Membership-dependent polynomial fuzzy control of a positive discrete time system: A symbol transfer technique.

This work explores the polynomial fuzzy stabilization for positive systems. The traditional quadratic Lyapunov function and basic stability analysis may not be favourable for stability investigation due to the absence of the positivity property and membership functions. Therefore, a fuzzy co-positive polynomial Lyapunov-Krasovskii (FCPL) function which considers the positivity is proposed firstly through an imperfect premise matching (IPM) approach. Secondly, the symbol transfer technique which takes into account fuzzy membership knowledge relaxes the stability conditions. The number of symbols is reduced by two constraints: (1) the last and next moments of the membership functions of the FCPL function; (2) membership functions of the fuzzy model and the controller. Finally, the polynomial fuzzy controller with symbols is obtained. Two examples are implemented to verify the proposed methods.

Guessability of Indian picture symbols for communication (IPSC) and picture communication symbols (PCS) among Malayalam-speaking typical adults.

The purpose of this study was to investigate the perceived symbol referent relationship for selected symbols in typical adults for two different symbol sets: Indian Picture Symbols for Communication (IPSC) and Picture Communication Symbols (PCS) to identify cultural influences on symbol recognition. A total of 240 typical adults, including 120 nonprofessionals, and 120 health professionals, from Kerala, a southern state in India, participated in the study. A guessability task involving IPSC and PCS symbols for 30 target referents was utilized. Guessability scores for each participant as well as each symbol stimuli across two symbol sets were determined. The guessability scores for IPSC were significantly (p <.001) higher than PCS. For both symbol sets, nouns were the most accurately guessed, followed by verbs, adjectives, and prepositions. The results also revealed that prompting and previous exposure to symbols tend to influence the transparency of symbols. Error analyses revealed that visual and conceptual cues within a symbol tend to influence guessability. The results indicate that cultural and linguistic factors play a role in symbol guessability. The study highlights the importance of investigating the iconicity of IPSC and PCS symbols across different populations within India, before using symbols for educational/clinical purposes.

osp ( 1 | 2 ) -trivial deformation of osp ( 2 | 2 ) -modules structure on the spaces of symbols S d 2 of differential operators acting on the space of weighted densities F d 2 .

Let osp ( 2 | 2 ) be the orthosymplectic Lie superalgebra and osp ( 1 | 2 ) a Lie subalgebra of osp ( 2 | 2 ) . In our paper, we describe the cup-product H 1 ∨ H 1 , where H 1 : = H 1 ( osp ( 2 | 2 ) , osp ( 1 | 2 ) ; D λ , µ 2 ) is the first differential osp ( 1 | 2 ) -relative cohomology of osp ( 2 | 2 ) with coefficients in D λ , µ 2 and D λ , µ 2 : = Ho m diff ( F λ 2 , F µ 2 ) is the space of linear differential operators acting on weighted densities. This result allows us to classify the osp ( 1 | 2 ) -trivial deformations of the osp ( 2 | 2 ) -module structure on the spaces of symbols S d 2 . More precisely, we compute the necessary and sufficient integrability conditions of a given infinitesimal deformation of this action. Furthermore, we prove that any formal osp ( 1 | 2 ) -trivial deformations of osp ( 2 | 2 ) -modules of symbols is equivalent to its infinitisemal part. This work is the simplest generalization of a result by Laraiedh [17].

The relational bottleneck as an inductive bias for efficient abstraction.

A central challenge for cognitive science is to explain how abstract concepts are acquired from limited experience. This has often been framed in terms of a dichotomy between connectionist and symbolic cognitive models. Here, we highlight a recently emerging line of work that suggests a novel reconciliation of these approaches, by exploiting an inductive bias that we term the relational bottleneck. In that approach, neural networks are constrained via their architecture to focus on relations between perceptual inputs, rather than the attributes of individual inputs. We review a family of models that employ this approach to induce abstractions in a data-efficient manner, emphasizing their potential as candidate models for the acquisition of abstract concepts in the human mind and brain.

