Bernard Leca

Charles-Clemens Rüling

Dominique Puthod

Charles-Clemens Ru ¨ling

Animated Times: Critical Transitions and the Maintenance of Field-Configuring Events

Keywords: Field-configuring events, critical transitions, conflict, local embeddedness, heterarchy JEL Classification: R12, L82, M19, Z13

Recent research has pointed to the challenge facing recurrent field-configuring events (FCEs) in trying to remain dominant in their fields over sustained periods. Based on a revelatory historical case study of the Annecy International Animation Film Festival, the leading FCE in its field, this paper explores how a fieldconfiguring role can be maintained over time. We focus specifically on the FCE organization, and highlight the importance of critical transitions, relatively short periods of time when fundamental changes were made to its formal and informal governance rules, which redefined the event's identity and scope, and thus ensured it remained the dominant event for field participants. In terms of the organizational dynamics facilitating critical transitions, we emphasize the importance of conflict as a driver of change, as well as the particular role of local stakeholders in renewing FCEs that are organized recurrently in the same location.

Introduction

Field-configuring events (FCEs) operate as temporary social organizations that capture and shape the development of professions, technologies, markets and industries [START_REF] Meyer | Organizing Far from Equilibrium: Nonlinear Change in Organizational Fields[END_REF]. They are temporal settings where members of such fields can learn about field innovations [START_REF] Bijker | The Social Construction of Technological Systems[END_REF] and evolution [START_REF] Zilber | Institutional Multiplicity in Practice: A Tale of Two High-Tech Conferences in Israel[END_REF], confront ideas and eventually develop field parameters such as new standards [START_REF] Garud | Conferences as Venues for the Configuration of Emerging Organizational Fields: The Case of Cochlear Implants[END_REF]. However, recent research has shown that the ability of event series to maintain their field-configuring and novelty-generating capacity cannot be taken for granted, and may even decline over time (e.g. Delacour and Leca 2011a;[START_REF] Schu ¨ßler | On Melting Summits: The Limitations of Field-Configuring Events as Catalysts of Change in Transnational Climate Policy[END_REF]. Building on these insights, this study analyzes the case of a successful field-configuring event series to identify the organizational mechanisms that enable it to maintain its dominant position in the field.

Reviewing the existing literature on recurring FCEs, we highlight the critical role of the organizations in charge of such series, and present findings from our inductive case study research to examine how such lead organizations manage to maintain FCE series as the dominant events in their fields. Empirically, the paper is based on a historical longitudinal analysis of the Annecy International Animation Film Festival, an FCE series that has succeeded in renewing itself over a period of over 50 years. We build and analyze a unique dataset comprising archival records and interviews with key stakeholders, benefitting from the advantages of an 'insider -outsider' perspective (Evered and Louis 1981;[START_REF] Gioia | Sensemaking and Sensegiving in Strategic Change Initiation[END_REF] enabled by the role of one author as an external, part-time board member of the festival organization.

We make three main contributions. First, we introduce the concept of critical transitions to characterize the relatively short periods during which fundamental changes were made in the formal and informal rules governing the FCE, and discuss the value of this notion for understanding the evolution of FCE series and their coevolution with their specific fields. Second, our study contributes to research on the local embeddedness of FCEs by highlighting the importance of local stakeholders in their renewal. Such event series often possess strong local embeddedness, a dimension that we argue has been inadequately addressed in the existing literature. Our findings emphasize the importance to local constituencies of hosting an FCE series, and show how such local actors seek to influence their evolution in line with their interests, such as developing city branding and the local economy. Based on our observations, we theorize on the strategic choices such local stakeholders are likely to make during critical transitions. Finally, we highlight the role of the event's governance structure in managing the tensions in and evolution of FCEs when they are misaligned with their fields. In particular, we highlight the role of conflict as a decisionmaking mechanism in such organizations when actors' different goals interact.

Theoretical Background

The Challenges FCEs Face in Retaining Dominant Field Positions Field-configuring events are "settings in which people from diverse organizations and with diverse purposes assemble periodically, or on a one-time basis, to announce new products, develop industry standards, construct social networks, recognize accomplishments, share and interpret information and transact business" [START_REF] Lampel | Guest Editors' Introduction[END_REF]Meyer 2008, 1026). Much of the initial research in this area focused on one-off FCEs, which intervened at threshold moments to contribute to the formation of fields (e.g. [START_REF] Oliver | Using Field-Configuring Events for Sense-Making: A Cognitive Network Approach[END_REF] or the shaping of institutions [START_REF] Garud | Conferences as Venues for the Configuration of Emerging Organizational Fields: The Case of Cochlear Implants[END_REF]). More recently, authors have distinguished between FCEs that take place just once and those that are organized on a regular basis-such as, for instance, climate summits (Schu ¨ßler, Ru ¨ling, and Wittneben 2014) and art exhibitions (Delacour and Leca 2011b).

