scholarly journals Flexible and accurate decoding of neural populations through stochastic comodulation

2019 ◽  
Author(s):  
Caroline Haimerl ◽  
Cristina Savin ◽  
Eero P. Simoncelli
Keyword(s):  
Large Population ◽  
Identification Problem ◽  
Relevant Information ◽  
Small Subset ◽  
Neural Responses ◽  
Stimulus Response ◽  
Specific Strength ◽  
Encode Task ◽  
The Relationship ◽  
Task Parameters

AbstractSensory-guided behavior requires reliable encoding of information (from stimuli to neural responses) and flexible decoding (from neural responses to behavior). In typical decision tasks, a small subset of cells within a large population encode task-relevant stimulus information and need to be identified by later processing stages for relevant information to be transmitted. A statistically optimal decoder (e.g., maximum likelihood) can utilize task-relevant cells for any given task configuration, but relies on complete knowledge of the relationship between the task and the stimulus-response and noise properties of the encoding population. The brain could learn an optimal decoder for a task through supervised learning (i.e., regression), but this typically requires many training trials, and thus lacks the flexibility of humans or animals, that can rapidly adjust to changes in task parameters or structure. Here, we propose a novel decoding solution based on functionally targeted stochastic modulation. Population recordings during different discrimination tasks have revealed that a substantial portion of trial-to-trial variability in cell responses can be explained by stochastic modulatory signals that are shared, and that seem to preferentially target task-informative neurons (Rabinowitz et al., 2015). The variability introduced by these modulators corrupts the encoded stimulus signal, but we propose that it also serves as a label for the informative neurons, allowing the decoder to solve the identification problem. We show in simulations of a modulated Poisson spiking model that a linear decoder with readout weights proportional to the estimated neuron-specific strength of modulation achieves performance close to an optimal decoder.

scholarly journals Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences

2015 ◽  
Vol 22 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Iulia Potorac ◽  
Patrick Petrossians ◽  
Adrian F Daly ◽  
Franck Schillo ◽  
Claude Ben Slama ◽  
...  
Keyword(s):  
Large Population ◽  
Optic Chiasm ◽  
Research Priority ◽  
Maximal Diameter ◽  
Magnetic Resonance Imaging Mri ◽  
Multimodal Management ◽  
Mri Characteristics ◽  
Weighted Sequences ◽  
The Relationship

Responses of GH-secreting adenomas to multimodal management of acromegaly vary widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying factors predictive of their evolution is a research priority. The aim of this study was to clarify the relationship between the T2-weighted adenoma signal on diagnostic magnetic resonance imaging (MRI) in acromegaly and clinical and biological features at diagnosis. An international, multicenter, retrospective analysis was performed using a large population of 297 acromegalic patients recently diagnosed with available diagnostic MRI evaluations. The study was conducted at ten endocrine tertiary referral centers. Clinical and biochemical characteristics, and MRI signal findings were evaluated. T2-hypointense adenomas represented 52.9% of the series, were smaller than their T2-hyperintense and isointense counterparts (P<0.0001), were associated with higher IGF1 levels (P=0.0001), invaded the cavernous sinus less frequently (P=0.0002), and rarely caused optic chiasm compression (P<0.0001). Acromegalic men tended to be younger at diagnosis than women (P=0.067) and presented higher IGF1 values (P=0.01). Although in total, adenomas had a predominantly inferior extension in 45.8% of cases, in men this was more frequent (P<0.0001), whereas in women optic chiasm compression of macroadenomas occurred more often (P=0.0067). Most adenomas (45.1%) measured between 11 and 20 mm in maximal diameter and bigger adenomas were diagnosed at younger ages (P=0.0001). The T2-weighted signal differentiates GH-secreting adenomas into subgroups with particular behaviors. This raises the question of whether the T2-weighted signal could represent a factor in the classification of acromegalic patients in future studies.

scholarly journals The Relationship Between TSH and Free T4 in a Large Population Is Complex and Nonlinear and Differs by Age and Sex

