The Bipolar Man Framework for Human-Centred Intelligent Systems

F. AMIGONI, V. SCHIAFFONATI, M. SOMALVICO Politecnico di Milano Artificial Intelligence and Robotics Project

Dipartimento di Elettronica e Informazione Politecnico di Milano

Piazza Leonardo da Vinci 32, 20133 Milano, Italy {amigoni,schiaffo,somalvic}@elet.polimi.it

Abstract. The consideration of a general theoretical scenario accounting for the relationships between humans and machines may enhance the design and development of human-centred intelligent systems. The aim of this paper is to present an abstract framework that accounts for the current tendencies within the field of human-machine interactions. This framework is based on a very precise theoretical position expressed by the concept of the bipolar man, which has an impact on both the analysis and the design of human-centred intelligent systems.

1. Introduction

The deep investigation of the human-machine interactions represents nowadays the necessary theoretical background to set a general scenario that may enhance both the design and the development of human-centred intelligent systems.

The aim of this paper is to present an abstract framework based on the peculiar concept of bipolar man to which potentially every kind of human-machine interaction can be traced back. According to this perspective, a man is considered as a unique subject who can perform his intellectual activities in two different poles: the man-body pole and the man-machine pole. In the first case, the man directly carries on his intellectual activities by his body; in the second case, the man indirectly carries on his intellectual activities by information machines. Moreover, this framework allows for a natural extension toward the social dimension of the human-machine interaction, namely toward the idea of a bipolar society as composed of different bipolar men. This theoretical systematization is based on a clearly defined epistemological perspective able to neatly separate the activities performed by the humans and those performed by the machines.

The adoption of the bipolar man framework has an impact on both the analysis and the design of human-centred intelligent systems. On the one hand, it helps in understanding the existing systems, their properties, and the relations among them. On the other hand, it stimulates profitable ideas for the conception of novel and improved systems. In this paper we practically evaluate the proposed approach in two significant real-world applications: the development of effective

interfaces for virtual reality settings and the adoption of robots for the elderly-care.

The paper is structured as follows. In Section 2, the idea of bipolar man is explored considering, as well, its extension to sociality. Section 3 presents two significant case studies, the first one related to virtual reality and the second one to elderly-care robotics, in which the previous concepts are applied to the analysis and the design of human-centred intelligent systems. Finally, Section 4 concludes the paper.

2. The Bipolar Man Framework

The advent of information machines (of which computers and robots are paradigmatic instances) has revolutionized the traditional framework of the human-machine interactions, since information machines are able to carry on intellectual activities usually considered as performed exclusively by humans. If the performance of manual activities by machines is considered a consolidated practice, the performing of intellectual activities is still considered as a remarkable fact and it is not clear what are exactly the intellectual activities that can be performed by information machines (as first outlined in [11]). Our attempt to evaluate the anthropological status of the man with the advent of information machines is based on the concept of bipolar man (introduced in [1]). The bipolar man approach is applicable to a broad scenario and describes in general the interaction between man and information machines. According to the bipolar man framework, a man is a unique subject - called man-mind subject to emphasize the unity and homogeneity of his nature - who can perform his intellectual and interactive activities in two different poles: the man-body pole and the man-machine

pole (see Fig. 1), which are associated with different modalities of performance. In the first case, the man-mind subject directly carries on his intellectual and interactive activities within his natural body; in the second case, the man-mind subject indirectly carries on some of his intellectual and interactive activities within artificial information machines. It is worth noting that this does not imply an autonomous role for the information machines in carrying on the activities traditionally performed by humans, but just a displacement of some activities, always performed by man, from one pole to the other pole.