Development and first-stage validation of a digital version of the Digit Symbol Substitution test for use in assessing cognitive function in older people with diabetes.

AIMS: To describe the development and report the first-stage validation of a digital version of the digit symbol substitution test (DSST), for assessment of cognitive function in older people with diabetes. MATERIALS AND METHODS: A multidisciplinary team of experts was convened to conceptualize and build a digital version of the DSST and develop a machine-learning (ML) algorithm to analyse the inputs. One hundred individuals with type 2 diabetes (aged ≥ 60 years) were invited to participate in a one-time meeting in which both the digital and the pencil-and-paper (P&P) versions of the DSST were administered. Information pertaining to demographics, laboratory measurements, and diabetes indices was collected. The correlation between the digital and P&P versions of the test was determined. Additionally, as part of the validation process, the performance of the digital version in people with and without known risk factors for cognitive impairment was analysed. RESULTS: The ML model yielded an overall accuracy of 89.1%. A strong correlation was found between the P&P and digital versions (r = 0.76, p < 0.001) of the DSST, as well as between the ML model and the manual reading of the digital DSST (r = 0.99, p < 0.001). CONCLUSIONS: This study describes the development of and provides first-stage validation data for a newly developed digital cognitive assessment tool that may be used for screening and surveillance of cognitive function in older people with diabetes. More studies are needed to further validate this tool, especially when self-administered and in different clinical settings.

Texture based feature extraction using symbol patterns for facial expression recognition.

Facial expressions can convey the internal emotions of a person within a certain scenario and play a major role in the social interaction of human beings. In automatic Facial Expression Recognition (FER) systems, the method applied for feature extraction plays a major role in determining the performance of a system. In this regard, by drawing inspiration from the Swastik symbol, three texture based feature descriptors named Symbol Patterns (SP1, SP2 and SP3) have been proposed for facial feature extraction. SP1 generates one pattern value by comparing eight pixels within a 3×3 neighborhood, whereas, SP2 and SP3 generates two pattern values each by comparing twelve and sixteen pixels within a 5×5 neighborhood respectively. In this work, the proposed Symbol Patterns (SP) have been evaluated with natural, fibonacci, odd, prime, squares and binary weights for determining the optimal recognition accuracy. The proposed SP methods have been tested on MUG, TFEID, CK+, KDEF, FER2013 and FERG datasets and the results from the experimental analysis demonstrated an improvement in the recognition accuracy when compared to the existing FER methods.

The Drug Burden Index Is Associated With Measures of Cognitive Function Among Older Adults in the Health, Aging, and Body Composition Study.

BACKGROUND: Anticholinergic and sedative medications affect cognition among older adults. The Drug Burden Index (DBI) is a validated measure of exposure to these medications, with higher DBI scores indicating higher drug burden. This ancillary analysis investigated the association between DBI and cognition assessed by the Modified Mini-Mental State Examination (3MS) and the Digit Symbol Substitution Test (DSST). METHODS: The Health, Aging, and Body Composition Study was a prospective study of community-dwelling adults aged 70-79 years at enrollment. Using data from years 1, 5, and 10, DBI was calculated using medication data per participant. Linear mixed modeling was used to assess cross-sectional and longitudinal effects of DBI on 3MS and DSST. Adjusted models included biological sex, race, education level, APOE status, and death. Sensitivity analyses included testing the strength of the associations for each year and testing attrition due to death as a possible confounding factor via Cox-Proportional Hazard models. RESULTS: After adjustment, DBI was inversely associated with 3MS and DSST scores. These associations became stronger in each subsequent year. Neither DBI at year 1 nor within-person change in DBI were predictive of longitudinal declines in either cognitive measure. Sensitivity analyses indicated that DBI, 3MS, and DSST were associated with a greater risk of attrition due to death. CONCLUSIONS: Results suggest that in years when older adults had a higher DBI scores, they had significantly lower global cognition and slower processing speed. These findings further substantiate the DBI as a useful pharmacological tool for assessing the effect of medication exposure.

