Improve Information Transmission Research Articles

Informational Lobbying and Pareto-Improving Agenda Constraint

Abstract Interest groups (IGs) lobby policymaker (PM) by offering verifiable, policy-relevant information. The PM is limited in (1) his ability to verify the information offered by the IGs (access constraint) and (2) the number of issues he can implement reform on (agenda constraint). We show that when there exists an access constraint but no agenda constraint, the equilibrium exhibits “overlobbying,” that is, an IG with unfavorable information may lobby hoping that, the PM, unable to verify the information, may take the costly act of lobbying as a signal of favorable information and therefore implement reform on its issue. We then show that the presence of an agenda constraint can improve information transmission by curbing overlobbying. We identify circumstances under which an agenda constraint improves the ex ante expected welfare of both the PM and of each IG, thereby generating a Pareto improvement. (JEL D72, D78, D83)

Lying to Speak the Truth: Selective Manipulation and Improved Information Transmission

We show that firms may benefit from allowing some earnings management, because it can make noisy signals more informative. We model a firm that cannot observe a manager's cost of effort, her effort choice, and whether she manipulated a publicly observable signal. An optimal contract links compensation to both the eventually realized firm value and the (possibly manipulated) signal, since both are noisy measures of effort provision. It may be optimal to allow for manipulation of the signal by a manager who exerted a high effort level: Doing so can convert a falsely unfavorable signal into a favorable signal, thereby strengthening the link between effort and compensation.

Locus coeruleus activation enhances thalamic feature selectivity via norepinephrine regulation of intrathalamic circuit dynamics.

We investigated locus coeruleus (LC) modulation of thalamic feature selectivity through reverse correlation analysis of single-unit recordings from different stages of the rat vibrissa pathway. LC activation increased feature selectivity, drastically improving thalamic information transmission. We found this improvement was dependent on both local activation of α-adrenergic receptors and modulation of T-type calcium channels in the thalamus and was not due to LC modulation of trigeminothalamic feedforward or corticothalamic feedback inputs. Tonic spikes with LC stimulation carried 3-times the information than did tonic spikes without LC stimulation. Modelling confirmed norepinephrine (NE) regulation of intrathalamic circuit dynamics led to the improved information transmission. Behavioral data demonstrated that LC activation increased the perceptual performance of animals performing tactile discrimination tasks through LC-NE optimization of thalamic sensory processing. These results suggest a new sub-dimension within the tonic mode in which brain state can optimize thalamic sensory processing through modulation of intrathalamic circuit dynamics.

Improving Information Transfer during Transitions of Care via Standardized Handoffs

Multiple studies have shown the detrimental effect of miscommunication during transitions of care. The aim of this study is to determine whether a certain method of "sign-out" can improve information transmission and thereby reduce medical errors. Surgical interns underwent a 90-minute training session before starting residency in five previously verified methods of sign-out. They were randomly assigned to six groups (five methods and a control group). They were then given seven simulated patient charts with varying levels of medical complexity. They were then instructed to "sign-out" the patients to randomly selected colleagues. The control group did not use any of the previously taught methods and passed on information in a manner of their choosing. None of the methods consistently results in excellent transitions of care. Patient information values ranged from 26 to 40 (depending on complexity). Major points were consistently missed by all methods, but this may have been a component of the time constraint placed on this study. The "SIGNOUT?" method resulted in superior data transmission when compared with the control group (P = 0.0401). The only method that seemed to be significantly inferior was the "9Ds" method (P = 0.0610). The "SIGNOUT?" method leads to the largest amount of relevant information transmitted to the incoming team. There was no statistically significant difference among the other methods. Improvement in "sign-out" modalities and training may improve transmission of relevant patient information, but larger studies are needed to verify the data seen in this small, single-site study.

Dial 911 for Murder: The Impact of Emergency Response Time on Homicides

Several theories have been offered to explain the recent declines in violent crime rates in the United States. We hypothesize that technological innovations, which improved information transmission and shortened the response time between an aggravated assault incident and treatment, reduced the cost of saving lives and caused much of the decline in homicide rates in recent decades. Using difference-in-differences and event studies, we show that improvements in emergency services (9-1-1) caused significant decreases in homicide rates. Various falsification tests support these findings.

