ABSTRACT:The ethics of high frequency trading are obscure, due in part to the complexity of the practice. This article contributes to the existing literature of ethics in financial markets by examining a recent trend in regulation in high frequency trading, the prohibition of deception. We argue that in the financial markets almost any regulation, other than the most basic, tends to create a moral hazard and increase information asymmetry. Since the market’s job is, at (...) least in part, price discovery, we argue that simplicity of regulation and restraint in regulation are virtues to a greater extent than in other areas of finance. This article proposes criteria for determining which high-frequency trading strategies should be regulated. (shrink)

Certain strands of contemporary media theory are concerned with the ways in which computational environments exploit the ‘missing half-second’ of human perception and thereby influence, control or exploit humans at an affective level. The ‘technological unconscious’ of our times is often understood to work at this affective level, and high-frequency trading is regularly provided as a primary illustrative example of the contagious dynamics it produces. We challenge and complicate this account of the relation between consciousness, affect and (...) media technologies by drawing on the recent work of N. Katherine Hayles and by focusing in detail on the ways in which the ‘costs of consciousness’ are accounted for and negotiated in high-frequency trading. We suggest that traders actively develop modes of awareness accounting for the costs of consciousness, and that the necessary ‘stupidity’ of high-frequency trading algorithms as well as competition pose limits to the full automation of financial markets. (shrink)

This paper has been published in 2015 in Environment and Planning D, 33 : p. 1080–1097. It is freely available from Copenhagen Business School. We thank the authors for the permission to reproduce it here.: This paper explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit and present-day high-frequency trading. Drawing on Henri - Management et Business – Nouvel article.

Recent concern over “high frequency trading” (HFT) has called into question the fairness of the practice. What does it mean for a financial market to be “fair”? We first examine how high frequency trading is actually used. High frequency traders often implement traditional beneficial strategies such as market making and arbitrage, although computers can also be used for manipulative strategies as well. We then examine different notions of fairness. Procedural fairness can be (...) viewed from the perspective of equal opportunity, in which all market participants are treated alike. The same rules apply to HFT as to other traders. Another approach to fairness is in the equality of outcomes. Many HFT strategies are beneficial to other market participants, so one cannot categorically denounce the practice as unfair. Other strategies, for both high and low frequency trading, are not. It is thus important to distinguish between the technology and the use of the technology to make judgments on fairness. (shrink)

All of finance is now automated, most notably high frequency trading. This paper examines the ethical implications of this fact. As automation is an interdisciplinary endeavor, we argue that the interfaces between the respective disciplines can lead to conflicting ethical perspectives; we also argue that existing disciplinary standards do not pay enough attention to the ethical problems automation generates. Conflicting perspectives undermine the protection those who rely on trading should have. Ethics in finance can be expanded (...) to include organizational and industry-wide responsibilities to external market participants and society. As a starting point, quality management techniques can provide a foundation for a new cross-disciplinary ethical standard in the age of automation. (shrink)

The article discusses the use of algorithmic models in finance (algo or high frequency trading). Algo trading is widespread but also somewhat controversial in modern financial markets. It is a form of automated trading technology, which critics claim can, among other things, lead to market manipulation. Drawing on three cases, this article shows that manipulation also can happen in the reverse way, meaning that human traders attempt to make algorithms ‘make mistakes’ by ‘misleading’ them. These (...) attempts to manipulate are very simple and immediately transparent to humans. Nevertheless, financial regulators increasingly penalize such attempts to manipulate algos. The article explains this as an institutionalization of algo trading, a trading practice which is vulnerable enough to need regulatory protection. (shrink)