2013 ◽  
Vol 98 (7) ◽  
pp. 2936-2943 ◽  
Author(s):  
Narelle C. Hadlow ◽  
Karen M. Rothacker ◽  
Robert Wardrop ◽  
Suzanne J. Brown ◽  
Ee Mun Lim ◽  
...  
Keyword(s):  
Large Population ◽  
Free T4 ◽  
The Relationship ◽  
Age And Sex

The Relationship of the −5, −8, and −24 Variant Alleles in African Americans to Triosephosphate Isomerase (TPI) Enzyme Activity and to TPI Deficiency

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2959-2962 ◽  
Author(s):  
Arthur Schneider ◽  
Linda Forman ◽  
Beryl Westwood ◽  
Catherine Yim ◽  
James Lin ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
African American ◽  
African Americans ◽  
Triosephosphate Isomerase ◽  
Small Subset ◽  
Nucleotide Substitutions ◽  
Severe Deficiency ◽  
American Society ◽  
Relationship Of ◽  
The Relationship

Abstract In 424 African-American and 75 white subjects, we found that the −5 (TPI 592 A→G), −8 (TPI 589 G→A), and −24 (TPI 573 T→G) variants in the triosephosphate isomerase (TPI) gene occurred frequently (41.0%) in the African-American subjects but did not occur in the whites. These data suggest that this set of polymorphisms may turn out to be one of the higher-incidence molecular markers of African lineage, a surprising finding because others had reported that these nucleotide substitutions were restricted to a small subset of African Americans who had been characterized as TPI-deficiency heterozygotes. Additionally, we investigated the relationship of these variants to TPI-enzyme activity. Although the variant substitutions (occurring in three haplotypes: −5 alone, −5 −8, and −5 −8 −24) were associated with moderate reduction in enzyme activity, severe-deficiency heterozygotes could not be identified with certainty, and none of the haplotypes were restricted to subjects with marked reduction of enzyme activity. Three subjects were homozygous for the −5 −8 haplotype, a finding inconsistent with the putative role of this haplotype as the cause of a null variant incompatible with life in homozygotes. Despite these findings, the possibility remains that the −5 −8 or −5 −8 −24 haplotypes may in some instances contribute to compound heterozygosity and clinical TPI deficiency. © 1998 by The American Society of Hematology.

Challenger Entry and Voter Learning

2007 ◽  
Vol 101 (2) ◽  
pp. 303-320 ◽  
Author(s):  
SANFORD C. GORDON ◽  
GREGORY A. HUBER ◽  
DIMITRI LANDA
Keyword(s):  
Empirical Research ◽  
Electoral Competition ◽  
Relevant Information ◽  
Strategic Interaction ◽  
Incumbency Advantage ◽  
Retrospective Voting ◽  
Positive Assessment ◽  
Threat Of Entry ◽  
The Relationship ◽  
Different Levels

We develop a model of strategic interaction between voters and potential electoral challengers to sitting incumbents, in which the very fact of a costly challenge conveys relevant information to voters. Given incumbent failure in office, challenger entry is more likely, but the threat of entry by inferior challengers creates an incentive for citizens to become more politically informed. At the same time, challenges to incumbents who perform well can neutralize a voter's positive assessment of incumbent qualifications. How a voter becomes politically informed can in turn deter challengers of different levels of competence from running, depending on the electoral environment. The model permits us to sharpen our understanding of retrospective voting, the incumbency advantage, and the relationship between electoral competition and voter welfare, while pointing to new interpretations of, and future avenues for, empirical research on elections.

Mourning and Reminiscence: Parallel Psychotherapeutic Processes for Elderly People

1989 ◽  
Vol 28 (4) ◽  
pp. 239-249 ◽  
Author(s):  
Linda L. Viney ◽  
Yvonne N. Benjamin ◽  
Carol Preston
Keyword(s):  
Elderly People ◽  
The Elderly ◽  
Relevant Information ◽  
Theoretical Explanation ◽  
Personal Construct ◽  
Elderly Persons ◽  
Personal Construct Theory ◽  
Psychotherapeutic Processes ◽  
Construct Theory ◽  
The Relationship