Normative data for the Digit Symbol Substitution for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA).

INTRODUCTION: Executive functioning and processing speed are crucial elements of neuropsychological assessment. To meet the needs of the Hispanic/Latino population, we aimed to provide normative data for the Digit Symbol Substitution (DSS) test. METHODS: The target population for the Study of Latinos-Investigation of Neurocognitive Aging included six heritage backgrounds (n = 6177). Average age was 63.4 ± 8.3 years, 54.5% were female, and mean education was 11.0 ± 4.7 years. Participants were administered the DSS as part of a larger battery. Heritage-adjusted DSS scores, and percentile cut-points were created using survey-adjusted regression and quantile regression models. RESULTS: Age, education, sex, heritage, and language preference were associated with DSS scores. DISCUSSION: Significant correlates of DSS performance should be considered when evaluating cognitive performance. Representative DSS norms for Hispanics/Latinos will advance assessment and accuracy of neurocognitive disorder diagnosis in clinical practice. To facilitate interpretation, we provide norms to reduce test biases and developed an online dashboard. Highlights: Normative data for the Digit Symbol Substitution (DSS) for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) This study is the first to develop norms for the DSS test across four regions of the United States.Factors such as age, education, sex, and Hispanic/Latino heritage and language preference are associated with differences in executive functioning and information processing speed.We created norms and an online dashboard (https://solincalab.shinyapps.io/dsst_shiny/) providing an easily accessible tool to evaluate processing speed and executive functioning in Hispanic/Latino adults.

The association between waist-to-height ratio and cognitive function in older adults.

OBJECTIVES: The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function. METHODS: The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities. RESULTS: Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (ß = -36.91, 95% CI: -54.54 to -19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68. CONCLUSION: This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

Symbol Digit Modalities Test in progressive multiple sclerosis.

INTRODUCTION: The Symbol Digit Modalities Test (SDMT) is a highly sensitive neuropsychological tool used for the assessment of information processing speed (IPS) in various neurological disorders. STATE OF THE ART: In this review, we have focused on the current knowledge regarding the use of SDMT selectively in the evaluation of progressive multiple sclerosis (PMS) patients. A literature review was performed regarding the application of SDMT in PMS, with a focus on the primary progressive and secondary progressive subtypes. Relationships of diverse disease-associated factors with SDMT have been described, including disease course, imaging findings, molecular biomarkers, treatment and others. CLINICAL IMPLICATIONS: SDMT is a very useful and easily applicable instrument in the diagnostic armamentarium of neurologists and neuropsychologists. It is especially valuable in the evaluation of PMS patients, in whom the prevalence of IPS deficits is higher than in relapsing-remitting multiple sclerosis subjects or in healthy individuals. FUTURE DIRECTIONS: An emphasis should be laid on larger study groups and differentiating between individual PMS subtypes and their separate analysis in the context of cognitive assessment.

Associations between cognitive test scores and pain tolerance: The Tromsø study.

OBJECTIVES: Previous studies have suggested that experimental pain sensitivity is associated with cognitive function. The aim of this study is to assess this relationship in a large population-based sample. METHODS: We included 5,753 participants (aged 40-84 years) from the seventh wave of the population-based Tromsø Study who had been examined with cognitive tests and experimental pain assessments, and for whom information on covariates were available. Cox regression models were fitted using standardized scores on cognitive tests (12-word immediate recall test, digit symbol coding test, and Mini-Mental State Examination [MMS-E]) as the independent variable and cold pressor or cuff pressure pain tolerance as the dependent variables. Statistical adjustment was made for putative confounders, namely, age, sex, education, smoking, exercise, systolic blood pressure, body mass index, symptoms indicating anxiety or depression, analgesic use, and chronic pain. RESULTS: In multivariate analysis, cold pressor tolerance time was significantly associated with test scores on the 12-word immediate recall test (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.90-0.97, p < 0.001), the digit symbol coding test (HR 0.94, 95% CI 0.89-0.98, p = 0.004), and the MMS-E (HR 0.93, 95% CI 0.90-0.96 p < 0.001). Tolerance to cuff pressure algometry was significantly associated with 12-word immediate recall (HR 0.94-0.97, p < 0.001) and Digit Symbol Coding test scores (HR 0.93, 95% CI 0.89-0.96, p < 0.001) while there was no significant association with Mini Mental State Examination test score (HR 0.98, 95% CI 0.95-1.00, p = 0.082). CONCLUSION: Lower pain tolerance was associated with poorer performance on cognitive tests.

