ExpertosLF: dynamic late fusion of CBIR systems using online learning with relevance feedback.

One of the main challenges in CBIR systems is to choose discriminative and compact features, among dozens, to represent the images under comparison. Over the years, a great effort has been made to combine multiple features, mainly using early, late, and hierarchical fusion techniques. Unveiling the perfect combination of features is highly domain-specific and dependent on the type of image. Thus, the process of designing a CBIR system for new datasets or domains involves a huge experimentation overhead, leading to multiple fine-tuned CBIR systems. It would be desirable to dynamically find the best combination of CBIR systems without needing to go through such extensive experimentation and without requiring previous domain knowledge. In this paper, we propose ExpertosLF, a model-agnostic interpretable late fusion technique based on online learning with expert advice, which dynamically combines CBIR systems without knowing a priori which ones are the best for a given domain. At each query, ExpertosLF takes advantage of user's feedback to determine each CBIR contribution in the ensemble for the following queries. ExpertosLF produces an interpretable ensemble that is independent of the dataset and domain. Moreover, ExpertosLF is designed to be modular, and scalable. Experiments on 13 benchmark datasets from the Biomedical, Real, and Sketch domains revealed that: (i) ExpertosLF surpasses the performance of state of the art late-fusion techniques; (ii) it successfully and quickly converges to the performance of the best CBIR sets across domains without any previous domain knowledge (in most cases, fewer than 25 queries need to receive human feedback).

Locations of objects are better remembered than their identities in naturalistic scenes: An eye-tracking experiment in mild cognitive impairment.

OBJECTIVE: Retaining the identity or location of decontextualized objects in visual short-term working memory (VWM) is impaired by healthy and pathological ageing, but research remains inconclusive on whether these two features are equally impacted by it. Moreover, it is unclear whether similar impairments would manifest in naturalistic visual contexts. METHOD: 30 people with mild cognitive impairment (MCI) and 32 age-matched control participants (CPs) were eye-tracked within a change detection paradigm. They viewed 120 naturalistic scenes, and after a retention interval (1 s) asked whether a critical object in the scene had (or not) changed on either: identity (became a different object), location (same object but changed location), or both (changed in location and identity). RESULTS: MCIs performed worse than CP but there was no interaction with the type of change. Changes in both were easiest while changes in identity alone were hardest. The latency to first fixation and first-pass duration to the critical object during successful recognition was not different between MCIs and CPs. Objects that changed in both features took longer to be fixated for the first time but required a shorter first pass compared to changes in identity alone which displayed the opposite pattern. CONCLUSIONS: Locations of objects are better remembered than their identities; memory for changes is best when involving both features. These mechanisms are spared by pathological ageing as indicated by the similarity between groups besides trivial differences in overall performance. These findings demonstrate that VWM mechanisms in the context of naturalistic scene information are preserved in people with MCI. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A modified Camel and Cactus Test detects presymptomatic semantic impairment in genetic frontotemporal dementia within the GENFI cohort.

Impaired semantic knowledge is a characteristic feature of some forms of frontotemporal dementia (FTD), particularly the sporadic disorder semantic dementia. Less is known about semantic cognition in the genetic forms of FTD caused by mutations in the genes MAPT, C9orf72, and GRN. We developed a modified version of the Camel and Cactus Test (mCCT) to investigate the presence of semantic difficulties in a large genetic FTD cohort from the Genetic FTD Initiative (GENFI) study. Six-hundred-forty-four participants were tested with the mCCT including 67 MAPT mutation carriers (15 symptomatic, and 52 in the presymptomatic period), 165 GRN mutation carriers (33 symptomatic, 132 presymptomatic), and 164 C9orf72 mutation carriers (56 symptomatic, 108 presymptomatic) and 248 mutation-negative members of FTD families who acted as a control group. The presymptomatic mutation carriers were further split into those early and late in the presymptomatic period (more than vs. within 10 years of expected symptom onset). Groups were compared using a linear regression model, adjusting for age and education, with bootstrapping. Performance on the mCCT had a weak negative correlation with age (rho = -0.20) and a weak positive correlation with education (rho = 0.13), with an overall abnormal score (below the 5th percentile of the control population) being below 27 out of a total of 32. All three of the symptomatic mutation groups scored significantly lower than controls: MAPT mean 22.3 (standard deviation 8.0), GRN 24.4 (7.2), C9orf72 23.6 (6.5) and controls 30.2 (1.6). However, in the presymptomatic groups, only the late MAPT and late C9orf72 mutation groups scored lower than controls (28.8 (2.2) and 28.9 (2.5) respectively). Performance on the mCCT correlated strongly with temporal lobe volume in the symptomatic MAPT mutation group (rho > 0.80). In the C9orf72 group, mCCT score correlated with both bilateral temporal lobe volume (rho > 0.31) and bilateral frontal lobe volume (rho > 0.29), whilst in the GRN group mCCT score correlated only with left frontal lobe volume (rho = 0.48). This study provides evidence for presymptomatic impaired semantic knowledge in genetic FTD. The different neuroanatomical associations of the mCCT score may represent distinct cognitive processes causing deficits in different groups: loss of core semantic knowledge associated with temporal lobe atrophy (particularly in the MAPT group), and impaired executive control of semantic information associated with frontal lobe atrophy. Further studies will be helpful to address the longitudinal change in mCCT performance and the exact time at which presymptomatic impairment occurs.

