Statistics of spontaneous electrical activity of supra- and ectosylvian gyri of the dog

1963 ◽  
Vol 204 (1) ◽  
pp. 51-59
Author(s):  
Archie R. Tunturi
Keyword(s):  
Standard Deviation ◽  
Electrical Activity ◽  
Negative Correlation ◽  
Evoked Potential ◽  
Correlation Coefficients ◽  
Moderate Correlation ◽  
Spontaneous Electrical Activity ◽  
Suprasylvian Gyrus ◽  
The Mean ◽  
Standard Deviations

The standard deviations of the spontaneous electrical activity (SEA) of the suprasylvian gyrus (SSG) ranged between 57–131 µv and for the middle ectosylvian (MES) gyrus, 88–175 µv. Correlation coefficients, r, served to distinguish three regions of the SSG. The rostral showed low correlation with the middle, high correlation with the caudal, and low to negative correlation with the MES. The middle showed moderate correlation with the MES, and the caudal showed zero to negative correlation with the MES. Within the SSG, correlation was low and in the MES high, for spacings of 2 mm. Cocaine applied to both areas sharpened the boundaries at the sulci, reduced standard deviations, did not affect the correlation between the caudal SSG and the MES area, and increased r between all locations in the MES but not in the SSG. Cocaine on the SSG had no effect on the mean and standard deviation of the evoked potential in the MES, but decreased r of the SEA significantly.

Components of the evoked potential in the MES auditory cortex

1960 ◽  
Vol 199 (3) ◽  
pp. 529-534 ◽  
Author(s):  
Archie R. Tunturi
Keyword(s):  
Standard Deviation ◽  
Auditory Cortex ◽  
Electrical Activity ◽  
Evoked Potential ◽  
Random Variable ◽  
Positive Component ◽  
Negative Component ◽  
Spontaneous Electrical Activity ◽  
Covariance Term ◽  
The Mean

The electrical activity during the potential evoked by a p pulse was analyzed statistically by considering amplitude at each 3-msec. epoch a random variable. The rise in standard deviation during the evoked potential was abolished a) by local cocaine on the cortex, b) by a preceding evoked potential and c) by ischemia. The residual mean positive component, with zero standard deviation, was subtracted from the mean of the evoked potential. This yielded a positive-negative component, with which the spontaneous electrical activity is believed to interact. The evoked potential is thus described as the sum of the three random variables: a) spontaneous electrical activity, b) positive component, and c) positive-negative component, with a covariance term involving the spontaneous electrical activity and the positive-negative component.

Statistical properties of spontaneous electrical activity in the MES auditory cortex of the anesthetized dog

1959 ◽  
Vol 196 (6) ◽  
pp. 1175-1180 ◽  
Author(s):  
Archie R. Tunturi
Keyword(s):  
Standard Deviation ◽  
Electrical Activity ◽  
Correlation Coefficients ◽  
Positive Component ◽  
Chi Square ◽  
True Response ◽  
Spontaneous Electrical Activity ◽  
Posterior Direction ◽  
The Mean ◽  
Anterior Posterior

The spontaneous electrical activity was sampled at 2-second intervals from 50 electrodes on the MES area. Chi-square tests indicated normality for the amplitude values of potential obtained at each electrode. The range for standard deviations was 43–113 µv but averaged between 77 and 85 for three animals. Correlation coefficients greater than 0.7 were obtained between electrodes 2 mm apart in the anterior-posterior direction with a decrement to 0.4 at a separation of 4 mm. Dorso-ventrally, correlations greater than 0.7 were obtained between electrodes 4–6 mm apart, suggesting a strip-like character. Low values of correlation were obtained between an electrode in the MES area and an electrode on the AES or PES area. Assuming independence of the true response and spontaneous electrical activity the mean curve and standard deviation curve of the true response were computed. The standard deviation curve of the true response increased during the positive component gradually decreasing toward the end of the negative component.

Effect of spontaneous activity on afferent response in the MES auditory cortex of the dog

1959 ◽  
Vol 197 (5) ◽  
pp. 1141-1146
Author(s):  
Archie R. Tunturi
Keyword(s):  
Standard Deviation ◽  
Auditory Cortex ◽  
Electrical Activity ◽  
Spontaneous Activity ◽  
Evoked Potential ◽  
Random Variables ◽  
Spontaneous Electrical Activity ◽  
Cocaine Hydrochloride ◽  
Afferent Response ◽  
Stimulation Of

Treating the spontaneous electrical activity (SEA) and the evoked potential due to a p pulse at the MES auditory cortex as random variables at 3-msec. epochs, an increase in standard deviation during the evoked potential was found suggesting the occurrence of two statistical processes. By suitable application of cocaine hydrochloride locally to the cortex, it was possible to suppress the standard deviation of SEA and obtain a potential with no or little variance. This potential was defined as the ‘afferent response’ representing the activity due to volleys from the ear. It was concluded that the locally arising SEA has connections to the nerve elements causing the afferent response, thus producing the variance of the evoked potential. The SEA, therefore, is an information destroying process, since it reduces the detectability of response from stimulation of the ear.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

