Performance on the Latin American version of the Face-Name Associative Memory Exam (LAS-FNAME) distinguishes individuals with Mild Cognitive Impairment from age-matched controls in a sample from Argentina.

INTRODUCTION: The Latin American Spanish version of the Face-Name Associative Memory Exam (LAS-FNAME) has shown promise in identifying cognitive changes in those at risk for Alzheimer's disease (AD). However, its applicability for Mild Cognitive Impairment (MCI) detection in the Latin American population remains unexplored. This study aims to analyze the psychometric properties in terms of validity and reliability and diagnostic performance of the LAS-FNAME for the detection of memory disorders in patients with amnestic MCI (aMCI). MATERIALS AND METHODS: The study included 31 participants with aMCI, diagnosed by a neurologist according to Petersen's criteria, and 19 healthy controls. Inclusion criteria for the aMCI group were to be 60 years of age or older, report cognitive complaints, have a memory test score (Craft Story 21) below a -1.5 z-score and have preserved functioning in activities of daily living. Participants completed LAS-FNAME and a comprehensive neuropsychological assessment. RESULTS: LAS-FNAME showed the ability to discriminate against healthy controls from patients with aMCI (AUC= 75) in comparison with a gold-standard memory test (AUC = 69.1). LAS-FNAME also showed evidence of concurrent and divergent validity with a standard memory test (RAVLT) (r = 0.58, p < .001) and with an attention task (Digit Span) (r = -0.37, p = .06). Finally, the reliability index was very high (α = 0.88). DISCUSSION: LAS-FNAME effectively distinguished aMCI patients from healthy controls, suggesting its potential for detecting early cognitive changes in Alzheimer's prodromal stages among Spanish speakers.

Alpha-Beta Hybrid Quantum Associative Memory Using Hamming Distance.

This work presents a quantum associative memory (Alpha-Beta HQAM) that uses the Hamming distance for pattern recovery. The proposal combines the Alpha-Beta associative memory, which reduces the dimensionality of patterns, with a quantum subroutine to calculate the Hamming distance in the recovery phase. Furthermore, patterns are initially stored in the memory as a quantum superposition in order to take advantage of its properties. Experiments testing the memory's viability and performance were implemented using IBM's Qiskit library.

Worse associative memory recall in healthy older adults compared to young ones, a face-name study in Spain and Mexico.

INTRODUCTION: The Face Name Associative Memory Exam (FNAME) is sensitive to associative memory changes early in the Alzheimer's disease spectrum, but little is known about how healthy aging affects FNAME performance. We aimed to assess aging effects on an extended version of the test, which captures further associative memory abilities beyond the recall and recognition domains measured in the original version. METHOD: We adapted FNAME versions in Spain and Mexico, adding new subtests (Spontaneous Name Recall, Face-Name Matching). We compared the performance of 21 young adults (YA) and 27 older adults (OA) in Spain, and 34 YA and 36 OA in Mexico. Recall was analyzed using a mixed-model ANOVA including subtest scores as dependent variables, age group as a fixed-factor independent variable, and recall subtest as a three-level repeated-measure independent variable. The rest of the associative memory domains were analyzed through t-tests comparing the performance of YA and OA. RESULTS: In Spain, we found significant effects for age group and recall subtest, with large effect sizes. The recognition subtests (Face Recognition, Name Recognition) displayed ceiling effects in both groups. The new subtests displayed medium-to-large effect sizes when comparing age groups. In Mexico, these results were replicated, additionally controlling for education. In both studies, recall performance improved after repeated exposures and it was sustained after 30 minutes in YA and OA. CONCLUSIONS: We document, in two different countries, a clear aging pattern on the extended FNAME: regardless of education, OA remember fewer stimuli than YA through recall subtests. The new subtests provide evidence on associative memory changes in aging beyond recall.

Identification of a Novel Retrieval-dependent Memory Process in the Crab Neohelice granulata.