Impact of Acute Dopamine Replacement on Cognitive Function in Parkinson's Disease.

BACKGROUND: PD causes striatal dopaminergic denervation in a posterior/dorsal to anterior/ventral gradient, leaving motor and associative cortico-striato-pallido-thalamic loops differentially susceptible to hyperdopaminergic effects with treatment. As the choice and titration of symptomatic PD medications are guided primarily by motor symptoms, it is important to understand their cognitive implications. OBJECTIVE: To investigate the effects of acute dopaminergic medication administration on executive function in Parkinson's disease (PD). METHODS: Participants with idiopathic PD were administered the oral Symbol Digit Modalities Test (SDMT; n = 181) and the Stroop test (n = 172) in the off-medication and "best on" medication states. ANCOVA was used to test for differences between off-medication and on-medication scores corrected for age and years of education. RESULTS: After administration of symptomatic medications, scores worsened on the SDMT (F = 11.70, P < 0.001, d = -0.13), improved on the Stroop color (F = 26.89, P < 0.001, d = 0.184), word (F = 6.25, P = 0.013, d = 0.09), and color-word (F = 13.22, P < 0.001, d = 0.16) test components, and the Stroop difference and ratio-based interference scores did not significantly change. Longer disease duration correlated with lower scores on the SDMT, Stroop color, word, and color-word scores; however, longer disease duration and higher levodopa-equivalents correlated with higher Stroop difference-based interference scores. CONCLUSIONS: Symptomatic medication differentially affects performance on two cognitive tests in PD. After acute treatment, core Stroop measures improved, Stroop interference was unchanged, and SDMT performance worsened, likely reflecting complex changes in processing speed and executive function related to acute treatment. When considering motor symptom therapies in PD, an individual's cognitive demands and expectations, especially regarding executive function, should be considered.

Effects of lunges inserted in walking (eccentric walking) on lower limb muscle strength, physical and cognitive function of regular walkers.

INTRODUCTION: Walking is a popular exercise but does not increase lower limb muscle strength and balance. We hypothesized that muscle strength, physical and cognitive function would be improved by inserting lunges in conventional walking. METHODS: Eleven regular walkers (54-88 years) who had more than 5000 steps in exercise walking a day at least 5 days a week participated in this study. They walked as usual for the first 4 weeks and included lunges and descending stairs or slope walking (i.e., eccentric walking) for the next 8 weeks. The steps of eccentric walking were gradually increased from 100 to 1000 steps per week over 8 weeks. RESULTS: The average steps per day were 10,535 ± 3516 in the first 4 weeks, and 10,118 ± 3199 in the eccentric walking period without a significant difference. No significant changes in maximal voluntary isometric contraction torque of the knee extensors (MVC), 30-s chair stand (CS), 2-min step, balance assessed by center of pressure movement area with eyes close, sit and reach, a digit symbol substitution test (DSST) for cognitive function were observed in the first 4 weeks. However, significant (P < 0.05) improvements were evident in MVC (18.6 ± 15.7%), CS (24.2 ± 17.3%), balance ( - 45.3 ± 34.5%), and DSST (20.8 ± 16.7%) from weeks 4 to 12. Serum complement component 1q concentration decreased (P < 0.05) from weeks 4 to 12, although no changes in serum glucose, triglyceride, and cholesterol concentrations were observed. CONCLUSION: These results supported the hypothesis, and suggest that eccentric walking provides effects that are not achieved by conventional walking.