The Effects of Ethyl Alcohol on a Driver's Driving Skill, Visual Perception, Risk Acceptance, Choice Reaction Times and Information Processing Rates

1974 ◽  
Vol 18 (2) ◽  
pp. 116-116
Author(s):  
Helmut T. Zwahlen
Keyword(s):  
Information Processing ◽  
Standard Deviation ◽  
Visual Perception ◽  
Reaction Times ◽  
Driving Skill ◽  
Alcohol Condition ◽  
The Mean ◽  
Risk Acceptance ◽  
Standard Deviations ◽  
Choice Reaction Times

Twelve subjects (20–37 years old) were tested in the laboratory and eleven out of these were also tested in a car in the field, first under a no alcohol condition and then under an alcohol condition (approximately 0.10% BAC). In the laboratory the subjects simple and choice reaction times for two uncertainty modes were measured and their information processing rates (3 bits unsertainty) were determined. In the field the subjects driving skill for driving through a gap with 20 inches total clearance at 20 MPH was measured, as well as their static visual perceptual capabilities and risk acceptance decisions for a 46 feet viewing distance using psychophysical experimental methods. Based upon the driving skill measure (standard deviation of centerline deviations in the gap), the mean of the psychometric visual gap perception function and the mean of the psychometric gap risk acceptance function, the “Safety Distance” and the “Driver Safety Index” (DSI) were obtained. Based upon a statistical analysis of the data we may conclude first that the effects of alcohol (approximately 0.10% BAC) vary widely from one subject to another (slighthly improved performance to highly impaired performance) and that the changes in the group averages of the means and standard deviations of the psychometric visual perception and risk acceptance functions, the driving skill distributions, the “Safety Distances” and the DSI's for the subjects (although all changes in the group averages are in the expected direction) are statistically not significant (α = .05). Second, the group average of the means of the choice reaction times for the subjects increased by 5% under the alcohol condition (statistically significant, α = .05), but more important the group average of the standard deviations of the choice reaction times for the subjects increased by 23% (statistically significant, α = .05). The group average of the information processing rates for the subjects decreased by 3% (statistically not significant, α = .05) under the alcohol condition. A system model in which the system demands on the driver are represented in terms of choice reaction times is used to demonstrate that the increase in performance variability (expressed by the standard deviation of choice reaction times) under the influence of alcohol provides a much better explanation for the higher accident involvement than the historically most frequently used rather small increase in average performance (expressed by the mean of choice reaction times).

Effect of thalamic lesions on spontaneous electrical activity in MES auditory cortex

1961 ◽  
Vol 201 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Archie R. Tunturi
Keyword(s):  
White Matter ◽  
Electrical Activity ◽  
Medial Geniculate Body ◽  
Correlation Coefficients ◽  
Spontaneous Electrical Activity ◽  
Moderate Number ◽  
Auditory Area ◽  
Before And After ◽  
Medial Geniculate ◽  
Thalamic Lesions

Standard deviations (sd) and spatial correlation coefficients ( r) of spontaneous electrical activity were computed for multiple locations on the surface of the middle ectosylvian auditory area of the dog, before and after lesions in the white matter under the area, thalamus, midbrain, and medial geniculate body. Locally applied cocaine decreased sd and increased r between locations greater than 6 mm apart from 0.3–0.5 to values > 0.75. Immediate subcortical aspiration after cocaine had no effect on sd or r, but after recovery from the cocaine, sd returned to normal and r was depressed (< 0.3–0.5) between distant locations. Lesions of the medial geniculate body decreased sd but had little effect on r. Large lesions of the thalamus produced significant decreases in r but only a moderate number of changes in sd. Lesions of the latera lemniscus caused moderate changes in sd and r.

A Proof for Rhiel's Range Estimator of the Coefficient of Variation for Skewed Distributions

2007 ◽  
Vol 100 (1) ◽  
pp. 208-210 ◽  
Author(s):  
G. Steven Rhiel
Keyword(s):  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Research Study ◽  
Skewed Distributions ◽  
The Mean ◽  
Standard Deviations

In this research study is proof that the coefficient of variation ( CVhigh-low) calculated from the highest and lowest values in a set of data is applicable to specific skewed distributions with varying means and standard deviations. Earlier Rhiel provided values for dn, the standardized mean range, and an, an adjustment for bias in the range estimator of μ. These values are used in estimating the coefficient of variation from the range for skewed distributions. The dn and an values were specified for specific skewed distributions with a fixed mean and standard deviation. In this proof it is shown that the dn and an values are applicable for the specific skewed distributions when the mean and standard deviation can take on differing values. This will give the researcher confidence in using this statistic for skewed distributions regardless of the mean and standard deviation.