Fully consolidated associative memories may be altered by alternative retrieval dependent memory processes. While a brief exposure to the conditioned stimulus (CS) can trigger reconsolidation of the original memory, a prolonged CS exposure will trigger memory extinction. The conditioned response is maintained after reconsolidation, but is inhibited after extinction, presumably by the formation of a new inhibitory memory trace. In rats and humans, it has been shown that CS exposure of intermediate duration leave the memory in an insensitive or limbo state. Limbo is characterised by the absence of reconsolidation or extinction. Here we investigated the evolutionary conserved nature of limbo using a contextual Pavlovian conditioning (CPC) memory paradigm in the crab Neohelice granulata. In animals with fully consolidated CPC memory, systemic administration of the protein synthesis inhibitor cycloheximide after 1 CS presentation disrupted the memory, presumably by interfering with memory reconsolidation. The same intervention given after 320 CSs prevented CPC memory extinction. Cycloheximide had no behavioural effect when administered after 80 CS presentations, a protocol that failed to extinguish CPC memory. Also, we observed that a stronger CPC memory engaged reconsolidation after 80 CS instead of limbo, indicating that memory strength affects the parametrical conditions to engage either reconsolidation or limbo. Altogether, these results indicate that limbo is an evolutionary conserved memory process segregating reconsolidation from extinction in the number of CSs space. Limbo appears as an intrinsic component of retrieval dependent memory processing, with a key function in the transition from memory maintenance to inhibition.

Novel Mathematical Model of Breast Cancer Diagnostics Using an Associative Pattern Classification.

Breast cancer is a disease that has emerged as the second leading cause of cancer deaths in women worldwide. The annual mortality rate is estimated to continue growing. Cancer detection at an early stage could significantly reduce breast cancer death rates long-term. Many investigators have studied different breast diagnostic approaches, such as mammography, magnetic resonance imaging, ultrasound, computerized tomography, positron emission tomography and biopsy. However, these techniques have limitations, such as being expensive, time consuming and not suitable for women of all ages. Proposing techniques that support the effective medical diagnosis of this disease has undoubtedly become a priority for the government, for health institutions and for civil society in general. In this paper, an associative pattern classifier (APC) was used for the diagnosis of breast cancer. The rate of efficiency obtained on the Wisconsin breast cancer database was 97.31%. The APC's performance was compared with the performance of a support vector machine (SVM) model, back-propagation neural networks, C4.5, naive Bayes, k-nearest neighbor (k-NN) and minimum distance classifiers. According to our results, the APC performed best. The algorithm of the APC was written and executed in a JAVA platform, as well as the experimental and comparativeness between algorithms.

Validation of the Latin American Spanish version of the face-name associative memory exam in a Colombian Sample.

OBJECTIVE: The Face-Name Associative Memory Exam (FNAME) has been used to detect subtle cognitive changes in clinically normal older adults at increased risk for Alzheimer's disease. FNAME assesses learning and delayed recall for face-name pairs. The aim of this study is to introduce a Latin American Spanish version of the FNAME (LAS-FNAME), examine its psychometric properties, and provide preliminary normative data in a sample of clinically normal, Spanish-speaking individuals from Antioquia, Colombia. METHOD: 59 clinically-normal individuals (71% females) were recruited by the Grupo de Neurociencias in Antioquia (Colombia). Age ranged from 27 to 82 years (M = 50.31, SD = 15.32) and years of education ranged from 2 to 17 years (M = 9.02, SD = 4.11). All participants completed the LAS-FNAME and a brief neuropsychological evaluation. We examined associations between age, education, and sex and performance on the LAS-FNAME. Internal consistency, convergent and discriminant validity were also assessed. Test-restest reliability was computed for a subset of participants (n = 32). RESULTS: LAS-FNAME exhibited moderate convergent validity with other memory measures (Free and Cued Selective Reminding Scale, rs=.465, p<.01; Wechsler Memory Scale III - Logical Memory Delayed Recall, rs=.479, p<.01). The subscales of the LAS-FNAME exhibited adequate internal consistency (α=.825). Test-retest reliability analyses demonstrated consistency of scores over time. Normative data was stratified by age (<50, 50-65, >65) and low and high educational attainment (≤8 and >8 years of education, respectively). CONCLUSIONS: The LAS-FNAME is a valid and reliable measure to assess memory in clinically normal, Spanish-speaking individuals from Colombia for clinical and research purposes.

