1,106 research outputs found
Automatic Response Assessment in Regions of Language Cortex in Epilepsy Patients Using ECoG-based Functional Mapping and Machine Learning
Accurate localization of brain regions responsible for language and cognitive
functions in Epilepsy patients should be carefully determined prior to surgery.
Electrocorticography (ECoG)-based Real Time Functional Mapping (RTFM) has been
shown to be a safer alternative to the electrical cortical stimulation mapping
(ESM), which is currently the clinical/gold standard. Conventional methods for
analyzing RTFM signals are based on statistical comparison of signal power at
certain frequency bands. Compared to gold standard (ESM), they have limited
accuracies when assessing channel responses.
In this study, we address the accuracy limitation of the current RTFM signal
estimation methods by analyzing the full frequency spectrum of the signal and
replacing signal power estimation methods with machine learning algorithms,
specifically random forest (RF), as a proof of concept. We train RF with power
spectral density of the time-series RTFM signal in supervised learning
framework where ground truth labels are obtained from the ESM. Results obtained
from RTFM of six adult patients in a strictly controlled experimental setup
reveal the state of the art detection accuracy of for the
language comprehension task, an improvement of over the conventional
RTFM estimation method. To the best of our knowledge, this is the first study
exploring the use of machine learning approaches for determining RTFM signal
characteristics, and using the whole-frequency band for better region
localization. Our results demonstrate the feasibility of machine learning based
RTFM signal analysis method over the full spectrum to be a clinical routine in
the near future.Comment: This paper will appear in the Proceedings of IEEE International
Conference on Systems, Man and Cybernetics (SMC) 201
Independence and consistency proofs in quadratic form theory
We consider the following properties of uncountable-dimensional quadratic spaces (E, Φ): (*) For all subspaces U ⊆ E of infinite dimension: dim U ˔ < dim E. (**) For all subspaces U ⊆ E of infinite dimension: dim U ˔ < ℵ0. Spaces of countable dimension are the orthogonal sum of straight lines and planes, so they cannot have (*), but (**) is trivially satisfied. These properties have been considered first in [G/O] in the process of investigating the orthogonal group of quadratic spaces. It has been shown there (in ZFC) that over arbitrary uncountable fields (**)-spaces of uncountable dimension exist. In [B/G], (**)-spaces of dimension ℵ1 (so (*) = (**)) have been constructed over arbitrary finite or countable fields. But this could be done only under the assumption that the continuum hypothesis (CH) holds in the underlying set theor
Progenitor Cell Therapy for Sensorineural Hearing Loss in Infants
Typical language development requires typical hearing. With sensorineural hearing loss (SNHL), the damaged hair cells of the organ of Corti within the cochlea interfere with typical hearing and, as a result, cause impaired language development. Untreated SNHL causes significant neurocognitive differences in affected children. SNHL is a permanent sensory disorder affecting more than 270 million people worldwide. Congenital SNHL is found in 4 of 1000 newborns. Approximately half of congenital SNHL is hereditary and is the result of genetic mutations causing improper development of cochlear hair cells. Non-genetic congenital SNHL is thought to be the result of an injury to the cochlea typically from premature birth, infection, or exposure to ototoxic medications or noise. In mammals, the cochlea is postmitotic at birth, and no spontaneous repair occurs thereafter. Existing treatments for SNHL (hearing aids and cochlear implants) function by augmenting the damaged organ of Corti. No reparative treatments currently exist. In preclinical and clinical studies, progenitor cell therapy (cord blood and mesenchymal stem cells) has shown promise in reversing the underlying pathology of SNHL, the loss of cochlear sensory hair cells. Progenitor cell therapy may also allow functional reorganization of the auditory pathways including primary auditory cortex (Heschl’s gyrus). We will present a summary of the effect of hearing loss on auditory development, existing preclinical and clinical data on progenitor cell therapy, and its potential role in the (re)habilitation of non-genetic SNHL
The need for better statistical testing in data-driven energy technology modeling
