keyword
MENU ▼
Read by QxMD icon Read
search

neural coding

keyword
https://www.readbyqxmd.com/read/28227738/tuning-electrical-stimulation-for-thalamic-visual-prosthesis-an-autoencoder-based-approach
#1
Amr Jawwad, Hossam H Abolfotuh, Bassem Abdullah, Hani M K Mahdi, Seif Eldawlatly, Amr Jawwad, Hossam H Abolfotuh, Bassem Abdullah, Hani M K Mahdi, Seif Eldawlatly, Amr Jawwad, Hani M K Mahdi, Bassem Abdullah, Seif Eldawlatly, Hossam H Abolfotuh
Visual prosthesis holds hope of vision restoration for millions with retinal degenerative diseases. Machine learning techniques such as artificial neural networks could help in improving prosthetic devices as they could learn how the brain encodes information and imitate that code. This paper introduces an autoencoder-based approach for tuning thalamic visual prostheses. The objective of the proposed approach is to estimate electrical stimuli that are equivalent to a given natural visual stimulus, in a way such that they both elicit responses that are as similar as possible when introduced to a Lateral Geniculate Nucleus (LGN) population...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227266/dictionary-learning-for-sparse-representation-and-classification-of-neural-spikes
#2
Ahmed H Dallal, Yiran Chen, Douglas Weber, Zhi-Hong Mao, Ahmed H Dallal, Yiran Chen, Douglas Weber, Zhi-Hong Mao, Douglas Weber, Zhi-Hong Mao, Yiran Chen, Ahmed H Dallal
Spike sorting is the problem of identifying and clustering neurons spiking activity from recorded extracellular electro-physiological data. This is important for experimental neuroscience. Existing approaches to solve this problem consist of three steps: spike detection, feature extraction, and clustering. In our method, we use Fisher discriminant based dictionary learning to learn dictionary, whose sub-dictionaries are class specific, and estimate discriminative sparse coding coefficients by minimizing the within class scatter and maximizing the between class scatter...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226816/neural-representation-of-different-mandarin-tones-in-the-inferior-colliculus-of-the-guinea-pig
#3
Fei Peng, Nan Xia, Xing Wang, Xiao L Zheng, Yi Zhou, Xing Y Fan, Wen S Hou, Fei Peng, Nan Xia, Xing Wang, Xiao L Zheng, Yi Zhou, Xing Y Fan, Wen S Hou, Xing Y Fan, Nan Xia, Wen S Hou, Xing Wang, Yi Zhou, Fei Peng, Xiao L Zheng
Mandarin speech has four different tones and the coding mechanism underlying tone identification still remain unclear. Here in the inferior colliculus (IC) of anesthetized guinea pigs, we recorded single neuron activities to one word with four tones using tungsten electrode. Peri-stimulus time histograms (PSTHs) and inter-spike-interval (ISI) were used to evaluate the neural response. The results showed that PSTHs grouped into frequency band reflected the spectrotemporal patterns of different tones; average population PSTHs matched envelops of different tones; and the peaks of histogram of ISIs in three time segments exhibited a displacement which reflected the profile of fundamental frequency (F0)...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226786/neural-decoding-of-code-modulated-visual-evoked-potentials-by-spatio-temporal-inverse-filtering-for-brain-computer-interfaces
#4
Jun-Ichi Sato, Yoshikazu Washizawa, Jun-Ichi Sato, Yoshikazu Washizawa, Jun-Ichi Sato, Yoshikazu Washizawa
This study addresses neural decoding of a code modulated visual evoked potentials (c-VEPs). c-VEP was recently developed, and applied to brain computer interfaces (BCIs). c-VEP BCI exhibits faster communication speed than existing VEP-based BCIs. In c-VEP BCI, the canonical correlation analysis (CCA) that maximizes the correlation between an averaged signal and single trial signals is often used for the spatial filter. However, CCA does not utilize information of given PN sequence, and hence, the filtered signal may not have properties of PN sequence...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28216125/population-responses-in-primary-auditory-cortex-simultaneously-represent-the-temporal-envelope-and-periodicity-features-in-natural-speech
#5
Daniel A Abrams, Trent Nicol, Travis White-Schwoch, Mitra Hartmann, Steven Zecker, Nina Kraus
Speech perception relies on a listener's ability to simultaneously resolve multiple temporal features in the speech signal. Little is known regarding neural mechanisms that enable the simultaneous coding of concurrent temporal features in the speech signal. Here we show that two categories of temporal features in speech, the low-frequency speech envelope and periodicity cues, are processed by distinct neural mechanisms within the same population of cortical neurons. We measured population activity in primary auditory cortex of anesthetized guinea pig in response to three variants of a naturally produced speech sentence...