Save Time, Save Lives: The Impact of 9-1-1 on the Lethality of Aggravated Assaults

Several theories have been offered to explain the recent declines in the lethality and homicide rates in the United States. We hypothesize that technological innovations, which improved information transmission and shortened the response time between an aggravated assault incident and treatment, reduced the cost of saving lives and caused much of the decline in lethality and homicide rates in recent decades. Using difference-in-differences and regression-discontinuity designs, we show that improvements in emergency services (9-1-1) caused significant decreases in lethality and homicide rates. Various placebo and falsification tests support these findings.

Overlobbying and Pareto-Improving Agenda Constraint

We develop a model of informational lobbying in which there are multiple issues and an uninformed policymaker must choose on each issue one of two policies, a reform or the status-quo. For each issue there is an informed interest group that favors the adoption of reform, and which can lobby the policymaker by offering to provide verifiable information about the state of the world for that issue. A key feature of our model is that the policymaker faces time/resource constraints which may restrict 1) his ability to grant access to and verify the information of all lobbying interest groups (i.e. an access constraint), and 2) his ability to implement reforms on all issues (i.e. an agenda constraint). We show that in the absence of the agenda constraint the act of lobbying by an interest group may signal information only imperfectly. In particular, an interest group may lobby the policymaker even when the state of the world is unfavorable in the hope that the policymaker is unable (due to the access constraint) to verify the information and yet implements the reform since he takes the act of lobbying as a signal that the state is favorable. We call such lobbying behavior 'overlobbying.' We then show that imposing an agenda constraint can eliminate overlobbying and thus improve information transmission. Importantly, we identify circumstances in which an agenda constraint improves the ex ante welfare of the policymaker as well as the interest groups, generating a Pareto improvement.

Dial 911 for Murder: The Impact of Emergency Response Time on Homicides

Several theories have been offered to explain the recent declines in violent crime rates in the United States. We hypothesize that technological innovations, which improved information transmission and shortened the response time between an aggravated assault incident and treatment, reduced the cost of saving lives and caused much of the decline in homicide rates in recent decades. Using difference-in-differences and event studies, we show that improvements in emergency services (9-1-1) caused significant decreases in homicide rates. Various falsification tests support these findings.

Research on Design and Implementation of Intelligent Warehouse Management System in Z Company

This paper aims at the practical problems of warehouse in Z enterprise, constructing the intelligent storage system, through the use of RFID technology, sensor technology, ZigBee technology to improve information transmission efficiency of the system, shortening the system response time. The paper solved the problem which the warehousing activities can’t be real-time controlled in the drawbacks of the product information in the warehouse.

Input nonlinearities can shape beyond-pairwise correlations and improve information transmission by neural populations

While recent recordings from neural populations show beyond-pairwise, or higher-order, correlations (HOC), we have little understanding of how HOC arise from network interactions and of how they impact encoded information. Here, we show that input nonlinearities imply HOC in spin-glass-type statistical models. We then discuss one such model with parametrized pairwise- and higher-order interactions, revealing conditions under which beyond-pairwise interactions increase the mutual information between a given stimulus type and the population responses. For jointly Gaussian stimuli, coding performance is improved by shaping output HOC only when neural firing rates are constrained to be low. For stimuli with skewed probability distributions (like natural image luminances), performance improves for all firing rates. Our work suggests surprising connections between nonlinear integration of neural inputs, stimulus statistics, and normative theories of population coding. Moreover, it suggests that the inclusion of beyond-pairwise interactions could improve the performance of Boltzmann machines for machine learning and signal processing applications.

Context-dependent coding and gain control in the auditory system of crickets.

