Aging Associated Specificity in Training Visual Short-Term Memory

There are numerous data in existence, the computerized cognitive training programs (CCTP) maintain or improve the plasticity of the neural networks in the brain. It is known as well that CCTP reduces the probability of cognitive dysfunctions associated with aging. In the chapter, the age-associated specificity in the temporal dynamics of changes in the visuospatial short-term memory (VSWM, also called visuospatial working memory) is presented. VSWM has been analyzed as there are evidence for age-related decline in visuospatial memory associated with hippocampus atrophy in aging. Memory retrieval decline in older women in comparison with young women while computerized training at home is shown. The elderly achieving results which are comparable to the youngs are determined by significantly increased duration while performing the memory tasks. To reveal factors of the CCTP’s efficiency, age-related differences in the attention systems using the Attention Network Test were resolved. In the group of older women, VSWM efficiency is negatively related to the errors of incongruent information selection whereas in young women—to the reaction time while testing. Thus, the success of long-term systematic training of visuospatial memory in old age is strongly related to the high level of executive control.

Allosteric Modulation of NMDARs Reverses Patients' Autoantibody Effects in Mice

Background and ObjectivesTo demonstrate that an analog (SGE-301) of a brain-derived cholesterol metabolite, 24(S)-hydroxycholesterol, which is a selective positive allosteric modulator (PAM) of NMDA receptors (NMDARs), is able to reverse the memory and synaptic alterations caused by CSF from patients with anti-NMDAR encephalitis in an animal model of passive transfer of antibodies.MethodsFour groups of mice received (days 1–14) patients' or controls' CSF via osmotic pumps connected to the cerebroventricular system and from day 11 were treated with daily subcutaneous injections of SGE-301 or vehicle (no drug). Visuospatial memory, locomotor activity (LA), synaptic NMDAR cluster density, hippocampal long-term potentiation (LTP), and paired-pulse facilitation (PPF) were assessed on days 10, 13, 18, and 26 using reported techniques.ResultsOn day 10, mice infused with patients' CSF, but not controls' CSF, presented a significant visuospatial memory deficit, reduction of NMDAR clusters, and impairment of LTP, whereas LA and PPF were unaffected. These alterations persisted until day 18, the time of maximal deficits in this model. In contrast, mice that received patients' CSF but from day 11 were treated with SGE-301 showed memory recovery (day 13), and on day 18, all paradigms (memory, NMDAR clusters, and LTP) had reversed to values similar to those of controls. On day 26, no differences were observed among experimental groups.DiscussionAn oxysterol biology-based PAM of NMDARs is able to reverse the synaptic and memory deficits caused by CSF from patients with anti-NMDAR encephalitis. These findings suggest a novel adjuvant treatment approach that deserves future clinical evaluation.

Validation of a Brief Computerized Cognitive Assessment in Multiple Sclerosis (BCCAMS) and comparison with reference batteries

Background: The Brief Computerized Cognitive Assessment in Multiple Sclerosis (BCCAMS) is a short neuropsychological battery for persons with multiple sclerosis (PwMS). Objectives: The main objective of the study is to validate the BCCAMS. Methods: PwMS and healthy subjects (HS) were evaluated using the BCCAMS which include two computerized tests, the Computerized Speed Cognitive Test and the Computerized Episodic Visual Memory Test (CEVMT), a newly developed visuospatial memory test, and the French learning test. The Minimal Assessment of Cognitive Function in MS (MACFIMS), including the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) tests, was also administered. Regression-based norms of the BCCAMS were calculated in 276 HS. BCCAMS was compared with BICAMS and MACFIMS for detection of cognitive impairment (CI). Results: Out of 120 PwMS, CI was detected using the BCCAMS, BICAMS (one impaired test), and MACFIMS (two impaired tests) in 59.1%, 50%, and 37.9%, respectively. The BCCAMS produced the same predictive value as that of the BICAMS battery for detecting CI in the MACFIMS. Conclusion: This study validated the BCCAMS as a validated computerized short assessment for information processing speed and learning in MS.

