scholarly journals Sparse coding and dimensionality reduction in cortex

2017 ◽  
Author(s):  
Michael Beyeler ◽  
Emily Rounds ◽  
Kristofor D. Carlson ◽  
Nikil Dutt ◽  
Jeffrey L. Krichmar
Keyword(s):  
Dimensionality Reduction ◽  
Sparse Coding ◽  
Visual Processing ◽  
Spatial Navigation ◽  
Brain Regions ◽  
High Dimensional ◽  
Computational Studies ◽  
Population Code ◽  
Brain Areas ◽  
The Brain

AbstractSupported by recent computational studies, sparse coding and dimensionality reduction are emerging as a ubiquitous coding strategy across brain regions and modalities, allowing neurons to achieve nonnegative sparse coding (NSC) by efficiently encoding high-dimensional stimulus spaces using a sparse and parts-based population code. Reducing the dimensionality of complex, multimodal sensory streams is critically important for metabolically constrained brain areas to represent the world. In this article, we provide an overview of NSC, summarize evidence for its role in neural computation in disparate regions of the brain, ranging from visual processing to spatial navigation, and speculate that specific forms of synaptic plasticity and homeostatic modulation may underlie its implementation. We suggest that NSC may be an organizing principle in the nervous system.

scholarly journals Hierarchy in sensory processing reflected by innervation balance on cortical interneurons

2021 ◽  
Vol 7 (20) ◽  
pp. eabf5676
Author(s):  
Guofen Ma ◽  
Yanmei Liu ◽  
Lizhao Wang ◽  
Zhongyi Xiao ◽  
Kun Song ◽  
...  
Keyword(s):  
Long Range ◽  
Sensory Processing ◽  
Visual Processing ◽  
Brain Regions ◽  
Brain Areas ◽  
Local Interneurons ◽  
Cortical Interneurons ◽  
Different Types ◽  
Virus Tracing ◽  
The Brain

Sensory processing is subjected to modulation by behavioral contexts that are often mediated by long-range inputs to cortical interneurons, but their selectivity to different types of interneurons remains largely unknown. Using rabies-virus tracing and optogenetics-assisted recording, we analyzed the long-range connections to various brain regions along the hierarchy of visual processing, including primary visual cortex, medial association cortices, and frontal cortices. We found that hierarchical corticocortical and thalamocortical connectivity is reflected by the relative weights of inputs to parvalbumin-positive (PV+) and vasoactive intestinal peptide–positive (VIP+) neurons within the conserved local circuit motif, with bottom-up and top-down inputs preferring PV+ and VIP+ neurons, respectively. Our algorithms based on innervation weights for these two types of local interneurons generated testable predictions of the hierarchical position of many brain areas. These results support the notion that preferential long-range inputs to specific local interneurons are essential for the hierarchical information flow in the brain.

Differential recovery of acetylcholinesterase in guinea pig muscle and brain regions after soman treatment

1998 ◽  
Vol 17 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Maxine C Lintern ◽  
Janet R Wetherell ◽  
Margaret E Smith
Keyword(s):  
Enzyme Activity ◽  
Time Course ◽  
Brain Regions ◽  
Similar Rate ◽  
Molecular Forms ◽  
Similar Degree ◽  
Brain Areas ◽  
Pig Muscle ◽  
Rate Of Recovery ◽  
The Brain

1 In brain areas of untreated guinea-pigs the highest activity of acetylcholinesterase was seen in the striatum and cerebellum, followed by the midbrain, medulla-pons and cortex, and the lowest in the hippocampus. The activity in diaphragm was sevenfold lower than in the hippocampus. 2 At 1 h after soman (27 mg/kg) administration the activity of the enzyme was dramatically reduced in all tissues studied. In muscle the three major molecular forms (A12, G4 and G1) showed a similar degree of inhibition and a similar rate of recovery and the activity had returned to normal by 7 days. 3 In the brain soman inhibited the G4 form more than the G1 form. The hippocampus, cortex and midbrain showed the greatest reductions in enzyme activity. At 7 days the activity in the cortex, medulla pons and striatum had recovered but in the hippocampus, midbrain and cerebellum it was still inhibited. 4 Thus the effects of soman administration varied in severity and time course in the different tissues studied. However the enzyme activity was still reduced in all tissues at 24 h when the overt signs of poisoning had disappeared.