Sensory systems process stimuli that greatly vary in intensity and complexity. To maintain efficient information transmission, neural systems need to adjust their properties to these different sensory contexts, yielding adaptive or stimulus-dependent codes. Here, we demonstrated adaptive spectrotemporal tuning in a small neural network, i.e. the peripheral auditory system of the cricket. We found that tuning of cricket auditory neurons was sharper for complex multi-band than for simple single-band stimuli. Information theoretical considerations revealed that this sharpening improved information transmission by separating the neural representations of individual stimulus components. A network model inspired by the structure of the cricket auditory system suggested two putative mechanisms underlying this adaptive tuning: a saturating peripheral nonlinearity could change the spectral tuning, whereas broad feed-forward inhibition was able to reproduce the observed adaptive sharpening of temporal tuning. Our study revealed a surprisingly dynamic code usually found in more complex nervous systems and suggested that stimulus-dependent codes could be implemented using common neural computations.

Optimizing information flow in small genetic networks. IV. Spatial coupling.

We typically think of cells as responding to external signals independently by regulating their gene expression levels, yet they often locally exchange information and coordinate. Can such spatial coupling be of benefit for conveying signals subject to gene regulatory noise? Here we extend our information-theoretic framework for gene regulation to spatially extended systems. As an example, we consider a lattice of nuclei responding to a concentration field of a transcriptional regulator (the input) by expressing a single diffusible target gene. When input concentrations are low, diffusive coupling markedly improves information transmission; optimal gene activation functions also systematically change. A qualitatively different regulatory strategy emerges where individual cells respond to the input in a nearly steplike fashion that is subsequently averaged out by strong diffusion. While motivated by early patterning events in the Drosophila embryo, our framework is generically applicable to spatially coupled stochastic gene expression models.

Orbital angular momentum (OAM) modes routing in a ring fiber based directional coupler

Optical modes carrying orbital angular momentum (OAM) are becoming a hot topic, for that it promises a greatly improved information transmission capacity for fiber-optic communication systems. In this paper, we report our study on the coupling characteristics (coupling length and power transfer behavior) of OAM modes routing in a ring fiber based directional coupler. We decomposed an OAM mode propagating along a ring fiber coupler into its corresponding HE even and odd modes using beam propagation method. We found a general description of OAM modes in a ring fiber based coupler, which provides useful information for further study of fiber components using OAM modes.

CP-049 Are pharmacist’s recommendations on drug compatibility applied by healthcare professionals? A randomised controlled study

BackgroundIn our institution, pharmacists advise healthcare professionals facing parenteral drug compatibility issues by answering questions via a hotline. Actual implementation of the verbal recommendations and transmission of the information among...

A strategic mediator who is biased in the same direction as the expert can improve information transmission

We model strategic mediation of the communication between an informed expert with a discrete type space and an uninformed decision maker. A strategic mediator can improve communication even when he is biased into the same direction as the expert.

Cross-Talk and Information Transfer in Mammalian and Bacterial Signaling

In mammalian and bacterial cells simple phosphorylation circuits play an important role in signaling. Bacteria have hundreds of two-component signaling systems that involve phosphotransfer between a receptor and a response regulator. In mammalian cells a similar pathway is the TGF-beta pathway, where extracellular TGF-beta ligands activate cell surface receptors that phosphorylate Smad proteins, which in turn activate many genes. In TGF-beta signaling the multiplicity of ligands begs the question as to whether cells can distinguish signals coming from different ligands, but transduced through a small set of Smads. Here we use information theory with stochastic simulations of networks to address this question. We find that when signals are transduced through only one Smad, the cell cannot distinguish between different levels of the external ligands. Increasing the number of Smads from one to two significantly improves information transmission as well as the ability to discriminate between ligands. Surprisingly, both total information transmitted and the capacity to discriminate between ligands are quite insensitive to high levels of cross-talk between the two Smads. Robustness against cross-talk requires that the average amplitude of the signals are large. We find that smaller systems, as exemplified by some two-component systems in bacteria, are significantly much less robust against cross-talk. For such system sizes phosphotransfer is also less robust against cross-talk than phosphorylation. This suggests that mammalian signal transduction can tolerate a high amount of cross-talk without degrading information content. This may have played a role in the evolution of new functionalities from small mutations in signaling pathways, allowed for the development of cross-regulation and led to increased overall robustness due to redundancy in signaling pathways. On the other hand the lack of cross-regulation observed in many bacterial two-component systems may partly be due to the loss of information content due to cross-talk.

