A one-way ANOVA test for functional data with graphical interpretation

A new functional ANOVA test, with a graphical interpretation of the result, is presented. The test is an extension of the global envelope test introduced by Myllymaki et al. (2017, Global envelope tests for spatial processes, J. R. Statist. Soc. B 79, 381--404, doi: 10.1111/rssb.12172). The graphical interpretation is realized by a global envelope which is drawn jointly for all samples of functions. If a mean function computed from the empirical data is out of the given envelope, the null hypothesis is rejected with the predetermined significance level $\alpha$. The advantages of the proposed one-way functional ANOVA are that it identifies the domains of the functions which are responsible for the potential rejection. We introduce two versions of this test: the first gives a graphical interpretation of the test results in the original space of the functions and the second immediately offers a post-hoc test by identifying the significant pair-wise differences between groups. The proposed tests rely on discretization of the functions, therefore the tests are also applicable in the multidimensional ANOVA problem. In the empirical part of the article, we demonstrate the use of the method by analyzing fiscal decentralization in European countries. The aim of the empirical analysis is to capture differences between the levels of government expenditure decentralization ratio among different groups of European countries. The idea behind, based on the existing literature, is straightforward: countries with a longer European integration history are supposed to decentralize more of their government expenditure. We use the government expenditure centralization ratios of 29 European Union and EFTA countries in period from 1995 to 2016 sorted into three groups according to the presumed level of European economic and political integration.Comment: arXiv admin note: text overlap with arXiv:1506.0164

HOME MEASUREMENT OF BLOOD PRESSURE: PRESENT PROBLEMS AND PERSPECTIVE IMPROVEMENTS

The most frequently performed health test is the measurement of blood pressure. Popularity of home measurement increased substantially with the introduction of inexpensive automatic instruments to the market. Accurate measurement of blood pressure is important for diagnosis and management of hypertension. Inaccuracies of measurement with automatic oscillometric instruments are caused by wrong size cuff and by errors in algorithmic measurement. The authors developed several perspective improvements in the measurement of systolic pressure. An experimental system for acquisition and processing of arterial pressure pulses facilitated the development of these methods. More accurate measurement of the systolic pressure was achieved with a dual-cuff method. A new method of wrist-cuff pulse analysis facilitated estimation of hemodynamics. Estimation of hemodynamics simultaneously with measurement of blood pressure provides the physician with more complete picture of the type of hypertension and it facilitates better diagnosis and management. An inexpensive commercial instrument based on the methods developed by the authors could be used by the patient in home care

Functional Age-Related Changes Within the Human Auditory System Studied by Audiometric Examination

Age related hearing loss (presbycusis) is one of the most common sensory deficits in the aging population. The main subjective ailment in the elderly is the deterioration of speech understanding, especially in a noisy environment, which cannot solely be explained by increased hearing thresholds. The examination methods used in presbycusis are primarily focused on the peripheral pathologies (e.g., hearing sensitivity measured by hearing thresholds), with only a limited capacity to detect the central lesion. In our study, auditory tests focused on central auditory abilities were used in addition to classical examination tests, with the aim to compare auditory abilities between an elderly group (elderly, mean age 70.4 years) and young controls (young, mean age 24.4 years) with clinically normal auditory thresholds, and to clarify the interactions between peripheral and central auditory impairments. Despite the fact that the elderly were selected to show natural age-related deterioration of hearing (auditory thresholds did not exceed 20 dB HL for main speech frequencies) and with clinically normal speech reception thresholds (SRTs), the detailed examination of their auditory functions revealed deteriorated processing of temporal parameters [gap detection threshold (GDT), interaural time difference (ITD) detection] which was partially responsible for the altered perception of distorted speech (speech in babble noise, gated speech). An analysis of interactions between peripheral and central auditory abilities, showed a stronger influence of peripheral function than temporal processing ability on speech perception in silence in the elderly with normal cognitive function. However, in a more natural environment mimicked by the addition of background noise, the role of temporal processing increased rapidly

Software for the Analysis of Species-Specific Vocalizations

Vocalization calls are behaviorally relevant complex sounds that typically contain several harmonics and show frequency and amplitude modulation. In this paper, an introduction to a software tool for the analysis of species-specific vocalizations is presented. The algorithm automatically or under user supervision detects time-varying amplitude and frequency parameters, which can serve for the statistical analysis of calls or as the substrate for the manipulation and synthesis of artificial calls. The described program and its results will be used in studying the representation of complex sounds in the central nervous system

Functional changes in the human auditory cortex in ageing.

Hearing loss, presbycusis, is one of the most common sensory declines in the ageing population. Presbycusis is characterised by a deterioration in the processing of temporal sound features as well as a decline in speech perception, thus indicating a possible central component. With the aim to explore the central component of presbycusis, we studied the function of the auditory cortex by functional MRI in two groups of elderly subjects (>65 years) and compared the results with young subjects (<lt;30 years). The elderly group with expressed presbycusis (EP) differed from the elderly group with mild presbycusis (MP) in hearing thresholds measured by pure tone audiometry, presence and amplitudes of transient otoacoustic emissions (TEOAE) and distortion-product oto-acoustic emissions (DPOAE), as well as in speech-understanding under noisy conditions. Acoustically evoked activity (pink noise centered around 350 Hz, 700 Hz, 1.5 kHz, 3 kHz, 8 kHz), recorded by BOLD fMRI from an area centered on Heschl's gyrus, was used to determine age-related changes at the level of the auditory cortex. The fMRI showed only minimal activation in response to the 8 kHz stimulation, despite the fact that all subjects heard the stimulus. Both elderly groups showed greater activation in response to acoustical stimuli in the temporal lobes in comparison with young subjects. In addition, activation in the right temporal lobe was more expressed than in the left temporal lobe in both elderly groups, whereas in the young control subjects (YC) leftward lateralization was present. No statistically significant differences in activation of the auditory cortex were found between the MP and EP groups. The greater extent of cortical activation in elderly subjects in comparison with young subjects, with an asymmetry towards the right side, may serve as a compensatory mechanism for the impaired processing of auditory information appearing as a consequence of ageing

Averaged cortical activity evoked by acoustic stimulation examined by fMRI in all 3 groups.

<p>A—YC, b—MP, c—EP; group statistics, p = 0.05 with FWE correction; red—pink noise centered at 350 Hz and 700 Hz; blue—pink noise centered at 1.5 kHz, 3 kHz and 8 kHz. The arrowheads accentuate an increase in the right AC activation in both elderly groups.</p

Speech discrimination score (SDS) in background babble noise.

<p>Level of babble noise was set at 65 and 70 dB. Average values with SEM, one way ANOVA, Tukey’s correction, * p<0.05.</p

Results of the pure tone audiometry in the extended high-frequency range in all three groups.

<p>Data shown as mean±SEM and medians (in case of no hearing sensation 110 dB was set as the threshold).</p