Activité cérébrale reliée à la rétention des sons en mémoire à court-terme auditive

Une variété d’opérations cognitives dépend de la capacité de retenir de l’information auditive pour une courte période de temps. Notamment l’information auditive prend son sens avec le temps; la rétention d’un son disparu permet donc de mieux comprendre sa signification dans le contexte auditif et mène ultimement à une interaction réussite avec l’environnement. L’objectif de cette thèse était d’étudier l’activité cérébrale reliée à la rétention des sons et, ce faisant, parvenir à une meilleure compréhension des mécanismes de bas niveau de la mémoire à court-terme auditive. Trois études empiriques se sont penchées sur différents aspects de la rétention des sons. Le premier article avait pour but d’étudier les corrélats électrophysiologiques de la rétention des sons variant en timbre en utilisant la technique des potentiels reliés aux événements. Une composante fronto-centrale variant avec la charge mnésique a été ainsi révélée. Dans le deuxième article, le patron électro-oscillatoire de la rétention a été exploré. Cette étude a dévoilé une augmentation de l’amplitude variant avec la charge mnésique dans la bande alpha pendant la rétention des sons ainsi qu’une dissociation entre l’activité oscillatoire observée pendant la rétention et celle observée pendant la présentation des sons test. En démontrant des différentes modulations des amplitudes dans la bande alpha et la bande beta, cette étude a pu révéler des processus distincts mais interdépendants de la mémoire à court-terme auditive. Le troisième article a davantage visé à mieux connaître les structures cérébrales soutenant la rétention de sons. L’activité cérébrale a été mesurée avec la magnétoencéphalographie, et des localisations des sources ont été effectuées à partir de ces données. Les résultats ont dévoilé l’implication d’un réseau cérébral contenant des structures temporales, frontales, et pariétales qui était plus important dans l’hémisphère droit que dans l’hémisphère gauche. Les résultats des études empiriques ont permis de souligner l’aspect sensoriel de la mémoire à court-terme auditive et de montrer des similarités dans la rétention de différentes caractéristiques tonales. Dans leur ensemble, les études ont contribué à l’identification des processus neuronaux reliés à la rétention des sons en étudiant l’activité électromagnétique et l’implication des structures cérébrales correspondantes sur une échelle temporelle fine.The capacity to retain auditory information for a short period of time is fundamental for a variety of cognitive operations. Sounds, in particular, often do not reveal their meaning before being integrated in their temporal context; the retention of tones that are no longer present in the environment is thus necessary for understanding the significance of auditory information. Retaining tones ultimately leads to a successful interaction with the environment. The goal of this thesis was to study brain activity related to the retention of tones, thereby providing a better understanding of low-level mechanisms related to auditory short-term memory. Three empirical studies have been conducted, each of them focusing on a different aspect of the retention of tones. The first article investigated electrophysiological correlates of the retention of tones differing in timbre using the event-related potential technique. The electrophysiological results revealed a fronto-central component that varied with memory load. In the second article, the oscillatory pattern of electric brain activity was explored using electroencephalography. The results revealed that alpha band amplitudes were modulated by memory load during retention. Furthermore, a dissociation of oscillatory activity between the retention of tones and the comparison of test tones against retained tone representations was observed. This study also revealed distinct but interrelated processes taking place at the same time by showing specific amplitude modulations in the alpha and beta bands. The third article focused more on brain areas underpinning the retention of tones. Brain activity was measured with magnetoencephalography and subsequent source localisations were performed. The results suggested the implication of a network of temporal, frontal, and parietal brain areas which was more pronounced in the right hemisphere than in the left hemisphere. The results of the empirical studies emphasized the sensory aspect of auditory short-term memory. In addition, they revealed similarities between the retention of tones differing in fundamental sound characteristics such as timbre and pitch. Considered as a whole, the studies of this thesis contributed to the identification of neural processing underlying the retention of tones by studying electromagnetic brain activity and the implication of corresponding brain areas on a fine temporal scale

Not what u expect:Effects of prediction errors on item memory

The characterization of the relationship between predictions and one-shot episodic encoding poses an important challenge for memory research. On the one hand, events that are compatible with our previous knowledge are thought to be remembered better than incompatible ones. On the other hand, unexpected situations, by virtue of their novelty, are known to cause enhanced learning. Several theoretical accounts try to solve this apparent paradox by conceptualizing prediction error (PE) as a continuum ranging from low PE (for expectation-matching events) to high PE (for expectation-mismatching ones). Under such a framework, the relationship between PE and memory encoding would be described by a U-shape function with higher memory performance for extreme levels of PE and lower memory for middle levels of PE. In this study, we tested the framework by using a gradual manipulation of the strength of association between scenes and objects to render different levels of PE and then tested for item memory of the (mis)matching events. In two experiments, in contrast to what was anticipated, recognition memory for object identity followed an inverted U-shape as a function of PE, with higher performance for intermediate levels of PE. Furthermore, in two additional experiments, we showed the relevance of explicit predictions at encoding to reveal such an inverted U pattern, thus providing the boundary conditions of the effect. We discussed our findings in light of existing literature relating PE and episodic memory, pointing out the potential roles of uncertainty in the environment, and the importance of the cognitive operations underlying encoding tasks

