Search results for "Principal Component Analysis"
showing 10 items of 486 documents
Endometrial gene expression in the window of implantation is altered in obese women especially in association with polycystic ovary syndrome
2010
Objective To determine whether luteal phase endometrial transcriptome is altered in obese women during the window of implantation (WOI), considering the presence of infertility, fat distribution and association with polycystic ovary syndrome (PCOS). Design Prospective study. Setting University-affiliated infertility clinic, between May 2007 and March 2009. Patient(s) One control group of women with normal weight (n = 4), and four study groups of obese women (n = 6 each one) according to the association with infertility, PCOS, and ovarian stimulation. Intervention(s) The endometrium was biopsied 7 days after LH surge or hCG administration in 28 women. Main Outcome Measure(s) Endometrial gene…
Psycholinguistic norms for 320 fixed expressions (idioms and proverbs) in French
2018
International audience; We provide psycholinguistic norms for a new set of 160 French idiomatic expressions and 160 proverbs: knowledge, predictability, literality, compositionality, subjective and objective frequency, familiarity, age of acquisition (AoA), and length. Different analyses (reliability, descriptive statistics, correlations) performed on the norms are reported and discussed. The norms can be downloaded as supplemental material.
Prevalence of alexithymia in eating disorders in a clinical sample of 800 Mexican patients.
2019
The inability to identify, express feelings, and not distinguish between emotions and bodily sensations, is known as alexithymia. In 1988, it developed The Toronto Alexithymia Scale (TAS-20), consists of 20 items and three factors: a) difficulty of identifying feelings and differences between feelings and bodily sensations; b) difficulty of describing feelings; and c) externally oriented thinking. It's considered that people with eating disorders have specific deficits in identify and communicate their feelings.The present study has as purpose to the instrument validation.It was a cross-sectional study and psychometric character design of a single sample, formed of 435 persons suffering eat…
Distributed BOLD-response in association cortex vector state space predicts reaction time during selective attention.
2006
Human cortical information processing is thought to be dominated by distributed activity in vector state space (Churchland, P.S., Sejnowski, T.J., 1992. The Computational Brain. MIT Press, Cambridge.). In principle, it should be possible to quantify distributed brain activation with independent component analysis (ICA) through vector-based decomposition, i.e., through a separation of a mixture of sources. Using event-related functional magnetic resonance imaging (fMRI) during a selective attention-requiring task (visual oddball), we explored how the number of independent components within activated cortical areas is related to reaction time. Prior to ICA, the activated cortical areas were d…
From Vivaldi to Beatles and back: predicting lateralized brain responses to music.
2013
We aimed at predicting the temporal evolution of brain activity in naturalistic music listening conditions using a combination of neuroimaging and acoustic feature extraction. Participants were scanned using functional Magnetic Resonance Imaging (fMRI) while listening to two musical medleys, including pieces from various genres with and without lyrics. Regression models were built to predict voxel-wise brain activations which were then tested in a cross-validation setting in order to evaluate the robustness of the hence created models across stimuli. To further assess the generalizability of the models we extended the cross-validation procedure by including another dataset, which comprised …
On application of kernel PCA for generating stimulus features for fMRI during continuous music listening
2017
Abstract Background There has been growing interest towards naturalistic neuroimaging experiments, which deepen our understanding of how human brain processes and integrates incoming streams of multifaceted sensory information, as commonly occurs in real world. Music is a good example of such complex continuous phenomenon. In a few recent fMRI studies examining neural correlates of music in continuous listening settings, multiple perceptual attributes of music stimulus were represented by a set of high-level features, produced as the linear combination of the acoustic descriptors computationally extracted from the stimulus audio. New method fMRI data from naturalistic music listening experi…
Inter-joint coordination of posture on a seesaw device
2016
Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechan…
Factors Related to Women’s Psychological Distress during the COVID-19 Pandemic: Evidence from a Two-Wave Longitudinal Study
2021
Background. A growing body of research has highlighted the negative effects of the COVID-19 pandemic on women’s mental health. Previous studies showed that women have higher levels of depression, anxiety and PTSD, and worse psychological adjustment than men, which also persisted after the earlier phase of the pandemic. This study aimed to evaluate changes in women’s psychological distress during the pandemic and to evaluate the factors that have a more significant impact in predicting women’s psychological distress. Methods. This two-wave longitudinal study (T1 = Italian first lockdown, and T2 = second phase, when the restrictive measures were eased) involved 893 women (Mage = 36.45, SD = 1…
Association between dietary and beverage consumption patterns in the SUN (Seguimiento Universidad de Navarra) cohort study.
2008
Objective: The objective of the present study was to determine the dietary patterns of a Mediterranean cohort and relate them to the observed patterns of beverage consumption. Design: Prospective cohort study. Dietary habits were assessed with a semiquantitative FFQ validated in Spain. A principal components factor analysis was used to identify dietary patterns and to classify subjects according to their adherence to these patterns. The association between adherence to each dietary pattern and beverage consumption was assessed cross-sectionally. In a longitudinal analysis (2-year follow-up), the relationship between adherence to the baseline dietary patterns and the likelihood of changing a…
''Alterations with Movement Duration in the Kinematics of a Whole Body Pointing Movement''
2013
Casteran, Matthieu | Manckoundia, Patrick | Pozzo, Thierry | Thomas, Elizabeth; International audience; ''Our aim was to investigate how the organization of a whole body movement is altered when movement duration (MD) is varied. Subjects performed the same whole body pointing movement over long, normal and short MDs. The kinematic trajectories were then analyzed on a normalized time base. A principal components analysis (PCA) revealed that the degree of coordination between the elevation angles of the body did not change with MD. This lack of significant differences in the coordination was interesting given that small spatial and temporal differences were observed in the individual kinemati…