February 16, 2017: Hearing Research
https://www.readbyqxmd.com/read/28209734/neural-representations-of-observed-actions-generalize-across-static-and-dynamic-visual-input
#6
Alon Hafri, John C Trueswell, Russell A Epstein
People interact with other people and with objects in distinct and categorizable ways (e.g., kicking is making contact with foot). We can recognize these action categories across variations in actors, objects, and settings; moreover, we can recognize them from both dynamic and static visual input. However, the neural systems that support action recognition across these perceptual differences are unclear. Here we used multivoxel pattern analysis of fMRI data to identify brain regions that support visual action categorization in a format-independent way...
February 16, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28207384/supervised-learning-of-semantics-preserving-hash-via-deep-convolutional-neural-networks
#7
Huei-Fang Yang, Kevin Lin, Chu-Song Chen
This paper presents a simple yet effective supervised deep hash approach that constructs binary hash codes from labeled data for large-scale image search. We assume that the semantic labels are governed by several latent attributes with each attribute on or off, and classification relies on these attributes. Based on this assumption, our approach, dubbed supervised semantics-preserving deep hashing (SSDH), constructs hash functions as a latent layer in a deep network and the binary codes are learned by minimizing an objective function defined over classification error and other desirable hash codes properties...
February 9, 2017: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/28203635/grounded-understanding-of-abstract-concepts-the-case-of-stem-learning
#8
REVIEW
Justin C Hayes, David J M Kraemer
Characterizing the neural implementation of abstract conceptual representations has long been a contentious topic in cognitive science. At the heart of the debate is whether the "sensorimotor" machinery of the brain plays a central role in representing concepts, or whether the involvement of these perceptual and motor regions is merely peripheral or epiphenomenal. The domain of science, technology, engineering, and mathematics (STEM) learning provides an important proving ground for sensorimotor (or grounded) theories of cognition, as concepts in science and engineering courses are often taught through laboratory-based and other hands-on methodologies...
2017: Cogn Res Princ Implic
https://www.readbyqxmd.com/read/28203609/zeb2-inhibiting-the-inhibitors-in-schwann-cells
#9
Bastian G Brinkmann, Susanne Quintes
Development of Schwann cells is tightly regulated by concerted action of activating and inhibiting factors. Most of the regulatory feedback loops identified to date are transcriptional activators promoting induction of genes coding for integral myelin proteins and lipids. The mechanisms by which inhibitory factors are silenced during Schwann cell maturation are less well understood. We could recently show a pivotal function for the transcription factor zinc finger E-box binding homeobox 2 (Zeb2) during Schwann cell development and myelination as a transcriptional repressor of maturation inhibitors...
2017: Neurogenesis (Austin, Tex.)
https://www.readbyqxmd.com/read/28202786/dopamine-modulates-adaptive-prediction-error-coding-in-the-human-midbrain-and-striatum
#10
Kelly M J Diederen, Hisham Ziauddeen, Martin D Vestergaard, Tom Spencer, Wolfram Schultz, Paul C Fletcher
Learning to optimally predict rewards requires agents to account for fluctuations in reward value. Recent work suggests that individuals can efficiently learn about variable rewards through adaptation of the learning rate, and coding of prediction errors relative to reward variability. Such adaptive coding has been linked to midbrain dopamine neurons in nonhuman primates, and evidence in support for a similar role of the dopaminergic system in humans is emerging from fMRI data. Here, we sought to investigate the effect of dopaminergic perturbations on adaptive prediction error coding in humans, using a between-subject, placebo-controlled pharmacological fMRI study with a dopaminergic agonist (bromocriptine) and antagonist (sulpiride)...
February 15, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28195187/sensory-augmentation-integration-of-an-auditory-compass-signal-into-human-perception-of-space
#11
Frank Schumann, J Kevin O'Regan
Bio-mimetic approaches to restoring sensory function show great promise in that they rapidly produce perceptual experience, but have the disadvantage of being invasive. In contrast, sensory substitution approaches are non-invasive, but may lead to cognitive rather than perceptual experience. Here we introduce a new non-invasive approach that leads to fast and truly perceptual experience like bio-mimetic techniques. Instead of building on existing circuits at the neural level as done in bio-mimetics, we piggy-back on sensorimotor contingencies at the stimulus level...
February 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28195037/generalizable-knowledge-outweighs-incidental-details-in-prefrontal-ensemble-code-over-time
#12
Mark D Morrissey, Nathan Insel, Kaori Takehara-Nishiuchi
Memories for recent experiences are rich in incidental detail, but with time the brain is thought to extract latent rules and structures common across past experiences. We show that over weeks following the acquisition of two distinct associative memories, neuron firing in the rat prelimbic prefrontal cortex (mPFC) became less selective for perceptual features unique to each association and, with an apparently different time-course, became more selective for common relational features. We further found that during exposure to a novel experimental context, memory expression and neuron selectivity for relational features immediately generalized to the new situation...
