Introduction

The concept of body model is a relatively new concept, which originates from the intersectoral science of human embodiment. Cognitive neuroscientists and psychologists active in this field of research interpret the concept as referring to an internal model or reference description of the anatomical, volumetric and structural properties of human corporality.¹ These properties are the shape and surface of the body, as well as the location, limits and internal compositional relationships of the body parts. It has been shown that the body model is innate, in the sense that it pre-exists with respect to (multi)sensory and sensorimotor events, providing that set of background conditions, which are necessary for the preservation of a coherent own-body perception by the human being.² Over the last decade there has been an important increase in empirical research, which has shed light both on the neurobiological substrate and on the functional mechanism of the body model. The former appeared to coincide with patterns of neural activity located in the right temporo-parietal junction.³ Alternatively, it was suggested that the internal model might be operated by bimodal and multimodal neural populations in the area 5 of the parietal cortex.⁴ The latter overlaps with so-called test-for-fit process used to filter sensorimotor or (multi)sensory input, and hence to discriminate between events that may be assigned to one’s own body and events that trigger a mismatch – because of their association with other bodies that co-habit the same surrounding world.⁵

Foundational research has also produced notable results. In this case, the attention of the researchers focused on conceptual distinctions, such as those that exist between the body model, on the one hand, body schema and body image, on the other.⁶ It has also been shown that the body model plays a normative role in shaping a pre-reflexive sense of body ownership addressed at the properly material or physical dimension of one’s own body.⁷ The dynamic characteristic of reconfigurability of the body model was found to be central in the incorporation of external objects, interpreted as a lived process of modification of the sense of body ownership, the so-called phenomenal incorporation. By reconfiguring itself, in fact, the model activates or inhibits the plasticity of the aforementioned process, for example where medical devices, such as prostheses or implants, are attached to or implanted in the human body.⁸

In this direction, despite the progress of the research just outlined, further investigations are necessary to fully understand the normative role of the body model in relation, in particular, to the so-called biosynthetic devices, designed to achieve a qualitatively higher level of incorporation than that obtained with classical medical devices.⁹ Biosynthetic devices are highly engineered artifacts or technological products based on advanced theories and techniques of Artificial Life, a field of research and innovation focused on the computational simulation and robotic synthesis of fundamental biological processes.¹⁰ In biosynthetic devices organic and inorganic components and/or materials are integrated to improve the biocompatibility of the artifact, i.e. the property of being integrated into the human body not only locally (tissues surrounding the annexation or implant), but also globally (whole body)¹¹. This seems to facilitate the phenomenal incorporation of the device: biocompatibility might induce an effect of reduction in the reconfiguration of the body model, forcing a loosening of its normative function. Some examples of biosynthetic devices are neural, vascular and ocular prostheses made of biointegrated materials.¹²

In this article I intend to contribute to the study of the normativity exercised by the body model in reference to the individual pre-reflexive sense of body ownership modified by the implantation of biosynthetic devices. My starting point is an interdisciplinary methodology, which is inspired by that introduced by postphenomenologists such as Don Ihde and Peter-Paul Verbeek. I will adopt, however, a classically inspired critical perspective of which postphenomenology have proved to be lacking. More specifically, the methodology I suggest combines empirical and foundational research on human embodiment, case studies of the clinical translation of biosynthetic devices and classical phenomenology-driven critical analysis.¹³ I will use as a reference frame the genetic phenomenology of human embodiment developed by the founder of classical phenomenology, Edmund Husserl, in a mature phase of his production. The analytical focus will be on a case study that I consider of particular interest as it is one of the few examples of advanced clinical translation of a biosynthetic device accompanied by a systematic tracking of the user-patient experience: the case of the implantation of biosynthetic extracellular matrices (ECMs) capable of regenerating the damaged organ in patients suffering from blindness induced by the irreversible loss of optical quality (transparency) of the cornea.¹⁴ These devices are evolving into 3D bio-printing prostheses.¹⁵

The article is structured in the following way: in § 2 I will propose a brief review of the current scientific literature on the individual pre-reflexive sense of body ownership and on the body model. In § 4 I will introduce the Husserlian genetic phenomenology of human embodiment as a conceptual framework on the basis of which it is possible to critically address the normative issue connected to the relationship between the body model and the incorporation of technological devices (§ 3). In § 5 and § 6 I will, therefore, proceed to the illustration and to a phenomenological-genetic investigation of the case study under exam. Finally, § 7 will be devoted to the conclusions of the article.