This essay examines three potential arguments against high-frequency trading and offers a qualified critique of the practice. In concrete terms, it examines a variant of high-frequency trading that is all about speed—low-latency trading—in light of moral issues surrounding arbitrage, information asymmetries, and systemic risk. The essay focuses on low-latency trading and the role of speed because it also aims to show that the commonly made assumption that speed in financial markets is morally (...) neutral is wrong. For instance, speed is a necessary condition for low-latency trading’s potential to cause harm in “flash crashes.” On the other hand, it also plays a crucial role in a Lockean defense against low-latency trading being wasteful developed in this essay. Finally, this essay discusses the implications of these findings for related high-frequency trading techniques like futures arbitrage or latency arbitrage—as well as for an argument as to why quote stuffing is wrong. Overall, the qualifications offered in this essay act as a counterbalance to overblown claims about trading at high speeds being wrong. (shrink)

The article examines two digital phenomena linked to money and finance, which are the bitcoin and high-frequency trading, through the lens of Vilém Flusser’s concept of technical image. Flusser’s theory highlights three aspects of technical images: they are engendered by the act of organizing particles, are produced by people who operate devices through keys, and are mediated by code, which is linear and pertains to the era of written text, which Flusser conflates with the notion of history. (...) In this article, the argument focuses on the aspects of high-frequency trading and the blockchain that relate to the idea of images. The sections investigate how money has historically operated in the logic of Flusser’s description of symbol manipulation in relation to consciousness and temporality: from the circular time of magical consciousness to the linear time of historical consciousness, and more recently, to the non-dimensional time of post-historical consciousness. The article argues that there are two levels, or layers, in the images involved in cryptocurrencies or algorithmic trading, but only one of them is visible to the human operator or viewer, in the form of a price. The other, which indeed represents the operations in the system, is only accessible to the machines themselves. The questions raised concern the role of these recent digital financial and monetary forms in the development of a reality dominated by apparatuses and technical images. (shrink)

All of finance is now automated, most notably high frequency trading. This paper examines the ethical implications of this fact. As automation is an interdisciplinary endeavor, we argue that the interfaces between the respective disciplines can lead to conflicting ethical perspectives; we also argue that existing disciplinary standards do not pay enough attention to the ethical problems automation generates. Conflicting perspectives undermine the protection those who rely on trading should have. Ethics in finance can be expanded (...) to include organizational and industry-wide responsibilities to external market participants and society. As a starting point, quality management techniques can provide a foundation for a new cross-disciplinary ethical standard in the age of automation. (shrink)

AbstractDuring the last 20 years, the financial sector has undergone an unprecedented transformation due to new regulations and the implementation of several technological advancements. The combination of regulation and technology has brought about new financial processes that have fundamentally changed how financial market making is done. This paper studies the ethics of financial market making and its implications for one of the most controversial financial innovations of modern times, namely high-frequency trading (HFT). We claim that the Aristotelian (...) distinction between natural chrematistics, which is aimed at serving the real economy, and unnatural chrematistics, whose ultimate purpose is wealth accumulation, can be a useful criterion to assess the ethics of financial market making and the goodness of an innovation as HFT, and how it can serve the common good of society. This approach can be defined as ‘purpose oriented’ or ‘purpose fulfillment’. (shrink)

The average annual profits before fees of the $10 billion plus Renaissance Technologies’ hybrid Medallion “Leveraged, High Frequency, Artificial Intelligence ” trading hedge fund between 1988 and 2019 were about 66 percent. Total trading profits during this period were over $100 billion. The fund has never had a losing year. The fund is not open to the general public. First, distinctions among, in more or less historical order, the traditional market-maker trading model, the hedge fund (...) trading model, the artificial intelligence trading model, and the hybrid LHFAI trading model are discussed. Second, the micro components of the LHFAI trading model are explained in the context of Renaissance Technologies’ Medallion Fund. Third, key positive contributions of the model with respect to profitability, low annual volatility, market liquidity, and intellectual property development; negative ethical issues concerning exclusive access, tax fairness, financial transparency, shared responsibility for losses and systemic risk, and short vs. long-term capital allocation are discussed. Potential reforms that retain the positives, reduce the negatives, and that could positively transform the model are discussed. Fourth, potential impacts that the potential reforms might have on the macro LHFAI form of finance capitalism and the larger finance capitalism political-economic system are considered. Fifth, conclusions are offered and discussed. (shrink)