scholarly journals Recent developments in cognitive fMRI for temporal lobe epilepsy

2019 ◽  
Vol 33 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Victor Schmidbauer ◽  
Silvia Bonelli
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Visual Memory ◽  
Imaging Modality ◽  
Memory Function ◽  
Brain Regions ◽  
Epileptogenic Zone ◽  
Brain Areas ◽  
Recent Developments ◽  
The Brain

AbstractEpilepsy is frequently accompanied by severe cognitive side effects. Temporal lobe epilepsy (TLE), and even successful surgical treatment, may affect cognitive function, in particular language as well as verbal and visual memory function. Epilepsy arising from the temporal lobe can be controlled surgically in up to 70% of patients. The goals of epilepsy surgery are to remove the brain areas generating the seizures without causing or aggravating neuropsychological deficits. This requires accurate localization of the brain areas generating the seizures (“epileptogenic zone”) and the areas responsible for motor and cognitive functions, such as language and memory (“essential brain regions”) during presurgical evaluation. In the past decades, functional magnetic resonance imaging (fMRI) has been increasingly used to noninvasively lateralize and localize not only primary motor and somatosensory areas, but also brain areas that are involved in everyday language and memory processes. The imaging modality also shows potential for predicting the effects of temporal lobe resection on language and memory function. Together with other MRI modalities, cognitive fMRI is a promising tool to improve surgical strategies tailored to individual patients with regard to functional outcome, by virtue of definition of epileptic cerebral areas that need to be resected and eloquent areas that need to be spared.The aim of this review is to provide an overview of recent developments and practical recommendations for the clinical use of cognitive fMRI in TLE.

Music, Maestro, Please: Thalamic multisensory integration in music perception, processing and production

2019 ◽  
Vol 11 (2) ◽  
pp. 98
Author(s):  
Artur Jaschke
Keyword(s):  
Multisensory Integration ◽  
Music Perception ◽  
Initial Point ◽  
Initial Step ◽  
Brain Regions ◽  
Thalamic Nuclei ◽  
Brain Areas ◽  
Neural Connections ◽  
Parietal Lobes ◽  
The Brain

Music activates a wide array of brain areas involved in different functions such as   perception, processing and execution of music. Understanding musical processes in the brain has multiple implications in the neuro- and health sciences.  Challenging the brain with a multisensory stimulus such as music activates responses beyond the auditory cortex of the temporal lobe. Other areas that are involved include the frontal lobes, parietal lobes, areas of the limbic system such as the amygdala, hippocampus and thalamus, the cerebellum and the brainstem. Nonetheless, there has been no attempt to summarize all involved brain areas in music into one overall encompassing map. This may well be, as there has been no thorough theory introduced, which would allow an initial point of departure in creating such a mapTherefore, a thorough systematic review has been conducted to identify all mentioned neural connections involved in the perception, processing and execution of music.  Communication between the thalamic nuclei is the initial step in multisensory integration, which lies at the base of the neural networks as proposed in this paper. Against this background, this manuscript introduces the to our knowledge first map of all brain regions involved in the perception, processing and execution of music.Consequently, placing thalamic multisensory integration at the core of this atlas allowed us to create a preliminary theory to explain the complexity of music induced brain activation.

scholarly journals Effect of Brightness of Visual Stimuli on EEG Signals

2019 ◽  
Author(s):  
Kübra Eroğlu ◽  
Temel Kayıkçıoğlu ◽  
Onur Osman
Keyword(s):  
Visual Processing ◽  
Time Window ◽  
Time Windows ◽  
Visual Stimuli ◽  
Average Power ◽  
Power Spectra ◽  
Brain Regions ◽  
Behavioral Data ◽  
Brain Responses ◽  
The Brain

