What are C-tactile afferents and how do they relate to "affective touch"?

Implementing social and affective touch to enhance user experience in human-robot interaction

In this paper, we discuss the potential contribution of affective touch to the user experience and robot performance in human-robot interaction, with an in-depth look into upper-limb prosthesis use as a well-suited example. Research on providing haptic feedback in human-robot interaction has worked to relay discriminative information during functional activities of daily living, like grasping a cup of tea. However, this approach neglects to recognize the affective information our bodies give and receive during social activities of daily living, like shaking hands. The discussion covers the emotional dimensions of affective touch and its role in conveying distinct emotions. In this work, we provide a human needs-centered approach to human-robot interaction design and argue for an equal emphasis to be placed on providing affective haptic feedback channels to meet the social tactile needs and interactions of human agents. We suggest incorporating affective touch to enhance user experience when interacting with and through semi-autonomous systems such as prosthetic limbs, particularly in fostering trust. Real-time analysis of trust as a dynamic phenomenon can pave the way towards adaptive shared autonomy strategies and consequently enhance the acceptance of prosthetic limbs. Here we highlight certain feasibility considerations, emphasizing practical designs and multi-sensory approaches for the effective implementation of affective touch interfaces.

Insecure Attachment, Oxytocinergic System and C-Tactile Fibers: An Integrative and Translational Pathophysiological Model of Fibromyalgia and Central Sensitivity Syndromes

Although the pathophysiology of fibromyalgia syndrome has been better understood in recent decades, a unified model of its pathogenesis and an effective therapeutic approach are still far from being realized. The main aim of this article will be to delve into the fundamental mechanisms of the pathophysiology of fibromyalgia conceptualized as stress intolerance syndrome. Using the biopsychosocial model of chronic pain syndromes, we will describe the potential role of the attachment system, C-tactile fibers, and oxytocinergic system dysfunction in the pathophysiology of fibromyalgia syndrome and other central sensitivity syndromes. At the end of the article, the therapeutic implications of this new global and translational pathophysiological model will be briefly discussed.

Maternal Psychological Well-Being as a Protector in Infantile Colic

(1) Background: Infantile colic (IC) is a functional gastrointestinal disorder that affects around 20% of infants, and postpartum (PPD) depression is a common disorder that affects between 15 and 22% of mothers. In this study, our objective was to evaluate the relationship between the maternal psychological state in the first postpartum year and IC, with the aim of assessing the importance of feeding type in infants and maternal well-being. (2) Methods: A cross-sectional study was conducted in women in their first year postpartum. Demographic, medical, and obstetric data of the mothers and infants were collected, and the type of feeding was identified. The emotional status of the mother was evaluated using the Edinburgh Postnatal Depression Scale (EPDS), and the Infant Colic Severity Questionnaire (ICSQ) was used for IC diagnosis. (3) Results: A total of 528 women were analyzed, of which 170 (32%) were diagnosed with possible PPD. Two-thirds of the women without depression breastfed their babies on demand; therefore, we report that exclusive breastfeeding (EBF) appears to reduce the risk of possible PPD (p < 0.001; OR = 2.353). IC was present in 39% of babies, and around 70% of babies without colic were breastfed on demand. Infants who were not exclusively breastfed showed almost double the risk of developing colic (p = 0.016; OR = 1.577). There was a significant association between the EPDS and ICSQ scores (p < 0.001). More than half of the women with PPD had babies with colic. However, our results show that 75% of babies without colic had mothers who reported optimal postpartum emotional well-being (p < 0.001; OR = 2.105). (4) Conclusions: The results of this study suggest that postpartum maternal psychological well-being reduces the risk of IC. Therefore, we report that EBF on demand, together with a healthy emotional state in new mothers, may be a protective factor against colic in infants.

WATSU (Water-Shiatsu) increases body awareness and improves pain and mood: A randomised controlled study

BACKGROUND AND PURPOSE

WATSU (Water-Shiatsu) is a body-oriented therapy in warm-water pool with passive movements, massage and breathing techniques. The present study investigated the short-term effect of a single session of WATSU on body awareness.

MATERIALS AND METHODS

In a randomized-controlled study 60 volunteers (18-65 years) were assigned to a 20-min intervention of WATSU or to a 20-min lecture on WATSU. Immediately before and after the intervention they had to answer questionnaires. Primary endpoint of the investigation was the change of the total score of the non-verbal Awareness Body Chart (ABC). Secondary endpoints were the changes of the scores of the 14 single body parts of the ABC, of the Visual Analogue Pain Scale, of a German self-perception questionnaire (KEKS) and changes in mood scored with a German questionnaire on mood (Bf-SR). To compare groups, Mann-Whitney U tests were used.

