This reasoning, which has been just developed about perception of objects in the analog dimension, may be applied to digital environments as well. I will take into consideration how the same kind of object (a ball) is perceived in four kinds of digital dimensions: (1) on-screen, (2) virtual, (3) augmented, and (4) hybrid. If we consider perceptual relation as a mere interaction between the whole and its parts, then an object shall be considered as the same in all these dimensions. However, our immediate experience of the object makes us sense it as different. I decided to take into consideration four basic modalities in which differences usually take place: (a) sensory spheres, (b) figure-ground connection, (c) affordances, (d) persistence. I have specifically chosen these ones, since they connect the whole-part relation to the surrounding environment. In this way, I will apply to digital dimensions the theoretical assumptions and arguments on perceptual relations I have made in the previous section. I will also argue that, if we take into consideration an extended concept of perception and its reference to the Umwelt, this relation will not involve either identity or radical difference, but analogy.
(1) Let us think about an on-screen ball and how we perceive it. The relation between the whole and its parts, which characterize the configuration of sphericity, is exactly the same. However, we immediately sense the on-screen ball as not coinciding with the analog one. (a) First, it happens because some sensory spheres are certainly inhibited: on a screen we may see the ball, but we cannot touch it, whereas in an analog environment the ball may also be an object of haptic perception. The sound of it bouncing on the ground may be somewhat reproduced, but the ground should be on-screen too. Olfactory and gustative experiences, even if we usually do not consider them in this specific case, are completely erased: the smell or the flavour of the rubber of the analog ball are absent and I may only perceive a sort of metallic sensation, which belongs to the screen, not to the ball it displays. It is immediately clear that, synesthetically speaking, there are perceptual differences between an analog and on-screen object.
Let us stick only to the visual dimension now. In our daily experience we may walk around the ball, look at a mirror in order to see other sides of it, manipulate or rotate it. If the on-screen ball is a tridimensional and not a bidimensional object, it may be rotated and seen from different angles as well. However, a question arises: do I see the 3D ball in the same way I see the analog ball? The relationship between the whole and the parts of the configuration through which I perceive the ball, that is sphericity, is on the screen the same as out of the screen? If perceptual relation was just an intrinsic relation, as Gestalttheorie classically states, a ball seen on a screen would not be distinct from a ball seen outside it. (b) However, if one carefully analyzes the figure-ground relation, a clear answer may be more difficult to give. Is the 3D ball, intended as a digital figure on the digital ground of a screen, the same as the analog ball, which is an analog figure on an analog ground? The texture of the background screen, which is also the same of the ball, is considerably different than the one belonging to the analog ground, made by different objects, and to the analog ball. Human eyes immediately perceive these differences in texture: even the best on-screen reproductions are seen by us as different from analog objects and situations. Figure-ground relation is just one of the elements (even if a very significant one) of visual perception.
(c) More differences may be individuated if one considers the affordances theorized by the ecological theory: in this case, the practical aspect of my interaction with objects influences also its perceptual modality. I cannot play with the ball on the screen, at least not in the same way as in analog reality, so that the affordances of the on-screen ball are different from the ones of the analog ball: the on-screen ball is not graspable and I cannot bounce it. (d) Other differences concern the relation between us and the persistence of the object. I can easily get rid of an on-screen ball: I just turn the screen off and the ball disappears. Getting rid of an analog ball, instead, is definitely more difficult: I must walk away, hide it somewhere, or tear it into pieces. If the ball is in front of me, I cannot just close my eyes and open them again: the ball will keep on being in front of me. The relation with the persistence of the object is thus evidently different.
If, as I have hypothesized, the relation between the whole and the parts of a configuration is inherent not to an isolated dimension, but to an extended one, this relation will change depending on whether its environment is analog or digital. Does it mean that the shape of the ball is completely reconfigured? I would say no, otherwise I could not perceive the ball on the screen as a sphere, but as a different object. Notwithstanding differences, there must be a somewhat relation of analogy between the two balls, an analogy which maintains the validity of Gestalt theory and allows the object to be recognized as such, to have “the meaning of the ball”, as classical phenomenology would say.