A systematic review of acquisition and mastery of skills taught using the Picture Exchange Communication System.

The Picture Exchange Communication System (PECS) is a popular augmentative and alternative communication intervention for individuals with developmental disabilities that includes six, sequential phases of instruction. We systematically reviewed published and unpublished single-case PECS studies for details about the percentage of participants mastering PECS phases, how long it took participants to master PECS phases (in trials to mastery), and what constituted mastery of PECS phases. We found most participants mastered only the first two phases of PECS, and Phases I, II, and IV showed the slowest and widest variability in trials to mastery. Moreover, participants who were taught the third PECS phase learned to select from an average array of three symbols, which may limit the range of messages they can communicate. We discuss our findings in light of a few important limitations and provide directions for future researchers along with recommendations for professionals who might consider PECS.

Impacts of metabolic disruption, body mass index and inflammation on cognitive function in post-COVID-19 condition: a randomized controlled trial on vortioxetine.

BACKGROUND: Post-COVID-19 Condition (PCC), as defined by the World Health Organization (WHO), currently lacks any regulatory-approved treatments and is characterized by persistent and debilitating cognitive impairment and mood symptoms. Additionally, metabolic dysfunction, chronic inflammation and the associated risks of elevated body mass index (BMI) have been reported. In this study, we aim to investigate the efficacy of vortioxetine in improving cognitive deficits in individuals with PCC, accounting for the interaction of metabolic dysfunction, elevated inflammation and BMI. METHODS: This is a post-hoc analysis of an 8-week randomized, double-blind, placebo-controlled trial that was conducted among adults aged 18 years and older living in Canada who were experiencing WHO-defined PCC symptoms. The recruitment of participants began in November 2021 and concluded in January 2023. A total of 200 individuals were enrolled, where 147 were randomized in a 1:1 ratio to receive either vortioxetine (5-20 mg, n = 73) or placebo (n = 74) for daily treatment under double-blind conditions. The primary outcome measure was the change in the Digit Symbol Substitution Test (DSST) score from baseline to endpoint. RESULTS: Our findings showed significant effects for time (χ2 = 7.771, p = 0.005), treatment (χ2 = 7.583, p = 0.006) and the treatment x time x CRP x TG-HDL x BMI interaction (χ2 = 11.967, p = 0.018) on cognitive function. Moreover, the between-group analysis showed a significant improvement with vortioxetine at endpoint (mean difference = 0.621, SEM = 0.313, p = 0.047). CONCLUSION: Overall, vortioxetine demonstrated significant improvements in cognitive deficits among individuals with baseline markers of metabolic dysfunction, elevated inflammation and higher BMI at endpoint as compared to placebo. TRIAL REGISTRATION: NCT05047952 (ClinicalTrials.gov; Registration Date: September 17, 2021).

Causal Influence of Linguistic Learning on Perceptual and Conceptual Processing: A Brain-Constrained Deep Neural Network Study of Proper Names and Category Terms.

Language influences cognitive and conceptual processing, but the mechanisms through which such causal effects are realized in the human brain remain unknown. Here, we use a brain-constrained deep neural network model of category formation and symbol learning and analyze the emergent model's internal mechanisms at the neural circuit level. In one set of simulations, the network was presented with similar patterns of neural activity indexing instances of objects and actions belonging to the same categories. Biologically realistic Hebbian learning led to the formation of instance-specific neurons distributed across multiple areas of the network, and, in addition, to cell assembly circuits of "shared" neurons responding to all category instances-the network correlates of conceptual categories. In two separate sets of simulations, the network learned the same patterns together with symbols for individual instances ["proper names" (PN)] or symbols related to classes of instances sharing common features ["category terms" (CT)]. Learning CT remarkably increased the number of shared neurons in the network, thereby making category representations more robust while reducing the number of neurons of instance-specific ones. In contrast, proper name learning prevented a substantial reduction of instance-specific neurons and blocked the overgrowth of category general cells. Representational similarity analysis further confirmed that the neural activity patterns of category instances became more similar to each other after category-term learning, relative to both learning with PN and without any symbols. These network-based mechanisms for concepts, PN, and CT explain why and how symbol learning changes object perception and memory, as revealed by experimental studies.

