Interozeption und Stress: die Psychophysiologie der bi-direktionalen Kommunikation auf der Hirn-Körper-Achse

in Schächinger, H. (Ed.) Abstractband 43. Tagung Psychologie und Gehirn (2017)

Gehirn und Körper tauschen permanent Informationen aus. Interozeption, die Wahrnehmung von Körperprozessen, ist ein wichtiges Beispiel für aufsteigende Informationsübermittlung vom Körper zum Gehirn ... [more ▼]

Gehirn und Körper tauschen permanent Informationen aus. Interozeption, die Wahrnehmung von Körperprozessen, ist ein wichtiges Beispiel für aufsteigende Informationsübermittlung vom Körper zum Gehirn. Stress wiederum kann als prototypisch für absteigende Informationen vom Gehirn zum Körper gesehen werden. Eine Veränderung der Kommunikation auf der Hirn-Körper-Achse kann zur Entstehung körperlicher Symptome bei psychischen Störungen führen. Neueste Theorien zu Interozeption weisen darauf hin, dass es sich nicht um ein uniformes Konstrukt handelt, sondern in die Facetten ‚Bewusstheit‘ (Awareness), ‚Sensibilität‘ (Sensibility), ‚Genauigkeit‘ (Accuracy) und ZNS-Repräsentation afferenter Körpersignale separiert werden kann. Körperliche Symptome können aus der selektiven Veränderung weniger Facetten entstehen. Stress kann differenziert werden in psychologische (selbstberichteten Stress), sowie physiologische Komponenten, wie die Aktivität der beiden physiologischen Stressachsen, des autonomen Nervensystems und der HPA-Achse. In diesem Symposium werden erstmals Erkenntnisse zum Zusammenhang von Interozeption und Stress auf allen Beobachtungsebenen integriert. Zunächst werden Zusammenhänge von akuter Stressreaktivität und –Erholung mit ‚Interozeptiver Genauigkeit‘ bei gesunden Probanden diskutiert (van Dyck/Luxemburg). Anschließend werden Erkenntnisse zu chronischem Stress, ‚Interozeptiver Bewusstheit‘ und gesundheitlichen Beschwerden bei Angestellten präsentiert (Trojan/Landau). Danach wird die ZNS-Repräsentation von Körpersignalen und ‚Interozeptive Genauigkeit‘ bei Kindern und Jugendlichen besprochen (Mai/Ulm), da sich das Jugendalter als entwicklungsbedingte Phase besonderer Stressvulnerabilität erweist. Im der folgenden Studie wird ‚Interozeptive Genauigkeit‘, Stressbelastung und –reaktivität bei Erwachsenen mit einer Trennungserfahrung der Eltern im Kindesalter als Stressor untersucht (Schaan/Luxemburg). Abschließend werden Daten zu ZNS-Repräsentation von Körpersignalen und HPA-Achsenaktivität bei posttraumatischer Belastungsstörung präsentiert (Müller/Heidelberg). Letztlich wird eine Synthese der Einzelbefunde in eine erweiterte Theorie zu Interozeption und Stress diskutiert. [less ▲]

Langzeitkonsequenzen von frühkindlichem Stress: quadratischer Zusammenhang zwischen Stress und Interozeptionsfähigkeit

in Schächinger, H. (Ed.) Abstractband 43. Tagung Psychologie und Gehirn (2017)

Traumatische Belastungen während der Kindheit können das Risiko für die Entwicklung unsicherer Bindungsstile erhöhen, die bereits mit langfristigen psychischen und körperlichen Gesundheitsproblemen in ... [more ▼]

