Introduction: There is no simple answer to the question as to when the brain function is back to normal after anaesthesia. Research done so far has identified different factors influencing the rate of cognitive function recovery and type of anaesthetic as one of those factors.Methods: This study encountered 90 patients hospitalized in neurosurgical department of University Clinical Centre Tuzla in period from October 2011 to may 2012 year. Aim of the study was to compare influence of three different anesthetics (propofol, isofl urane and sevofl urane) on recovery rate of cognitive performance 1, 5 and 10 minutes following extubation. Assessment of cognitive functions was preformed using the short Orientation-Memory-Concentration (OMC) Test. All patients included in the study underwent lumbar microdiscectomy surgery and were allocated to one of three groups: propofol, sevoflurane and isoflurane.Results: Trough comparison of OMC test values there is obvious superiority in recovery of cognitive functions between propofol group and inhaled anesthetic group, after 1 minute (p = 0.008) and after 5 minutes (p =0.009). Comparison of propofol and isoflurane anesthesia shows significantly faster recovery of cognitive performance in propofol group (after 1 minute p = 0.002, 5 minutes p = 0.004, 10 minutes p = 0.038). Faster recovery of cognitive function is present in sevoflurane compared to isoflurane group only 1 minute after extubation p = 0.049.Conclusions: Fastest recovery of cognitive performance appears after propofol anesthesia, than follows sevofl urane based anesthesia and after that isoflurane anesthesia.

Preoperative Dispositional Optimism Correlates With a Reduced Incidence of Postoperative Delirium and Recovery of Postoperative Cognitive Function in Cardiac Surgical Patients

To determine if preoperative psychosocial factors including dispositional optimism, perceived social support, and perceived stress correlate with the recovery of postoperative cognition. Observational study. Veterans Affairs medical center. Cardiac surgical patients. None. Age- and education-balanced patients (> or =55 years of age) undergoing cardiac surgery (n = 40) and nonsurgical controls (n = 40) were recruited. A psychosocial evaluation for dispositional optimism, perceived social support, perceived stress, and depression was performed before surgery using standardized questionnaires. Delirium was assessed with the Intensive Care Delirium Screening Checklist before and for 5 consecutive days after surgery. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Preoperative perceived stress significantly (p < 0.01) correlated with preoperative depression scores. Preoperative dispositional optimism significantly (p < 0.05) correlated with preoperative perceived social support. A multiple logistic regression revealed that dispositional optimism significantly (p < 0.02) predicted the absence of postoperative delirium within 5 days of surgery. Patients who showed high levels of dispositional optimism suffered a significantly (p < 0.03) lower incidence of postoperative delirium. Preoperative dispositional optimism also significantly (p < 0.001) correlated with a postoperative cognitive performance determined by composite z scores. A stepwise multiple regression analysis revealed that dispositional optimism significantly (p < 0.05, R(2) = 35%) predicted postoperative cognitive function. Preoperative dispositional optimism, but not perceived social support, perceived stress, and depression positively correlated with a reduced incidence of postoperative delirium within 5 days and recovery of cognitive performance 1 week after cardiac surgery.

Recovery of Cognitive Performance and Fatigue after One Night of Sleep Deprivation

The aim of this study was to investigate how subjective sleepiness, mood states, simple and high-order cognitive performance change after one night of sleep deprivation (SD) and recover to after 7 h normal recovery sleep opportunity during three recovery days. Ten healthy subjects participated in this study. We measured their subjective sleepiness, mood states and their performances of 2 simple tasks and 4 high-order cognitive tasks twice a day for 5 days, on the baseline day, post-vigil day and 3 recovery days after SD. This study was conducted considering each participant's motivation for task, learning effect and diurnal variation of performance. The performances of simple tasks such as addition or short-term memory were not reduced after SD and were the poorest on the baseline day, and improved gradually; however the high-order cognitive performances were at their lowest on the post-vigil day and needed 2 recovery sleep opportunities to return to the baseline level. Fatigue and confusion in mood states and subjective sleepiness were also at their lowest after SD. Subjective sleepiness nearly recovered to the baseline level on the 1st recovery day, but fatigue and confusion reached the baseline levels on the 2nd recovery day. These results suggest that cognitive deterioration and the recovery process may differ between simple task performance and high-order cognitive task performance, which needed 2 ordinary sleep opportunities to recover to the baseline level, and the change of subjective mood states were also different for each mood.