Pre-reflexive sense of body ownership and the body model

In the current scientific literature, body ownership is considered as one of the two basic components of a minimal, sub-personal kind of body self-consciousness known as the bodily self.¹⁶ The concept of bodily self is strictly related to the so-called “subjective turn” that is having place in the science of human embodiment since the beginning of the century.¹⁷ Here, the attention is given not only to intentional conscious acts, but also and above all to the subject or ego that lives through these acts. In other terms, conscious acts are being studied with regard to both the character of object-directedness (i.e. intentionality) and the character of subject-relatedness (i.e. subjectivity). In this context, where a theoretical perspective is coming to light which is more and more centred on the human embodied subjectivity, body ownership is defined as an affection, a feeling, a pre-reflexive sense of being mine (“mineness”), experienced by the individual in relation to the material dimension of one’s own body.¹⁸ The other component, agency, depends on the body schema and coincides with a pre-reflexive sense of being-agent, that is, the cause of the initiation, control and/or inhibition of a given action.¹⁹ If agency contributes to shaping the sense of body ownership during the course of human development,²⁰ the latter modulates the perception of self-orientation and self-motility – at least in healthy individuals.²¹ In both cases we are dealing with pre-reflexive senses that do not involve conceptualisation processes, but rather a-thematic body representations that can also be connoted as implicit. More specifically, body ownership is distinguished from the reflexive sense of body possession, based on a thematic, explicit representation of the material dimension of one’s own body. In what follows I will present the main results achieved in the science of human embodiment with regard to the pre-reflexive sense of body ownership and to the closely associated concept of body model.

Brief review of the current scientific literature

The pre-reflexive sense of body ownership is difficult to study in experimental terms because of the “apparently ineluctable permanence of the body”²², which determines the impossibility of directly manipulating the conditions of experimental control – in our specific case the absence of the body experienced as its own by the participants. Nonetheless, the empirical research on the sense of body ownership made some progresses. The elaboration of the experimental paradigm, known as Body Ownership Illusions (BOI), was decisive in this direction. The BOIs are characterised by the use of sensorimotor or multisensory stimulation, typically tactile-visual (a)synchronicities, to alter the own-body experience of the participants.²³ They thus guarantee the comparison between verification conditions, in particular between the presence of one’s own body (condition to be corroborated) and the absence of the same (control condition). BOIs are generated both in relation to parts of one’s own body, as in the well-known illusion of the rubber hand,²⁴ and in relation to one’s entire body, as in the body swapping illusion.²⁵ Vision, touch and kinaesthesis are involved in the rubber hand illusion: the participant looks at a rubber hand while it is being stroked simultaneously to his/her hand, which is hidden from view. The integration of visual, tactile and kinaesthetic signals determines the attribution of the alien hand to its own corporality. According to the well-known expression of Botvinick and Cohen, the rubber hand is “felt as if it were my hand”²⁶. In analogous terms, in the illusion of body swapping, the mislocalisation – in this case of the whole body experienced as one’s own – is elicited by synchronous tactile-visual stimulations: the illusion is generated thanks to the use of a humanoid mannequin, manipulating the visual first-or third-person perspective of the participant.²⁷

Intended as an experimental paradigm, BOIs have allowed researchers to elaborate various theoretical proposals aimed at explaining and/or predicting the sense of body ownership. The pioneering study by Tsakiris and Haggard highlighted the existence of conditions that limit the generation of BOIs.²⁸ More specifically, they would coincide not only with spatiotemporal incongruencies (i.e. different spatial configuration between the external object and the natural body or the natural limb and stimulatory asynchrony), but also with a morphology and a posture of the external object, for example of the mannequin or of the rubber hand, which are not homologous, respectively, to those of one’s own body or of a body part of the participant. The identification of these conditions led the researchers to abandon the dominant theoretical approach focused on processes of integration of multimodal body-related sensory data and to elaborate a more complex theoretical proposal, which is able to combine two orders of processes: the bottom-up processes of sensory integration and the top-down processes of the body model.

A focus on the integrated theoretical approach

The sense of body ownership implies a process of preconceptual categorisation which is used to distinguish between self-related events and other events in the outside world. In preconceptual categorisation the key role is played by multimodal signals on the basis of which stable representations are produced, which are classified (pre-conceptually) by the perceiver as his/her own or as extraneous.²⁹ This elementary classification process seems to be attributable to the so-called action-effect registration, thanks to which a sensory event is experienced as the effect of a self-or hetero-caused action.³⁰ At a functional level, the recording of the action-effect depends on the presence/absence of reafference cycles of the signal that reaches the tendon receptors during a muscle contraction.³¹ Reafference is activated by the comparison between afferent and efferent signals: if the comparison reveals coincident elements, then the reafference cycles are present and the variations of the sensory content are experienced by the perceiver as self-caused; if the comparison does not reveal coincident elements, then the reafference cycles are absent and the variations of the sensory content are experienced by the perceiver as hetero-caused.

