35 research outputs found
Neural Responses to Heartbeats in the Default Network Encode the Self in Spontaneous Thoughts
The default network (DN) has been consistently associated with self-related cognition, but also to bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line with theories proposing that selfhood is grounded in the neural monitoring of internal organs, such as the heart. We measured with magnetoencephalograhy neural responses evoked by heartbeats while human participants freely mind-wandered. When interrupted by a visual stimulus at random intervals, participants scored the self-relatedness of the interrupted thought. They evaluated their involvement as the first-person perspective subject or agent in the thought (âIâ), and on another scale to what degree they were thinking about themselves (âMeâ). During the interrupted thought, neural responses to heartbeats in two regions of the DN, the ventral precuneus and the ventromedial prefrontal cortex, covaried, respectively, with the âIâ and the âMeâ dimensions of the self, even at the single-trial level. No covariation between self-relatedness and peripheral autonomic measures (heart rate, heart rate variability, pupil diameter, electrodermal activity, respiration rate, and phase) or alpha power was observed. Our results reveal a direct link between selfhood and neural responses to heartbeats in the DN and thus directly support theories grounding selfhood in the neural monitoring of visceral inputs. More generally, the tight functional coupling between self-related processing and cardiac monitoring observed here implies that, even in the absence of measured changes in peripheral bodily measures, physiological and cognitive functions have to be considered jointly in the DN
Afferent cardiac signals modulate attentional engagement to low spatial frequency fearful faces
Despite the growing consensus that the continuous dynamic cortical representations of internal bodily states shape the subjective experience of emotions, physiological arousal is typically considered only a consequence and rarely a determinant of the emotional experience. Recent experimental approaches study how afferent autonomic signals from the heart modulate the processing of sensory information by focussing on the phasic properties of arterial baroreceptor firing that is active during cardiac systole and quiescent during cardiac diastole. For example, baroreceptor activation has been shown to enhance the processing of threat-signalling stimuli. Here, we investigate the role of cardiac afferent signals in the rapid engagement and disengagement of attention to fear stimuli. In an adapted version of the emotional attentional cueing paradigm, we timed the presentation of cues, either fearful or neutral faces, to coincide with the different phases of the cardiac cycle. Moreover, we presented cues with different spatial frequency ranges to investigate how these interoceptive signals influence the processing of visual information. Results revealed a selective enhancement of attentional engagement to low spatial frequency fearful faces presented during cardiac systole relative to diastole. No cardiac cycle effects were observed to high spatial frequency nor broad spatial frequency cues. These findings expand our mechanistic understanding of how bodyâbrain interactions may impact the visual processing of fearful stimuli and contribute to the increased attentional capture of threat signals
Heartbeat Counting is Unrelated to Heartbeat Detection::A Comparison of Methods to Quantify Interoception
Neuroimaging the consciousness of self: Review, and conceptual-methodological framework
We review neuroimaging research investigating self-referential processing (SRP), that is, how we respond to stimuli that reference ourselves, prefaced by a lexical-thematic analysis of words indicative of âself-feelingsâ. We consider SRP as occurring verbally (V-SRP) and non-verbally (NV-SRP), both in the controlled, âtop-downâ form of introspective and interoceptive tasks, respectively, as well as in the âbottom-upâ spontaneous or automatic form of âmind wanderingâ and âbody wanderingâ that occurs during resting state. Our review leads us to outline a conceptual and methodological framework for future SRP research that we briefly apply toward understanding certain psychological and neurological disorders symptomatically associated with abnormal SRP. Our discussion is partly guided by William Jamesâ original writings on the consciousness of self
Measures of CNS-Autonomic Interaction and Responsiveness in Disorder of Consciousness