Mourning and reminiscence are therapeutic processes common in therapeutic work with the elderly. However, a theoretical explanation of why they are effective has been lacking. Personal construct theory accounts for both in terms of the search of elderly persons for validation of their construct systems. In this article, this explanation of the parallel psychotherapeutic processes is explored, together with relevant information from the literature on mourning and reminiscence. Therapeutic case studies illustrate the characteristics of the two processes and the relationship between them.

scholarly journals The relationship between apathy and impulsivity in large population samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pierre Petitet ◽  
Jacqueline Scholl ◽  
Bahaaeddin Attaallah ◽  
Daniel Drew ◽  
Sanjay Manohar ◽  
...  
Keyword(s):  
Young Adults ◽  
Large Population ◽  
Assessment Tools ◽  
Self Assessment ◽  
Social And Emotional ◽  
Scale Scores ◽  
Recent Addition ◽  
The Relationship ◽  
Gathering Data ◽  
Neuropsychiatric Conditions

AbstractApathy and impulsivity are debilitating conditions associated with many neuropsychiatric conditions, and expressed to variable degrees in healthy people. While some theories suggest that they lie at different ends of a continuum, others suggest their possible co-existence. Surprisingly little is known, however, about their empirical association in the general population. Here, gathering data from six large studies ($$n = 3755$$ n = 3755 ), we investigated the relationship between measures of apathy and impulsivity in young adults. The questionnaires included commonly used self-assessment tools—Apathy Evaluation Scale, Barratt Impulsiveness Scale (BIS-11) and UPPS-P Scale—as well as a more recent addition, the Apathy Motivation Index (AMI). Remarkably, across datasets and assessment tools, global measures of apathy and impulsivity correlated positively. However, analysis of sub-scale scores revealed a more complex relationship. Although most dimensions correlated positively with one another, there were two important exceptions revealed using the AMI scale. Social apathy was mostly negatively correlated with impulsive behaviour, and emotional apathy was orthogonal to all other sub-domains. These results suggest that at a global level, apathy and impulsivity do not exist at distinct ends of a continuum. Instead, paradoxically, they most often co-exist in young adults. Processes underlying social and emotional apathy, however, appear to be different and dissociable from behavioural apathy and impulsivity.

scholarly journals Quality of service in the Heineken supply chain, México: an empirical investigation in the west of Mexico

2020 ◽  
pp. 1-8
Author(s):  
Omar Alejandro PÉREZ-CRUZ ◽  
José de Jesús AMEZCUA-VIVAS ◽  
Johann MEJÍAS-BRITO ◽  
Jesús Francisco TEJEDA-CASTREJÓN
Keyword(s):  
Supply Chain ◽  
Empirical Investigation ◽  
Quality Criteria ◽  
Relevant Information ◽  
Western Region ◽  
Quality Factors ◽  
Economic Sectors ◽  
Western Regional ◽  
The Relationship

The general objective of this work is to analyze the quality factors of the supply chain service in the western regional direction of the company Cervezas Cuauhtémoc Moctezuma - Heineken México. The analysis was framed in a model proposed by Gohain, Thambiah and Hong (2018) which measures six dimensions of service quality: the object, the process, the infrastructure, the interaction, the environment and social responsibility. A survey was applied as an instrument to collect the responses of active providers in the western region of Mexico. The results were estimated by using STATA 14 to evaluate the relationship between the proposed factors. The results highlight that the quality of the supply chain is influenced by the quality criteria of the product, the process and the interaction. In this way, this research contributes with relevant information that allows them to make quick and practical decisions to use those responsible for the company's supply chain, as well as other economic sectors.

scholarly journals DAMPAK SISTEM PEMBAYARAN SEWA KENDARAAN TRUCKING TERHADAP KEGIATAN OPERASIONAL PERUM DAMRI LOGISTIK

LOGISTIK ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 55-67
Author(s):  
Sylvira Ananda Azwar ◽  
Kencana Verawati ◽  
Meliana Safitri ◽  
Anthony Costa
Keyword(s):  
Linear Regression ◽  
Data Collection ◽  
Relevant Information ◽  
Simple Linear Regression ◽  
Statistical Data Analysis ◽  
Regression Test ◽  
Correlation Tests ◽  
Operational Activities ◽  
The Relationship ◽  
Regression Tests