The body model imposes constraints of a morphological and anatomical-postural nature to the preconceptual categorisation of the representations based on multimodal signals, thus limiting the plasticity of the phenomenal incorporation of external objects. This is what has been demonstrated to date in the context of the experimental paradigm of BOI, where at least three moments in the interaction between sensory data and body model are distinguished: a moment focused on morphology as a visual datum, a moment focused on posture and anatomy as tactile-visual data and a moment focused on visual and tactile information and on the visual and tactile coordinate system.³² The researchers then proved that processes of reconfiguration or internal reorganisation of the body model are present in the event that the perceptual illusion actually takes place.³³ This reconfiguration involves a so-called egopetal process consisting in the appropriation, assimilation or internalisation of the external object, which implies the modification of some perceived properties of the object in adherence to the model.³⁴ The body model would exercise a normative role of content filtering and structural modulation with respect to the sense of body ownership. This role is active on a double level, as well as being internally divided into a double component. The double plan of intervention of the body-model coincides with the double material and formal dimension of the sense of body-ownership. Not only the content, therefore, but also the content-independent structure of the mineness experienced by the perceiver would be subject to an autonomous internal regulation. The dual normative component overlaps with the inhibition (negative component) or the activation (positive component) of the plasticity of the incorporation.³⁵

Phenomenological perspectives on technological incorporation

Postphenomenology and mediation theory

The scientific results that I just briefly retraced as distinctive of the subjective turn in the contemporary science of human embodiment are today at the centre of a lively debate linked, in particular, to the philosophical movement, known as postphenomenology.³⁶ Postphenomenology is presented as a philosophical style of investigation that places science and technology at the centre of its analytical interest, focusing on the close relationship of the two systems interpreted as cultural phenomena.³⁷ The main objective of postphenomenology is to systematically address, from within the tradition of phenomenological philosophy, the plexus of issues concerning the active role played by artifacts, technological products in the bodily-perceptual experience of surrounding world,³⁸ and more in general in the personal experience of cultural worlds.³⁹ Postphenomenology, therefore, pays attention to technology as a force capable of shaping human subjectivity itself. It makes use of an interdisciplinary methodology characterised by a strong empirical root, an aspect that gives it a very peculiar position in the field of postmodern philosophical studies.⁴⁰ In postphenomenological methodology, the conceptual analysis of phenomenological style is applied to case studies of high informative value, based on a reworking of the principles and methodical operations of classical phenomenology conducted in a pragmatic direction.⁴¹ As has been noted, the “shift towards materiality and concrete practices reveals an influence of American pragmatism. The phenomenon of technological mediation can be studied in the concrete practices of interaction with technologies, where it takes place”⁴². Postphenomenological investigations have affected a wide variety of technological domains including, mainly, the biomedical domain, developing in a very branched way into sub-theories, the main one being mediation theory.

The central idea of ​​mediation theory is that technological devices play a mediating role in the human-world relationship, interpreted as a resulting dynamic of the relations between human beings and technology.⁴³ Mediation theory has been interested in the phenomenal incorporation of technological devices, proposing a series of useful conceptual distinctions, for example, with regard to the relations of fusion, in which “the physical boundaries between human and technology is blurred, and technology merges with our bodies”⁴⁴. Despite the results achieved, postphenomenology and mediation theory have proved ineffective to address the dimension of technological normativity in its various aspects in sufficient depth.⁴⁵ The aforementioned limitation is largely due to the lack of an adequate processing of the critical issue.⁴⁶ More specifically, it was found to depend on the inability to validate, to rationally justify the conceptual position embraced regarding technological normativity.

A classic-inspired alternative

As previously anticipated, in this article I propose an alternative path to that pursued by postphenomenologists and mediation theorists. This path is characterised by the presence of a critical aspect that integrates the methodology illustrated in the previous sub-paragraph through the recovery of a component of the classical phenomenological method, the genetic component, instead of the pragmatist component of the postphenomenological methodology in the light of two remarks. First of all, as I will clarify in what follows, the genetic insight returns a “concrete” dimension to the critical investigation of classical phenomenology, specifically that of Husserl, the (presumed) absence of which is at the basis of the pragmatist reorientation of the same attempted by postphenomenologists. The latter is in fact based on a fundamental observation carried out in relation to the Husserlian approach, according to which the analytical focus maintained on the essential units and relations of lived experience, which are by their very nature universally valid units and relations, would prevent classical phenomenology from understanding the human-technology relations and technological mediation in their concreteness, peculiarity or, better said, uniqueness. This suspicion of essentialism, however, leaves a distinctive feature of Husserl’s methodological reflection in the shadow – and here I insert the second remark: the complexity, that is, of interpretation and articulation of the critical instance. This aspect has been ignored by recent trends in contemporary phenomenology, such as naturalized phenomenology, and, above all, postphenomenology. According to what I will be able to illustrate shortly, it is nevertheless central in Husserl’s work, where it depends on the variety of formulations to which the critical analysis is subjected, formulations that are systematically harmonised within the framework of a unitary methodology.