Neuroimaging studies have demonstrated functional interactions between autonomic (ANS) and brain (CNS) structures involved in higher brain functions, including attention and conscious processes. These interactions have been described by the Central Autonomic Network (CAN), a concept model based on the brain-heart two-way integrated interaction. Heart rate variability (HRV) measures proved reliable as non-invasive descriptors of the ANS-CNS function setup and are thought to reflect higher brain functions. Autonomic function, ANS-mediated responsiveness and the ANS-CNS interaction qualify as possible independent indicators for clinical functional assessment and prognosis in Disorders of Consciousness (DoC). HRV has proved helpful to investigate residual responsiveness in DoC and predict clinical recovery. Variability due to internal (e.g. homeostatic and circadian processes) and environmental factors remains a key independent variable and systematic research with this regard is warranted. The interest in bidirectional ANS-CNS interactions in a variety of physiopathological conditions is growing, however these interactions have not been extensively investigated in DoC. In this brief review we illustrate the potentiality of brain-heart investigation by means of HRV analysis in assessing patients with DoC. The authorsâ opinion is that this easy, inexpensive and non-invasive approach may provide useful information in the clinical assessment of this challenging patient population
Ancrer le soi au traitement des signaux viscéraux par le cerveau : comment les réponses neuronales aux battements cardiaques encodent le soi
The self has been hypothesized to be anchored in the neural monitoring of visceral signals; yet experimental evidence is scarce. The goal of this thesis was to address this question, by testing whether we could find a link between heart-brain coupling and the self. We operationalized the concept of self by defining two self-dimensions: the experiential âIâ and the introspective âMeâ. We showed in a first magnetoencephalography (MEG) experiment, that the self-relatedness of spontaneous thoughts was encoded in the amplitude of heartbeat-evoked responses (HERs), in midline regions of the default-network. HERs in the posterior cingulate cortex / ventral precuneus encoded the âIâ dimension, whereas the âMeâ dimension was associated with HERs in the ventromedial prefrontal cortex (vmPFC). In addition, these results were specific to each self-dimension.In a second study, we extended these results using intracranial recordings and new analyses of the MEG data. Here, HER amplitude co-varied with the self-relatedness of spontaneous thoughts, at the single trial level. Moreover, an analysis of the right anterior insula showed that HERs in this region were also associated with the âIâ. A third study aimed at testing these results in the context of oriented thoughts, in an imagination task. We found that HER amplitude in medial motor regions (anterior precuneus, mid-cingulate and supplementary motor area), and vmPFC, varied depending on whether the self or a friend was being imagined. Cardiac signals could contribute to a body-centered reference frame, to which the brain would refer to in order to tag thoughts as being self-related. This could be a mechanism for implementing the self.Les thĂ©ories sur le soi ont postulĂ© que celui-ci serait ancrĂ© dans le suivi des signaux viscĂ©raux par le cerveau. Cependant, peu de preuves expĂ©rimentales soutiennent ce postulat. Lâobjectif de cette thĂšse Ă©tait de tester si on peut trouver un lien entre couplage cĆur-cerveau et soi. Nous avons opĂ©rationnalisĂ© le concept de soi en dĂ©finissant deux dimensions: le «Je», expĂ©rientiel, et le «Moi», introspectif.Nous avons dâabord montrĂ©, en magnĂ©toencĂ©phalographie, que le rapport au soi des pensĂ©es spontanĂ©es est encodĂ© dans lâamplitude des rĂ©ponses Ă©voquĂ©es aux battements cardiaques (heartbeat-evoked responses, HERs), dans les rĂ©gions mĂ©diales du rĂ©seau du mode par dĂ©faut. Les HERs dans le cortex cingulaire postĂ©rieur et precuneus ventral encodent le «Je», alors que la dimension «Moi» est associĂ©e Ă des HERs dans le cortex prĂ©frontal ventromĂ©dian. De plus, ces rĂ©sultats sont spĂ©cifiques de chacune des dimensions du soi.Nous avons ensuite Ă©tendu ces rĂ©sultats Ă lâaide dâenregistrements intracĂ©rĂ©braux. Nous avons montrĂ© une covariation entre lâamplitude des HERs et le rapport au soi des pensĂ©es, essai par essai. Une analyse de lâinsula antĂ©rieure droite a dĂ©montrĂ© que les HERs dans cette rĂ©gion sont modulĂ©s par la dimension «Je».Dans une tĂąche dâimagination, nous avons trouvĂ© que dans les rĂ©gions motrices mĂ©diales et le cortex prĂ©frontal ventromĂ©dian, lâamplitude des HERs varie en fonction de la personne imaginĂ©e, soi-mĂȘme ou un ami.Les signaux cardiaques pourraient donc contribuer Ă lâĂ©tablissement dâun rĂ©fĂ©rentiel centrĂ© sur le corps, utilisĂ© par le cerveau pour attribuer un «label soi» aux pensĂ©es. Ceci pourrait constituer un mĂ©canisme pour lâimplĂ©mentation du soi