Vortioxetine for the treatment of post-COVID-19 condition: a randomized controlled trial.

Hitherto no therapeutic has received regulatory approval for the treatment of post-COVID-19 condition (PCC). Cognitive deficits, mood symptoms and significant reduction in health-related quality of life (HRQoL) are highly replicated and debilitating aspects of PCC. We sought to determine the impact of vortioxetine on the foregoing symptoms and HRQoL in persons living with PCC. An 8-week randomized, double-blind, placebo-controlled study of adults ≥ 18 years of age residing in Canada and who are experiencing symptoms of World Health Organization (WHO)-defined PCC, with a history of confirmed SARS-CoV-2 infection, was conducted. Recruitment began November 2021 and ended January 2023. Of the 200 participants enrolled (487 invited: 121 ineligible and 59 eligible but declined participation; 307 cleared pre-screening stage), a total of 149 participants were randomized (1:1) to receive either vortioxetine (5-20 mg, n = 75) or placebo (n = 74) daily for 8 weeks of double-blind treatment (i.e. end point). The primary outcome was the change from baseline-to-end point in the Digit Symbol Substitution Test. Secondary outcomes included the effect on depressive symptoms and HRQoL, as measured by changes from baseline-to-end point on the Quick Inventory of Depressive Symptomatology 16-item and WHO Wellbeing Scale 5-item, respectively. A total of 68 (90.7%) participants randomized to vortioxetine and 73 (98.6%) participants randomized to placebo completed all 8 weeks. Between-group analysis did not show a significant difference in the overall change in cognitive function [P = 0.361, 95% confidence interval (CI) (-0.179, 0.492)]. However, in the fully adjusted model, a significant treatment × time interaction was observed in favour of vortioxetine treatment with baseline c-reactive protein (CRP) as a moderator (P = 0.012). In addition, a significant improvement in Digit Symbol Substitution Test scores were observed in vortioxetine versus placebo treated participants in those whose baseline CRP was above the mean (P = 0.045). Moreover, significant improvement was obtained in measures of depressive symptoms [P < 0.001, 95% CI (-4.378, -2.323)] and HRQoL [P < 0.001, 95% CI (2.297, 4.647)] in vortioxetine-treated participants and between the treatment groups [depressive symptoms: P = 0.026, 95% CI (-2.847, -0.185); HRQoL: P = 0.004, 95% CI (0.774, 3.938)]. Although vortioxetine did not improve cognitive function in the unadjusted model, when adjusting for CRP, a significant pro-cognitive effect was observed; antidepressant effects and improvement in HRQoL in this debilitating disorder were also noted.

A misinterpreted psychoanalyst: Herbert Silberer and his theory of symbol-formation.

The primary aim of this article is to give a more detailed exposition of the cultural, personal, and theoretical contexts in which the Viennese psychoanalyst, Herbert Silberer's theories were born. When assessing the broader picture that this approach offers, it can be concluded that Silberer was an innovative thinker who inspired several of his contemporaries. Recognized in many respects by the society and scholars of this time, he represented quite a different viewpoint that was significantly influenced by several forms of Western esoteric thinking. Yet his main aim was to contribute to the field of psychoanalysis and develop a theory in which rationalistic psychoanalytic interpretations were combined with nonreductive approaches to mystical experiences. Silberer's name is frequently mentioned in a specific context in which his tragic suicide is emphasized rather than his innovations. Upon evaluating the materials recording Silberer's private life, it seems very likely that his suicide was not triggered by the criticism of Freud alone. Silberer's family affairs, his relationship with his father, and his financial and professional struggles could have all contributed to his tragic decision. This paper contends that Silberer's oeuvre deserves greater attention and must be evaluated based upon its own merit.