Remembering to carry out intentions following traumatic brain injury in older adults

Research with young adults has found that many cognitive domains can be affected by mild traumatic brain injury (TBI), including attention, processing speed, learning and memory. Nevertheless, recovery of cognitive performance is generally expected by 3 months following an uncomplicated mild TBI. Whether similar good levels of recovery can be expected in an older population remains to be demonstrated. Furthermore, it has been argued that remembering delayed intentions (prospective memory) may be a more insightful outcome measure as it requires the integration and co-ordination of a number of cognitive processes, thus making it a sensitive and ecologically valid measure of cognitive functioning post-TBI.

Alcohol-impaired speed and accuracy of cognitive functions: A review of acute tolerance and recovery of cognitive performance.

Much research on the effects of a dose of alcohol has shown that motor skills recover from impairment as blood alcohol concentrations (BACs) decline and that acute tolerance to alcohol impairment can develop during the course of the dose. Comparable alcohol research on cognitive performance is sparse but has increased with the development of computerized cognitive tasks. This article reviews the results of recent research using these tasks to test the development of acute tolerance in cognitive performance and recovery from impairment during declining BACs. Results show that speed and accuracy do not necessarily agree in detecting cognitive impairment, and this mismatch most frequently occurs during declining BACs. Speed of cognitive performance usually recovers from impairment to drug-free levels during declining BACs, whereas alcohol-increased errors fail to diminish. As a consequence, speed of cognitive processing tends to develop acute tolerance, but no such tendency is shown in accuracy. This "acute protracted error" phenomenon has not previously been documented. The findings pose a challenge to the theory of alcohol tolerance on the basis of physiological adaptation and raise new research questions concerning the independence of speed and accuracy of cognitive processes, as well as hemispheric lateralization of alcohol effects. The occurrence of alcohol-induced protracted cognitive errors long after speed returned to normal is identified as a potential threat to the safety of social drinkers that requires urgent investigation.

Recovery of Cognitive Performance from Sleep Debt: Do a Short Rest Pause and a Single Recovery Night Help?

We studied the recovery of multitask performance and sleepiness from acute partial sleep deprivation through rest pauses embedded in performance sessions and an 8 h recovery sleep opportunity the following night. Sixteen healthy men, aged 19–22 yrs, participated in normal sleep (two successive nights with 8 h sleep) and sleep debt (one 2 h night sleep followed by an 8 h sleep the following night) conditions. In both conditions, the participants performed four 70 min multitask sessions, with every other one containing a 10 min rest pause with light neck‐shoulder exercise. The multitask consisted of four simultaneously active subtasks, with the level of difficulty set in relation to each participant's ability. Physiological sleepiness was assessed with continuous electroencephalography/electro‐oculography recordings during the multitask sessions, and subjective sleepiness was self‐rated with the Karolinska Sleepiness Scale. Results showed that multitask performance and physiological and subjective sleepiness were impaired by the sleep debt (p>.001). The rest pause improved performance and subjective sleepiness for about 15 min, regardless of the amount of prior sleep (p>.01–.05). Following recovery sleep, all outcome measures showed marked improvement (p<.001), but they failed to reach the levels observed in the control condition (p<.001–.05). A correlation analysis showed the participants whose multitask performance deteriorated the most following the night of sleep loss tended to be the same persons whose performance was most impaired following the night of the recovery sleep (p<.001). Taken together, our results suggest that a short rest pause with light exercise is not an effective countermeasure in itself for sleep debt‐induced impairments when long‐term effects are sought. In addition, it seems that shift arrangements that lead to at least a moderate sleep debt should be followed by more than one recovery night to ensure full recovery. Persons whose cognitive performance is most affected by sleep debt are likely to require the most sleep to recover.