Cos tech Connaissances Organisation et Systèmes Techniques EA 2223

1. Costech Connaissances Organisation et Systèmes Techniques EA 2223 Technicalmediation of sensorimotorcoupling: a minimalistapproach Charles Lenay, Gunnar Declerck, Olivier Gapenne, Barthelemy Maillet, John Stewart & Indira Thouvenin Costech - CRED Enactive /08 5th International Conference on Enactive Interface November 19-21 PISA

2. Plan • Studying enaction • Methodological Principles • Perceptual Space • Shape recognition • Common world and the recognition of others • Conclusion

3. I. Studying Enaction • Enactive approach to perception : • the world of lived experience is constituted through the sensori-motor coupling between an organism and its environment. • Enactive interfaces : • modification of this coupling by employing technical interfaces  transformation of the lived world • How can we study this coupling, its modifications, and the way it gives rise to a lived world ? •  Surely not by considering independently: • - the psychology of an isolated “natural” subject and • - the physical environment on the other, • - and only subsequently studying their relations. •  Internal representations  internal mental model of the mediation  no augmentation of our cognition.

4. Perception II. Methodological Principles II.1. Sensorimotor coupling principle • The dynamic coupling between an organism and its environment is primary (It is only subsequently that it is possible to distinguish the point of view of the subject on one hand, and the objects of their lived world on the other) Enactive interface Actions « a » a  s s  a Sensations « s »

5. II.2. Technical prism principle • The technical interface functions as a “prism” which makes it possible to vary experimentally the components of the coupling. • Extreme technical situation of perceptual supplementation. II.3. Minimalist principle • By reducing the sensory inputs s and the actions a to a strict minimum, we can force an externalisation of the sensorimotor activity, and we render feasible a complete modelling of both the environmental causality (as), and the strategy (sa). II.4. The principle of double description • Working with conscious adult subjects enables us to systematically combine: • third-person empirical analysis with • first-person phenomenological descriptions of the lived experience

6. Paul Bach y Rita III. Perceptual Space Enactive interface : Tactile Vision Substitution Systems • Immobile camera: • limited discrimination • forms are perceived on the skin • With manipulation of the camera : • spectacular abilities to recognise forms • exteriorisation of perception: objects are perceived out there in the world

7. Lived experience of spatial exteriority 3 3D space of localisation Minimalist sensori-motor coupling device

8. Perceptual trajectories Projection of the pointing movements on 2 planes which include a luminous target Indira Thouvenin, Charles Lenay, Cynthia Cottereau

9. Explanation Perception : - Localisation - Projection in space - Neglect of sensory input But : two "contacts" with the target are not sufficient. L = b(sin  - cos  tan()) where [0, /2] et 

10. Laws of sensory-motor contingencyKevin O’Regan / Alva Noe If the movements cease, there is not spatialisation of the object : no perception without action. Invariance and reversibility : exteriority  + Atan b sinLb cos If the possibilities of action are reduced, there is no more depth

11. Constitution of a space within which there is a separation between a point of view, and objects perceived. The invariants of the sensorimotrice activity, constitute at the same time: Positions of the point of view: all that moves with me Positions of the objects: all that compared to what I move Phenomenological constitution • If the possibilities of action are reduced, there is no more depth • The depth requires the capacity to engage in perceived space. Here thanks to the size of the arm: spatiality of the lived body

12. IV. Shape recognition • Methodological principle : minimal device (Tactos) : only one all or none stimulation, and limited possibilities of action. • By restricting to the maximum the possibilities of sensation and of action one forces a spatial and temporal deployment of the perceptive activity. Examples of perceptive trajectories Examples of perceptual trajectories

13. Experiments and Results Ability to recognize shapes

14. Perceptual trajectories Emergence of stereotyped behaviors • Micro-scanning orthogonal to the contour • Localisation • Contour following • But, subjects are frequently lost in the «tactile picture» : proprioceptive drift • Perception of forms • Gesture of constitution of the perceived shape (Similar to the gesture of drawing) • Independance with respect to the tactile, visual or auditory mode of stimulation Enaction : To be perceived, a form must be actively and concretely constitued.

15. V. Common world and the recognition of Others • ExperimentalperceptualCrossing

16. Experimentaldevice Fixed object Receptor field of P1 perceptible by P2 Receptor field of P2 Fixed object perceptible by P1 tactile stimulator of P2 tactile stimulator of P1

17. Experimentaldevice Fixed object Receptor field of P1 Mobile object perceptible by P2 perceptible by P2 Mobile object perceptible by P1 Receptor field of P2 Fixed object perceptible by P1 tactile stimulator of P2 tactile stimulator of P1

18. Results: 63% of the distribution laid between ± 30 pixels, as indicated by the dotted lines. Note the slight peak at a distance of 50 pixels that corresponds to clicks on the mobile object

19. Trajectories of the perceptual crossings Clicks on the perceptual crossing Clicks on the mobile object

20. VI Conclusion • Few illustrative examples to show that starting from the coupling itself is feasible to understand the constitution of the corresponding lived experience. • When the laws of coupling make it possible to account for the constitution of space and objects, they correspond to the laws of physics. • When the laws of coupling make it possible to account for the constitution of shapes and meaning, they correspond to the laws of psychology. • When the laws of coupling make it possible to account for the constitution of a common world and the institution of norms, they correspond to the laws of sociology

21. In the brain? or where the body acts? or the "plunger" The "submarine" Espace de représentations distinct de l’espace des choses externes Deux espaces The internal space of representation is different from external physical space The space of perceived objects is the space of body and action Where is space of perception?

22. IV. Conclusion There is only one space • For perception and action, • For the lived body and the objects • Constitution of this space of action and perception with concrete body engagement (spatiality of the lived body) and sensory returns. • Space is a practical group of displacements.

23. Internal model of the mediation for the calculation of a representation Consequences Representation Enaction Internalism Externalism Enactive interface : Technical mediation Active constitution of the lived world (umwelt) through the technical mediation

24. Thank you

26. A = Sujets aveugles : direction B = Sujets voyants aveuglés : distance C = Sujets voyants aveuglés : direction A = Blind Subjects : direction B = Blindfolded sighted subjects : distance C = Blindfolded sighted subjects : direction Results : confidence ellipses Ellipses de confiance[1] Bianca Hardy, Marie-Martine Ramantsoa, and Sylvain Hanneton.

27. Perception Enaction: Active Perception The constitution of spatial percepts is realized by the determination of an invariant relation between: - actions (movements of the body and the instrument) and - sensory input. Enactive interface Actions « a » a  s s  a Sensations « s »