Suprathreshold stochastic resonance in neural processing tuned by correlation

Suprathreshold stochastic resonance (SSR) is examined in the context of integrate-and-fire neurons, with an emphasis on the role of correlation in the neuronal firing. We employed a model based on a network of spiking neurons which received synaptic inputs modeled by Poisson processes stimulated by a stepped input signal. The smoothed ensemble firing rate provided an output signal, and the mutual information between this signal and the input was calculated for networks with different noise levels and different numbers of neurons. It was found that an SSR effect was present in this context. We then examined a more biophysically plausible scenario where the noise was not controlled directly, but instead was tuned by the correlation between the inputs. The SSR effect remained present in this scenario with nonzero noise providing improved information transmission, and it was found that negative correlation between the inputs was optimal. Finally, an examination of SSR in the context of this model revealed its connection with more traditional stochastic resonance and showed a trade-off between supratheshold and subthreshold components. We discuss these results in the context of existing empirical evidence concerning correlations in neuronal firing.

Nonrenewal spike train statistics: causes and functional consequences on neural coding.

Many neurons display significant patterning in their spike trains (e.g. oscillations, bursting), and there is accumulating evidence that information is contained in these patterns. In many cases, this patterning is caused by intrinsic mechanisms rather than external signals. In this review, we focus on spiking activity that displays nonrenewal statistics (i.e. memory that persists from one firing to the next). Such statistics are seen in both peripheral and central neurons and appear to be ubiquitous in the CNS. We review the principal mechanisms that can give rise to nonrenewal spike train statistics. These are separated into intrinsic mechanisms such as relative refractoriness and network mechanisms such as coupling with delayed inhibitory feedback. Next, we focus on the functional roles for nonrenewal spike train statistics. These can either increase or decrease information transmission. We also focus on how such statistics can give rise to an optimal integration timescale at which spike train variability is minimal and how this might be exploited by sensory systems to maximize the detection of weak signals. We finish by pointing out some interesting future directions for research in this area. In particular, we explore the interesting possibility that synaptic dynamics might be matched with the nonrenewal spiking statistics of presynaptic spike trains in order to further improve information transmission.

The gains from improved market efficiency: trade before and after the transatlantic telegraph

This article looks at the gains from improved market efficiency in long-distance grain trade in the second half of the nineteenth century, when violations of the law of one price were reduced due to improved information transmission. Two markets, a major export centre, Chicago, and a major importer, Liverpool, are analysed. We show that the law of one price equilibrium was an ‘attractor equilibrium’. The implication is that prices converged to that equilibrium in a tâtonnement process. Because of asymmetrically timed information between markets separated by long distances there were periods of excess demand as well as excess supply, which triggered off the tâtonnement process. Over time, adjustments to equilibrium, as measured by the half-life of a shock, became faster and violations of the law of one price become smaller. There were significant gains from improved market efficiency, which took place after the information ‘regime’ shifted from pre-telegraphic communication to a regime with swift transmission of information in an era that saw the development of a sophisticated commercial press and telegraphic communication. This article is the first attempt to actually measure the gains from improved market efficiency and it demonstrates that improved market efficiency probably stimulated trade more than falling transatlantic transport costs. Deadweight losses decline significantly as markets became more efficient. The conventional view that Harberger triangles are almost always insignificant is challenged.

Feature Selection in Simple Neurons: How Coding Depends on Spiking Dynamics

The relationship between a neuron's complex inputs and its spiking output defines the neuron's coding strategy. This is frequently and effectively modeled phenomenologically by one or more linear filters that extract the components of the stimulus that are relevant for triggering spikes and a nonlinear function that relates stimulus to firing probability. In many sensory systems, these two components of the coding strategy are found to adapt to changes in the statistics of the inputs in such a way as to improve information transmission. Here, we show for two simple neuron models how feature selectivity as captured by the spike-triggered average depends on both the parameters of the model and the statistical characteristics of the input.