Due to the inherent chaotic and fractal dynamics in the price series of Bitcoin, this paper proposes a two-stage Bitcoin price prediction model by combining the advantage of variational mode decomposition and technical analysis. VMD eliminates the noise signals and stochastic volatility in the price data by decomposing the data into variational mode functions, while technical analysis uses statistical trends obtained from past trading activity and price changes to construct technical indicators. The support vector regression accepts input from a (...) hybrid of technical indicators and reconstructed variational mode functions. The model is trained, validated, and tested in a period characterized by unprecedented economic turmoil due to the COVID-19 pandemic, allowing the evaluation of the model in the presence of the pandemic. The constructed hybrid model outperforms the single SVR model that uses only TI and rVMF as features. The ability to predict a minute intraday Bitcoin price has a huge propensity to reduce investors’ exposure to risk and provides better assurances of annualized returns. (shrink)

In the spring of 2010, major newspapers in the U.S. announced arrival of a “recovery” from the economic recession precipitated by the 2008 financial crisis. This essay examines the biopolitics of recovery in the wake of the disaster capitalism of the financial meltdown, arguing that twentieth-century social welfare biopolitics that derived wealth from the populace have been replaced by new forms of financial power whose global circulations and convergences exploit wealth informatically and transactionally, rather than biopolitically, through devices such as (...) derivatives and technologies such a high-frequency trading. Carbon derivatives trading is used to illustrate how wealth can be generated informatically from a thanatopolitics of destruction. (shrink)

In a talk in 2013, Karin Knorr Cetina referred to ‘the interaction order of algorithms’, a phrase that implicitly invokes Erving Goffman's ‘interaction order’. This paper explores the application of the latter notion to the interaction of automated-trading algorithms, viewing algorithms as material entities (programs running on physical machines) and conceiving of the interaction order of algorithms as the ensemble of their effects on each other. The paper identifies the main way in which trading algorithms interact (via electronic (...) ‘order books’, which algorithms both ‘observe’ and populate) and focuses on two particularly Goffmanesque aspects of algorithmic interaction: queuing and ‘spoofing’, or deliberate deception. Following Goffman's injunction not to ignore the influence on interaction of matters external to it, the paper examines some prominent such matters. Empirically, the paper draws on documentary analysis and 338 interviews conducted by the author with high-frequency traders and others involved in automated trading. (shrink)

This article puts into perspective the practice of financial regulation in contemporary financial markets, while a new normative order has emerged. This order, heralded by algorithmic technologies, changes the conditions for the exercise of regulation: to date, it has not yet been fully acknowledged nor understood by regulatory bodies. Computer code, replacing speech and writing, induces a changeover from one normative order to another in contemporary markets: the norm, previously explicated with recourse to interpretation, is now replaced by an order (...) characterized by calculation. Such paradigm change is identified based on a discussion of works by Gilles Deleuze. In so doing, it contributes to the developing research programme in the cultures of high-frequency trading (Lange et al. 2016) and also points at broader issues for conceptualising financial regulation. (shrink)

continent. 1.4 (2011): 239. In 1998 the Securities and Exchange Commission authorized electronic exchanges. Not only did this give day traders access to buy and sell securities from their desktops, it also made it possible for high powered Wall Street traders to program algorithms to make trades at speeds on the order of milliseconds.(1) The advent of automatic algorithmic trading, now known as high-frequency trading, has vastly accelerated the already increasing speed and volume of (...) class='Hi'>trading. This project was an attempt to capture in an ephemeral and environmental way the dizzying acceleration of networked markets. The change in the daily closing value of the Dow and daily trading volume were each set to control a sine wave oscillator between 20 and 800hz. The oscillators were combined to ‘sonify’ the data, creating a changing noise reflecting the daily change and trading volume of the market. The resulting sound is somewhat tedious until the trading volume begins increasing in the 60s and then becomes increasingly complex as high-frequency trading and market volatility set in during the 1990s and 2000s. NOTES 1. Charles Duhigg. “Stock Traders Find Speed Pays, in Milliseconds.” New York Times . July 23, 2009. (shrink)

