Contingent biofeedback outperforms other methods to enhance the accuracy of cardiac interoception: A comparison of short interventions.

BACKGROUND AND OBJECTIVES: Deviations in interoception might contribute to the development and maintenance of mental disorders. The improvement of interoceptive accuracy (IA) is desirable but assessment and training methods remain controversial. For instance, it was assumed that performance increases in heartbeat counting paradigms after cardiac feedback were due to an improvement of knowledge with regard to heart rate rather than due to an actual improvement in IA. METHODS: Here, we examined effects of contingent cardiac feedback training, non-contingent cardiac feedback, mindfulness practice, and a waiting period with external attentional focus on IA. 100 healthy participants underwent a mental tracking paradigm before and after 20 min of training or waiting. RESULTS: Results revealed a significant increase of IA in the contingent feedback condition (d = 1.21, p ≤ .001) and no significant changes after non-contingent feedback, mindfulness practice or waiting (d ≤ 0.37; p ≥ .06). Furthermore, IA increase was significantly higher after the contingent feedback training compared to all other conditions, including non-contingent feedback. LIMITATIONS: Future studies need to replicate these findings in clinical samples and examine time dependent effects. CONCLUSIONS: The results provide evidence for the trainability of heartbeat perception. IA improvements may reduce the symptom burden in people suffering from mental disorders and psychophysiological conditions that have been linked to lower interoceptive accuracy such as depression, somatic symptom disorder, chronic pain, and functional somatic syndromes. Consequently, exploration of biofeedback training procedures shall be continued with the aim of identifying relevant mediators of beneficial effects and future implementation in clinical practice.

Don't worry, be happy - Neural correlates of the influence of musically induced mood on self-evaluation.

Self-evaluation affects one's own mental state, social interactions and everyday life. Mood, in turn, has an impact on self-evaluation. However, the influence of mood on self-evaluation at the neural level has barely been examined. In this fMRI study, the interaction of mood and self-perception was investigated in 20 healthy participants. Happy, sad and neutral music was presented while participants were instructed to immerse themselves in the mood of the music and to rate how well presented traits characterized themselves. In a lexical control condition, subjects had to count a specific letter in the word. Behavioral data reflected successful mood induction. While self-ascription of positive traits was unaffected by mood, self-ascription of negative characteristics was decreased by negative affect. A positive correlation was found between self-worth scores and the difference in the amount of self-ascribed positive versus negative traits during negative mood induction. At the neural level, amygdalo-hippocampal, superior and middle temporal structures were differently involved in self-evaluation (vs. lexical processing) depending on the mood. While activation of the amygdalo-hippocampal complex was found during sad in comparison to both happy and neutral mood, superior/middle temporal gyrus (STG/MTG) activation was only found when contrasting sad vs. neutral mood. Further, a correlation analysis with self-worth ratings revealed a positive relation to STG activation during self-ascription of trait adjectives in sad compared to neutral mood. Our results underscore the importance of the current emotional state for self-evaluation and identify some neural correlates of this effect. Our findings in healthy research participants suggest a compensatory mechanism during sad mood induction to maintain a positive self-image, which is supported by activation of limbic and fronto-temporal cortex. Studies in clinically depressed populations could reveal whether this compensatory mechanism is aberrant.