Effect of education on cognitive performance in patients with mild cognitive impairment.

This study aims to investigate if education (as a cognitive reserve proxy) modifies the profile of cognitive performance. We hypothesize that participants with higher education can remain functional (due to a better executive performance), despite a more severe memory impairment, compared with lower education individuals. One hundred and sixty-six mild cognitive impairment (MCI) individuals with at least one comprehensive neuropsychological evaluation were included in a retrospective, cross-sectional study and divided into two groups (Low Education-LE [1-4 years] and Medium-to-High Education-MHE [> 4 years]). A total of 22 neuropsychological measures were analyzed. Age-adjusted results were subject to simple regression analyses to determine the variance explained by education. Average scores and proportions of low performances were subject to group comparison. The results showed similar cognitive decline patterns between individuals with LE and MHE, with no significant difference in each cognitive domain. However, MHE revealed a steeper decline in certain cognitive domains, such as sustained attention and episodic memory, compared with the LE. Moreover, MHE showed a trend to higher proportion of tests affected when compared to LE. These suggest that individuals with higher education may remain in a MCI stage despite a more widespread cognitive impairment, reflecting a higher cognitive reserve.

Cognitive aging in migraine sufferers is associated with more subjective complaints but similar age-related decline: a 5-year longitudinal study.

OBJECTIVES AND BACKGROUND: The effect of headache on cognitive performance is controversial, due to conflicting results obtained from studies in clinical or population settings. We aimed to understand if migraine and other headaches modify the rates of decline on different cognitive measures, during a 5-year interval. DESIGN AND METHOD: A cohort of community dwelling adults (> 50 years) with migraine (MH), non-migraine headaches (NMH) and controls without headache (WoH), was assessed by a comprehensive neuropsychological battery with tests of memory, language and executive functions, repeated 5 years apart. Change in performance between baseline and reevaluation was compared between groups, and controlled for age, gender, literacy and depressive symptoms. RESULTS: A total of 275 participants (78.5% WoH, 12.7% MH, 8.7% NMH) were reevaluated (average age 70.40 + 8.34 years, 64% females). Cognitive decline or dementia occurred in 11.4%, with a similar proportion among the three groups. Although MH participants had significantly more subjective cognitive complaints (p = 0.030, 95%CI:]-3.929,-0.014[), both MH and NMH subjects showed an age-associated decline identical to controls. Furthermore, migraine features (disease and attack duration, frequency and aura) were unrelated with cognitive performance. CONCLUSION: Migraine and non-migraine headache are not associated with increasing risk of dementia or cognitive decline at an older age although subjects with migraine have more cognitive complaints. Longer longitudinal studies are necessary to understand if this pattern persists for more than 5 years.

Predictors of cognitive stability or decline during aging: A longitudinal study in primary care.