Figure 1 – The man-mind subject (dashed line) composed of man-body pole (left) and man-machine

pole (right)

Within this framework, it is interesting to evaluate which intellectual activities can be performed by the man-machine pole. We claim (according to a well-established epistemological mainstream [10]) that the activities performed within the man-machine pole are those that can be modelled, namely those that can be described in rational terms and that belong to the “fabricative intelligence”, where by this term we mean the rational part of human intelligence which is alternative to “creative intelligence”, where by this term we mean the inventive part of human intelligence. The activities performed by the fabricative intelligence can be modelled and usually can be expressed by algorithms and, as a consequence, can be performed by an information machine. An interesting example of such activities is theorem proving. There exist several theorem prover systems, namely information machines devoted to prove formally expressed sentences starting from a set of axioms and a set of inferential rules [8]. The available knowledge about a topic is described by axioms (expressed for instance in first-order logic) to which the inferential rules are systematically applied. This means that the process to explore the search space of derivations from initial knowledge can be expressed as an algorithm and, as a consequence, can be performed by an information machine. A number of expert systems for diagnosis, maintenance, and scheduling have been developed based on the above ideas [8]. In all these systems, some of the intellectual activities of human experts (man-body poles) are

delegated to information machines (man-machine poles).

We explicitly note that the man-body pole and the man-machine pole do not only denote the distinction between body and machine, but stress the central role of man who displays some of his activities in the machine that, in this epistemological perspective, is not regarded as an autonomous subject.

When we consider a man-mind subject, we observe that the main interaction is the intrabipolar interaction between the man-body and the man-machine poles, which is evidenced by the arrows of Fig. 1. The features of the intrabipolar interaction can be better understood at the light of the evolution of man-machine communica-tion. In the past this communication required a pre-processing of the input information performed by the man in order to prepare it in a form suitable to be communicated to the machine. Thus, the form of the information to be communicated to the machine was very different from the form of information used to communicate among humans. The advances of intelligent and adaptive interfaces [2] [3] [5] promote an increasingly graceful communication environment: the flow of messages from the man-body pole to the man-machine pole can be expressed more easily and naturally. For example, the communication toward the computer or the robot can be performed more naturally and handily when natural language is used, maybe enriched by some borderline (often unconscious) acts, such as prosody, mimicry, gestures, and body language. Although these acts are not formally captured in any natural language structure, they are very important in revealing the real cognitive intentions of the person using them. In order to cover these requirements, a non-invasive and natural communication to the machine must be composed of two parts: the representation of the conscious human intentions in a multimedia-based natural language and the representation of unconscious human intentions through non-classical communication acts (see [4] for these perceptual user interfaces). The development of interfaces for virtual reality applications presented in Section 3.1 is an example of a modern and sophisticated intrabipolar interaction. In the context of the bipolar framework the analysis of interaction can be completed and enriched by adding the interbipolar interaction, namely the interaction occurring among two or more man-mind subjects, each one composed of a man-body pole and a man-machine pole. We will further discuss this case in the following.

The anthropological scenario of bipolar man can be enriched in an interesting and realistic way by encompassing the social dimension of human activities. In the real world, several human activities are carried on by groups of people who interact together and form a society. According to our view, a society (convention-ally intended as a group of interacting people) can be

seen as composed of several interacting bipolar men and can be called bipolar society (Fig. 2). We have before identified a man-body pole and a man-machine pole as the two different poles of a single man. In a similar way, we can now identify a society-body pole and a society-machine pole as the two different poles of a bipolar society, when such a society is thought as a single subject composed of bipolar men who perform their activities both by their bodies and by information machines.

Figure 2 – The bipolar society (the big dashed box) composed of society-body pole (the dot and dash box on the left) and of society-machine pole (the dot and

dash box on the right)

When we consider a bipolar society, the main interactions occur between the different man-mind subjects and represent what we call interbipolar interaction. Similarly to the intrabipolar interaction, the interbipolar interaction has received a lot of attention in the last few years, but many issues are still unexplored. Let us consider the interaction between two man-mind subjects: we can have three different situations according to the nature of poles that interact: two man-body poles interacting, a man-body pole and a man-machine pole interacting, and two man-machine poles interacting (see Fig. 3). The first situation is typical of human interactions and will be not further discussed. The second situation is comparable to the intrabipolar interaction (within a single man-mind subject, whereas in this case we have different man-mind subjects) previously presented. The third situation, when the man-machine poles of different subjects interact together, is in our opinion the most significant one. In particular, the interaction among the man-machine poles of different subjects can be profitably cast in the field of multiagent systems [12], where the discussion about the