The classical genetic phenomenology of human embodiment

The classical phenomenological methodology of Husserlian matrix is ​​based on the interaction of three components, namely the descriptive component, the constitutive component and the genetic or explanatory component. These components are interrelated in systematic terms in the light of a complementary relationship established between the so-called static and genetic method.⁴⁷ The static method includes phenomenological descriptions and constitutions. By carrying out the former, the phenomenologist analyses the structures of lived experience in detail in terms of its correlated intentional elements, namely the act-process (noesis) and what is understood by this as an objective sense (noema). Phenomenological constitutions, instead, allow us to understand the processes by which the objective senses are synthesised or unified in the object of experience – interpreted as an instance of the noematic sense. Between 1917 and 1921 Husserl begins to distinguish a genetic component of the phenomenological method. The genetic method (genetische Methode) is used to expand static constitutions from a time-dependent perspective and is now presented as distinct and complementary to the static one (statische Methode), previously identified with the phenomenological method tout court.

A presentation in depth of genetic phenomenology certainly cannot be given here. Without advancing claims of exhaustiveness, therefore, in the next paragraph I will limit myself to recalling the distinctive aspects of the genetic method, the three basic interpretations of the concept of genesis provided by Husserl together with some structures of the genetic phenomenology of embodiment. These considerations will allow me to outline a classic approach to the normative issue regarding the incorporation of biosynthetic devices.

The genetic method and the three Husserlian interpretations of the concept of genesis

As anticipated, the genetic method broadens the spectrum of phenomenological investigation. The intentional structures of consciousness are no longer simply described and/or studied in constitutive terms by the phenomenologist but are also “explained” by means of if-then relationships of a motivational kind. Genetic explanations are thus non-naturalistic (i.e. non-causal) explanations: as motivational or pure (rein) explanations, they allow the phenomenologist to understand how a given lived experience becomes structured, that is, how it assumes its characteristic intentional configuration, with a noetic pole and a noematic pole. By motivation here we mean both “the inner lawfulness of consciousness”, and the “central methodological principle of genetic phenomenology”⁴⁸.

According to Husserl, explaining intentionality in genetic terms means bringing to light affectivity as a concrete and originary dimension of experience: the prominence of the affectively induced data can then be structured in an abstract interest, for example in cases in which a given conceptual position is deliberately assumed.⁴⁹ The interest (Interesse) is presented by Husserl as a consciousness articulated in the double dimension of the foreground-background (Vorgrund-Hintergrund). This consciousness operates by constitutive “stratifications”, according to dominant syntheses and supporting syntheses that respond to a fundamental organisation, that of inner time.⁵⁰

This being said, at least three interpretations of the concept of genesis can be identified in Husserl’s vast and complex work. More specifically: 1) the “primordial” or passive genesis; 2) the active genesis, and 3) the genesis that is active and passive at the same time.⁵¹ The distinction between passivity and activity here concerns the affective character of the genetic process, or its spontaneous character. The active genesis implies the presence of the ego (Ich), which leads to a spontaneous, non-reactive experience of the object as intentional correlate. The active synthesis is thus egoic. On the other hand, the primordial genesis overlaps with a reactive, non-spontaneous experience of the object as intentional correlate: the passive synthesis is mediated by the body understood as animated or living body. The genetic process can also take place between activity and passivity, therefore, as a genesis that is both active and passive.

Associative and kinaesthetic bases of embodiment

As has been observed, “the phenomenological tradition has been addressing the theme of embodiment from the very beginning. Indeed, Husserl was already describing the kinaesthetics of vision even before the Logische Untersuchungen appeared”⁵². Compared to pre-phenomenological studies dating back to the last decade of the XIX century, the phenomenological descriptions that Husserl carried out during the first and the second decades of the XX century undoubtedly represent a more in-depth analysis, being focused on the genesis of human embodiment from a primitive kind of consciousness, i.e. association (Assoziation).

Husserl interprets associative consciousness as a temporal synthesis: the identity of the object as an object that has duration (temporal continuity) implies connecting, associating impressions that determine the present moment of consciousness – the so-called “living present” (lebendinge Gegenwart) with the corresponding retentional and protensional phases of the immediate past and the immediate future – to mnemonic reproductions of past impressions and imaginative anticipations of expected future impressions. In the Husserlian sense, therefore, association “does not characterise a form of objective, psycho-physical causality, as it does for psychologists”⁵³. Husserl described association from a formal as well as a material point of view. The form of associative consciousness is a form of ordering, the form of succession (being antecedent-being posterior in the temporal order), which structures the object as a continuum in the temporal sense of duration. The matter of associative consciousness is that discrete sensory datum informed by the succession – and by a subordinate form not of ordering but of field indicated as simultaneity (i.e. being co-existing in a sensory field or among several sensory fields) – which Husserl calls hyle.⁵⁴ The hyletic datum is internally articulated in the group of sensory sensations, for example tactile and visual sensations, and in the group of sensory feelings, such as pain, pleasure and fatigue.⁵⁵ Husserl examined a series of associative structures (fusion, contrast, similarity, dissimilarity, homogeneity, heterogeneity and gradation), describing them mostly in pairs according to a logic of opposition (fusion vs contrast; similarity vs dissimilarity; homogeneity vs heterogeneity). The phenomenon of prominence, originating mainly from the associative structure of contrast, brings out a higher level of consciousness, more complex than the associative one: kinaesthesia understood as motor consciousness.