We aimed to identify the early predictors of cognitive decline, and primary care physicians' (PCP) ability to diagnose cognitively impaired subjects, in a cohort of individuals recruited in primary care centers. Independent adults, aged ≥50 years at inception, with an overall low level of education, undertook a prospective clinical and cognitive evaluation targeting memory, attention and executive functions. At follow-up subjects were classified as cognitively normal (CN) or impaired (CI). Of 275 subjects (70.4 ± 8.3 years old, 176 females, 7.5 ± 4.4 education, 162 with MRI), 31 (11.2%) presented CI 4.9 years later, the majority (64.5%) presenting subjective cognitive complaints. PCP could correctly identify 40% of CI individuals, particularly if they presented current cognitive complaints. Male sex (OR = 3.117; CI95%: 1.007-9.645), age (OR = 1.063; CI95%: 1.004-1.126) and baseline scores on TMT-B (OR = 0.225; CI95%: 0.073-0.688) and Vocabulary (OR = 0.940; 95% CI: 0.894-0.986) predicted CI. This study shows that measures indicating poor cognitive reserve and low executive performance (as shown by low vocabulary and executive test scores, respectively) can be early indicators of the risk of decline, stressing the role of cognitive assessment as part of prevention/early intervention programs. The results also underline the need to help PCP to improve the detection of subjects with cognitive decline.

Brain state monitoring for the future prediction of migraine attacks.

BACKGROUND: Migraine attacks are unpredictable, precluding preemptive interventions and leading to lack of control over individuals' lives. Although there are neurophysiological changes 24-48 hours before migraine attacks, so far, they have not been used in patients' management. This study evaluates the applicability and the ability to identify pre-attack changes of daily "at home" electroencephalography obtained with a portable system for migraine patients. METHODS: Patients with episodic migraine fulfilling ICHD-3 beta criteria used a mobile system composed of a wireless EEG device (BrainStation®, Neuroverse®, Inc., USA) and mobile application (BrainVitalsM®, Neuroverse®, Inc., USA) to self-record their neural activity daily at home while resting and while performing an attention task, over the course of 2 weeks. Standard EEG spectral analysis and event-related brain potentials (ERP) methods were used and recordings were grouped by time from migraine attacks (i.e. "Interictal day", "24 h Before Migraine", "Migraine day" and "Post Migraine"). RESULTS: Twenty-four patients (22 women) recorded an average of 13.3 ± 1.9 days and had 2 ± 0.9 attacks. Twenty-four hours before attack onset, there was a statistically significant modulation of relative power in the delta (decrease) and beta (increase) frequency bands, at rest, and a significant reduction of the amplitude and inter-trial coherence measures of an attention event-related brain potential (P300). CONCLUSIONS: This proof-of-concept study shows that brain state monitoring, utilising an easy-to-use wearable EEG system to track neural modulations at home, can identify physiological changes preceding a migraine attack enabling valuable pre-symptom prediction and subsequent early intervention.

May Subjective Language Complaints Predict Future Language Decline in Community-Dwelling Subjects?

Subjective cognitive complaints are rather prevalent in the elderly population and are associated with an increased risk of cognitive impairment and dementia. However, the predictive role of specific types of cognitive complaints has been less systematically assessed. The aim of the present study is to examine the predictive value of language complaints for cognitive and language decline in a cohort of community-dwelling healthy older adults, followed longitudinally over a 5-year period. A total of 402 subjects were enrolled in a prospective longitudinal study on aging and cognition. Participants answered a cognitive complaints questionnaire including two questions directed to language and were classified at baseline as having "Language Complaints" (LC) or "No Language Complaints" (NLC). They also performed a neuropsychological assessment tackling attention/processing speed, memory, executive functioning, and language at baseline. From these, 275 (68.4%) participated in a follow-up evaluation 4.9 (±0.6) years later. At re-evaluation, subjects had a mean age of 70.4 (±8.3) years, 7.5 (±4.4) years of education, and 63.3% were female. Multivariate linear regression analysis was used to investigate whether language complaints at baseline predicted poorer language performance at follow-up or increased the risk of cognitive decline, with correction for sex, depressive symptoms, living status, baseline performance, and composite memory and executive performance. Results indicated that LC subjects had significantly worse performances than NLC subjects on semantic fluency 5 years later, but with a similar rate of decline overtime that was not associated with a follow-up outcome of cognitive decline/dementia. Language difficulties may represent a specific type of age-related cognitive complaints. Longer follow-ups are necessary to understand if they are associated with an increased risk of language or cognitive decline.