The aim of this study was to examine brightness effect, which is the perceptual property of visual stimuli, on brain responses obtained during visual processing of these stimuli. For this purpose, brain responses of the brain to changes in brightness were explored comparatively using different emotional images (pleasant, unpleasant and neutral) with different luminance levels. Moreover, electroencephalography recordings from 12 different electrode sites of 31 healthy participants were used. The power spectra obtained from the analysis of the recordings using short time Fourier transform were analyzed, and a statistical analysis was performed on features extracted from these power spectra. Statistical findings obtained from electrophysiological data were compared with those obtained from behavioral data. The results showed that the brightness of visual stimuli affected the power of brain responses depending on frequency, time and location. According to the statistically verified findings, the distinctive effect of brightness occurred in the parietal and occipital regions for all the three types of stimuli. Accordingly, the increase in the brightness of pleasant and neutral images increased the average power of responses in the parietal and occipital regions whereas the increase in the brightness of unpleasant images decreased the average power of responses in these regions. However, the increase in brightness for all the three types of stimuli reduced the average power of frontal and central region responses (except for 100-300 ms time window for unpleasant stimuli). The statistical results obtained for unpleasant images were found to be in accordance with the behavioral data. The results also revealed that the brightness of visual stimuli could be represented by changing the activity power of the brain cortex. The main contribution of this research was to comprehensively examine brightness effect on brain activity for images with different emotional content and different frequency bands at different time windows of visual processing for different brain regions. The findings emphasized that the brightness of visual stimuli should be viewed as an important parameter in studies using emotional image techniques such as image classification, emotion evaluation and neuro-marketing.

scholarly journals A Core Set of Brain Regions Helps Kids Achieve Their Goals

2021 ◽  
Vol 9 ◽  
Author(s):  
AnnaCarolina Garza ◽  
Alice Aizza ◽  
Janchira K. Charoenworawat ◽  
Jessica A. Church
Keyword(s):  
Young People ◽  
Executive Functions ◽  
Brain Regions ◽  
Simple Games ◽  
Brain Areas ◽  
Core Set ◽  
The Brain

Your brain is always adjusting to the changing swirl of activities and interactions you have every day. Every time you accomplish a goal, you are exercising what are called the brain’s executive functions. These skills include resisting impulses, switching between tasks, and updating information in your memory. We asked whether these different skills relied on the same brain areas, and whether young people used the same brain areas as adults. We took pictures of kids’ and teens’ brains to see which areas of the brain they were using while they played three simple games related to these executive functions. We found that youth used similar brain regions to adults while playing the three games, and that many parts of the brain were used across all three games. These results help us understand how kids use their brains to be successful and how these skills develop.

Prediction of Resting-State EEG Using High-Dimensional Patterns

2013 ◽  
Vol 421 ◽  
pp. 528-533
Author(s):  
Hua Chin Lee ◽  
Li Wei Ko ◽  
Kuan Lin Lai ◽  
Hui Ling Huang ◽  
Meng Shue Song ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Region ◽  
Feature Selection Method ◽  
Brain Regions ◽  
Selection Method ◽  
High Dimensional ◽  
Prediction System ◽  
Medical Database ◽  
Class Prediction ◽  
The Brain

Prediction of resting-state electroencephalography (EEG) usinghigh-dimensional pattern is a challenge due to the uniqueness of each persons brainwave. This study uses the headache EEG recording as the example, and predicts the informative different states by using an intelligent feature selection method. Vomiting and nausea are usually appeared in headache attacks, andit is sensitive to light, sound, or movement. In this study, we use the EEG recording with four classes (inter-headache, pre-headache, headache and post-headache) as the medical database. This study focuses three merits: First, we establish two balanced datasets which contain 2-class (inter-headache and headache) and 4-class brainwave datasets from the original imbalanced headache database so that there is no bias of the prediction system. The 2-class dataset consists of 22 subjects and 176 trials, and the 4-class dataset consists of 40 subjects and 320 trials. Secondly, we propose an efficient SVM-based method for predicting the headache attacks from the EEGby using an inheritable bi-objective combinatorial genetic algorithm (IBCGA). IBCGA automatically selects important features from the brainwave, and the 2-class prediction accuracy of leave-one-trial-out independenttest is 81.25%. Third, from the analysis of the brain region and channel frequency, the brain region T4 is the most important brain regions and alpha and beta frequencies are the most informative frequencies.

