Contributions of the Event-Related Potential Technique to Narcissism Research Exemplified by Variations of Admiration and Rivalry with Face and Error Processing ERP Components

Highly narcissistic individuals perceive reality in favour of their grandiosity. Research has examined these distorted perceptions thoroughly at the self-report and behavioural level. However, we do know little about the underlying neural processes that lead to these distorted perceptions. The event-related potential (ERP) technique appears well-suited to uncover these processes and elucidate intrapersonal self-regulation in narcissism. Surprisingly, narcissism research has hardly applied this method. The current thesis describes two studies that relate Admiration and Rivalry (two narcissism dimensions; Back et al., 2013) to face- and error-processing ERP components and, thereby, illustrates the usefulness of the ERP technique for narcissism research. Study 1 analysed variations of Admiration and Rivalry with two face processing ERP components, P1 and N170, which were registered while participants (N = 59) viewed their own, a celebrity’s, and a stranger’s face. Multilevel models revealed variations of Admiration with the P1 and variations of Rivalry with the P1 and the N170. Study 2 explored variations of Admiration and Rivalry with two error processing ERP components, Ne and Pe, which were recorded while participants (N = 89) performed a speeded Go/noGo task under ego-threatening conditions. Multilevel models discovered variations of Rivalry with Ne but did not indicate variations of either Admiration or Rivalry with the Pe. Given the respective ERP literature, the results of both studies pointed to several intrapersonal self-regulation strategies that highly narcissistic individuals might use to protect and enhance their grandiosity, including attentional inhibition, an expectancy-driven perception, rapid mobilisation of defensive systems, and a trait-like defensive reactivity. Thereby, both studies demonstrated that ERP research can generate revealing and unique data on narcissistic functioning. In light of the current results and the global neuronal workspace theory, which provides further ideas on the neural mechanisms underlying narcissistic perception, the thesis discusses promising future neuro-cognitive research on narcissism, which might help us better understand this complex construct

Pseudo random postfix orthogonal frequency division multiplexing

Dans le contexte de cette thèse, un nouveau schéma de modulation est proposé en introduisant une séquence déterministe pondérée par un scalaire pseudo aléatoire: Pseudo Random Postfix OFDM (PRP-OFDM). Il est proposé de remplacer l'extension cyclique du Cyclic Prefix OFDM (CP-OFDM) classique par un postfixe connu à l'émetteur et au récepteur. Grâce a la nature déterministe de cette séquence, le récepteur peut exploiter sa connaissance afin d'estimer la réponse impulsionnelle du canal de propagation par une approche semi-aveugle d'ordre un. Ceci permet d'éviter l'introduction des séquences d'apprentissage ou des symboles pilotes. L'efficacité spectrale du système est donc améliorée par rapport à des architectures classiques comme le CP-OFDM, Zero-Padded OFDM (ZP-OFDM), etc. Par la suite, plusieurs algorithmes sont proposés. Ceux-ci permettent d'effectuer une estimation du canal dans un contexte statique et dans un contexte de mobilité. En delà, la dérivation d'une séquence de postfixe optimisée est présentée. Ensuite, les études sont étendues à un raffinement de la synchronisation temporelle et fréquentielle d'une estimation initiale approximative. Après, une utilisation optimale des codes LDPC (Low Density Parity Check) est discutée dans le contexte de l'OFDM: il est montré comment il faut attribuer des mots de codes LDPC à des porteuses OFDM en prenant en compte une connaissance préalable du canal de propagation à l'émetteur. Le schéma de modulation PRP-OFDM est une de plusieures propositions dans le contexte du projet européen IST-BroadWay et plus récemment par IST-WINNER.This thesis presents a novel Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme replacing the cyclic extension known from classical Cyclic Prefix OFDM (CP-OFDM) by a deterministic pseudo randomly weighted postfix sequence: {\bf Pseudo Random Postfix OFDM (PRP-OFDM). The postfix sequence is known to both, the transmitter and the receiver and can thus be exploited for order-one (semi-)blind channel estimation without any repeated introduction of learning symbols and/or pilot tones within a frame. The corresponding overhead, usually present in CP-OFDM and Zero-Padded OFDM (ZP-OFDM) systems, is thus reduced or even avoided leading to an improved spectral efficiency. Suitable approaches, including postfix design considerations, are discussed for both single-antenna and multiple-antennas systems in static and time-variant environments.The studies are then further extended to time and frequency synchronization \cite{ieeewireless.muck06}. It is shown how to exploit the pseudo-randomly weighted postfixes for the refinement of an initial (rough) time/frequency synchronization. This part is followed by a study on Low-Density Parity Check (LDPC) coded OFDM systems, proposing an adaptation of the LDPC code word mapping onto OFDM carriers to the constraints of OFDM systems in a frequency selective fading environment; this approach can be interpreted as the design of an adaptive interleaver for a specific context. For a given irregular LDPC code, a low-complexity algorithm is derived indicating which code word bits should be modulated onto which OFDM carriers in function of a known or estimated channel impulse response.PARIS-CNAM (751032301) / SudocPARIS-Télécom ParisTech (751132302) / SudocSudocFranceF