interbipolar interaction is particularly profitable and interesting. In this case, a number of information machines interact, coordinate, cooperate, and compete. For example, many efforts have been devoted to the e-commerce issues involving several theoretical and practical challenges in order to design and build agents (man-machine poles, in the language of our abstract framework) able to negotiate the buying of goods on behalf of their users. In general, the interbipolar interaction involves more than two man-mind subjects. In this case, the interactions among different poles deserve deeper investigations in future research. The development of service robots for the elderly-care, presented in Section 3.2, is an example of an interbipolar interaction occurring among several man-mind subjects.

Figure 3 – The three kinds of interbipolar interactions in a bipolar society composed of two

bipolar men: between man-body poles (continuous box), between different man-body and man-machine poles (dot and dash box), and between man-machine

poles (dotted box)

3. Two Significant Examples

In this section we report two significant examples of human-machine interaction in order to show how the bipolar man framework can be applied to enhance the analysis and the design of human-centred intelligent systems. The first example is aimed to evidence the expansion of the communication channels between humans and machines, in particular when the interface between them is extremely complex. The second example is devoted to enlighten the new role of sociality in the human-machine interactions. Finally, we outline some of the contributions the bipolar man framework can provide both in the analysis and in the design of human-centred intelligent systems.

3.1 Intelligent Interfaces for Virtual Reality Applications

Let us start from the investigation of the evolution (outlined in Section 2) that brings the intrabipolar interaction from a contemplative role to a participative role. In the contemplative interaction the man communicates to the machine his desires and his intentions, namely his will, and receives some information from the machine. With the passage to a participative interaction, the man communicates to the machine not only his will but also, we could say, his being by means of natural language and of borderline acts; conversely, the information from the machine to the man influences the being of the man.

The participative interaction is usually required in virtual reality settings when the information machine, the man-machine pole according to our framework, performs the activity of simulating a scene in which an avatar of a real man, namely of the man-body pole, is acting in a simulated world (possibly including other men). In this schema, the man is both a part of the simulation environment (as a model reproducing him) and an observer (as a real person) of the simulated happening. In order to simulate the real man the information machine must contain a model of the man. In this scenario, the information that the real man conveys to the machine does not concern only the representation of his desires, but also the representation of the model of himself involved in the simulated scene (e.g., information about his posture). Conversely, the information that the machine conveys to the real man involves the model of the simulated man acting in the simulated scene (e.g., information about the orientation of the simulated head). According to this perspective, the interface between man and machine plays a fundamental role. It can be called inverse robot (since it has sensors and actuators as any robot, see Fig. 4) and represents an example of human-centred intelligent systems.

Figure 4 - The role of inverse robot in virtual reality

The inverse robot is an interface that receives from the real man the information about what he wants and that conveys it to the simulation machine. Moreover, the inverse robot conveys to the man the model of what his simulated model experiences in the simulated setting. In this framework, both the man-body pole (the real user) and the simulation machine play the role of direct subjects (in particular we will denote simulation machine as direct machine). We have thus a scenario composed of a man-body pole and two man-machine poles represented by the inverse robot and the direct

machine (see Fig. 5). The activities delegated to the inverse robot are those of converting the information provided by the real user to a format suitable for being used by the direct machine and vice versa. By means of this delegation, the interaction between man and machine shifts from contemplative toward participative interaction, as discussed above.

As illustrated in Fig. 4, the inverse robot has actuators corresponding to the sensors of the real man and, conversely, it has sensors corresponding to the actuators of the real man. Hence, the natural sensors of man receive their input from the artificial actuators of the inverse robot. For example, two LCD displays (artificial actuators) are placed on a pair of goggles in front of man’s eyes (natural sensors) to form a so-called head-mounted display. Similarly, the natural actuators of man provide their output to the artificial sensors of inverse robot. For example, a glove (artificial sensor) is placed on man’s hand (natural actuator) to perceive the flexion of fingers.

