Increased Information Transmission Research Articles

Adaptation of retinal discriminability to natural scenes.

Sensory systems discriminate stimuli to direct behavioral choices, a process governed by two distinct properties - neural sensitivity to specific stimuli, and stochastic properties that importantly include neural correlations. Two questions that have received extensive investigation and debate are whether visual systems are optimized for natural scenes, and whether noise correlations contribute to this optimization. However, the lack of sufficient computational models has made these questions inaccessible in the context of the normal function of the visual system, which is to discriminate between natural stimuli. Here we take a direct approach to analyze discriminability under natural scenes for a population of salamander retinal ganglion cells using a model of the retinal neural code that captures both sensitivity and stochasticity. Using methods of information geometry and generative machine learning, we analyzed the manifolds of natural stimuli and neural responses, finding that discriminability in the ganglion cell population adapts to enhance information transmission about natural scenes, in particular about localized motion. Contrary to previous proposals, noise correlations reduce information transmission and arise simply as a natural consequence of the shared circuitry that generates changing spatiotemporal visual sensitivity. These results address a long-standing debate as to the role of retinal correlations in the encoding of natural stimuli and reveal how the highly nonlinear receptive fields of the retina adapt dynamically to increase information transmission under natural scenes by performing the important ethological function of local motion discrimination.

Eye movement intervention facilitates concurrent perception and memory processing.

A widely used psychotherapeutic treatment for post-traumatic stress disorder (PTSD) involves performing bilateral eye movement (EM) during trauma memory retrieval. However, how this treatment-described as eye movement desensitization and reprocessing (EMDR)-alleviates trauma-related symptoms is unclear. While conventional theories suggest that bilateral EM interferes with concurrently retrieved trauma memories by taxing the limited working memory resources, here, we propose that bilateral EM actually facilitates information processing. In two EEG experiments, we replicated the bilateral EM procedure of EMDR, having participants engaging in continuous bilateral EM or receiving bilateral sensory stimulation (BS) as a control while retrieving short- or long-term memory. During EM or BS, we presented bystander images or memory cues to probe neural representations of perceptual and memory information. Multivariate pattern analysis of the EEG signals revealed that bilateral EM enhanced neural representations of simultaneously processed perceptual and memory information. This enhancement was accompanied by heightened visual responses and increased neural excitability in the occipital region. Furthermore, bilateral EM increased information transmission from the occipital to the frontoparietal region, indicating facilitated information transition from low-level perceptual representation to high-level memory representation. These findings argue for theories that emphasize information facilitation rather than disruption in the EMDR treatment.

Collective sensing in electric fish.

A number of organisms, including dolphins, bats and electric fish, possess sophisticated active sensory systems that use self-generated signals (for example, acoustic or electrical emissions) to probe the environment1,2. Studies of active sensing in social groups have typically focused on strategies for minimizing interference from conspecific emissions2-4. However, it is well known from engineering that multiple spatially distributed emitters and receivers can greatly enhance environmental sensing (for example, multistatic radar and sonar)5-8. Here we provide evidence from modelling, neural recordings and behavioural experiments that the African weakly electric fish Gnathonemus petersii utilizes the electrical pulses of conspecifics to extend its electrolocation range, discriminate objects and increase information transmission. These results provide evidence for a new, collective mode of active sensing in which individual perception is enhanced by the energy emissions of nearby group members.

Shared input and recurrency in neural networks for metabolically efficient information transmission.

Shared input to a population of neurons induces noise correlations, which can decrease the information carried by a population activity. Inhibitory feedback in recurrent neural networks can reduce the noise correlations and thus increase the information carried by the population activity. However, the activity of inhibitory neurons is costly. This inhibitory feedback decreases the gain of the population. Thus, depolarization of its neurons requires stronger excitatory synaptic input, which is associated with higher ATP consumption. Given that the goal of neural populations is to transmit as much information as possible at minimal metabolic costs, it is unclear whether the increased information transmission reliability provided by inhibitory feedback compensates for the additional costs. We analyze this problem in a network of leaky integrate-and-fire neurons receiving correlated input. By maximizing mutual information with metabolic cost constraints, we show that there is an optimal strength of recurrent connections in the network, which maximizes the value of mutual information-per-cost. For higher values of input correlation, the mutual information-per-cost is higher for recurrent networks with inhibitory feedback compared to feedforward networks without any inhibitory neurons. Our results, therefore, show that the optimal synaptic strength of a recurrent network can be inferred from metabolically efficient coding arguments and that decorrelation of the input by inhibitory feedback compensates for the associated increased metabolic costs.