Kinaesthesia selects prominent hyletic data from the link of temporal association according to a motivational nexus, the so-called kinaesthetic motivation, which is genetically constitutive for the simultaneity of the hyletic data, therefore, for the field structure of sensoriality and for the objective synthesis of the percept.⁵⁶ The perceptive prominence has a double directionality: alongside the environmental one it also knows a proper-bodily direction linked, in particular, to the tactile sensorial field. As asserted by Husserl: “Necessarily bound to the tactual perception of the table (this perceptual apprehension) is a perception of the body, along with its concomitant sensation of touch”⁵⁷. The kinaesthetic-visual embodiment as lived experience depends on the localisation “on or in” the body of the hyletic data made possible by touch.⁵⁸ In fact, unlike the finger that touches, the eye that sees does not locate the respective data. There is certainly a field of visual localisation. However, it is gained in a mediated way, that is, through kinaesthesia and touch: “An eye does not appear to one’s own vision […] We do not have a kind of extended ocularity such that, by moving, one eye could rub past the other and produce the phenomenon of double sensation […] Actually, the eye, too, is a field of localisation but only for touch sensation, and, like every organ “freely moved” by [the] subject, it is a field of localised muscle sensations”⁵⁹.

The kinaesthetic-visual embodiment that I briefly outlined in the previous sub-paragraph was characterised by Husserl as solipsistic: it does not coincide with the phenomenon tout court, which, in fact, also has an intersubjective genesis in empathic experience.⁶⁰ An important integration of the experience of embodiment is due to the intersubjective genesis, which is articulated along a double line. First of all, the expansion of the possibility of locating hyletic data “on or in” one’s own body, which is the body both of the experiencer (as an “other” individual embodied as a term of empathic experience) and of other individuals empathised by the same. Secondly, the emergence of the plexus of psychic states and processes involving the aforementioned data. The body as a real bearer of the psychic dimension (Träger von Psychischem) is the object of study of psychology interpreted as a natural science.

The solipsistic genetic structure of ideopsychic quasi-causality

Within the systematics of natural sciences elaborated by Husserl, psychology appears as a specular discipline to physiology, which is intended as the study of organic functions of the body precisely in its material dimension. Both disciplines branch out from somatology, the natural science of the animated body interpreted as a space of localisation of sensory data (Leibesempfindungen and Empfindnisse). However, psychology may be classified as a human science too.⁶¹ Accordingly, as to its solipsistic aspect, the phenomenological grounding of psychology as both a natural and a human science is traced by back to two genetic structures: physical-psychic quasi-causality and ideopsychic quasi-causality. Such structures are often presented by Husserl in the context of a critical discussion of parallelism and interactionism, conceived as competing theoretical positions at the level of scientific clarification of the soul-body problem.

Physical-psychic quasi-causality captures, as to its principles, the explanatory set-up of psychology interpreted as a natural science. This explanatory set-up concentrates on a specific kind of dependences where the psyche, the soul is conditioned by its material substrate, namely by the physical body. Here, the conditioning only resembles the causality exercised by physical bodies on each other – in this sense, it represents a kind of quasi-causality. According to Husserl, “it is well known that the psyche depends on the body and thereby on the physical nature and its many relationships. First of all, this dependency exists throughout with regards to the totality of sensations (including the sensuous sensations of feeling and instinct) and further also with regard to their concomitant reproductions, and thereby the whole life of consciousness is affected by this dependency”⁶². Ideopsychic quasi-causality, on the other hand, refers to psychology as a human science. It concerns, indeed, the dependence of low-level psychic events (i.e. sensory events) linked to the animated body on the stream of lived experiences polarised by the ego as a psychic subject. This kind of psychic self-dependence ensures an internal coherence to the individual’s conscious life. In Husserl’s words: “Within one and the same soul, the present stock of lived experiences, as a totality, is dependent on earlier stocks of lived experiences […] even where a sensation occurs as ʿan effect of external stimulationʾ, the mode of its acceptance into consciousness is co-determined by this new regulation”⁶³.

In the next paragraphs I will propose an application of the structure of ideopsychic quasi-causality in order to clarify the role played by the body-model in the incorporation of biosynthetic devices, in particular of the latest generation of corneal implants. The selection of the structure is in line with the general interpretation of technology as a cultural phenomenon promoted by postphenomenology and mediation theory as well as with the centrality acquired by the character of subject-relatedness (i.e. subjectivity) in the contemporary scientific explication of (minimal kinds of) embodied consciousness.