VISUOSPATIALSKILLS AND ANTISEIZURE MEDICATIONSIN CHI

Aim: The aim of this study was to investigate visuospatial abilities in children and adolescents with different types of epilepsy treated with antiseizure monotherapy. Methods: A neuropsychological assessment was performed at baseline and after one year. 207 subjects diagnosed with epilepsy and pharmacologically treated with monotherapy including levetiracetam, ethosuximide, valproic acid, carbamazepine or oxcarbazepine and 45 controls were recruited and were compared by gender and age. To evaluate visuospatial perception and memory we used Rey-Osterrieth Complex Figure. All subjects performed the test at baseline and after 12 month of drug therapy. For the statistical analyzes we regarded: age at onset of epilepsy, epilepsy type, seizure frequency, side and lobe of seizure onset, ASM dose, epilepsy duration, non-verbal intelligence, age, sex, executive functions. EEG, seizure frequency, and drug dose were also recorded. Results: Subjects with epilepsy executed only in the Immediate Recall test significantly worse than controls at baseline. There are no differences between clinical groups. We observed a correlation between Instant Recall scores and executive functions, age of seizure onset and epilepsy duration. There was a significantly worsened re-evaluation in the mean score to Immediate Recall in the valproic acid, ethosuximide and carbamazepine groups while no change was noticed in the levetiracetam and oxcarbazepine group. Conclusion: A visuospatial memory deficit may be present in children with epilepsy compared to control, and this deficit may be related to some aspects of epilepsy and to executive functions; visuospatial memory should be monitored in pediatric subjects which can be influenced by some drugs used for the treatment of seizures.

EEG Alpha and Beta Band Functional Connectivity and Network Structure Mark Hub Overload in Mild Cognitive Impairment During Memory Maintenance

Background: While decreased alpha and beta-band functional connectivity (FC) and changes in network topology have been reported in Alzheimer’s disease, it is not yet entirely known whether these differences can mark cognitive decline in the early stages of the disease. Our study aimed to analyze electroencephalography (EEG) FC and network differences in the alpha and beta frequency band during visuospatial memory maintenance between Mild Cognitive Impairment (MCI) patients and healthy elderly with subjective memory complaints.Methods: Functional connectivity and network structure of 17 MCI patients and 20 control participants were studied with 128-channel EEG during a visuospatial memory task with varying memory load. FC between EEG channels was measured by amplitude envelope correlation with leakage correction (AEC-c), while network analysis was performed by applying the Minimum Spanning Tree (MST) approach, which reconstructs the critical backbone of the original network.Results: Memory load (increasing number of to-be-learned items) enhanced the mean AEC-c in the control group in both frequency bands. In contrast to that, after an initial increase, the MCI group showed significantly (p < 0.05) diminished FC in the alpha band in the highest memory load condition, while in the beta band this modulation was absent. Moreover, mean alpha and beta AEC-c correlated significantly with the size of medial temporal lobe structures in the entire sample. The network analysis revealed increased maximum degree, betweenness centrality, and degree divergence, and decreased diameter and eccentricity in the MCI group compared to the control group in both frequency bands independently of the memory load. This suggests a rerouted network in the MCI group with a more centralized topology and a more unequal traffic load distribution.Conclusion: Alpha- and beta-band FC measured by AEC-c correlates with cognitive load-related modulation, with subtle medial temporal lobe atrophy, and with the disruption of hippocampal fiber integrity in the earliest stages of cognitive decline. The more integrated network topology of the MCI group is in line with the “hub overload and failure” framework and might be part of a compensatory mechanism or a consequence of neural disinhibition.

P051 SLEEP SPINDLES AND SWA DIFFERENTIALLY CORRELATE WITH OVERNIGHT EPISODIC AND VISUOSPATIAL MEMORY CONSOLIDATION IN OLDER ADULTS WITH AND WITHOUT MILD COGNITIVE IMPAIRMENT

Introduction Sleep microarchitecture disruption is a feature of ageing that is further altered in neurodegenerative disorders. Sleep-memory links in younger adults have been established, however mechanistic pathways of this uncoupling in ageing is poorly understood. Method Our sample consisted of n=46 mild cognitively impaired (MCI) older adults and n=32 cognitively-intact controls who underwent overnight polysomnography and episodic (Rey Auditory Verbal Learning test) and visuospatial (Rey-Osterrieth Complex Figure task) memory tasks that were administered before and after sleep. We examined group differences in overnight memory % retention and associations with NREM slow oscillations (SO, 0.25–1 Hz), delta power (0.5–4 Hz), N2 spindle events (occurrence [11–16 Hz] and slow [11–13 Hz] and fast [13–16 Hz] spindle density p/min) and REM theta power (4.5–8 Hz). Results Repeated measures ANCOVA, controlling for age, indicated greater memory scores in Controls compared to MCI on the episodic task, F=6.7 (p=.01), and no group differences in the visuospatial task (F=1.8, p=.17). In Controls, greater delta power was associated with increased episodic memory retention (r=.515, p=.006). In the MCI group, episodic memory was associated with fast spindle density (r=-.352, p=.04), and visuospatial memory was also associated with fast spindle density (r=-.385, p=.01) and spindle occurrence (r=-.479, p=.003). Conclusion Sleep spindles appear to be negatively associated with memory retention, specifically in MCI. However, given the heterogeneity of MCI, further analysis of its cognitive subtypes is warranted. Comprehensive cognitive and neural pathophysiology profiling are required to better delineate the function of spindles in ageing.