Building an Urban Smart Community System Based on Association Rule Algorithms

Intelligent system development is an integral component of smart community development and has a significant impact on the development of smart communities. Some cities continue to implement personalized smart community services, resulting in the formation of smart city communities with unique characteristics. Urban smart communities are based on the principle of owner-occupant convenience, integrating a wealth of community information and making it more relevant to each and every resident through intelligent management. Increasing information transmission rates have enhanced the ability of smart community systems to integrate information, but the smart community recommendation method is still based on traditional categorized recommendations. This paper addresses the deficiency of recommended information in smart urban communities. By analyzing user interaction and operation data, we can determine the interest and recognition of browsing attractions among users. Compared to conventional classification recommendations, weighted association rules can identify potentially very important rules applicable to small groups, thereby meeting the needs of various groups and enabling personalized services. Through continuous feedback from user behavior data, the system gradually identifies the community information that users are interested in during the specific recommendation process. After testing, the smart community system’s recommendation accuracy and real-time performance have vastly improved in comparison to categorical recommendations, and it can effectively meet the needs of tenants for community recommendations.

The impact of digital technology development on carbon emissions: A spatial effect analysis for China

We investigate the influence of digital technology development on carbon emissions in the framework of spatial analysis. Using a sample of 283 prefecture-level cities in China, we find that digital technology development can positively influence carbon abatement through the “spillover effect”, that is, it can not only reduce local carbon emissions, but also promote carbon abatement in the surrounding cities. The “siphon effect” which could negatively affect carbon abatement in the surrounding cities is outweighed by the “spillover effect”. In addition, due to increasing information transmission costs and local protectionism, the “spillover effect” of digital technology development on carbon emissions has geographical boundaries. Although no economic boundary is found, there exists an optimal economic distance interval. Furthermore, the heterogeneous analysis shows that government intervention would reduce the carbon abatement effect of digital technology development. Compared with the eastern cities, this negative impact is more significant in the central and western cities of China. Our results suggest that governments could achieve the dual goals of digital technology development and carbon abatement by promoting regional cooperation, and reducing local protectionism and administrative divisions.

Psychophysical Studies of Interleaving Narrowband Tactile Stimuli to Achieve Broadband Perceptual Effects

Despite the ubiquitous presence of tactile actuators (tactors) in mobile devices, there is a continuing need for more advanced tactors that can cover the entire frequency range of human tactile perception. Broadband tactors can increase information transmission and enrich sensory experience. The engineering challenges are multifold in that the ideal tactors should exhibit an effective bandwidth of at least 300 Hz, small form factor, robustness, power efficiency and low cost. For wearable applications, there are the additional challenges of ease of mounting and maintaining adequate skin contact during body movements. We propose an approach to interleave narrowband tactile stimuli to achieve broadband effects, taking advantage of the limited spatial resolution of the skin on the torso and limbs. Three psychophysical experiments were conducted to assess the validity of this approach. Participants performed pairwise discriminations of two broadband stimuli delivered using one or two tactors. The broadband stimuli consisted of one mid-frequency and one high-frequency component delivered through one tactor by mixing the two components, or through two tactors (one component per tactor). The first two experiments revealed extraneous cues such as localization and mutual masking of mid- and high-frequency components that were subsequently eliminated in the third experiment. Results from 12 participants confirmed that performance on pairwise comparisons was below the discrimination threshold, confirming that broadband haptic effects can be achieved through narrowband tactors placed within the skin’s two-point limen.