Uso del test de evaluación cognitiva de Montreal (MoCA) en América Latina: revisión sistemática / Use of the Montreal Cognitive Assessment (MoCA) in Latin America: a systematic review

Objetivo. Analizar la frecuencia del uso del test de evaluación cognitiva de Montreal (MoCA) como instrumento de cribado cognitivo, su adaptación transcultural, la existencia de baremos y estudios de validación clínica en países de habla hispana en América Latina. Sujetos y métodos. Se ha realizado una revisión sistemática de todos los estudios desarrollados en América Latina, con referencia al MoCA, que incluyan datos normativos, datos psicométricos y estudios de baremación o de validación clínica. Fueron consultadas sistemáticamente, entre abril y junio de 2017, las bases de datos Medline, PsycINFO, Web of Science, Scopus y Scielo, conforme a la metodología PRISMA. Resultados. De los 80 estudios encontrados, 19 cumplieron los criterios de inclusión. La mayoría de los estudios menciona el uso de la versión española y comunica un efecto significativo del sexo, la edad y la escolaridad. El punto de corte adoptado por la mayoría de los autores para el diagnóstico de deterioro cognitivo es el mismo del estudio original. Conclusiones. El reducido número de artículos identificados refleja posiblemente un inicio tardío de la utilización del MoCA en América Latina. Esto pone de manifiesto una tendencia en la región a utilizar la prueba sin hacer una adaptación transcultural de la versión original y sin recurrir a normas internacionales para el diagnóstico. La presente revisión sistemática demuestra la necesidad de trabajos futuros de investigación que puedan ofrecer una versión lingüísticamente adaptada del MoCA para América Latina y un estudio de sus propiedades psicométricas, con miras a una evaluación cognitiva de mayor calidad

Aim. To analyze the frequency of use of the Montreal Cognitive Assessment (MoCA) as a cognitive screening instrument, cross-cultural adaptation, the existence of normative data and clinical validation studies in Latin America Hispanic countries. Subjects and methods. The Medline, PsycINFO, Web of Science, Scopus and Scielo databases were consulted between April and June 2017 according to the PRISMA methodology. We included all studies referencing the MoCA as an instrument to evaluate cognitive deterioration conducted in Latin America and that included normative and psychometric data, as well as its clinical validation. Results. Of the 80 studies identified, 19 met the inclusion criteria. Most of the studies mentioned the use of the Spanish version of the MoCA and reported a statistically significant effect of gender, age and, most of all, education on the performance of this test. Only five studies presented with a detailed analysis of the psychometric characteristics of the test, and in most articles cut-off scores for the diagnosis of cognitive impairment were the same as the original study. Conclusions. The small number of articles identified may reflect a late start of the use of MoCA in Latin America. A tendency towards the use of this test without making a cross-cultural adaptation and the use of international norms was observed in this region. The present systematic review demonstrates the need for future research tackling the development of a linguistically adapted version of the MoCA to Latin America and the study of its psychometric properties, with the aim of improving cognitive assessment

Depression with melancholic features is associated with higher long-term risk for dementia.

BACKGROUND: Depression has been reported to increase the risk of subsequently developing dementia, but the nature of this relation remains to be elucidated. Depression can be a prodrome/manifestation of dementia or an early risk factor, and the effect may differ according to depression subtypes. Our aim was to study the association between early-onset depression and different depression subtypes, and the later occurrence of dementia. METHODS: We conducted a cohort study including 322 subjects with depression, recruited between 1977 and 1984. A comparison cohort (non-exposed) was recruited retrospectively, to include 322 subjects admitted at the same hospital for routine surgery (appendicectomy or cholecystectomy), at the same period as the depressed cohort. Subjects were contacted again between 2009 and 2014, to assess their dementia status. We computed the risk for dementia in subjects with early onset depression and quantified the association between different depression subtypes (namely melancholic, anxious, and psychotic) and dementia. RESULTS: The odds of dementia were increased by 2.90 times (95% C.I. 1.61-5.21; p<0.0001) for the depressed cohort when compared to the surgical cohort. When the analysis was restricted to patients younger than 45 years old at baseline, the odds for dementia in the depressed cohort were also significantly higher when compared to the surgical cohort (8.53; 95% C.I. 2.40-30.16). In the multivariate Cox analysis, subjects having depression with melancholic features had an increased risk for developing dementia compared to those without melancholic features (HR=3.64; 95% C.I. 1.78-11.26; p=0.025). LIMITATIONS: About 59% of the participants with depression and 53% of those non-exposed were lost during follow up. The inclusion of biological biomarkers would strengthen the results. The sample included a low number of bipolar patients. CONCLUSIONS: These results support depression as an early risk factor for dementia. Depression with melancholic features was found as an important risk factor for dementia, playing a main role in the relation between these disorders.