Figure 5 - The inverse robot acting as an interface between man and direct machine

On the other hand, the artificial actuators of the inverse robot are connected to the virtual sensors of the man’s model within the direct machine (e.g., the LCD displays show what the virtual eyes of the simulated man see). In addition, the artificial sensors of the inverse robot are connected to the virtual representation of the scene within the direct machine (e.g., the movements perceived by the glove influence the simulated scene by, for example, moving objects). The role of the inverse robot can thus be intended as devoted to set up a correspondence between the natural sensors and actuators of man and the virtual sensors and actuators of the man’s model within the direct machine. We recall that the inverse robot, together with the direct machine, represents the man-machine pole of a bipolar man whose intrabipolar interaction is characterized as participative.

Within this scenario, an example of the contribu-tions of our approach to the analysis of human-centred intelligent systems can be individuated in a classification of the different kinds of virtual reality intelligent interfaces [6]. As we have seen with the examples of the head-mounted display and gloves, this classification can

be grounded on the opposition between natural sensors (actuators) and artificial actuators (sensors). More precisely, the core point of the bipolar man schema contributions lies in the clear conceptual separation between the direct machine, where the simulation takes place, and the inverse robot, which is the interface between the user and the direct machine. The identification of this separation drives also toward a more accurate design of the interfaces for virtual reality applications. For example, a realistic sound setting could be obtained by separating the design of sound origination and propagation in the simulated scene, on the one hand, from the design of the virtual sensors that allow perceiving in a more realistic way the artificially generated sound, on the other hand. In the former case, the design should be focused on the production of background noise, which is fundamental to give the person the feeling to be immersed in a “believable” world [6]. In the latter case, the design should be oriented to enhance the “cocktail party effort”, namely the ability of a person to pick out some specific sounds from the background. In our framework these two aspects exclusively involve the direct machine and the inverse robot, exclusively. Although in a still elementary way, this simple example points out how the bipolar man framework could be a useful conceptual tool for tackling the analysis and the design of human-centred intelligent systems.

3.2 The Elderly-Care Robots

Service robotics represents nowadays an increasing area of research, which has significant scientific, economic, and social impacts. It includes various robotic systems presenting difficult technical challenges in their development due mainly to the unstructured environment in which they operate [9]. Among the several researches, the health care for assistance to the elderly and disabled people is one of the most promising for the positive repercussions in the everyday life. In particular, as a consequence of the extension of longevity, a strong effort has been put in technologies that increase independence and quality of life among older people.

The “Nursebot Project” is a very significant re-search, started in 1998 and involving a multidisciplinary team from three different universities [7]. It has the aim to develop mobile robots for assisting the elderly; in particular, one of such robots has been implemented and tested in a retirement community (Fig. 6). The robot has basically two functions: to remind people about routine activities and to guide them through the environments, which are strong challenges as regarding to the human-robot interaction. It is clear that these are among the activities that elderly users (i.e., man-body poles) delegate to the robot (i.e., man-machine pole). By dealing in particular with the elderly, the robot must exhibit, from the one side, a very friendly user interface

and, on the other side, a high degree of autonomy. Moreover, the same robot, in our framework the same man-machine pole, has to adapt to be used by different people, namely by different man-body poles, with different goals. Hence, a sociality aspect has to be considered in the human-robot interaction. In order to fulfill these requirements, from the hardware perspective, particular attention has been reserved to the design of the man-machine pole: in particular the robot is equipped with a head unit that gives a sensation of friendliness and safeness. From the software perspective, the robot features a tele-presence interface, a speech interface (to recognize and synthesize voice), a system to detect and track faces, and a navigation system.