Traumatische Belastungen während der Kindheit können das Risiko für die Entwicklung unsicherer Bindungsstile erhöhen, die bereits mit langfristigen psychischen und körperlichen Gesundheitsproblemen in Beziehung gebracht wurden. Die zugrundeliegenden Prozesse sind allerdings noch weitestgehend unklar. Da interozeptive Signale die Regulation negativer Emotionen als Reaktion auf sozialer Zurückweisung begünstigen können, die infolge einer Stressbelastung verändert sein könnten, wurde insbesondere der Effekt von kindlichem Stress auf Interozeption untersucht. Wir präsentieren zwei Studien, die den Zusammenhang zwischen kindlichem Stress und Gesundheit im Erwachsenenalter sowie Körperwahrnehmung und Gedächtnisfähigkeit untersuchen. In der ersten Studie nahmen 199 Teilnehmer an einer Onlineumfrage teil, bei der Gesundheit, frühkindliches Trauma, Resilienz und Zurückweisungssensitivität gemessen wurden. Teilnehmer mit geschiedenen Eltern berichteten erhöhte psychische Belastungswerte, kindliches Trauma, Zurückweisungssensitivität und weniger Resilienz. Die Beziehung zwischen elterlicher Scheidung und psychischer Gesundheit konnte vollständig durch diese vier Faktoren erklärt werden (Varianzaufklärung 44%). In einer zweiten Studie wurden bei 60 Teilnehmern verschiedene Selbstberichts-Parameter erhoben und die Gedächtnis- und Interozeptionsfähigkeit (Schandry Herzschlagwahrnehmungstest/EKG) vor und nach einem sozial-evaluativen Kaltwasser-Stresstest untersucht. Die Reaktion des autonomen Nervensystems wurde mithilfe von Herzraten- und Blutdruckvariabilität bestimmt. Erwachsene mit einer Vorgeschichte von elterlicher Trennung berichteten mehr bindungsbezogene Angst und Vermeidung als Kontrollpersonen. Das Erlebnis einer elterlichen Scheidung war negativ mit der Gedächtnisleistung nach dem Stresstest korreliert. Weiterhin weisen die Ergebnisse auf einen quadratischen Zusammenhang zwischen kindlicher Stressbelastung und Interozeptionsfähigkeit hin. Basierend auf diesen Ergebnissen könnte ein ‚gesunder Normbereich‘ der Interozeptionsfähigkeit existieren. Kindlicher Stress könnte sowohl eine Verringerung, als auch eine Erhöhung der Interozeptionsfähigkeit bewirken, was beides mit gesundheitlichen Problemen assoziiert sein könnte. [less ▲]

Gastric modulation of startle eye blink

in Biological Psychology (2017), 127(1), 25-33

Abstract: Previous assessment methods of gastric interoception either rely on self-reports, or imply invasive procedures. We investigated the reliability of startle methodology as a non-invasive ... [more ▼]

Abstract: Previous assessment methods of gastric interoception either rely on self-reports, or imply invasive procedures. We investigated the reliability of startle methodology as a non-invasive alternative for the assessment of afferent gastric signals. Twenty-four participants were tested on three separate days, on which they were requested to ingest water (either 0, 300 or 600 ml), after 8 h of fasting. On each assessment day, eye blink responses (EMG) to 10 acoustic startle stimuli (105 dB) were assessed at 4 measurement points (before, 0, 7, 14 min. after ingestion). Increased normogastric responses (EGG), ratings of satiety and fullness, and higher heart rate variability (RMSSD) suggested effective non-invasive induction of gastric distention. Startle responses were lower directly after ingestion of 600 ml as compared to earlier and later measurements. These results suggest that startle methodology provides a reliable method to investigate afferent gastric signals. It could be useful to study possible dissociations between subjective reports and objective afferent gastric signals in eating or somatoform disorders. [less ▲]

Affective evaluation of body images in anorexia nervosa

in Psychophysiology (2017), 54(S1),

Anorexia nervosa is characterized by fear of weight gain. This is reflected in amygdala activation during confrontation with distorted photographs of oneself simulating weight gain. In contrast ... [more ▼]