Sexually signalling animals must trade off the benefits of attracting mates with the consequences of attracting predators. For male guppies, predation risk depends on their behaviour, colouration, environmental conditions and changing intensity of predation throughout the day. Theoretically, this drives diel patterns of display behaviour in native Trinidadian populations, where males display more under low-light conditions when their most dangerous predator is less active. Here, we observed Australian guppies in a laboratory setting to investigate their diel display pattern, and if (...) this pattern is controlled by ambient light intensity. We also quantified individual variation in both the daily frequency and diel pattern of displays, and if such variation relates to body size, colouration and a non-sexual behaviour. Under a typical daily light regime, male guppies displayed mostly in the first hour of observation. Extending the duration of dawn-like lighting, however, resulted in an extended period of high display, demonstrating that light intensity per se is an important cue for this behaviour. These findings mirror those obtained for Trinidadian populations, suggesting that male courtship timing is likely shaped by broad, potentially generalizable features of guppy ecology. The effect of acclimation to captive conditions on male behaviour is also discussed. Whereas the temporal pattern of display appeared consistent, individuals varied in their daily display frequency, and this was correlated with variation in colour phenotype and a measure of non-sexual risk acceptance behaviour. Such relationships pose promising avenues for integrating behavioural and sensory ecology with contemporary work on behavioural syndromes and animal personality. (shrink)

This special issue introduces the study of financial technologies and finance to the field of philosophy of technology, bringing together two different fields that have not traditionally been in dialogue. The included articles are: Digital Art as ‘Monetised Graphics’: Enforcing Intellectual Property on the Blockchain, by Martin Zeilinger; Fundamentals of Algorithmic Markets: Liquidity, Contingency, and the Incomputability of Exchange, by Laura Lotti; ‘Crises of Modernity’ Discourses and the Rise of Financial Technologies in a Contested Mechanized World, by Marinus Ossewaarde; Two (...) Technical Images: Blockchain and High-Frequency Trading, by Diego Viana; and The Blockchain as a Narrative Technology: Investigating the Social Ontology and Normative Configurations of Cryptocurrencies, by Wessel Reijers and Mark Coeckelbergh. (shrink)

The view from inside improves our understanding on market failure and regulation failure in financial market. The EMH fails to understand the causes of financial bubbles and crashes. Behavioral finance introduces insight from psychology. The heuristic and biases approach studied behavioral asymmetry in static environment that leads to market irrationality and information distortion. The fast and frugal thinking in decision-making further explore more complex situation under changing environment. They argue that soft-paternalistic regulation is needed under information overload. The most critical (...) issue is information uncertainty and complexity. Lacking information in frequency domain is the main barrier in managing business cycles. Data form inside reveals current limitations of financial data mainly in the short-term price changes. Microstructure studies show that pricing process is shaped by trading rules. Quantitative analysis reveals severe instability in high frequency trading and derivative market. Feasible regulation should aim to encourage new technology and sustainable growth, rather than protect obsolete technology and short-term speculation. The most fundamental challenge to sustainable economic order is the excessive size of the derivative markets that crowding out investment in real economy. This is a more severe issue than the climate change. (shrink)