Synchronous inhibitory pathways create both efficiency and diversity in the retina

Sensory receptive fields combine features that originate in different neural pathways. Retinal ganglion cell receptive fields compute intensity changes across space and time using a peripheral region known as the surround, a property that improves information transmission about natural scenes. The visual features that construct this fundamental property have not been quantitatively assigned to specific interneurons. Here, we describe a generalizable approach using simultaneous intracellular and multielectrode recording to directly measure and manipulate the sensory feature conveyed by a neural pathway to a downstream neuron. By directly controlling the gain of individual interneurons in the circuit, we show that rather than transmitting different temporal features, inhibitory horizontal cells and linear amacrine cells synchronously create the linear surround at different spatial scales and that these two components fully account for the surround. By analyzing a large population of ganglion cells, we observe substantial diversity in the relative contribution of amacrine and horizontal cell visual features while still allowing individual cells to increase information transmission under the statistics of natural scenes. Established theories of efficient coding have shown that optimal information transmission under natural scenes allows a diverse set of receptive fields. Our results give a mechanism for this theory, showing how distinct neural pathways synthesize a sensory computation and how this architecture both generates computational diversity and achieves the objective of high information transmission.

Task-Space Trajectory Tracking Control for Coordinated Manipulation Using Sampled Coupling Data

This letter studies the task-space synchronization control problem of networked manipulators which are commanded to track the desired task-space trajectories to achieve the coordinated manipulation transportation tasks in industrial and logistic applications. To guarantee the practical applicability and increase information transmission efficiency, sampled data-coupling strategy is utilized and the transmission delays as well as dynamics uncertainties are modelled explicitly. Firstly, the discrete-time-style synchronization error with sampled data is transferred into an equivalent continuous-time version with time-varying communication delays. Secondly, a distributed task-space tracking control law is presented based on the dynamic model by introducing the task-space end-position synchronization error for coordinated manipulation tasks of networked manipulators. Thirdly, a sufficient condition is derived from the Lyapunov-Krasovskii stability analysis approach to ensure the convergence of the dynamic control of each manipulator. By solving the proposed condition, the upper bound of the acceptable sampling period can be calculated. Simulational experiment results on a group of PUMA560 manipulators validate the task-space trajectory tracking performance, end-position synchronization performance and robustness to external force interference of the multiple-manipulator systems. To the best knowledge of the authors, this is the first letter which resolves the task-space tracking control of coordinated manipulators in the presence of coupling data sampling, transmission delays and dynamics model uncertainties.

How inhibitory neurons increase information transmission under threshold modulation.

SUMMARYModulation of neuronal thresholds is ubiquitous in the brain. Phenomena such as figure-ground segmentation, motion detection, stimulus anticipation, and shifts in attention all involve changes in a neuron’s threshold based on signals from larger scales than its primary inputs. However, this modulation reduces the accuracy with which neurons can represent their primary inputs, creating a mystery as to why threshold modulation is so widespread in the brain. We find that modulation is less detrimental than other forms of neuronal variability and that its negative effects can be nearly completely eliminated if modulation is applied selectively to sparsely responding neurons in a circuit by inhibitory neurons. We verify these predictions in the retina where we find that inhibitory amacrine cells selectively deliver modulation signals to sparsely responding ganglion cell types. Our findings elucidate the central role that inhibitory neurons play in maximizing information transmission under modulation.

Guaxi and financial exclusion: Empirical evidence from households in China

The world has attached great importance to the development of inclusive finance. As the most populous country, the promotion of inclusive finance in China is crucial to the realization of global financial inclusion. Guanxi, translated as social relations, is the core structure of Chinese society. Whether and how Guanxi affects financial exclusion has attracted special attention. Using data from the China Household Finance Survey (CHFS) in 2017, this study found Guanxi has a significantly negative impact on household financial exclusion, and the impact on liability financial exclusion is greater than that on asset financial exclusion. This study also shows that Guanxi will promote household participation in financial markets by increasing information transmission and knowledge dissemination and reducing the probability of asset financial exclusion. Guanxi could alleviate liability financial exclusion by facilitating information transmission, providing soft information and guarantees.