Anorexia nervosa is characterized by fear of weight gain. This is reflected in amygdala activation during confrontation with distorted photographs of oneself simulating weight gain. In contrast, photographs of emaciated women induce startle attenuation, suggesting a positive valuation of extreme slimness. To combine these findings, we applied an affective startle modulation paradigm containing photos of the participants simulating weight gain and photos simulating weight loss. We assessed eye-blink startle responses via EMG in 20 women with anorexia nervosa (AN; mean age = 25 years; mean BMI = 23) and 20 healthy control women (HC; mean age = 25 years; mean BMI = 23). We were able to replicate affective startle modulation of standard positive, negative, and neutral pictures, except for an absence of startle attenuation for positive pictures in AN. Body images did not modulate the startle response in either group. This was in contrast to the subjective ratings, in which the AN group indicated negative valence and high arousal for distorted body images. The body photographs used in our study emphasized general body shape and it appears that this was not threatening to AN patients. Photos highlighting body details might produce different results. Considering that body image exposure, a frequently used intervention tool for AN, aims at fear reduction through habituation, it is essential to determine which aspects of the body actually elicit fear responses to maximize therapy outcome. [less ▲]

Polymorphisms of genes related to the hypothalamic-pituitary-adrenal axis influence the cortisol awakening response as well as self-perceived stress

in Biological Psychology (2016), 119(1), 112-121

The hypothalamus-pituitary-adrenal (HPA) axis is a crucial endocrine system for coping with stress. A reliable and stable marker for the basal state of that system is the cortisol awakening response (CAR ... [more ▼]

The hypothalamus-pituitary-adrenal (HPA) axis is a crucial endocrine system for coping with stress. A reliable and stable marker for the basal state of that system is the cortisol awakening response (CAR). We examined the influence of variants of four relevant candidate genes; the mineralocorticoid receptor gene (MR), the glucocorticoid receptor gene (GR), the serotonin transporter gene (5-HTT) and the gene encoding the brain-derived neurotrophic factor (BDNF) on CAR and self-perceived stress in 217 healthy subjects. We found that polymorphisms of GR influenced both, the basal state of the HPA axis as well as self-perceived stress. MR only associated with self-perceived stress and 5-HTT only with CAR. BDNF did not affected any of the investigated indices. In summary, we suggest that GR variants together with the CAR and supplemented with self reports on perceived stress might be useful indicators for the basal HPA axis activity. [less ▲]

Cardiac modulation of startle is altered in depersonalization-/derealization disorder: evidence for impaired brainstem representation of baro-afferent neural traffic

in Psychiatry Research (2016), 240(1), 4-10

Patients with depersonalization-/derealization disorder (DPD) show altered heartbeat-evoked brain potentials, which are considered psychophysiological indicators of cortical representation of visceral ... [more ▼]

Patients with depersonalization-/derealization disorder (DPD) show altered heartbeat-evoked brain potentials, which are considered psychophysiological indicators of cortical representation of visceral-afferent neural signals. The aim of the current investigation was to clarify whether the impaired CNS representation of visceral-afferent neural signals in DPD is restricted to the cortical level or is also present in sub-cortical structures. We used cardiac modulation of startle (CMS) to assess baro-afferent signal transmission at brainstem level in 22 DPD and 23 healthy control individuals. The CMS paradigm involved acoustic startle stimuli (105 dB(A), 50 ms) elicited 0, 100, 200, 300, 400 and 500 ms after a cardiac R-wave. In healthy control individuals, we observed lower startle responses at 100 and 300 ms than at 0 and 400 ms after an R-wave. In DPD patients, no effect of the cardiac cycle on startle response magnitude was found. We conclude that the representation of visceral-afferent neural signals at brainstem level may be deficient in DPD. This effect may be due to increased peripheral sympathetic tone or to dysregulated signal processing at brainstem level. [less ▲]

Interozeption bei Anorexia nervosa: Befunde auf subjektiver und elektrophysiologischer Ebene

in 15. Kongress der Deutschen Gesellschaft für Verhaltensmedizin und Verhaltensmodifikation. Verhaltensmedizin 2.0 - von eHealth zu mHealth. 25. bis 27. Februar 2016, Johannes Gutenberg-Universität Mainz. Abstractband (2016, February)

Reduced early visual processing of own body images in anorexia nervosa: An event-related potentials study

Poster (2016)

Introduction. Although body image distortion in anorexia nervosa (AN) has been extensively studied over the past decades, its underlying mechanisms are not yet fully understood. Neuro-imaging studies have ... [more ▼]