It may be objected that on-screen reality is not immersive and that, in order to test our perceptual structures, we should rather refer to other kinds of digital environments. (2) Let us think to virtual reality, where the perceiving subject, through a headset and/or other devices, just as a haptic glove, is projected in a simulated dimension. (a) Suddenly, it becomes clear that synaesthetic relations are different, since immersive devices which can reproduce smells or flavours have not been invented yet and we do not know if they ever will. (b) Figure-ground relations, instead, tend to be quite similar in virtual and analog realities, since the presence of other objects, close or far to the virtual ball, with similar textures in the surrounding environments may be simulated. (c) Even some affordances, when they do not involve other sensory spheres than visual, auditory, and haptic ones may similarly take place in virtual and analog realities. If I see and touch the virtual ball through a headset and haptic gloves, the sensation and the manipulation of the ball will show similarities with the approach to the real ball. I can see it, walk around it, touch it, grab it, bounce it, etc. The ball is touchable, graspable, “bounceable”, etc., so that its practical relation to me mostly resembles the one taking place in the analog dimension.
Yet, even in this case, I am able to distinguish analog from digital dimensions. I will say, for instance: “This ball looks like a real one!” or “I play with this ball as I play with a real ball!”. I will not say: “This ball is real!” or “I play with it because it is real!”. The immediate experience of a virtual ball is different from the immediate experience of an analog one. For instance, I recognize the virtual ball as a non-analog object, so much that, if I have not devices attached to my legs or feet, I will not be able to kick it. However, even if I had them, the practical relation to the virtual ball would be different than the one in the analog dimension, because I immediately recognize the virtual ball as such. (d) Just as it happens with the on-screen ball, even the persistence of the object is perceived differently. When I take off headset, gloves, etc., the ball will disappear. The same cannot be said about the analog ball. However, just as in the previous case, I recognize it as a ball anyway, by virtue of its relationship of analogy due to the entanglement of our perceptual structures and the things we meet in the world.
I would like to point out that an increasing number of studies on Human Computer Interaction (Slater, 2018; Piryankova et al., 2014; Kilteni et al., 2013; Burin et al., 2019; Jong et al., 2017; Tosi et al., 2020) find that experiences of immersive virtual reality change our bodily conscience, both from the theoretical (awareness that the virtual bodily parts belong to me) and practical (awareness of one’s actions in the virtual world). Such effects have been proved to persist even after the end of a virtual experience. It means that the immersion in another dimension affects our way to relate to analog reality, so that the relation of analogy is not easy to be defined.
What does it happen, instead, in mixed situations, just as augmented reality or hybridization between humans and digital technology? (3) In the case of augmented reality, there is an interaction between on-screen and analog reality. I was particularly impressed by the technology used at Gaudí’s House Batlló: here the visitors receive some devices and, through their screen, extensions of the elements of the house of the famous architect appear, along with animations, reproductions of the original aspect of the objects, etc. If we apply this concept to the ball, we may see it, through specific glasses or screens, as multicolored or with informative writing on it. In this case, how do we perceive the ball in augmented reality? Actually, we grasp it as the same object, but developing different and extended perceptual possibilities. The model of augmented reality is very close to what I intend with perceptual relation: it concerns whole-part relations of an object, extending out of the object itself and expanding the possibilities of experiencing that object.
(a) As far as sensory spheres are concerned, the tactile, olfactory, and gustatory experiences of the object remain the same. There is also an addition of new auditory elements: I may still hear the ball bouncing on the ground, but also rings or tunes coming from the device. Visual stimuli tend to be different instead: the reference ball is the analog one, but I see other characteristics of it (a different size or color, for instance). (b) The figure-ground relation is configured as a composite one, since the extended version of the figure of the perceived object relates to the extended version of its ground. In this way, the digital device allows our perception not to lose contact with analog reality, but shaping it differently: for instance, we see an augmented ball on an augmented floor with an augmented chair next to it as the extended version of an analog ball on an analog floor next to an analog chair. Even if color, contours, or other elements are different, we do not perceive a radical change of configuration, but only its modified version, as I have previously stated. (c) Something similar may be said about affordances. Because of the entanglement between analog and digital configurations, the augmented ball may be seen as touchable, graspable, “bounceable”, etc. I cannot individuate evident differences with an analog ball, even if the adjustment of our body in space may be slightly affected: when I try to reach the augmented ball with my hand, I will perceive an extended space, which will affect my kinaesthetic sense of it. (d) As far as persistence is concerned, if I turn the augmented reality device off, I cannot see the modifications and the additions allowed by the device anymore, but the object is still there: I would say that it is the same ball I see and touch, even if I experience different possibilities of it, depending on whether the device is turned on or off. In this case, the relation of analogy is more evident than in the previous cases (on-screen and virtual reality).