Prediction of Inefficient BCI Users based on Cognitive Skills and Personality Traits

BCI inefficiency is one of the major challenges of motor imagery brain-computer interfaces (MI-BCI). Past research suggests that certain cognitive skills and personality traits correlate with MI-BCI real-time performance. Other studies have examined sensorimotor rhythm changes (also known as μ suppression) as a valuable indicator of successful execution of the MI task. This research aims to combine these insights by investigating whether cognitive factors and personality traits can make predictions of a user’s ability to modulate μ rhythms during a MI-BCI task. Data containing 55 subjects who completed a MI task was employed, and a stepwise linear regression model was implemented to select the most relevant features for μ suppression prediction. The most accurate model was based on these factors: Spatial Ability, Visuospatial Memory, Autonomy, and Vividness of Visual Imagery. Further correlation analyses showed that a novice user’s μ suppression during a MI-BCI task can be predicted based on their visuospatial memory ability, as measured by the Design Organization Test (DOT).

A preliminary study to evaluate white matter structural correlates of delayed visuospatial memory and one-week motor skill retention in nondemented older adults

Skill retention is important for motor rehabilitation outcomes. Recent work has demonstrated that delayed visuospatial memory performance may predict motor skill retention in older and neuropathological populations. White matter integrity between parietal and frontal cortices may explain variance in upper-extremity motor learning tasks and visuospatial processes. We performed a whole-brain analysis to determine the white matter correlates of delayed visuospatial memory and one-week motor skill retention in nondemented older adults. We hypothesized that better frontoparietal tract integrity would be positively related to better behavioral performance. Nineteen participants (age>58) completed diffusion-weighted imaging, then a clinical test of delayed visuospatial memory and 50 training trials of an upper-extremity motor task; participants were retested on the motor task one week later. Principal component analysis was used to create a composite score for the behavioral data for each participant, i.e., shared variance between delayed visuospatial memory and motor skill retention, which was then entered into a voxel-based regression analysis. Behavioral results demonstrated that participants learned and retained their skill level after a week of no practice, and their delayed visuospatial memory score was positively related to the extent of skill retention. Consistent with previous work, neuroimaging results indicated that regions within bilateral anterior thalamic radiations, corticospinal tracts, and superior longitudinal fasciculi were related to better delayed visuospatial memory and skill retention. Results of this study suggest that the simple act of testing for specific cognitive impairments prior to therapy may identify older adults who will receive little to no benefit from the motor rehabilitation regimen, and that these neural regions may be potential targets for therapeutic intervention.

Does daytime sleepiness alter visual memory in schoolchildren aged 9 to 11 at different times during the school semester?

Daytime sleepiness could reduce the memorization of children who are in school. Thus, the aim of this study was to study the effect of daytime sleepiness on the visual memory of schoolchildren at different times during the school semester. Individuals of both genders (n = 88) aged 9 to 11 years and regularly enrolled at the Mariana Amália Municipal School were selected. Data collection occurred in two moments: at the beginning and end of the academic semester. A semi-structured questionnaire was used to collect sociodemographic information, the Epworth Sleepiness Scale to assess sleepiness and the Rey-Osterrieth complex figure, object recall, scrambling figures and addition of dictated numbers for memory analysis tests. The data revealed that there is no direct relationship between sleepiness and impaired memory by the tests used in any of the analyzed moments. However, children showed lower visuospatial memory efficiency at the beginning of the school semester, indicating that they may have greater difficulty in memory retention. Lastly, there was an abnormality in the degree of sleepiness at the end of the school semester and the female gender showed efficiency in immediate and late memory.