A case study: biosynthetic corneal extracellular matrices (ECMs)

Design, manufacturing of the device and tracking of the user-patient experience

The cornea is the protective frontal part of the human eye responsible for transmitting and refracting incident light rays that are focused on the retina by the lens, i.e. the natural lens of the eye. The irreversible loss of optical quality of the cornea, i.e. the loss of its transparency due to disease and/or damage, is the second cause of blindness in humans and is typically addressed either with corneal transplantation or with the use of synthetic prostheses.⁶⁴ However, the gap between the availability and demand of the transplantable organ, on the one hand, and the complex implantation procedures as well as the frequent post-operative complications, on the other hand, have highlighted the need to pursue new therapeutic approaches, attempted, above all, in the field of regenerative medicine.⁶⁵

Towards this end, a research group active for over a decade in Sweden, Canada and the United States first developed in the laboratory and then tested on animals and humans a corneal metaplasm, consisting of biosynthetic corneal extracellular matrices (ECMs).⁶⁶ Once implanted in the eye, the biosynthetic ECMs have the ability to regenerate the damaged organ, emulating the functions of the natural ECMs, which constitute the part of the tissues not composed of cells. Like the natural ones, biosynthetic ECMs are made of a biopolymer (recombinant collagen of human origin). Unlike natural ECMs, however, they are devoid of cellular filling to ensure the repopulation by the cells of the natural organ and thus prevent reactions of rejection.⁶⁷ As the results of the aforementioned study suggest, the biosynthetic ECMs, which were first tested on animal subjects and then implanted in a group of ten human subjects, were shown to be stably incorporated by the patients in the long term (two years of follow-up), leading to an improvement in the pre-pathological visual capacity in six out of ten patients tested as well as to the regeneration of the epithelium, nerves, stroma and tear film in all the subjects involved in the study.⁶⁸

Recent evolutions

In 2018 another research group based at the Institute of Genetic Medicine of Newcastle University succeeded for the first time in producing perfectly functional biosynthetic human corneas by using an advanced 3D bioprinting technique.⁶⁹ The step forwards compared to the production of corneal metaplasm concerns the fabrication of entire biosynthetic corneal structures that can act as real prostheses. To this end, the research team first constructed a model of an adult human cornea using a rotating Scheimpflug camera equipped with a keratoscope (Placido’s disc)⁷⁰. The model obtained was utilised by the researchers as a basis to reproduce the microarchitecture of the natural organ through a 3D printing process that uses a bio-ink composed of the combination of two biopolymers (collagen and alginate) and of corneal stroma cells from a healthy donor.⁷¹ After the 3D printing of the corneal microstructures, the research group induced a self-assembly process of the tissue, by exploiting the natural ability proper of corneal keratocytes, which are specialised fibroblasts residing in the corneal stroma, to produce components of the ECM.⁷² The clinical translation phase of the device is still in progress.⁷³ Further contributions to the development of bio-printing techniques have stemmed from numerous research groups and companies specialised in bio-ophthalmology.⁷⁴

According to the introductory findings, the tracking carried out of the user-patient experience gives a particular value to biosynthetic ECMs as a case study to begin a critical reflection on an advanced topic of body normativity. It seems to me that this reflection should be oriented on a particular aspect: the existence or not of a relationship between the increased biocompatibility of the device and the reduction of the reconfiguration of the body model. The latter would seem to imply a loosening of the morphological, anatomical-postural and informational-structural normative constraints imposed by the model on the modification of the pre-reflexive sense of body ownership, a modification that in our case would be connected to the phenomenal incorporation of biosynthetic ECMs. As I will attempt to outline in the next section, the solipsistic genetic structure of ideopsychic quasi-causality allows us to shed light on this phenomenon of functional loosening of the body norm.

Genesis of the body norm in the phenomenal incorporation of latest generation medical devices such as biosynthetic corneal ECMs

The brief presentation given in § 4 provides a somewhat abstract description of the structure of ideopsychic quasi-causality, conducted in terms of the self-dependence relationship. In other words, the discussion was focused on the (partial) determination, in the motivational sense, of the hyletic basis of sensory data by what Husserl indicated as the totality of psychic events. To give greater substance to this description it is necessary to characterise both the hyletic basis and the psychic totality in relation to the case study selected. Towards this end, the sensory data that interest us are kinaesthetic-visual data (re)acquired by the user-patient thanks to the implantation of biosynthetic ECMs and to the anatomical-functional regeneration made possible by the matrices themselves. The totality of psychic events to which reference is made coincides with the body model itself, understood as an internal description of the anatomical, volumetric and structural properties of one’s own body composed of both static elements (anatomical, volumetric and structural representations) and dynamic elements (processes of reconfiguration of the body model). Following this characterisation, it is possible to trace the genesis of the body norm in implanted users-patients, and hence to try to understand if there is a phenomenon of functional loosening of the body norm regulating the phenomenal incorporation of biosynthetic ECMs. This attempt can only involve a passive level of experience and, therefore, can call into question that interpretation of the phenomenological genesis that we have seen to have been connoted by Husserl as primordial, as it refers not to an egological activity but to the affectivity of the body that is a precondition of that activity.