Technology modeling is a vital part of developing and understanding energy system scenarios and policy, but it is challenging due to data limitations, deep uncertainty, and the complex social and technological dynamics involved in the evolution of energy systems. These difficulties are often compounded by unsound technology forecasting practice, including overfitting, data selection bias, and ad hoc assumptions, leading to unreliable conclusions. We flag several cases where this has been problematic and analyze in detail a recent model for predicting the pace of solar photovoltaic and wind energy deployment. We discuss general takeaways and provide suggestions for how statistical testing should be conducted to avoid such problems in the future and to quantify the reliability of forecasts
Electrical Skin Impedance at Acupuncture Points
Objective: To test whether electrical skin impedance at each of three acupuncture points (APs) is significantly lower than at nearby sites on the meridian (MP) and off the meridian (NP). Design: Two instruments—Prognos (MedPrevent GmbH, Waldershof, Germany), a constant-current (DC) device, and PT Probe (designed for this study), a 100-Hz sinusoidal-current (AC) device—were used to record electrical impedance at three APs (right Gallbladder 14, right Pericardium 8, and left Triple Energizer 1), and two control sites for each AP. Each AP, MP, and NP was measured four times in random order with each device. Setting: The study was conducted over a period of 4 days at the Oregon College of Oriental Medicine (OCOM). Subjects: Twenty (20) healthy adults (14 women and 6 men), all recruited from the OCOM student body and faculty, participated in the study. Results: The Prognos measurements had an intraclass correlation (ICC) 0.84 and coefficient of variation (CV) 0.43. The PT Probe had ICC 0.81 and CV 0.31. Impedance values at APs were not significantly less than at MPs or NPs. Impedance values at MPs were also not significantly less than NPs, although their individual p values were 0.05 in 4 of 6 cases. There was a significant trend of increasing impedance with repeated measurements with both the Prognos (p 0.003) and the PT Probe (p 0.003). Conclusions: Within the reliability limits of our study methods, none of the three APs tested has lower skin impedance than at either of the nearby control points. These results are not consistent with previous studies that detected lower skin impedance at APs than nearby sites. Further study is necessary to determine whether MPs have lower skin impedance than nearby NPs. Our study suggests caution is warranted when developing, using, and interpreting results from electrodermal screening devices. Further studies are needed to clarify the clinically important and controversial hypothesis that APs are sites of lower impedance
Residents' reactions to long-term sonic boom exposure: Preliminary results
This presentation is about residents' reactions to sonic booms in a long-term sonic boom exposure environment. Although two phases of the data collection have been completed, the analysis of the data has only begun. The results are thus preliminary. The list of four authors reflects the complex multi-disciplinary character of any field study such as this one. Carey Moulton is responsible for Wyle Laboratories' acoustical data collection effort. Robert Baumgartner and Jeff Thomas of HBRS, a social science research firm, are responsible for social survey field work and data processing. The study is supported by the NASA Langley Research Center. The study has several objectives. The preliminary data addresses two of the primary objectives. The first objective is to describe the reactions to sonic booms of people who are living where sonic booms are a routine, recurring feature of the acoustical environment. The second objective is to compare these residents' reactions to the reactions of residents who hear conventional aircraft noise around airports. Here is an overview of the presentation. This study will first be placed in the context of previous community survey research on sonic booms. Next the noise measurement program will be briefly described and part of a social survey interview will be presented. Finally data will be presented on the residents' reactions and these reactions will be compared with reactions to conventional aircraft. Twelve community studies of residents' reactions to sonic booms were conducted in the United States and Europe in the 1960's and early 1970's. None of the 12 studies combined three essential ingredients that are found in the present study. Residents' long-term responses are related to a measured noise environment. Sonic booms are a permanent feature of the residential environment. The respondents' do not live on a military base. The present study is important because it provides the first dose/response relationship for sonic booms that could be expected to apply to residents in civilian residential areas
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