(4) What happens, instead, in the case of cyborgs, of the hybridization between human body and mechanical parts, namely digital ones? Following a Merleau-pontian interpretation given in a recent paper (Ferro, 2021a), devices may be ontologically considered as extensions of our bodies, of our flesh. Moreover, there is a common texture, an element that, according to what Merleau-Ponty states in The Visible and the Invisible, is shared by all beings (Merleau-Ponty, 1968, p. 144). This texture is the flesh, also called “the flesh of the world”, which indicates the presence of an “original connectedness” (Clarke, 2002, p. 213), wiping out the dualism between subject and object: it is not the phenomenal body anymore, but the body as such, which is the expression of both subjectivity and objectivity.
By applying Merleau-Ponty’s concept of flesh, I may state that the digital prosthesis can become a part of me and that I can interact with other objects through it. If I was blind and a bionic eye was installed on my body, this eye would allow me to see, to gain access to a set of sensible data that I could not perceive otherwise. Through an ocular prosthesis a blind person may gain sight and perceive the world similarly as those who can see without the help of a prosthesis. We should wonder, however, if the former blind person who sees, through a bionic eye, an object in an analog environment has an identical perception to those who have “fleshy” eyes. Is the ball perceived by the former blind person the same object as perceived by a sighted person? Even in this case, I would answer both yes and no. a) Synesthetically speaking, an interaction of all the sensory spheres is possible. The only difference is that the presence of a prosthesis may affect some specific sensory spheres. Let us think to a former blind person seeing an analog ball with a digital prosthesis. He or she will touch it, hear it, etc. as he or she did before, singularly speaking. However, synaesthetic perception requires an interaction between different spheres. How is sight affected by the prosthesis? Are the signals that the bionic eye send to the brain identical to the one sent by the “fleshy” eye? As far as I know, such a technology has not been developed yet, allowing blind people to see exactly as sighted people, so that I may speak only hypothetically. Still talking about the domain of possibilities, technological development will not allow the person using a prosthesis simply to “catch up” with the others, but also to gain access to further information. Let us think to the bionic eye, which looks at the ball and, at the same time, perceives its inner structure and reads information written on it: here hybridization is even mixed with augmented reality. If sight is affected, then synaesthetic perception, which involves a relation between all the sensory spheres, will be differently reconfigured as well.
b) As far as figure-ground relations are concerned, the ball perceived by a prosthesis is seen in relation to background objects, belonging to a specific sensorial field. In this case, there are many similarities with augmented reality: we do not perceive a radical change of configuration, but only some differences due to the medium of the prosthesis (contours, shades of color, etc.). c) About affordances, there are some similarities with both analog and augmented reality. If I have a bionic hand which allows me to regain sensitivity, then I can touch, grab, and bounce the ball anyway. However, the way in which I do it will be different: the ability to move my fingers or to adjust my strength will not be the same, since the prosthesis extends my body, but does not entirely coincide with it. I will feel and move my right “fleshy” hand and my left prosthetic hand differently, even if I am able to use both effectively. The prosthesis may also have augmented reality features: for instance, I touch the ball and the number of its temperature appears on my prosthetic hand or a voice linked to my ear tells it to me. In this case, there are clear modifications of affordances as well.
d) The issue of persistence, instead, seems to show evident similarities with analog reality: I cannot either let the ball disappear (unless I destroy it or walk away) or change my extended perception of it. A prosthesis is by definition an ineliminable part of my body, thus making me a hybrid or a cyborg.Footnote 3 In augmented reality, instead, I can switch the device off and come back to the analog object as such. The object perceived in a hybridized situation, then, persists as much as an analog object.
In this case, are perceptual relations, taking place between the whole and the parts of a configuration, defined in the same way whether they refer to purely human subjects or to hybrids between humans and digital technology? Devices are extensions of our bodies, which are bond to their perceptual modalities, entangling with the latter and allowing the body itself to feel differently from when the prosthesis are not there. My hypothesis is that there is a relation of analogy, not of identity, between the perception of a non-hybridized and the one of a hybridized body. This issue shall be taken into consideration, since we are increasingly moving towards a “hybrid intentionality”, just as the post-phenomenologist Verbeek (2008) states, and towards artificial extensions, namely digital ones (Callus & Herbrechter, 2012; Longo, 2002).