Figure 6 - The robot employed in the retirement community (from Nursebot Project Web site,

http://www.cs.cmu.edu/~nursebot)

The tele-presence interface is particularly important in allowing nurses to monitor and interact with the user. Therefore, instead of replacing a nurse, the robot facilitates the communication between patients, nurses, and doctors. It is worth noting that this example enlightens not only the importance of sociality but also that of communication, since the man-machine pole, namely the service robot, acts as an interface for the communication between different man-body poles, namely humans. In such a way, the robot increases also the user’s contact with the outside, giving to her or him the idea of a minor isolation. In addition, the tele-presence offers the control of the robot also to a remote user, such as a relative or a friend that can drive the robot around the user’s room. Also the speech interface and the face detection allow for a more natural interaction. In the first case, the system is controlled in real-time by a speech dialog manager device able to generate the appropriate response and to avoid other forms of communication (such keyboards and computer screens) particularly unfriendly for the elderly people. In the second case, the face detection enables to direct the robot’s sensors toward the user’s face, who is particularly important when he or she is an elderly

person with cognitive and speech impairments. Finally, the navigation system is specifically designed for interacting with people, exploiting functions such as adapting velocity to that of the user and abilities such as an accurate localization.

This example is paradigmatic of a new tendency in human-machine interaction, related to machines (including robots) able to interact with several humans at the same time. In our case, the robot interacts with different elderly people, nurses, doctors, and relatives (Fig. 7): the social aspect embedded in the bipolar society is particularly emphasized. The robots interacting with several people represent an original example of a society-machine pole in which different people share the same robot. The patients, the nurses, the doctors, and the relatives are different man-mind subjects that communicate and interact together through the mediation of their man-machines poles, in particular by delegating some of their communicative activities to a single shared machine.

Figure 7 - The social interaction among patients, nurses, doctors, and relatives in the elderly-care robotic application (note that this schema is a

specialization of that of Fig. 2)

3.3 The Importance of the Bipolar Man Framework

The two above examples have outlined some of the contributions that the bipolar man framework can offer to the analysis and the design of human-centred systems.

From the analysis perspective, the bipolar man framework has proved to be a mean to classify different cases of human-machine interaction both when a single human and a single machine are involved and when more humans and more machines are involved. The precise and clear distinction between humans and machines (represented as poles) and the taxonomy of all

the possible interactions (both intrabipolar and interbipolar) between them are the main contributions of the bipolar man framework to the analysis of human-centred systems. Moreover, from a conceptual point of view, our approach clearly identifies and defines the boundaries for the actions of machines.

The contributions of our approach to the design of human-centred systems are still under investigation. However, even in this preliminary phase, some ideas can be assessed. For example, it is possible to conceive scenarios that extend those presented in Figs. 5 and 7 by allowing more users to interact with a single machine by means of different inverse robots (see Fig. 8). Such a system could be useful in situations when, for example, a pool of surgeons cooperatively work on the same patient in particularly complex operations conducted by advanced telemanipulation systems or in entertainment systems when different players are acting in the same virtual world. As this example suggests, the contribution of the bipolar man framework to the design of human-centred systems lies mainly in its power of envisaging interesting scenarios and situations that can be taken as architectural bases for the development of new systems.

Figure 8 - The social interaction that can be useful for cooperative surgery and entertainment

4. Conclusions

In this paper we have illustrated a general and abstract framework in which the analysis and the design of human-centred intelligent systems can be proficiently settled. The framework is based on the idea of bipolar man, where the modern man is conceived as a unique subject who performs his intellectual activities in two different poles: in his natural body and in artificial information machines. Moreover, the general framework we discussed in this paper can be extended to a social interbipolar interaction between different subjects. We have

presented two different applications to preliminary assess the appropriateness of our approach. In the first one, interfaces for virtual reality are considered. The inverse robot example is related to the increasingly powerful intrabipolar interaction between the man-body and the man-machine poles of a single subject. In the second one, we considered service robotics in order to stress the importance of the social aspect in modern human-centred systems.

The future work will be devoted to further validate our approach in several other cases, involving both the bipolar man framework, where the intrabipolar interaction plays a fundamental role, and the bipolar society, where the interbipolar interaction is central. In general, we aim to apply the bipolar man framework to a number of different situations to assess its role as a solid and effective tool for understanding and developing human-centred intelligent systems.

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