Single-Cell Information Analysis Reveals That Skeletal Muscles Incorporate Cell-to-Cell Variability as Information Not Noise

Cell-to-cell variability in signal transduction in biological systems is often considered noise. However, intercellular variation (i.e., cell-to-cell variability) has the potential to enable individual cells to encode different information. Here, we show that intercellular variation increases information transmission of skeletal muscle. We analyze the responses of multiple cultured myotubes or isolated skeletal muscle fibers as a multiple-cell channel composed of single-cell channels. We find that the multiple-cell channel, which incorporates intercellular variation as information, not noise, transmitted more information in the presence of intercellular variation than in the absence according to the "response diversity effect," increasing in the gradualness of dose response by summing the cell-to-cell variable dose responses. We quantify the information transmission of human facial muscle contraction during intraoperative neurophysiological monitoring and find that information transmission of muscle contraction is comparable to that of a multiple-cell channel. Thus, our data indicate that intercellular variation can increase the information capacity of tissues.

Orbital angular momentum multiplexed deterministic all-optical quantum teleportation

Quantum teleportation is one of the most essential protocol in quantum information. In addition to increasing the scale of teleportation distance, improving its information transmission capacity is also vital importance for its practical applications. Recently, the orbital angular momentum (OAM) of light has attracted wide attention as an important degree of freedom for realizing multiplexing to increase information transmission capacity. Here we show that by utilizing the OAM multiplexed continuous variable entanglement, 9 OAM multiplexed channels of parallel all-optical quantum teleportation can be deterministically established in experiment. More importantly, our parallel all-optical quantum teleportation scheme can teleport OAM-superposition-mode coded coherent state, which demonstrates the teleportation of more than one optical mode with fidelity beating the classical limit and thus ensures the increase of information transmission capacity. Our results open the avenue for deterministically implementing parallel quantum communication protocols and provide a promising paradigm for constructing high-capacity all-optical quantum communication networks.

Methodology for Maximizing Information Transmission of Haptic Devices: A Survey

This is a survey article on the information transmission capability of haptic devices and ways of maximizing it. It is intended for readers who are engineering professionals interested in developing novel haptic interfaces for a variety of applications but are not necessarily trained in haptic science or human user research. We posit that the ultimate goal of any interface is the exchange of information between a machine and a user, and as such, the evaluation should involve estimating the information-transmission capability with human users. We conducted a literature survey on studies of haptic devices evaluated with human users using an information theoretic framework. Our goal was to discover and summarize best practices that can lead to high information transmission. The results confirmed findings from our own previous studies, uncovered new ways to effectively increase information transmission, and pointed to the need for broader dissemination of proper experimental methodology. We, therefore, present a concise yet comprehensive tutorial on psychophysical methodology for estimating information transfer (IT) and IT rate with humans, survey results on the typical IT achievable with haptic devices, and guidelines for maximizing information transmission with any human–machine interfaces. Although we focus on haptic systems, the information-theoretic framework, the psychophysical methods, and the guidelines presented in this article are applicable to other sensory modalities and multimodal interface systems also.

Visual and Action-control Expressway Associated with Efficient Information Transmission in Elite Athletes

Effective information transmission for open skill performance requires fine-scale coordination of distributed networks of brain regions linked by white matter tracts. However, how patterns of connectivity in these anatomical pathways may improve global efficiency remains unclear. In this study, we hypothesized that the feeder edges in visual and motor systems have the potential to become “expressways” that increase the efficiency of information communication across brain networks of open skill experts. Thirty elite athletes and thirty novice subjects were recruited to participate in visual tracking and motor imagery tasks. We collected structural imaging data from these subjects, and then resolved structural neural networks using deterministic tractography to identify streamlines connecting cortical and subcortical brain regions of each participant. We observed that superior skill performance in elite athletes was associated with increased information transmission efficiency in feeder edges distributed between orbitofrontal and basal ganglia modules, as well as among temporal, occipital, and limbic system modules. These findings suggest that there is an expressway linking visual and action-control system of skill experts that enables more efficient interactions of peripheral and central information in support of effective performance of an open skill.