Theorists, historians, and artists address the precarious futurity of the notion of the future. Not long ago, a melancholic left and a manic neoliberalism seemed to arrive at an awkward consensus: the foreclosure of futurity. Whereas the former mourned the failure of its utopian project, the latter celebrated the triumph of a global marketplace. The radical hope of realizing a singularly different, more equitable future displaced by a belief that the future had already come to pass, limiting post-historical society to (...) an uneventful life of endless accumulation. Today, amidst an abundance of neofuturisms, posthumanisms, futurologies, speculative philosophies and accelerationist scenarios, there is as well an expanding awareness of a looming planetary catastrophe driven by the extractionist logic of capitalism. Despite this return to the future, the temporal horizon of our present moment is perhaps more aptly characterized by the “shrinking future” of just-in-time production, risk management, high-frequency trading, and the futures market. In Futurity Report, theorists, historians, and artists address the precarious futurity of the notion of the future itself. Contributors McKenzie Wark, China Miéville, Kerstin Stakemeier, Diedrich Diederichsen, Natascha Sadr Haghighian, Marina Vishmidt, Johannes Paul Raether, Felicity D. Scott, Silvia Maglioni, Graeme Thomson, Doreen Mende, Pedro Neves Marques, Achille Mbembe, Kodwo Eshun, Haytham El-Wardany, T. J. Demos, Ana Teixeira Pinto. (shrink)

The integration of the global economy has led to an increasingly strong connection between the futures and spot markets of commodities. First, based on one-minute high-frequency prices, this paper applies the thermal optimal path method to examine the lead-lag relationship between Chinese crude oil futures and spot from March 2018 to December 2021. Second, we apply the Mixed Frequency Data Sampling Regression model and indicators such as deviation degree to test the degree of prediction of high- (...) class='Hi'>frequency prices in the futures market to the spot market. The experimental results show that the futures markets lead the spot market most of the time, but the lead effect reverses when major events occur; 60-minute futures high-frequency prices are the most predictive of daily spot data; crude oil futures’ predictive power declined after the Covid-19 outbreak and is more predictive when night trading is available. This study has important implications, not only to guide investors but also to provide empirical evidence and valid information for policy makers. (shrink)

Rationale: High-frequency oscillations in intracranial EEG are used to delineate the epileptogenic zone during presurgical diagnostic assessment in patients with epilepsy. HFOs are historically divided into ripples, fast ripples, and their co-occurrence. In a previous study, we had validated the rate of FRandRs during deep sleep to predict seizure outcome. Here, we ask whether epileptic FRandRs might be confounded by physiological FRandRs that are unrelated to epilepsy.Methods: We recorded iEEG in the medial temporal lobe MTL in 17 patients (...) while they performed cognitive tasks. The three cognitive tasks addressed verbal working memory, visual working memory, and emotional processing. In our previous studies, these tasks activated the MTL. We re-analyzed the data of these studies with the automated detector that focuses on the co-occurrence of ripples and FRs.Results: For each task, we identified those channels in which the HFO rate was modulated during the task condition compared to the control condition. However, the number of these channels did not exceed the chance level. Interestingly, even during wakefulness, the HFO rate was higher for channels within the seizure onset zone than for channels outside the SOZ.Conclusion: Our prospective definition of an epileptic HFO, the FRandR, is not confounded by physiological HFOs that might be elicited by our cognitive tasks. This is reassuring for the clinical use of FRandR as a biomarker of the EZ. (shrink)

High-frequency oscillations (HFO) are a promising biomarker for the identification of epileptogenic tissue. While HFO rates have been shown to predict seizure outcome, it is not yet clear whether their morphological features might improve this prediction. We validated HFO rates against seizure outcome and delineated the distribution of HFO morphological features. We collected stereo-EEG recordings from 20 patients (231 electrodes; 1,943 contacts). We computed HFO rates (the co-occurrence of ripples and fast ripples) through a validated automated detector during (...) non-rapid eye movement sleep. Applying machine learning, we delineated HFO morphological features within and outside epileptogenic tissue across mesial temporal lobe (MTL) and Neocortex. HFO rates predicted seizure outcome with 85% accuracy, 79% specificity, 100% sensitivity, 100% negative predictive value, and 67% positive predictive value. The analysis of HFO features showed larger amplitude in the epileptogenic tissue, similar morphology for epileptogenic HFO in MTL and Neocortex, and larger amplitude for physiological HFO in MTL. We confirmed HFO rates as a reliable biomarker for epilepsy surgery and characterized the potential clinical relevance of HFO morphological features. Our results support the prospective use of HFO in epilepsy surgery and contribute to the anatomical mapping of HFO morphology. (shrink)

