Calming Effects of Touch in Human, Animal, and Robotic Interaction—Scientific State-of-the-Art and Technical Advances

Abstract

Small everyday gestures such as a tap on the shoulder can affect the way humans feel and act. Touch can have a calming effect and alter the way stress is handled, thereby promoting mental and physical health. Due to current technical advances and the growing role of intelligent robots in households and healthcare, recent research also addressed the potential of robotic touch for stress reduction. In addition, touch by non-human agents such as animals or inanimate objects may have a calming effect. This conceptual article will review a selection of the most relevant studies reporting the physiological, hormonal, neural, and subjective effects of touch on stress, arousal, and negative affect. Robotic systems capable of non-social touch will be assessed together with control strategies and sensor technologies. Parallels and differences of human-to-human touch and human-to-non-human touch will be discussed. We propose that, under appropriate conditions, touch can act as (social) signal for safety, even when the interaction partner is an animal or a machine. We will also outline potential directions for future research and clinical relevance. Thereby, this review can provide a foundation for further investigations into the beneficial contribution of touch by different agents to regulate negative affect and arousal in humans.

RECOVARI – Efficacy and Safety of Massage on Surgical Stress in Colorectal Cancer Patients: Study Protocol for A Randomized Controlled, Three-Arm Parallel Group, Clinical Trial

“…The effect of human touch is increasingly investigated in psychological and medical research. Especially the bene cial effects of social and therapeutic touch on stress levels have been studied, which has led to the discovery of C-tactile afferents that have special properties to mediate tactile stimuli from another person and calming effects of touch [42][43][44][45]. Massage has shown to be effective in clinical settings of pain and conditions of the musculoskeletal system [46][47][48][49].…”

Physical contact in parent-infant relationship and its effect on fostering a feeling of safety

“…After the sensory thalamus, whereas Aβ-LTMR information is transmitted to the primary somatosensory cortex to process fine-grained signals for discriminative touch, C-tactile information is transmitted to and activates the insular cortex, thereby reflecting a positive valence ( McGlone et al., 2014 ; Morrison, 2016 ; Olausson et al., 2002 ). The insular cortex has dense fiber connections, receives direct input from the somatosensory thalamus, and processes somatosensory experiences in conjunction with emotional valence and autonomic responses ( Eckstein et al., 2020 ; Gogolla, 2017 ; Uddin et al., 2017 )( Figure 2 ). In addition, pleasant skin stroking activates the posterior superior temporal sulcus, which correlates with subjective pleasantness ( Davidovic et al., 2016 ).…”

“…The beneficial effects of physical contact can be used to develop mechanical devices to reduce social stress and physical pain for children in institutions, orphanages, hospitals, or any other situation in which they are in need ( Eckstein et al., 2020 ). These effects can ease the amount of distress in adults who suffer from social pain and loneliness in an aging and individualistic society.…”

Feel-Good Requirements: Neurophysiological and Psychological Design Criteria of Affective Touch for (Assistive) Robots

“…As explained in the previous section, in addition to myelinated fibers, CT fibers allow humans to perceive soft and gentle stroking usually as a positive affective experience (Olausson et al, 2002 ). The relaxing and pleasant effects of affective touch in human-human interactions (Ditzen et al, 2008 ) and even human-animal interactions (Vormbrock and Grossberg, 1988 ) inspires the research in human-machine interaction (Eckstein et al, 2020 ). The technical requirements of affective touch with its effects on psychological factors are investigated in this section by extending the previous study presented by Beckerle et al ( 2018 ).…”