Alum Production from some Nigerian Kaolinite Deposits

2012 ◽  
Vol 7 ◽  
pp. 13-19 ◽  
Author(s):  
L.C. Edomwonyi-Otu ◽  
B.O. Aderemi ◽  
O. Edomwonyi-Otu ◽  
A. Simo ◽  
M. Maaza
Keyword(s):  
Standard Deviation ◽  
Surface Area ◽  
Science And Technology ◽  
Mineral Resources ◽  
Kaolinite Clay ◽  
Processing Technologies ◽  
Commercial Alumina ◽  
Bet Analysis ◽  
The Mean ◽  
Standard Deviations

The Development of Sustainable Processing Technologies for the Vast Mineral Resources Available in Nigeria and their Varied Applications Is a Major Pursuit by the Federal Ministry of Science and Technology. in this Work, Alum Was Produced from Three Different Kaolin Deposits in Nigeria Namely Kankara Brown, Bauchi and Kankara White by Acid Dealumination of the Metakaolin Obtained by Calcination of the Beneficiated Kaolinites and the Yields Were Measured to Ascertain the Process Repeatability. the Reproducibility Studies Carried Out on Samples from each Deposit Showed a Mean Yield of 80 %, 92 % and 87 % and Standard Deviation of 2.50 %, 1.063 % and 1.296 %, for Kankara Brown, Bauchi and Kankara White Respectively. the Values from the Three Deposits Fall within 3 Standard Deviations of the Mean in Accordance with the 68-95-99.7/three-Sigma Rule. the Alum Quality Also Compares Well with Available Commercial Alums in the Market. BET Analysis, of the Alumina Obtained by Calcination of the Alum (Kankara White), Gave a Surface Area of 192.2441m2/g Comparable to Commercial Alumina. these Results Suggest/establishes the Huge Possibility of Commercial Alum Production, Including Alumina, Using Kaolinite Clay from these Deposits as Starting Materials.

scholarly journals The GRIMMER test: A method for testing the validity of reported measures of variability

2016 ◽  
Author(s):  
Jordan Anaya
Keyword(s):  
Standard Deviation ◽  
Sample Size ◽  
Standard Error ◽  
Standard Errors ◽  
Rounding Error ◽  
Small Variance ◽  
The Mean ◽  
Standard Deviations ◽  
Mathematical Foundations ◽  
Repetitive Pattern

GRIMMER (Granularity-Related Inconsistency of Means Mapped to Error Repeats) builds upon the GRIM test and allows for testing whether reported measures of variability are mathematically possible. GRIMMER relies upon the statistical phenomenon that variances display a simple repetitive pattern when the data is discrete, i.e. granular. This observation allows for the generation of an algorithm that can quickly identify whether a reported statistic of any size or precision is consistent with the stated sample size and granularity. My implementation of the test is available at PrePubMed (http://www.prepubmed.org/grimmer) and currently allows for testing variances, standard deviations, and standard errors for integer data. It is possible to extend the test to other measures of variability such as deviation from the mean, or apply the test to non-integer data such as data reported to halves or tenths. The ability of the test to identify inconsistent statistics relies upon four factors: (1) the sample size; (2) the granularity of the data; (3) the precision (number of decimals) of the reported statistic; and (4) the size of the standard deviation or standard error (but not the variance). The test is most powerful when the sample size is small, the granularity is large, the statistic is reported to a large number of decimal places, and the standard deviation or standard error is small (variance is immune to size considerations). This test has important implications for any field that routinely reports statistics for granular data to at least two decimal places because it can help identify errors in publications, and should be used by journals during their initial screen of new submissions. The errors detected can be the result of anything from something as innocent as a typo or rounding error to large statistical mistakes or unfortunately even fraud. In this report I describe the mathematical foundations of the GRIMMER test and the algorithm I use to implement it.

scholarly journals Bone alignment after minimally invasive plate osteosynthesis of the tibia in dogs

2021 ◽  
Vol 51 (9) ◽  
Author(s):  
Jose Sergio Costa Junior ◽  
Rafael Manzini Dreibi ◽  
Guilherme Galhardo Franco ◽  
Luis Gustavo Gosuen Gonçalves Dias ◽  
Rogerio Giuffrida ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Minimally Invasive ◽  
Negative Correlation ◽  
Bone Healing ◽  
Plate Osteosynthesis ◽  
Image Intensifier ◽  
Tibial Fractures ◽  
Minimally Invasive Plate Osteosynthesis ◽  
The Mean ◽  
Image Intensifiers

ABSTRACT: This study assessed radiographically changes in tibial alignment in the frontal and sagittal planes in dogs that underwent minimally invasive plate osteosynthesis (MIPO) without the aid of image intensifiers. Radiographs of dogs with complete non-articular tibial fractures submitted to MIPO were included and evaluated, without the aid of a transoperative image intensifier and / or an association of implants. The tibial mechanical angles (mMPTA, mMDTA, mCaPTA and mCrDTA) were measured by three evaluators. The data obtained were compared with results from previously published studies. Twenty-seven animals were included in the study. The mean and standard deviation of the angular changes were as follows: mMPTA, 2.54° ± 3.10 (-1.1º to 8.7º); mMDTA, 0.03º ± 0.16 (-3.44º to 0.79º); mCaPTA, 37º ± 4.29 (-6.23º to 14.87º); and mCrDTA, 8.25° ± 5.53 (-0.2º to 17.28º). There was a negative correlation between “mCaPTA” and “mCrDTA”. MIPO of the tibia without using image intensifiers and implant association can potentially cause angular changes, which can lead to clinically relevant deformities after bone healing.

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