This work presents a thorough derivation of the full-wave transmission-line equations on the basis of Maxwell’s theory. The multiconductor system is assumed to be composed of nonuniform thin wires. It is shown that the mixed potential integral equations are equivalent to generalized telegrapher equations. Novel, exact, and compact expressions for the multiconductor transmission-line parameters are derived, and their connection to radiation effects is shown. Iteration and perturbation procedures are proposed for the solution of the generalized transmission-line equations.

Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style toward flexibility, which in turn should increase the crosstalk (...) between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task—an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style toward more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias. (shrink)

Mammalian outer hair cells generate mechanical forces at acoustic frequencies and can thus amplify the sound stimulus within the inner ear. The mechanism of force generation depends upon the plasma membrane potential but not upon either calcium or ATP. Forces are generated in the lateral cortex along the full length of the cell. The cortex includes a two‐dimensional cytoskeletal lattice composed of circumferential filaments 6–7 nm thick that are cross‐linked by filaments 3–4 nm thick and 40–60 nm long. The two (...) filament types may, respectively, be actin and some form of spectrin. The lattice reinforces the cylindrical shape of the cell and permits limited changes in length. Beneath it lie the lateral cisternae, a regular system of multi‐layered membranes. Force–generation may depend upon voltage‐dependent shape changes in proteins that lie either in the plasma membrane or in the cytoskeletal lattice. (shrink)

The current study examines similarity or disparity of a frontally mediated physiological response of mental effort among multiple executive functioning tasks between children and adults. Task performance and phasic heart rate variability (HRV) were recorded in children (6 to 10 years old) and adults in an examination of age differences in executive functioning skills during periods of increased demand. Executive load levels were varied by increasing the difficulty levels of three executive functioning tasks: inhibition (IN), working memory (WM), and planning/problem (...) solving (PL). Behavioral performance decreased in all tasks with increased executive demand in both children and adults. Adults’ phasic high frequency HRV was suppressed during the management of increased IN and WM load. Children’s phasic HRV was suppressed during the management of moderate WM load. HRV was not suppressed during either children’s or adults’ increasing load during the PL task. High frequency phasic HRV may be most sensitive to executive function tasks that have a time-response pressure, and simply requiring performance on a self-paced task requiring frontal lobe activation may not be enough to generate HRV responsitivity to increasing demand. (shrink)

Research into the potential associations between tinnitus and cognition has investigated specific cognitive domains in laboratory settings despite adults with tinnitus reporting broad cognitive difficulties in every-day life. To address this limitation, the present study compared performance and perceived exertion on a visual office-like task in 38 adults with tinnitus and 38 adults without tinnitus matched for age, sex and educational background. All participants were also assessed for hearing, anxiety and depression, and participants with tinnitus were also assessed for tinnitus (...) handicap. No associations were found between presence of tinnitus and cognitive performance and perceived exertion on the visual office-like task when corrected for standard and extended high frequency hearing thresholds, anxiety, and depression. The correction for extended high frequency average hearing threshold was significant for performance but not perceived exertion on the visual office-like task. Overall, the results showed extended high frequency hearing, but not tinnitus, was associated with every-day cognitive performance. This indicates clinical testing of hearing thresholds above 8 kHz could support clinicians’ identification and management of cognitive difficulties. One management method suggested by the current findings would include provision of auditory stimulation at frequencies exceeding the frequency response of many current hearing aids. (shrink)