Review of the case study

As in any genetic investigation conducted at a passive or primordial level, the starting point is given by the formal structure of the present of consciousness, while its development involves the associative propagation of the same along a double direction: the temporal direction of the past, which can be reproduced mnemonically, and of the expected future through anticipations, and the direction of coexistence in one or more sensory field structures, integrated in the synthesis or unity identifying the percept. Compared to a non-pathological conscience, the living present of users-patients treated with biosynthetic ECMs is characterised by kinaesthetic-visual impressions, retentions and protensions equipped with greater motivational strength due to the intensification of the prominence of the data. This intensification depends on a phenomenon of contrast that we could define as hyper-structured. Not only because it provides the involvement of the hyletic basis, but also the involvement of the mnemonic reproduction of a sense of lacking-of directed towards the aforementioned basis that is felt by the perceiver in the pathological state of blindness, which, precisely, contrasts and is in conflict with the presence of the sensory content in the impression that determines the present moment of visual consciousness, its living present. A first moment in which the (quasi-)causation or motivational force exerted by the body model can be said to be active is this living present of the kinaesthetic-visual consciousness of the user-patient, a present that, as we have just seen, is structured not only according to the form of ordering of the internal succession of the immediate temporal phases, but also according to the form of ordering of the external succession of present and past moments that distinguishes consciousness as a reproductive association.

That a normative regulatory value is connected to this consciousness and that this value can help to clarify phenomenal aspects of the process of reconfiguration of the body model in technological incorporation, can be explained, in my opinion, by recovering an interpretation of the norm as ideopsychic optimisation, which has been suggested by Husserl in the context of a genetic investigation conducted on the verification of mnemonic impressions.⁷⁵ Intended as a (re)constitutive process, the verification or ascertainment of the past impressional data reproduced in the current present of consciousness reveals a sense of the norm that can be said to be embodied because it coincides with (the ideal of) a complete pre-reflexive appropriation, which is therefore passively or bodily lived, of an already realised psychic course that is accessible by the experiencer as a whole.⁷⁶ The body norm thus conceived expresses an ideal that can be approached in the light of a gradation of moments of passive experience. This phenomenon of passive experiential gradation shows a double internal articulation: on the one hand, the progressive intensification of the motivational force exerted on the living present of consciousness by the psychic totality and, on the other hand, the progressive internal differentiation of the correlated noetic-noematic components of the lived experience.⁷⁷ In the case in question, the sense of the body norm just described (i.e. ideopsychic optimisation), together with the corresponding phenomenon of gradation, appears in connection with the motivational action exercised by the model on the present of the kinaesthetic-visual consciousness of the user-patient. In fact, the determination of the sensory content of this consciousness is conditioned by the pre-reflexive appropriation that the perceiver gains with regard to the entire series of reconfigurations of the body-model, an appropriation that occurs concurrently first with the entry and then with the exit from the pathological state of loss of visual function.

It has already been noted that the determination of the sensory content or hyletic data of the living present implies that the kinaesthetic-visual consciousness of the user-patient is structured as a reproductive connection or association, acquiring a temporal form that extends along the direction of the past of consciousness. This temporal form is not the only one linked to the normative regulatory aspect of the body model. In fact, there exists a temporal form that extends along the direction of the future of consciousness, which, in analogy to the one previously illustrated, consists not only in the form of ordering of the internal succession of the immediate temporal phases, but also in the form of ordering of the external succession of present moments and future moments. Both of these forms are distinctive of consciousness as an anticipatory association.⁷⁸ Understood as a psychic totality, the body model motivates an imaginative prefiguration or anticipation in the present of the kinaesthetic-visual consciousness of the user-patient. This prefiguration makes it possible to configure a set of data that we could define as pre-prominent, as not yet highlighted, precisely as prominent data, by the (recovered) kinaesthesia of vision. The pre-prominent data and the structure of the anticipatory association, to which they belong to, provide a first organisation of consciousness to the preconceptual categorisation implied by the sense of body ownership. It is in this organisation that there is a new expression of the body norm as ideopsychic optimisation and of the corresponding phenomenon of passive experiential gradation, an expression rooted in the close interconnection existing between the body model and the body schema.⁷⁹ According to this new declination, the body norm coincides with (the ideal of) a complete pre-reflexive appropriation of the multimodal sensory synthesis – not yet of the perceptual object –, in particular of the physicality or materiality of one’s own body and of the environmental bodies seen as kinaesthetic-visual units. As in the case of the body norm relating to consciousness as a reproductive association, also in this case the norm is approachable in the light of a gradation of moments of passive experience. In consciousness as an anticipatory association, the phenomenon of gradation shows the known double internal articulation, although the progressive intensification of the motivational force as well as the progressive internal differentiation of the correlated noetic-noematic components are here due to the action exerted by the multimodal sensory synthesis prefigured in the current present of consciousness by virtue of that psychic totality, which is the body model – as an internal description interconnected with the body schema.