Neural responses to heartbeats distinguish self from other during imagination
International audienc
The Journal of neuroscience : the official journal of the Society for Neuroscience
The default network (DN) has been consistently associated with self-related cognition, but also to bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line with theories proposing that selfhood is grounded in the neural monitoring of internal organs, such as the heart. We measured with magnetoencephalograhy neural responses evoked by heartbeats while human participants freely mind-wandered. When interrupted by a visual stimulus at random intervals, participants scored the self-relatedness of the interrupted thought. They evaluated their involvement as the first-person perspective subject or agent in the thought ("I"), and on another scale to what degree they were thinking about themselves ("Me"). During the interrupted thought, neural responses to heartbeats in two regions of the DN, the ventral precuneus and the ventromedial prefrontal cortex, covaried, respectively, with the "I" and the "Me" dimensions of the self, even at the single-trial level. No covariation between self-relatedness and peripheral autonomic measures (heart rate, heart rate variability, pupil diameter, electrodermal activity, respiration rate, and phase) or alpha power was observed. Our results reveal a direct link between selfhood and neural responses to heartbeats in the DN and thus directly support theories grounding selfhood in the neural monitoring of visceral inputs. More generally, the tight functional coupling between self-related processing and cardiac monitoring observed here implies that, even in the absence of measured changes in peripheral bodily measures, physiological and cognitive functions have to be considered jointly in the DN. SIGNIFICANCE STATEMENT: The default network (DN) has been consistently associated with self-processing but also with autonomic regulation. We hypothesized that these two functions could be functionally coupled in the DN, inspired by theories according to which selfhood is grounded in the neural monitoring of internal organs. Using magnetoencephalography, we show that heartbeat-evoked responses (HERs) in the DN covary with the self-relatedness of ongoing spontaneous thoughts. HER amplitude in the ventral precuneus covaried with the "I" self-dimension, whereas HER amplitude in the ventromedial prefrontal cortex encoded the "Me" self-dimension. Our experimental results directly support theories rooting selfhood in the neural monitoring of internal organs. We propose a novel functional framework for the DN, where self-processing is coupled with physiological monitoring
Neural responses to heartbeats in the default network encode the self in spontaneous thoughts
The default network (DN) has been consistently associated with self-related cognition, but alsoto bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line with theories proposing that selfhood is grounded in the neural monitoring of internal organs, such as the heart. We measured with magnetoencephalograhy neural responses evoked by heartbeats while human participants freely mind-wandered. When interrupted by a visual stimulus at random intervals, participants scored the self-relatedness of the interrupted thought. They evaluated their involvement as the firstperson perspective subject or agent inthethought (âIâ), and on another scaleto what degreethey werethinking aboutthemselves (âMeâ). During the interrupted thought, neural responses to heartbeats in two regions of the DN, the ventral precuneus and the ventromedial prefrontal cortex, covaried, respectively, with the âIâ and the âMeâ dimensions of the self, even at the single-trial level. No covariation between self-relatedness and peripheral autonomic measures (heart rate, heart rate variability, pupil diameter, electrodermal activity, respiration rate, and phase) or alpha power was observed. Our results reveal a direct link between selfhood and neural responses to heartbeats in the DN and thus directly support theories grounding selfhood in the neural monitoring of visceral inputs. More generally, the tight functional coupling between self-related processing and cardiac monitoring observed here implies that, even in the absence of measured changes in peripheral bodily measures, physiological and cognitive functions have to be considered jointly in the DN
Neuroimage
A fundamental feature of the temporal organization of neural activity is phase-amplitude coupling between brain rhythms at different frequencies, where the amplitude of a higher frequency varies according to the phase of a lower frequency. Here, we show that this rule extends to brain-organ interactions. We measured both the infra-slow (~0.05Hz) rhythm intrinsically generated by the stomac