Decrease in APP and CP mRNA expression supports impairment of iron export in Alzheimer's disease patients.

Alzheimer's disease (AD) is a neurodegenerative disorder of still unknown etiology and the leading cause of dementia worldwide. Besides its main neuropathological hallmarks, a dysfunctional homeostasis of transition metals has been reported to play a pivotal role in the pathogenesis of this disease. Dysregulation of iron (Fe) metabolism in AD has been suggested, particularly at the level of cellular iron efflux. Herein, we intended to further clarify the molecular mechanisms underlying Fe homeostasis in AD. In order to achieve this goal, the expression of specific Fe metabolism-related genes directly involved in Fe regulation and export was assessed in peripheral blood mononuclear cells (PBMCs) from 73AD patients and 74 controls by quantitative PCR. The results obtained showed a significant decrease in the expression of aconitase 1 (ACO1; P=0.007); ceruloplasmin (CP; P<0.001) and amyloid-beta precursor protein (APP; P=0.006) genes in AD patients compared with healthy volunteers. These observations point out to a significant downregulation in the expression of genes associated with ferroportin-mediated cellular Fe export in PBMCs from AD patients, when compared to controls. Taken together, these findings support previous studies suggesting impairment of Fe homeostasis in AD, which may lead to cellular Fe retention and oxidative stress, a typical feature of this disease.

Classification of primary progressive aphasia: Do unsupervised data mining methods support a logopenic variant?

Our objective was to test whether data mining techniques, through an unsupervised learning approach, support the three-group diagnostic model of primary progressive aphasia (PPA) versus the existence of two main/classic groups. A series of 155 PPA patients observed in a clinical setting and subjected to at least one neuropsychological/language assessment was studied. Several demographic, clinical and neuropsychological attributes, grouped in distinct sets, were introduced in unsupervised learning methods (Expectation Maximization, K-Means, X-Means, Hierarchical Clustering and Consensus Clustering). Results demonstrated that unsupervised learning methods revealed two main groups consistently obtained throughout all the analyses (with different algorithms and different set of attributes). One group included most of the agrammatic/non-fluent and some logopenic cases while the other was mainly composed of semantic and logopenic cases. Clustering the patients in a larger number of groups (k > 2) revealed some clusters composed mostly of non-fluent or of semantic cases. However, we could not evidence any group chiefly composed of logopenic cases. In conclusion, unsupervised data mining approaches do not support a clear distinction of logopenic PPA as a separate variant.

Delayed auditory feedback simulates features of nonfluent primary progressive aphasia.

The pathophysiology of nonfluent primary progressive aphasia (nfvPPA) remains poorly understood. Here, we compared quantitatively speech parameters in patients with nfvPPA versus healthy older individuals under altered auditory feedback, which has been shown to modulate normal speech output. Patients (n=15) and healthy volunteers (n=17) were recorded while reading aloud under delayed auditory feedback [DAF] with latency 0, 50 or 200 ms and under DAF at 200 ms plus 0.5 octave upward pitch shift. DAF in healthy older individuals was associated with reduced speech rate and emergence of speech sound errors, particularly at latency 200 ms. Up to a third of the healthy older group under DAF showed speech slowing and frequency of speech sound errors within the range of the nfvPPA cohort. Our findings suggest that (in addition to any anterior, primary language output disorder) these key features of nfvPPA may reflect distorted speech input signal processing, as simulated by DAF. DAF may constitute a novel candidate pathophysiological model of posterior dorsal cortical language pathway dysfunction in nfvPPA.

Genetic and biochemical markers in patients with Alzheimer's disease support a concerted systemic iron homeostasis dysregulation.