The coexistence of impressions in the sensory fields, as well as the coexistence of the same fields that structure the user-patient consciousness as perceptual consciousness, represents a new sphere of action of ideopsychic normative regulation exercised by the body model. This action is carried out on a hyletic basis informed by a more complex field (and between fields) organisation of a higher level than that organisation of the ordering characteristic of temporal succession as a form of associative consciousness. It is at this level that the normative role exercised by the body model affects the phenomenal incorporation of external objects, activating or inhibiting the plasticity of body ownership, according to those constraints that have been mentioned in the previous paragraphs. The high biocompatibility of biosynthetic corneal EMCs does not cause a loosening of the morphological, anatomical-postural and informational-structural constraints imposed by the body model, since the devices not only emulate the functionality of natural ECMs but actually regenerate the natural organ.⁸⁰ At least in this case, therefore, the increased biocompatibility of the biosynthetic device compared to a classic device does not involve a reduction in the reconfiguration of the body model following its incorporation. This means that there is no functional loosening of the body norm interpreted as regulating the activation or the inhibition of the plasticity of the pre-reflexive sense of body ownership.

The investigation carried out in this paragraph shows that, if there are nuances of the norm expressed by the body model in cases of incorporation of biosynthetic ECMs, this phenomenon does not concern the loosening of the morphological, anatomical-postural and informational-structural constraints imposed by the body model. It rather concerns the pre-reflexive appropriation, passively experienced, of the body model itself, understood as a psychic totality given in the past of the kinaesthetic-visual consciousness of the user-patient. This phenomenon of passive experiential gradation also concerns the pre-reflexive appropriation of the body precisely in its material dimension and of the environmental bodies, interpreted as multimodal sensory syntheses to which the kinaesthetic-visual consciousness of the user-patient has access in his/her next, future development.

Conclusion

In the present article I proposed an investigation concerning the normative role exercised by the body model in the incorporation of the latest generation of biosynthetic devices, namely biosynthetic corneal ECMs. To this end, I made use of the normative regulation of ideopsychic quasi-causality, identified by Husserl in the context of his genetic phenomenology of human embodiment. The interdisciplinary methodology adopted was inspired by that developed by postphenomenologists and mediation theorists, distinguishing itself for the adoption of a classically inspired critical perspective of which postphenomenology and mediation theory have proved to be lacking. I focused my attention on the alleged phenomenon of functional loosening of the body norm, a phenomenon that turned out to be inconsistent with genetic-phenomenological data on user experience. The results achieved are certainly not exhaustive concerning the complexity of the normative issue addressed. However, taking into account the high informative value of the case study selected, which, in fact, exemplifies the small group of cases in which biosynthetic devices have reached the phase of clinical translation with a systematic tracking of the corresponding user-patient experience, these results may be evaluated as a first, initial step towards a systematic treatment of the normative issue connected to the phenomenal incorporation of an emerging class of medical devices.

In this direction, it seems to me that at least two aspects deserve a more careful and thorough examination. First of all, the aspect of the intersubjective genesis of the pre-reflexive sense of body ownership, with the corresponding normative dimension. The latter could reveal a new problematic plexus within an important line of research in the contemporary science of human embodiment focused on the study of the neurobiological basis and of the functional mechanisms of the interconnection between body model and body image.⁸¹ The second aspect concerns the monitoring of a research and innovation sector that is constantly and rapidly evolving: Artificial Life. It has been observed that the technological development of biosynthetic devices is strictly linked to this sector. A future selection of case studies cannot, therefore, ignore the aforementioned monitoring commitment, which could result not only in an expansion of the interdisciplinary dialogue between phenomenology and the science of human embodiment, but also the establishment of a new view of interdisciplinarity extended to critical and scientific disciplines, as well as advanced sectors of research and technological innovation.

Abstract

The body model is a relatively new concept, which originates from the intersectoral science of human embodiment. Cognitive neuroscientists and psychologists that work in this research field usually interpret the concept of body model as an internal model or reference description of the anatomical, volumetric and structural properties of human corporality. It has been demonstrated that the body model plays a normative role in shaping a pre-reflexive sense of body ownership, which is centrally involved in the lived experience of incorporating medical devices, such as prostheses or implants, the so-called phenomenal incorporation. Further investigation is required to understand the normativity of the body model, especially in relation to the emerging generation of so-called biosynthetic devices designed to lead incorporation to a qualitatively higher degree compared to traditional medical devices. The main objective of this article is to contribute to a critical analysis of the normative role of the body model in the lived experience of incorporating biosynthetic devices. My starting point is an interdisciplinary methodology, which is inspired by that developed by postphenomenologists such as Don Ihde and Peter-Paul Verbeek. I will adopt, however, a classically inspired critical perspective of which postphenomenology have proved to be lacking. More specifically, I will use as a reference frame for critical analysis the genetic phenomenology of human embodiment, which was developed by the founder of classical phenomenology, Edmund Husserl, in a mature phase of his production.