Perfectionism-related variations in error processing in a task with increased response selection complexity

Perfectionists strive for a flawless performance because they are intrinsically motivated to set and achieve high goals (personal standards perfectionism; PSP) and/or because they are afraid to be negatively evaluated by others (evaluative concern perfectionism; ECP). We investigated the differential relationships of these perfectionism dimensions with performance, post-response adaptation, error processing (reflected by two components of the event-related potential: error/correct negativity – Ne/c; error/correct positivity – Pe/c) and error detection. In contrast to previous studies, we employed a task with increased response selection complexity providing more room for perfectionistic dispositions to manifest themselves. Although ECP was related to indicators of increased preoccupation with errors, high-EC perfectionists made more errors than low-EC perfectionists. This observation may be explained by insufficient early error processing as indicated by a reduced Ne/c effect and a lack of post-response adaptation. PSP had a moderating effect on the relationship between ECP and early error processing. Our results provide evidence that pure-EC perfectionists may spend many of their cognitive resources on error-related contents and worrying, leaving less capacity for cognitive control and thus producing a structural lack of error processing

Larger error negativity peak amplitudes for accuracy versus speed instructions may reflect more neuro-cognitive alignment, not more intense error processing

Article number: 2259 (2023

Remote sensing applications for assessing water-related risks and its interdependencies with land cover change and biodiversity in southern Africa

Given the ongoing population growth and changes in land management as well as projected climate scenarios, a key challenge in the African sub-Saharan countries is to secure water at sufficient quality and quantity for both the stability of ecosystems, with their functions and services and for human use. Changing conditions will severely affect hydrological pattern in southern Africa, for example in terms of increasing flood frequencies and magnitudes or change in groundwater levels, which in turn will create even more pressure on existing land management pattern and biodiversity. To monitor and assess such interrelated phenomena in data scarce regions like southern Africa, innovative remote sensing data and techniques can be successfully applied. Three case studies addressing flood monitoring, wetland inundation variability and groundwater recharge in the SASSCAL (Southern African Science Service Centre for Climate Change and Adaptive Land Management) region demonstrate the potential of optical and radar satellite products to assess water-related risks and associated impacts on land cover change and biodiversity in Southern African landscapes

Prevalence of sexual dysfunction and impact of contraception in female German medical students

Female sexual dysfunction (FSD) is a very common disorder, with an estimated prevalence of having at least one sexual dysfunction of about 40%

Is It Possible to Replace Conventional Radiography (CR) with a Dose Neutral Computed Tomography (CT) of the Cervical Spine in Emergency Radiology—An Experimental Cadaver Study

The purpose of this experimental study on recently deceased human cadavers was to investigate whether (I) the radiation exposure of the cervical spine CT can be reduced comparable to a dose level of conventional radiography (CR); and (II) whether and which human body parameters can be predictive for higher dose reduction potential (in this context). Materials and Methods: Seventy serial CT scans of the cervical spine of 10 human cadavers undergoing postmortem virtual autopsy were taken using stepwise decreasing upper limits of the tube current (300 mAs, 150 mAs, 110 mAs, 80 mAs, 60 mAs, 40 mAs, and 20 mAs) at 120 kVp. An additional scan acquired at a fixed tube current of 300 mAs served as a reference. Images were reconstructed with filtered back projection and the upper (C1-4) and lower (C4-7) cervical spine were evaluated by three blinded readers for image quality, regarding diagnostic value and resolution of anatomical structures according to a semiquantitative three-point-scale. Dose values and individual physical parameters were recorded. The relationship of diagnostic IQ, dose reduction level, and patients’ physical parameters were investigated. The high-contrast resolution of the applied CT protocols was tested in an additional phantom study. Results: The IQ of the upper cervical spine was diagnostic at 1.69 ± 0.58 mGy (CTDI) corresponding to 0.20 ± 0.07 mSv (effective dose) in all cadavers. IQ of the lower cervical spine was diagnostic at 4.77 ± 1.86 mGy corresponding to 0.560 ± 0.21 mSv (effective dose) in seven cadavers and at 2.60 ± 0.93 mGy corresponding to 0.31 ± 0.11 mSv in four cadavers. Significant correlation was detected for BMI (0.8366; p = 0.002548) and the anteroposterior (a.p.) chest diameter (0.8363; p = 0.002566), shoulder positioning (0.79799; p = 0.00995), and radiation exposure. Conclusions: Conventional radiography can be replaced with a nearly dose-neutral CT scan of the cervical spine