Alzheimer's disease (AD) is the most common form of dementia in the elderly individuals, resulting from a complex interaction between environmental and genetic factors. Impaired brain iron homeostasis has been recognized as an important mechanism underlying the pathogenesis of this disease. Nevertheless, the knowledge gathered so far at the systemic level is clearly insufficient. Herein, we used an integrative approach to study iron metabolism in the periphery, at both genotypic and phenotypic levels, in a sample of 116 patients with AD and 89 healthy control subjects. To assess the potential impact of iron metabolism on the risk of developing AD, genetic analyses were performed along with the evaluation of the iron status profile in peripheral blood by biochemical and gene expression studies. The results obtained showed a significant decrease of serum iron, ferritin, and transferrin concentrations in patients compared with the control subjects. Also, a significant decrease of ferroportin (SLC40A1) and both transferrin receptors TFRC and TFR2 transcripts was found in peripheral blood mononuclear cells from patients. At the genetic level, significant associations with AD were found for single nucleotide polymorphisms in TF, TFR2, ACO1, and SLC40A1 genes. Apolipoprotein E gene, a well-known risk factor for AD, was also found significantly associated with the disease in this study. Taken together, we hypothesize that the alterations on systemic iron status observed in patients could reflect an iron homeostasis dysregulation, particularly in cellular iron efflux. The intracellular iron accumulation would lead to a rise in oxidative damage, contributing to AD pathophysiology.

Executive performance in older Portuguese adults with low education.

Evaluation of executive functions is essential in clinical diagnosis, yet there are limited data regarding the performance of participants with low education. We present results on several measures of executive functions obtained in community-dwelling adults with an overall low education and study the effect of this variable in each test. A sample of 479 adults (64% female, mean age 66.4 years) was assessed by a battery comprising 13 measures of executive function (Trail Making Test; Symbol Search; Matrix reasoning; Semantic and phonemic verbal fluencies; Stroop test; and digit spans). Tests' psychometric properties and the effects of age, gender, and education were studied across education levels within each age group. Tests showed good psychometric properties. Education explained more variance than age in the majority of measures, with lower educational levels being significantly associated to worse scores. Tables are presented with mean scores, standard deviation, and the value of extreme percentiles for younger (50-65, N = 232) and older (>65 years, N = 247) × education (0-3, 4, 5-9, and >9 years) subgroups. Education-adjusted norms are necessary for an adequate interpretation of test results. The present data may be useful for clinicians caring for populations with low literacy.

Surgical control of limbic encephalitis associated with LGI1 antibodies.

Limbic encephalitis with LGI1 antibodies may cause drug-resistant temporal lobe epilepsy. We report a case of a young man with progressive drug-resistant focal epilepsy, hyperhidrosis, and memory impairment associated with a left mesial temporal lesion. Epilepsy surgery was performed with the provisional diagnosis of cortical dysplasia or tumour. A neuropathological study following amygdalohippocampectomy revealed limbic encephalitis and LGI1 antibodies were identified in the serum. Two and a half years after surgery, the patient remains seizure-free without medication, with normal memory and without hyperhidrosis. Although immunosuppression is the first-line therapy for autoimmune limbic encephalitis, this case suggests that, in selected cases, a lasting response can be achieved with surgery.

Speech therapy in primary progressive aphasia: a pilot study.

BACKGROUND: Primary progressive aphasia (PPA) is a neurodegenerative disorder with no effective pharmacological treatment. Cognition-based interventions are adequate alternatives, but their benefit has not been thoroughly explored. Our aim was to study the effect of speech and language therapy (SLT) on naming ability in PPA. METHODS: An open parallel prospective longitudinal study involving two centers was designed to compare patients with PPA submitted to SLT (1 h/week for 11 months) with patients receiving no therapy. Twenty patients were enrolled and undertook baseline language and neuropsychological assessments; among them, 10 received SLT and 10 constituted an age- and education-matched historical control group. The primary outcome measure was the change in group mean performance on the Snodgrass and Vanderwart naming test between baseline and follow-up assessments. RESULTS: Intervention and control groups did not significantly differ on demographic and clinical variables at baseline. A mixed repeated measures ANOVA revealed a significant main effect of therapy (F(1,18) = 10.763; p = 0.005) on the performance on the Snodgrass and Vanderwart naming test. CONCLUSION: Although limited by a non-randomized open study design with a historical control group, the present study suggests that SLT may have a benefit in PPA, and it should prompt a randomized, controlled, rater-blind clinical trial.