February 14, 2017: ELife
https://www.readbyqxmd.com/read/28193818/processing-of-single-photon-responses-in-the-mammalian-on-and-off-retinal-pathways-at-the-sensitivity-limit-of-vision
#13
Daisuke Takeshita, Lina Smeds, Petri Ala-Laurila
Visually guided behaviour at its sensitivity limit relies on single-photon responses originating in a small number of rod photoreceptors. For decades, researchers have debated the neural mechanisms and noise sources that underlie this striking sensitivity. To address this question, we need to understand the constraints arising from the retinal output signals provided by distinct retinal ganglion cell types. It has recently been shown in the primate retina that On and Off parasol ganglion cells, the cell types likely to underlie light detection at the absolute visual threshold, differ fundamentally not only in response polarity, but also in the way they handle single-photon responses originating in rods...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28188216/amygdalar-gating-of-early-sensory-processing-through-interactions-with-locus-coeruleus
#14
Cynthia D Fast, John P McGann
Fear- and stress-induced activity in the amygdala has been hypothesized to influence sensory brain regions through the amygdala's influence on neuromodulatory centers. To directly examine this relationship, we used optical imaging to observe odor-evoked activity in populations of olfactory bulb inhibitory interneurons and of synaptic terminals of olfactory sensory neurons (the olfactory system's primary sensory neurons, which provide the initial olfactory input to the brain) during pharmacological inactivation of amygdala and locus coeruleus (LC) in mice...
February 10, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28184188/stimulus-phase-locking-of-cortical-oscillations-for-rhythmic-tone-sequences-in-rats
#15
Takahiro Noda, Tomoki Amemiya, Tomoyo I Shiramatsu, Hirokazu Takahashi
Humans can rapidly detect regular patterns (i.e., within few cycles) without any special attention to the acoustic environment. This suggests that human sensory systems are equipped with a powerful mechanism for automatically predicting forthcoming stimuli to detect regularity. It has recently been hypothesized that the neural basis of sensory predictions exists for not only what happens (predictive coding) but also when a particular stimulus occurs (predictive timing). Here, we hypothesize that the phases of neural oscillations are critical in predictive timing, and these oscillations are modulated in a band-specific manner when acoustic patterns become predictable, i...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28182905/cracking-the-neural-code-for-sensory-perception-by-combining-statistics-intervention-and-behavior
#16
REVIEW
Stefano Panzeri, Christopher D Harvey, Eugenio Piasini, Peter E Latham, Tommaso Fellin
The two basic processes underlying perceptual decisions-how neural responses encode stimuli, and how they inform behavioral choices-have mainly been studied separately. Thus, although many spatiotemporal features of neural population activity, or "neural codes," have been shown to carry sensory information, it is often unknown whether the brain uses these features for perception. To address this issue, we propose a new framework centered on redefining the neural code as the neural features that carry sensory information used by the animal to drive appropriate behavior; that is, the features that have an intersection between sensory and choice information...
February 8, 2017: Neuron
https://www.readbyqxmd.com/read/28179553/mouth-and-voice-a-relationship-between-visual-and-auditory-preference-in-the-human-superior-temporal-sulcus
#17
Lin L Zhu, Michael S Beauchamp
Cortex in and around the human posterior superior temporal sulcus (pSTS) is known to be critical for speech perception. The pSTS responds to both the visual modality (especially biological motion) and the auditory modality (especially human voices). Using fMRI in single subjects with no spatial smoothing, we show that visual and auditory selectivity are linked. Regions of the pSTS were identified that preferred visually-presented moving mouths (presented in isolation or as part of a whole face) or moving eyes...
February 8, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28178266/accuracy-maximization-analysis-for-sensory-perceptual-tasks-computational-improvements-filter-robustness-and-coding-advantages-for-scaled-additive-noise
#18
Johannes Burge, Priyank Jaini
Accuracy Maximization Analysis (AMA) is a recently developed Bayesian ideal observer method for task-specific dimensionality reduction. Given a training set of proximal stimuli (e.g. retinal images), a response noise model, and a cost function, AMA returns the filters (i.e. receptive fields) that extract the most useful stimulus features for estimating a user-specified latent variable from those stimuli. Here, we first contribute two technical advances that significantly reduce AMA's compute time: we derive gradients of cost functions for which two popular estimators are appropriate, and we implement a stochastic gradient descent (AMA-SGD) routine for filter learning...
February 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28177571/optimizing-for-generalization-in-the-decoding-of-internally-generated-activity-in-the-hippocampus
#19
Matthijs A A van der Meer, Alyssa A Carey, Youki Tanaka
The decoding of a sensory or motor variable from neural activity benefits from a known ground truth against which decoding performance can be compared. In contrast, the decoding of covert, cognitive neural activity, such as occurs in memory recall or planning, typically cannot be compared to a known ground truth. As a result, it is unclear how decoders of such internally generated activity should be configured in practice. We suggest that if the true code for covert activity is unknown, decoders should be optimized for generalization performance using cross-validation...
February 8, 2017: Hippocampus
https://www.readbyqxmd.com/read/28174616/optimal-path-finding-through-mental-exploration-based-on-neural-energy-field-gradients
#20
Yihong Wang, Rubin Wang, Yating Zhu
Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed...
February 2017: Cognitive Neurodynamics
keyword
keyword
31719
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"