Activation of Carotid Baroreceptors and Respiratory Resistance: Disappearance of the Respiratory Component of Baroreflex in the Course of Aging

Wstęp Jednym z efektorów odruchu z baroreceptorów zatokowych są drogi oddechowe. Na uwagę zasługuje wpływ pobudzenia baroreceptorów zatokowych na opór oddechowy u ludzi w różnym wieku. Materiał i metody Badaniom poddano 125 zdrowych mężczyzn w różnych grupach wiekowych. U wszystkich badanych analizowano odpowiedź sercową (wydłużenie odstępu R-R EKG) i zmiany oporu oddechowego w odpowiedzi na pobudzenie baroreceptorów zatok szyjnych podciśnieniem aplikowanym od zewnątrz na okolicę zatok szyjnych. Opór oddechowy mierzono metodą oscylacyjną. Wyniki W młodszych grupach wiekowych (21-40 lat) obserwowano spadek oporu obwodowego w odpowiedzi na pobudzenie baroreceptorów tętniczych. Reakcja ta była stopniowo coraz mniej wyraźna u badanych z coraz starszych grup wiekowych, a u osób w wieku 51-70 lat całkowicie zanikła. Odpowiedź sercowa była mniejsza w kolejnych grupach wiekowych. Wnioski Uzyskane wyniki świadczą o zmniejszającej się wraz z wiekiem efektywności odruchu z baroreceptorów zatokowych, obejmującej zarówno komponent sercowy, jak i oddechowy odruchu.Background Previous study shows a respiratory effector of carotid baroreceptor activation: the respiratory resistance. In the present study the age-related changes of respiratory response to carotid baroreceptor activation were studied. Material and methods 125 healthy men 21-70 years old were involved in the study. The heart responses (the increase in R-R interval) and reflex changes of respiratory resistance were analysed during activation of carotid baroreceptors. Results In the younger groups of subjects (21-40) a brief decrease of respiratory resistance was observed in response to carotid baroreceptors activation. In the course of aging we found a decrease of heart response and a disappearance of respiratory response. Conclusions We suggest that both components of carotid baroreceptors reflex: cardiac and respiratory, are impaired during biological aging

Why are we not flooded by involuntary thoughts about the past and future? Testing the cognitive inhibition dependency hypothesis

© The Author(s) 2018In everyday life, involuntary thoughts about future plans and events occur as often as involuntary thoughts about the past. However, compared to involuntary autobiographical memories (IAMs), such episodic involuntary future thoughts (IFTs) have become a focus of study only recently. The aim of the present investigation was to examine why we are not constantly flooded by IFTs and IAMs given that they are often triggered by incidental cues while performing undemanding activities. One possibility is that activated thoughts are suppressed by the inhibitory control mechanism, and therefore depleting inhibitory control should enhance the frequency of both IFTs and IAMs. We report an experiment with a between-subjects design, in which participants in the depleted inhibition condition performed a 60-min high-conflict Stroop task before completing a laboratory vigilance task measuring the frequency of IFTs and IAMs. Participants in the intact inhibition condition performed a version of the Stroop task that did not deplete inhibitory control. To control for physical and mental fatigue resulting from performing the 60-min Stroop tasks in experimental conditions, participants in the control condition completed only the vigilance task. Contrary to predictions, the number of IFTs and IAMs reported during the vigilance task, using the probe-caught method, did not differ across conditions. However, manipulation checks showed that participants’ inhibitory resources were reduced in the depleted inhibition condition, and participants were more tired in the experimental than in the control conditions. These initial findings suggest that neither inhibitory control nor physical and mental fatigue affect the frequency of IFTs and IAMs.Peer reviewedFinal Published versio

The role of inhibitory control and ADHD symptoms in the occurrence of involuntary thoughts about the past and future : an individual differences study

© 2021 Elsevier Inc. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.concog.2021.103208The present study focused on involuntary thoughts about personal past events (i.e., involuntary autobiographical memories; IAMs), and involuntary thoughts about future events and plans (i.e., involuntary future thoughts; IFTs). The frequency of these involuntary thoughts is influenced by cognitive demands of ongoing activities, but the exact underlying mechanism(s) has yet to be revealed. The present study tested two possible explanations: (1) the special inhibitory mechanism switches on when one is engaged in attentionally demanding activities; (2) different levels of cognitive load interfere with cue-noticing that act as triggers for IAMs and IFTs. We report a study with pre-selected groups of participants that differed in terms of their individual level of inhibitory control capacity (high vs. low), and completed both standard and attentionally demanding versions of a laboratory vigilance task with irrelevant cue-words to trigger IAMs and IFTs, and random thought-probes to measure their frequency. To examine the level of incidental cue-noticing, participants also completed an unexpected cue-recognition task. Despite large differences between groups in inhibitory control capacity, the number of IFTs and IAMs, reported in the attentionally demanding condition, was comparable. In addition, high cognitive load reduced the number of IAMs, but not IFTs. Finally, the recognition of incidental cues encountered in the vigilance task was reduced under high cognitive load condition, indicating that poor cue-noticing may be the main underlying mechanism of cognitive load effect rather than the lack of inhibitory resources needed to suppress involuntary retrieval. This and other possible mechanisms and avenues for future research are discussed.Peer reviewe