RESULTS

The WATSU group had a significantly higher increase in the ABC total score in comparison to the lecture group (WATSU: 0.3 (IQR 0 - 0.8), lecture: 0.1 (IQR -0.2 - 0.2), p = 0.014). In the KEKS no group differences were seen. In WATSU a significantly stronger improvement of pain (Visual Analogue Pain Scale: WATSU: -15 (IQR -29 to -8), lecture: -4 (IQR -9 - 2), p < 0.001) and of mood (Bf-SR: WATSU: -6 (IQR -14 to -2), lecture: -1 (IQR -5 - 1), p = 0.003) could be observed.

CONCLUSION

This study showed that WATSU immediately increases body awareness and improves pain and mood.

Determinants for positive and negative experiences of interpersonal touch: context matters

The goal of the study was to determine which aspects of interpersonal touch interactions lead to a positive or negative experience. Previous research has focused primarily on physical characteristics. We suggest that this may not be sufficient to fully capture the complexity of the experience. Specifically, we examined how fulfilment of psychological needs influences touch experiences and how this relates to physical touch characteristics and situational factors.In two mixed-method studies, participants described their most positive and most negative interpersonal touch experience within a specific time frame. They reported fulfilment of nine needs, affect, intention, and reason for positivity/negativity, as well as the body part(s) touched, location, type of touch, interaction partner, and particular touch characteristics (e.g. humidity).Positive and negative touch experiences shared similar touch types, locations, and body parts touched, but differed in intended purpose and reasons. Overall, the valence of a touch experience could be predicted from fulfilment of relatedness, the interaction partner and initiator, and physical touch characteristics. Positive affect increased with need fulfilment, and negative affect decreased.The results highlight the importance of relatedness and reciprocity for the valence of touch, and emphasise the need to incorporate psychological needs in touch research.

Touch medicine: bridging the gap between recent insights from touch research and clinical medicine and its special significance for the treatment of affective disorders

Interpersonal touch represents the primal sensory experience between humans, fostering social bonding from the cradle to the death bed. In recent decades "affective touch" has been intensely studied, stimulated by the discovery of a population of mechanosensitive unmyelinated C-tactile afferents in mammalian skin. A lack of touch in childhood is associated with negative consequences for psychosocial and physical health and the benefits of professional touch techniques in the prevention and treatment of various diseases have been shown over and over again in clinical studies. However, its application in mainstream clinical applications remains limited. To bridge the gap between recent discoveries in touch research and clinical medicine, we propose the establishment of a new discipline: 'Touch Medicine'. Here, we unfold the potential of Touch Medicine by focusing on the treatment of depression, which in our view is primarily a disorder of the lived body. Controlled studies and systematic reviews have demonstrated the antidepressant, anxiolytic and analgesic effects of specific massage techniques. Underlying mechanisms of action are currently under investigation, ranging from interoceptive, endocrinological, to stress-related or psychological underpinnings. Touch Medicine represents a novel interdisciplinary field connected to various medical specialities such as neonatology, pediatrics, pain medicine, neurology, psychiatry, and geriatrics - but also clinical psychology and psychosomatic medicine might benefit from the integration of these findings into their daily practice.

The skin-brain connection and pleasant touch as supportive care for psychocutaneous disorders

Psychodermatology is a subdiscipline of dermatology at the intersection of dermatology, psychiatry, and psychology. In dermatology clinical practice, patients may present with skin disease that affects their mental health, or skin disorders induced or worsened by psychological/psychiatric problems so there is a need for specialised education of dermatologists, as well as multidisciplinary teams, to achieve better management of these patients. Understanding the interaction between the central nervous system and the skin underlying psychocutaneous disorders could help identify alternative therapies that may improve patient well-being. The concept of pleasurable touch has received increasing attention following the discovery of C-tactile (CT) fibres. While afferent C-fibre stimulation is usually associated with pain, temperature, or itch, CT-fibres are stimulated optimally by a stimulus not in the nociceptor range but by a gentle, low-force stroking. As this affective touch may counteract unpleasurable sensations, such as pain and itch, and elicit positive feelings, the potential benefits of gentle touch and massage are interesting for dermatological, especially psychocutaneous, disorders. Here we provide an overview of the skin-brain connection to help understand the benefits of touch and massage, as illustrated with studies on atopic dermatitis and burns, as an adjunct to dermatological treatment for improving patient well-being and optimising treatment outcomes.