BackgroundIndividuals who use methamphetamine for a long period of time may experience decreased inhibition and increased impulsivity. In order to reduce impulsivity or improve inhibitory control ability, high-frequency repetitive transcranial magnetic stimulation has attracted much attention of researchers. Recent studies on addiction have shown that rTMS can stimulate different brain regions to produce different therapeutic effects. Recent work also suggests that HF-rTMS over right dorsolateral prefrontal cortex does not affect the impulsivity of patients with alcohol use disorder; while (...) HF-rTMS over left DLPFC could improve the impulsivity of patients with alcohol use disorder and cigarette smokers. However, it should be noted that empirical studies applying HF-rTMS over left DLPFC of patients with MA use disorders are still lacking.MethodsTwenty-nine patients with MAUD underwent five sessions of HF-rTMS on the left DLPFC per week for 4 consecutive weeks. The cue-induced craving and stop-signal and NoGo task were assessed pre-rTMS and post-rTMS. In addition, 29 healthy controls were recruited. There was no rTMS intervention for the controls, the performance of the stop-signal and NoGo task was evaluated on them.ResultsIn total, HF-rTMS of the left DLPFC significantly decreased MA-dependent patients’ cue-induced craving and stop-signal reaction time. For SSRT, the pre-test of experimental group was significantly higher than the score of control group. In the experimental group, the pre-test score was significantly higher than the post-test score. For Go and stop-signal delay, the pre-test scores of the experimental group was significantly lower than the scores of the control group. No significant difference was found between the pre-test and the post-test scores of the experimental group.ConclusionAdd-on HF-rTMS of left DLPFC may be an effective intervention for reducing impulsivity and cue-induced craving of patients with MAUD. Future research with a control group of MAUD that does not undergo the treatment is needed to confirm the effectiveness. (shrink)

Considering background quantization of gravitational fields, it is generally assumed that the classical background satisfies Einstein's gravitational equations. However, there exist arguments showing that, for high frequency (quantum) fluctuations, this assumption has to be replaced by a condition describing the back reaction of fluctuations on the background. It is shown that such an approach leads to limitations for the quantum procedure which occur at distances larger than Planck's elementary lengthl=(Gh/c 3)1/2.

Background High-frequency oscillation (HFO) represents a promising biomarker of epileptogenicity. However, the significant interindividual differences among patients limit its application in clinical practice. Here, we applied and evaluated an individualized, frequency-based approach of HFO analysis in stereoelectroencephalography (SEEG) data for localizing the epileptogenic zones (EZs). Methods Clinical and SEEG data of 19 patients with drug-resistant focal epilepsy were retrospectively analyzed. The individualized spectral power of all signals recorded by electrode array, i.e., the relative strength of HFO, was (...) computed with a wavelet method for each patient. Subsequently, the clinical value of the relative strength of HFO for identifying the EZ was evaluated. Results Focal increase in the relative strength of HFO in SEEG recordings were identified in all 19 patients. HFOs identified inside the clinically identified seizure onset zone had more spectral power than those identified outside ( p p Conclusion The relative strength of HFO, especially fast ripples, is a promising effective biomarker for identifying the EZ and can lead to a favorable seizure outcome if used to guide epilepsy surgery. (shrink)

Phillips & Silverstein's focus on schizophrenia as a failure of “cognitive coordination” is welcome. They note that a simple hypothesis of reduced Gamma synchronisation subserving impaired coordination does not fully account for recent observations. We suggest that schizophrenia reflects a dynamic compensation to a core deficit of coordination, expressed either as hyper- or hyposynchronisation, with neurotransmitter systems and arousal as modulatory mechanisms.

In chronic schizophrenic patients with both positive and negative symptoms (see Table 1), interhemispheric connections at the high frequency beta2-rhythm are absent during cognitive tasks, in contrast to normal controls, who have many interhemispheric connections at this frequency in the same situation. Connectivity is a fundamental brain feature, evidently greatly promoted by the NMDA system. It is a more reliable measure of brain function than the spectral power of this rhythm.

