Back to the roots: the role of sensory sensitivity and respiration pattern variability in mental health

Sensory perception and respiration are two core features fundamental for human life, behavior and well-being. We are only able to live when we breathe and to understand the world when we perceive stimuli from it which we then interpret. Both features vary between individuals and between situations, for example during emotional challenges, and are likely relevant for mental health. Initial evidence suggests that body perception and respiration are coupled, but systematic research about their relationship and their association with mental disorders is currently lacking. The presented work aims at advancing the understanding of sensory sensitivity and respiration pattern variability with regard to mental disorders and proposes biological mechanisms linking both together. Based on the results of two studies, one with autistic and one with remitted depressed participants, and supplemental analyses of a large independent sample these relationships are addressed. In a sample of autistic individuals, sensory sensitivity was assessed with the sensory inventory, a newly developed standardized questionnaire on sensory sensitivity in which higher sensory sensitivity in autistic individuals was found. Scores of the inventory could further be used to discriminate autistic individuals with a sensitivity of 92% correctly from controls. In another sample more sensory content of memories was found to be related to increased memory for autobiographical events, pointing to a high relevance of sensory features in autism. In the second study, remitted depressed participants underwent a sad mood induction functional magnetic resonance imaging paradigm with negative autobiographical events as cues and were also assessed with the sensory inventory. In the remitted depressed participants higher respiration pattern variability during sad mood was found which was associated with lower body perception ability, worse outcome and relapse, and increased default mode network connectivity in comparison to healthy controls, demonstrating the importance of both concepts and their relationship in depression. Furthermore, in autistic and formerly depressed participants body perception was lower in comparison to controls, suggesting a broader distribution of this sensory alteration in mental disorders. These relationships of sensory features as well as respiration and associated alterations with the intensity and course of mental disorders might also highlight important concepts for the development of future sensory and respiration-based interventions. Sensory aided trainings for everyday activities and interactions could be helpful to better memorize learned content. Respiration focused training could be a promising additional tool as it might not only influence respiration directly but also body perception, default mode connectivity and could be helpful for coping with stress and relaxing in general. Taken together, the present thesis might stimulate an increased attention of body related processes like sensory sensitivity and respiration pattern variability in the investigation of causes and treatments of mental disorders

Early Memories of Individuals on the Autism Spectrum Assessed Using Online Self-Reports

"When I was one and a half years old, I was on a ferry lying on red seats" - while several autobiographical accounts by people with autism reveal vivid memories of early childhood, the vast amount of experimental investigations found deficits in personal autobiographic memory in autism. To assess this contradiction empirically, we implemented an online questionnaire on early childhood events to compare people on the autism spectrum (AS) and non-autistic people with respect to their earliest autobiographical episodic memories and the earliest semantic know event as told by another person. Results indicate that people on the AS do not differ from non-autistic people in the age of their earliest know events but remember events from an earlier age in childhood and with more sensory details, contradicting the assumption of an overall deficit in personal episodic memory in autism. Furthermore, our results emphasize the supporting influence of language for memory formation and give evidence for an important role of sensory features in memories of people on the AS.publishe

Increased involvement of the parahippocampal gyri in a sad mood predicts future depressive symptoms

Behavioral studies suggest a relationship between autobiographical memory, rumination and depression. The objective of this study was to determine whether remitted depressed patients show alterations in connectivity of the posterior cingulate cortex (PCC, a node in the default mode network) with the parahippocampal gyri (PHG, a region associated with autobiographical memory) while intensively recalling negative memories and whether this is related to daily life symptoms and to the further course of depression. Sad mood was induced with keywords of personal negative life events in participants with remitted depression (n = 29) and matched healthy controls (n = 29) during functional magnetic resonance imaging. Additionally, daily life assessments of mood and rumination and a 6-month follow-up were conducted. Remitted depressed participants showed greater connectivity than healthy controls of the PCC with the PHG, which was even stronger in patients with more previous episodes. Furthermore, patients with increased PCC–PHG connectivity showed a sadder mood and more rumination in daily life and a worsening of rumination and depression scores during follow-up. A relationship of negative autobiographical memory processing, rumination, sad mood and depression on a neural level seems likely. The identified increased connectivity probably indicates a ‘scar’ of recurrent depression and may represent a prognostic factor for future depression

Modulation of respiration pattern variability and its relation to anxiety symptoms in remitted recurrent depression

BackgroundDepression is related to default mode network (DMN) connectivity and higher respiration pattern variability (RPV). In addition, DMN connectivity and RPV are interrelated and predict a poorer clinical course of depression. The association of RPV and depression might further be boosted by anxiety levels. Aim of the present study was to investigate whether a mindfulness-based training in emotionally challenged remitted depressed participants (rMDD) leads to reduced DMN connectivity and lower RPV, and if RPV interacts with anxiety levels.MethodsTo challenge participants, sad mood was induced with keywords of personal negative life events in 49 rMDD during fMRI before and after a 4-week mindfulness-based attention training (MBAT) or progressive muscle relaxation. Respiration was measured by means of a built-in respiration belt.ResultsAfter both trainings, rMDD showed no significant changes in DMN connectivity. However, MBAT was effective in reducing the RPV which was related to lower anxiety levels especially in high anxious individuals.ConclusionsRPV can be influenced by training which may hint to an underlying biological pathway of training effects. Importantly, these effects seem to be associated with anxiety levels. Therefore, respiration focused training might be an important tool assisting the treatment of depression and anxiety.publishe