Signal Propagation and Analysis in Wireless Underground Sensor Networks

The most challenging issue in the design of wireless sensor networks for the application of localization in the underground environment, mostly for miner’s location, is the sensor nodes’ energy consumption, efficiency and communication. Underground Wireless Sensor Networks are active and promising area of application of Wireless Sensor Networks (WSNs), whereby sensor nodes perform sensing duties in the underground environment. Most of the communication techniques used in the underground environment experience a high path loss and hence, hinders the range needed for transmission. However, the available option to increase information transmission is to increase the transmission power which needs large size of apparatus which is also limited in the underground. To solve the mentioned problems, this paper proposed a Magnetic Induction based Pulse Power. Analytical results of the Magnetic Induction based Pulse Power with an ordinary magnetic induction communication technique show an improvement in Signal-to-Noise Ratio (SNR) and path loss with variation in distance between nodes and frequency of operation. This paper further formulates a nonlinear program to determine the optimal data (events) extraction in a grid based WUSNs.

Negative feedback increases information transmission, enabling bacteria to discriminate sublethal antibiotic concentrations.

In the cell, noise constrains information transmission through signaling pathways and regulatory networks. There is growing evidence that the channel capacity of cellular pathways is limited to a few bits, questioning whether cells quantify external stimuli or rely on threshold detection and binary on/off decisions. Here, using fluorescence microscopy and information theory, we analyzed the ability of the transcriptional regulator TetR to sense and quantify the antibiotic tetracycline. The results showed that noise filtering by negative feedback increased information transmission up to 2 bits, generating a graded response able to discriminate different antibiotic concentrations. This response matched the antibiotic subinhibitory selection window, suggesting that information transmission through TetR is optimized to quantify sublethal antibiotic levels. Noise filtering by negative feedback may thus boost the discriminative power of cellular sensors, enabling signal quantification.

Habitat complexity and predictability effects on finding and collecting food when ants search as cooperative groups

Cooperatively foraging groups have two sequential goals: to find food and thereafter efficiently exploit or retrieve it. Previous research has largely focused on searching behaviours of individuals or organization of food retrieval processes, rather than on how groups initially distribute themselves to find ephemeral food items that are unpredictable in time and space. In the present study, we examined how Argentine ants, Linepithema humile, search environments in anticipation of food appearing briefly in areas with differing spatial complexity. Nests were connected to three foraging arenas containing 1, 9 or 25 cells. Food appeared briefly in one cell each day, either randomly or more predictably in distant cells (but equally often in each arena). We recorded the number of ants in cells when food had not been recently present, and thereafter whether ants successfully located the food when presented. Surprisingly, as food location became more predictable, ants found it less frequently. Foragers were located more often in cells closer to the nest (i.e. at information ‘choke points’ that returning foragers needed to traverse), and in cells with higher connectivity and greater centralness within foraging arenas. Such distributions reduce search coverage area but likely increase information transmission. Thus, it appears that L. humile foragers distribute themselves to favour rapid recruitment when food is found rather than maximizing food encounter rates. Although the reduced foraging success with more predictably located food suggests that ants did not adjust expectations in a Bayesian manner within arenas towards individual cells, they did appear Bayesian across arenas. Because foragers missed food more often in higher-complexity arenas than in lower-complexity arenas, this could increase perceptions that the latter are more rewarding. Shifts in distributions were consistent with such biased perceptions. Future studies to determine whether other group-foraging species use analogous solutions would be highly useful.

Noise Gated by Dendrosomatic Interactions Increases Information Transmission

Brains process information reliably despite the presence of noise introduced by their molecular machinery. New computer simulations of neurons show that these cells might use noise to their advantage by employing dendrites to detect low-intensity signals and using the main cell body to process more powerful signals.

NANOMATERIALS AND OPTOELECTRONICS IN HIGH-SPEED COMMUNICATION SYSTEMS

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The article considers issues concerning increase in capacity of fiber-optic systems used on railways. The main directions of increasing information transmission speed are reviewed and analyzed, particularly enhancement of high-speed response of optical modulators and photodetectors through improving functional environment of optoelectronic devices and reducing inertia of the material. For this purpose, new materials are proposed in the form of multilayer nanostructures, along with manufacturing techniques and methods of assessing their quality characteristics required for design of new optoelectronic devices, that will positively affect railway communication systems’ performance. Keywords: railways, communication channels, information network, isotope effect, bandwidth, nanostructure, fiber-optic system, optoelectronic devices.