ELISA Evaluation of Tau Accumulation in the Brains of Patients with Alzheimer Disease

2021 ◽  
Author(s):  
Mitsuru Shinohara ◽  
Junko Hirokawa ◽  
Akemi Shimodaira ◽  
Yoshitaka Tashiro ◽  
Kaoru Suzuki ◽  
...  
Keyword(s):  
Alzheimer Disease ◽  
Brain Regions ◽  
Insoluble Fraction ◽  
The Other ◽  
Disease Stage ◽  
Brain Areas ◽  
Postmortem Brains ◽  
Biochemical Level ◽  
The Brain ◽  
Control Samples

Abstract Despite the routine use of sandwich enzyme-linked immunosorbent assays (ELISAs) for quantifying tau levels in CSF and plasma, tau accumulations in the brains of patients with Alzheimer disease (AD) have rarely been evaluated by this method. Thus, by introducing several tau ELISAs that target different epitopes, we evaluated accumulated tau levels in postmortem brains depending on disease stage, brain areas, and other AD-related changes. Notably, tau levels in insoluble fraction determined by each ELISAs differ depending on the epitopes of antibodies: non-AD control samples yield relatively high signals when an antibody against the N-terminal region of tau is used. On the other hand, ELISAs combining antibodies against the later-middle to C-terminal regions of tau produced substantially increased signals from AD samples, compared to those from non-AD controls. Such ELISAs better distinguish AD and non-AD controls, and the results are more closely associated with Braak neurofibrillary tangles stage, Aβ accumulation, and glial markers. Moreover, these ELISAs can reflect the pattern of tau spread across brain regions. In conclusion, Tau ELISAs that combine antibodies against the later-middle to C-terminal regions of tau can better reflect neuropathological tau accumulation, which would enable to evaluate tau accumulation in the brain at a biochemical level.

scholarly journals Imbalanced Dopaminergic Transmission Mediated by Serotonergic Neurons in L-DOPA-Induced Dyskinesia

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Sylvia Navailles ◽  
Philippe De Deurwaerdère
Keyword(s):  
Brain Regions ◽  
Term Treatment ◽  
Serotonergic Neurons ◽  
Brain Areas ◽  
Dopaminergic Transmission ◽  
The Core ◽  
Long Term Treatment ◽  
The Brain ◽  
Serotonergic Innervation

L-DOPA-induced dyskinesias (LIDs) are one of the main motor side effects of L-DOPA therapy in Parkinson's disease. The review will consider the biochemical evidence indicating that the serotonergic neurons are involved in the dopaminergic effects of L-DOPA in the brain. The consequences are an ectopic and aberrant release of dopamine that follows the serotonergic innervation of the brain. After mid- to long-term treatment with L-DOPA, the pattern of L-DOPA-induced dopamine release is modified. In several brain regions, its effect is dramatically reduced while, in the striatum, its effect is quite preserved. LIDs could appear when the dopaminergic effects of L-DOPA fall in brain areas such as the cortex, enhancing the subcortical impact of dopamine and promoting aberrant motor responses. The consideration of the serotonergic system in the core mechanism of action of L-DOPA opens an important reserve of possible strategies to limit LIDs.

scholarly journals Beat Detection Recruits the Visual Cortex in Early Blind Subjects

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 296
Author(s):  
Rodrigo Araneda ◽  
Sandra Silva Moura ◽  
Laurence Dricot ◽  
Anne G. De Volder
Keyword(s):  
Brain Plasticity ◽  
Brain Activity ◽  
Sensory Modality ◽  
Brain Regions ◽  
Rhythm Perception ◽  
Brain Areas ◽  
Sensory Modalities ◽  
Beat Detection ◽  
The Brain ◽  
Early Blindness

Using functional magnetic resonance imaging, here we monitored the brain activity in 12 early blind subjects and 12 blindfolded control subjects, matched for age, gender and musical experience, during a beat detection task. Subjects were required to discriminate regular (“beat”) from irregular (“no beat”) rhythmic sequences composed of sounds or vibrotactile stimulations. In both sensory modalities, the brain activity differences between the two groups involved heteromodal brain regions including parietal and frontal cortical areas and occipital brain areas, that were recruited in the early blind group only. Accordingly, early blindness induced brain plasticity changes in the cerebral pathways involved in rhythm perception, with a participation of the visually deprived occipital brain areas whatever the sensory modality for input. We conclude that the visually deprived cortex switches its input modality from vision to audition and vibrotactile sense to perform this temporal processing task, supporting the concept of a metamodal, multisensory organization of this cortex.

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