Motivation: There is an ongoing search for definitive and reliable biomarkers to forecast or predict imminent seizure onset, but to date most research has been limited to EEG with sampling rates <1,000 Hz. High-frequency oscillations have gained acceptance as an indicator of epileptic tissue, but few have investigated the temporal properties of HFOs or their potential role as a predictor in seizure prediction. Here we evaluate time-varying trends in preictal HFO rates as a potential biomarker of seizure prediction.Methods: (...) HFOs were identified for all interictal and preictal periods with a validated automated detector in 27 patients who underwent intracranial EEG monitoring. We used LASSO logistic regression with several features of the HFO rate to distinguish preictal from interictal periods in each individual. We then tested these models with held-out data and evaluated their performance with the area-under-the-curve of their receiver-operating curve. Finally, we assessed the significance of these results using non-parametric statistical tests.Results: There was variability in the ability of HFOs to discern preictal from interictal states across our cohort. We identified a subset of 10 patients in whom the presence of the preictal state could be successfully predicted better than chance. For some of these individuals, average AUC in the held-out data reached higher than 0.80, which suggests that HFO rates can significantly differentiate preictal and interictal periods for certain patients.Significance: These findings show that temporal trends in HFO rate can predict the preictal state better than random chance in some individuals. Such promising results indicate that future prediction efforts would benefit from the inclusion of high-frequency information in their predictive models and technological architecture. (shrink)

Journal Name: Cognitive Linguistics Issue: Ahead of print.

Individuals regaining reliable day-to-day walking function after incomplete spinal cord injury report persisting unsteadiness when confronted with walking challenges. However, quantifiable measures of walking capacity lack the sensitivity to reveal underlying impairments of supra-spinal locomotor control. This study investigates the relationship between intramuscular coherence and corticospinal dynamic balance control during a visually guided Target walking treadmill task. In thirteen individuals with iSCI and 24 controls, intramuscular coherence and cumulant densities were estimated from pairs of Tibialis anterior surface EMG recordings during (...) normal treadmill walking and a Target walking task. The approximate center of mass was calculated from pelvis markers. Spearman rank correlations were performed to evaluate the relationship between intramuscular coherence, clinical parameters, and center of mass parameters. In controls, we found that the Target walking task results in increased high-frequency intramuscular coherence, which negatively related to changes in the center of mass movement, whereas this modulation was largely reduced in individuals with iSCI. The impaired modulation of high-frequency intramuscular coherence during the Target walking task correlated with neurophysiological and functional readouts, such as motor-evoked potential amplitude and outdoor mobility score, as well as center of mass trajectory length. The Target walking effect, the difference between Target and Normal walking intramuscular coherence, was significantly higher in controls than in individuals with iSCI [F = 13.042, p < 0.001]. Intramuscular coherence obtained during challenging walking in individuals with iSCI may provide information on corticospinal gait control. The relationships between biomechanics, clinical scores, and neurophysiology suggest that intramuscular coherence assessed during challenging tasks may be meaningful for understanding impaired supra-spinal control in individuals with iSCI. (shrink)

Patient RP suffers a unilateral right homonymous quadrant anopia but demonstrates better than chance discrimination for stimuli presented in the blind field at temporal frequencies between 33 and 47 Hz . Examination of her reports of visual experience during blind-field discrimination suggests a more complex picture in which experiences particular to correct discrimination are not found at low-mid-gamma frequencies, but are significantly more likely than average at a lower frequency at which blindsight is not observed. We believe that visual (...) experience may serve to support blindsight if discrimination tasks are generally impaired at frequencies outside of the low-mid-gamma band. If this is so, although generally experienced as non-specific and unstructured light, the visual experience that accompanies discrimination performance must be based upon a neural representation which includes information on the visual features present in the stimulus. (shrink)