Introduction. Although body image distortion in anorexia nervosa (AN) has been extensively studied over the past decades, its underlying mechanisms are not yet fully understood. Neuro-imaging studies have identified functional and structural alterations in brain areas involved in visual body perception, but the time course of visual body processing in AN remains mostly unexplored. The current study used event-related brain potentials (ERPs) to investigate single processing steps along the time course, particularly the visual processing of physical body image characteristics (featural processing, P1) and the recognition of a body as such (configural processing, N1). Methods. Twenty in-patients with AN, and 20 healthy women viewed photographs of themselves, of another woman’s body and of their own and another woman’s standardized object (cup) with concurrent EEG recording. Results. Body images elicited an accentuation of the P1 component (105-160 ms), which was absent for the comparison between own-body and own-cup images in the AN group. Results regarding the N1 component suggest alterations in object processing in AN. Conclusions. Our results demonstrate that individuals with AN show reduced featural processing of their own body image, a process which, due to its position early in the visual processing stream, is unlikely to involve higher cognitive stimulus processing. This suggests a possible role of previously undetected pre-conscious mechanisms in body image disturbance. [less ▲]

Making sense of what you sense: Disentangling interoceptive awareness, sensibility and accuracy

in International Journal of Psychophysiology (2016), 109(1), 71-80

Garfinkel and Critchley (2013) recently proposed a three level model of interoception. Only few studies, however, have empirically tested this theoretical model thus far. The present study aimed at ... [more ▼]

Garfinkel and Critchley (2013) recently proposed a three level model of interoception. Only few studies, however, have empirically tested this theoretical model thus far. The present study aimed at investigating (1) the central assumptions of this model, i.e. that Accuracy, Sensibility and Awareness are distinguishable facets of interoception and that Interoceptive Accuracy is the basic level of interoception, and (2) whether cardiovascular activation (as indexed by heart rate) is differentially related to the three facets of interoception. Analyses were conducted on a total sample of N=159 healthy participants (118 female [74.2%]; mean age = 23.9 years, SD = 3.3, range = 19-45) who performed either the heartbeat tracking task, the heartbeat discrimination task or both. The results suggest that Accuracy, Sensibility and Awareness are empirically distinct facets of interoception, showing no correlation when based on heartbeat tracking, but moderate correlations when based on heartbeat discrimination. The assumption that Interoceptive Accuracy is the basic level of interoception could only be partially confirmed. Instead, we conclude that the level of objective physiological states should be considered as the most basic level of interoceptive signal processing. [less ▲]

Blood pressure and the perception of illusive pain

in Psychophysiology (2016), 53(8), 1282-1291

Numerous studies have documented an inverse relationship between blood pressure and sensitivity to experimental nociceptive stimulation. The present study aimed to investigate possible associations ... [more ▼]

Numerous studies have documented an inverse relationship between blood pressure and sensitivity to experimental nociceptive stimulation. The present study aimed to investigate possible associations between blood pressure and the occurrence and intensity of paradoxical pain induced by the thermal grill paradigm. Thirty-one healthy subjects were stimulated three times for 1 minute with the non-noxious temperatures of 15°C and 41°C set at the interlaced cold and warm bars of a water bath-driven thermal grill. Blood pressure and heart rate were recorded concomitantly. On account of previous observations of an association between the sensitivity of the cardiac baroreflex and pain perception, this parameter was additionally obtained. Numerical rating scales were used to quantify subjective pain intensity and pain unpleasantness; subjects were classified as responders and non-responders to thermal grill stimulation based on pain intensity ratings. Responders exhibited lower systolic and diastolic blood pressure than non-responders, and inverse linear associations arose between blood pressure and pain intensity and unpleasantness. Baroreflex sensitivity was unrelated to pain ratings. The findings confirmed the hypothesis of a blood pressure dependence of paradoxical pain and support the notion that the cardiovascular and pain regulatory systems interact not only in the processing of pain elicited by noxious input, but also in non-noxiously generated illusive pain. While this finding is not consistent with the assumption of an involvement of the baroreflex system in mediating the observed interaction, psychological traits and neurochemical factors are alternatively considered. [less ▲]