Kinase and Phosphatase Engagement Is Dissociated Between Memory Formation and Extinction.

Associative long-term memories (LTMs) support long-lasting behavioral changes resulting from sensory experiences. Retrieval of a stable LTM by means of a large number of conditioned stimulus (CS) alone presentations produces inhibition of the original memory through extinction. Currently, there are two opposing hypotheses to account for the neural mechanisms supporting extinction. The unlearning hypothesis posits that extinction affects the original memory trace by reverting the synaptic changes supporting LTM. On the contrary, the new learning hypothesis proposes that extinction is simply the formation of a new associative memory that inhibits the expression of the original one. We propose that detailed analysis of extinction-associated molecular mechanisms could help distinguish between these hypotheses. Here we will review experimental evidence regarding the role of protein kinases and phosphatases (K&P) on LTM formation and extinction. Even though K&P regulate both memory processes, their participation appears to be dissociated. LTM formation recruits kinases, but is constrained by phosphatases. Memory extinction presents a more diverse molecular landscape, requiring phosphatases and some kinases, but also being constrained by kinase activity. Based on the available evidence, we propose a new theoretical model for memory extinction: a neuronal segregation of K&P supports a combination of time-dependent reversible inhibition of the original memory [CS-unconditioned stimulus (US)], with establishment of a new associative memory trace (CS-noUS).

Probiotics and Prebiotics as a Therapeutic Strategy to Improve Memory in a Model of Middle-Aged Rats.

Aging is associated with morphological, physiological and metabolic changes, leading to multiorgan degenerative pathologies, such as cognitive function decline. It has been suggested that memory loss also involves a decrease in neurotrophic factors, including brain-derived neurotrophic factor (BDNF). In recent years, microbiota has been proposed as an essential player in brain development, as it is believed to activate BDNF secretion through butyrate production. Thus, microbiota modulation by supplementation with probiotics and prebiotics may impact cognitive decline. This study aimed to evaluate the effects of probiotics and prebiotics supplementation on the memory of middle-aged rats. Sprague-Dawley male rats were randomized in four groups (n = 13 per group): control (water), probiotic (E. faecium), prebiotic (agave inulin), symbiotic (E. faecium + inulin), which were administered for 5 weeks by oral gavage. Spatial and associative memory was analyzed using the Morris Water Maze (MWM) and Pavlovian autoshaping tests, respectively. Hippocampus was obtained to analyze cytokines [interleukin (IL-1ß) and tumor necrosis factor (TNF-α)], BDNF and γ-aminobutyric acid (GABA) by enzyme-linked immunosorbent assay (ELISA). Butyrate concentrations were also evaluated in feces. The symbiotic group showed a significantly better performance in MWM (p < 0.01), but not in Pavlovian autoshaping test. It also showed significantly lower concentrations of pro-inflammatory cytokines (p < 0.01) and the reduction in IL-1ß correlated with a better performance of the symbiotic group in MWM (p < 0.05). Symbiotic group also showed the highest BDNF and butyrate levels (p < 0.0001). Finally, we compared the electrophysiological responses of control (n = 8) and symbiotic (n = 8) groups. Passive properties of CA1 pyramidal cells (PCs) exhibited changes in response to the symbiotic treatment. Likewise, this group showed an increase in the N-methyl-D-aspartate receptor (NMDA)/AMPA ratio and exhibited robust long-term potentiation (LTP; p < 0.01). Integrated results suggest that symbiotics could improve age-related impaired memory.