Have I Been Touched? Subjective and Objective Aspects of Tactile Awareness.
Emanuele Cirillo, Claudio Zavattaro, Roberto Gammeri, Hilary Serra, Raffaella Ricci, Anna Berti
Brain sciences June 27, 2024 DOI: 10.3390/brainsci14070653 via PubMed
Summary
Tactile experience is essential for interacting with objects, controlling actions, and forming relationships, and it is a foundational part of body awareness. How touch comes to consciousness is not a single, uniform process; it is modulated by factors such as whether we perceive our bodies as belonging to us. This review examines pathological conditions where people lack conscious touch yet show implicit processing, uses tactile illusions in healthy individuals and brain-damaged patients to reveal higher-order processes affecting tactile awareness, and discusses these observations in relation to models of touch and body representation.
Study at a glance
| Characteristics | Review Peer reviewed |
|---|---|
| Keywords | Body integrity disphoria Embodiment Mirror box illusion Rubber hand illusion Somatoparaphrenia |
| Citations | 5 |
| Key finding | Tactile awareness is modulated by higher-order processes including body ownership, as shown by pathological conditions and illusions. |
Abstract
Somatosensory tactile experience is a key aspect of our interaction with the environment. It is involved in object manipulation, in the planning and control of actions and, in its affective components, in the relationships with other individuals. It is also a foundational component of body awareness. An intriguing aspect of sensory perception in general and tactile perception in particular is the way in which stimulation comes to consciousness. Indeed, although being aware of something seems a rather self-evident and monolithic aspect of our mental states, sensory awareness may be in fact modulated by many different processes that impact on the mere stimulation of the skin, including the way in which we perceive our bodies as belonging to us. In this review, we first took into consideration the pathological conditions of absence of phenomenal experience of touch, in the presence of implicit processing, as initial models for understanding the neural bases of conscious tactile experience. Subsequently, we discussed cases of tactile illusions both in normal subjects and in brain-damaged patients which help to understand which high-order processes impact tactile awareness. Finally, we discussed the observations reported in the review in light of some influential models of touch and body representation.