This Research aims to find out the causes and impacts caused by delays in payment of trucking vehicle rentals at Perum DAMRI Logistik, especially on the company's operational activities. Data collection was carried out in 3 divisions in Perum DAMRI Logistics, namely the operational division, the financial division and the engineering division. Data collection was done by interviewing the staff on duty and making observations and observations while in the field. The data obtained is then analyzed and elaborated so as to form a relevant information. In addition to describing the results of interviews, there are some data that are processed using statistical analysis using correlation tests and simple linear regression tests. The statistical data analysis was used to determine the relationship between vehicle rental payments and operational activities and to find out what percentage of the effect was obtained from the two variables. The results of the correlation test using SPSS statistic 25 which shows that vehicle rental payments and operational activities have a positive relationship, the results of a simple linear regression test get the equation Y = 200534,257 + 0.659X. The value of R square is 0.559.

scholarly journals The unbiased estimation of r2 between two sets of noisy neural responses

2021 ◽  
Author(s):  
Dean Pospisil ◽  
Wyeth A Bair
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Unbiased Estimation ◽  
Pearson Correlation Coefficient ◽  
Neural Responses ◽  
Neural Data ◽  
Tuning Curves ◽  
The Relationship

The Pearson correlation coefficient squared, r2, is often used in the analysis of neural data to estimate the relationship between neural tuning curves. Yet this metric is biased by trial-to-trial variability: as trial-to-trial variability increases, measured correlation decreases. Major lines of research are confounded by this bias, including the study of invariance of neural tuning across conditions and the similarity of tuning across neurons. To address this, we extend the estimator, r̂2ER, developed for estimating model-to-neuron correlation to the neuron-to-neuron case. We compare the estimator to a prior method developed by Spearman, commonly used in other fields but widely overlooked in neuroscience, and find that our method has less bias. We then apply our estimator to the study of two forms of invariance and demonstrate how it avoids drastic confounds introduced by trial-to-trial variability.

scholarly journals High serum non-high-density lipoprotein and the risk of ischemic stroke: A systematic review

2021 ◽  
Vol 20 (1) ◽  
pp. 15-20
Author(s):  
Nyoman Tyas Apsari ◽  
◽  
Kumara Tini ◽  
I Putu Eka Widyadharma ◽  
◽  
...  
Keyword(s):  
Systematic Review ◽  
Ischemic Stroke ◽  
High Density Lipoprotein ◽  
Large Population ◽  
Density Lipoprotein ◽  
High Serum ◽  
High Density ◽  
Inclusion Criteria ◽  
Increased Risk ◽  
The Relationship

Objectives. High levels of non high density lipoprotein cholesterol (non-HDL-C) are known to contribute to an increased risk of ischemic stroke. This systematic review was conducted to identify the relationship between high non-HDL-C levels and the risk of ischemic stroke. Material and methods. This systematic review using PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement guideline, with a pre-determined search strategy. The search was conducted in Pubmed Central (PMC) and Pubmed from 2009 until 2020 with inclusion criteria, patients with a diagnosis of ischemic stroke, age >18 years, with non-HDL-C levels. The title and abstract of these articles were reviewed for relevance, based on inclusion criteria. This systematic review using STROBE to evaluate the quality in individual study which consists of 22 domains. Results. In the final stage, this systematic review identifies six cohort study consisting 166.720 participants. Overall, the quality in individual studies based on STROBE is good. We reported that there are two studies report that high non-HDL-C levels can significantly increase the risk of ischemic stroke. Meanwhile, there are four studies that report there was no significant relationship between high non-HDL-C levels and the risk of ischemic stroke. Conclusions. Overall, this systematic review provides the result about relationship between high levels of nonHDL-C and the risk of ischemic stroke, there are two studies with a larger population support that high levels of non-HDL-C can increase the risk of ischemic stroke. However, further studies is needed with a large population that specifically identify the relationship between non-HDL-C levels and risk of ischemic stroke and makes a better adjustments for confounding variables.

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