Diagnosis and treatment of schizotypal personality disorder: evidence from a systematic review

The main objective of this review was to evaluate studies on the diagnosis, treatment, and course of schizotypal personality disorder and to provide a clinical guidance on the basis of that evaluation. A systematic search in the PubMed/MEDLINE databases was conducted. Two independent reviewers extracted and assessed the quality of the data. A total of 54 studies were eligible for inclusion: 18 were on diagnostic instruments;22, on pharmacological treatment;3, on psychotherapy;and 13, on the longitudinal course of the disease. We identified several suitable and reliable questionnaires for screening (PDQ-4+ and SPQ) and diagnosing (SIDP, SIDP-R, and SCID-II) schizotypal personality disorder. Second-generation antipsychotics (mainly risperidone) were the most often studied drug class and were described as beneficial. Studies on the longitudinal course described a moderate remission rate and possible conversion rates to other schizophrenia spectrum disorders. Because of the heterogeneity of the studies and the small sample sizes, it is not yet possible to make evidence-based recommendations for treatment. This is a systematic evaluation of diagnostic instruments and treatment studies in schizotypal personality disorder. We conclude that there is currently only limited evidence on which to base treatment decisions in this disorder. Larger interventional trials are needed to provide the data for evidence-based recommendations

Häusliche Trinkwasserinstallation von Fällen mit Legionärskrankheit: Effizient ermitteln – systemisch sanieren

Im Rahmen der von 2016-2020 durchgeführten Berliner LeTriWa-Studie (LeTriWa = Legionellen in der Trinkwasserinstallation) wurden 19 nach Trinkwasserverordnung untersuchungspflichtige Trinkwasserinstallationen untersucht, wo im zugehörigen Haushalt eine Fallperson wohnhaft war. Im Beitrag wird dargestellt, an welchen Stellen in der Trinkwasserinstallation des Gebäudes und des betroffenen Haushalts monoklonale Antikörper (MAb) Typ 3/1-positive (virulenzassoziierte) Stämme mit welcher Wahrscheinlichkeit zu finden waren und ob auch Kaltwasserproben positiv waren. Wir untersuchten, welche Konsequenzen sich aus den Ergebnissen von Standard-Haushaltsproben sowie den Ergebnissen aus einer weitergehenden Untersuchung für die Ermittlung von Fällen von Legionärskrankheit generell ableiten lassen

Recent smell loss is the best predictor of COVID-19 among individuals with recent respiratory symptoms

In a preregistered, cross-sectional study we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC=0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable

The role of response set overlap for flexibility and cognitive control in auditory multitasking

Highlights • We introduced a new variant of auditory task-switching. • Motor response set overlap was varied systematically across two experiments. • Switch costs and congruency effects were similar for manual and vocal responses. • Switch costs were not reduced with reduced motor response set overlap. • We dissociated effects of motor response modality from motor response set overlap. Abstract We developed a new variant of auditory task-switching in order to systematically investigate shifting and cognitive control in auditory task-switching and their relation to motor response overlap in a comprehensive way. In two experiments, participants classified either pitch or loudness of a simple tone as either low or high, hence, both tasks were constructed around a common underlying dimension ranging from low to high. In Experiment 1, response sets overlapped in both category and motor modality (both manual), whereas each task was related to a specific response category and motor response modality (manual vs. vocal) in Experiment 2. The data revealed reliable switch costs that were, contrary to our expectations, not reduced with reduced response set overlap. In addition, we found reliable congruency effects and their sequential modulation in both experiments with manual as well as vocal responses, and in the absence of competing motor activation (i.e., without motor response overlap). Congruency effects after auditory task switches were smaller when response sets did not overlap. Our data thus provides an important empirical generalization of known effects to auditory stimuli as well as with both manual and vocal responses. In addition, we demonstrated that reduced congruency effects after switches for non-overlapping response sets were due to the extent of overlap between different response sets in task-switching

Preparing auditory task switching in a task with overlapping and non-overlapping response sets

We used a variant of cued auditory task switching to investigate task preparation and its relation to response-set overlap. Previous studies found increased interference with overlapping response sets across tasks relative to non-overlapping motor response sets. In the present experiments, participants classified either pitch or loudness of a simple tone as low or high, hence, both tasks were constructed around common underlying integrated semantic categories ranging from low to high. Manual responses overlapped in both category and modality for both tasks in Experiment 1A, whereas each task was related to a specific response category and response modality (manual vs. vocal) in Experiment 1B. Focusing on the manual responses in both experiments, the data showed that non-overlapping response sets (Experiment 1B) resulted in a decreased congruency effect, suggesting reduced response-based crosstalk and thus better task shielding, but at the same time switch costs were increased, suggesting less efficient switching between task sets. Moreover, varying preparation time (cue-stimulus interval, CSI) showed that long CSI led to better performance overall. Our results thus suggest that when non-overlapping response sets share common semantic categories across tasks, there is no general benefit over overlapping response sets