Research on such recurrent FCEs has pointed out that they risk losing their power to configure their fields over time. Various reasons have been identified: first is that an FCE might become a victim of its own success, as the growing diversity of actors and increasing complexity involved can induce fragmentation (Schu ¨ßler, Ru ¨ling, and Wittneben 2014). As FCE participants interact less during an event, it ceases to be a focal moment for exchange and learning. A second reason is the closure of FCEs to field innovation, as they become increasingly entangled in their own routines and unable to take any radical input into account (Delacour and Leca 2011a), forcing field members to set up other events that can respond to the field's evolutions. Finally, decline might come from the development of competing events whose promoters make significant efforts to ensure their prominence [START_REF] Schu ¨ßler | Backstage: Organizing Events as Proto-Institutional Work in the Popular Music Industry[END_REF]. Research has established that it cannot be taken for granted that once dominant recurrent FCEs will maintain their prominence, and identified some reasons why their configuring power might wane, but it has not yet considered how FCEs can resist such decline and retain their dominance over time. Our intention is to address the issue, focusing on how the organization that mange a recurrent FCE can ensure it retains its dominant position over time: this will include examining further the unexplored role of such organizations.

The Role of Organizations Which Manage FCEs

Most research on FCEs so far has focused on what happens during the events, and on how FCEs influence the evolution of their fields. This research has revealed the importance of the organization behinds such events. For instance, [START_REF] Zilber | Institutional Multiplicity in Practice: A Tale of Two High-Tech Conferences in Israel[END_REF] has shown that field members' interpretations of the same FCEs can diverge significantly depending on how they are organized. Examining two high-tech conferences, she argues that their organization, including the artifacts and discourses used, impacts the way members make sense of the fields in which they are embedded. Schu ¨ßler, Ru ¨ling, and Wittneben (2014) argued that organizers can experiment with different FCE formats, each of which can define different field boundaries and promote different practices, so setting alternative trajectories for the field's development. While this research highlights the central roles of organizations that stage such events over time, FCE research in general has paid them surprisingly little attention. We anticipate that examining those organizations can give us insights into how FCEs can maintain their prominence over time, and develop a more 'organizational' view of FCEs, which can consider their underlying organizational mechanisms. We explore this organizational dimension to address the following overall research question: How does an organization in charge of a series of field-configuring events renew those events so that they remain dominant in a field?

Method

To address our research question, we build on an inductive case study of the Annecy International Animation Film Festival, the leading competitive festival and market event in the global animation film industry. The festival originated in 1956 as a non-competitive animation week held at the Cannes Film Festival. It moved to Annecy in 1960 and has since succeeded in remaining a dominant event among global animation events, addressing a wide variety of audiences including animation artists, producers, distributors, investors, software providers, public policy actors, animation students, educators, critics and journalists [START_REF] Ru ¨ling | Festivals as Field-Configuring Events: The Annecy International Animated Film Festival and Market[END_REF][START_REF] Ru ¨ling | Event Institutionalization and Maintenance: The Annecy Animation Festival 1960-2010[END_REF].

Based on its almost continuous growth and overall success in a highly dynamic context over more than five decades, we consider Annecy a revelatory case for investigating how an organization in charge of a FCE series can sustain its dominant position. Our research adopted a combined insider-outsider approach (Evered and Louis 1981;[START_REF] Gioia | Sensemaking and Sensegiving in Strategic Change Initiation[END_REF][START_REF] Gioia | Forging an Identity: An Insider -Outsider Study of Processes Involved in the Formation of Organizational Identity[END_REF], using both immersion in the festival organization and detached, external data analysis and interpretation. One author acted as an "insider researcher" (Evered and Louis 1981). Following an "opportunistic ethnography" logic [START_REF] Tracey | Bridging Institutional Entrepreneurship and the Creation of New Organizational Forms: A Multilevel Model[END_REF], his involvement as an external, part-time board member of the festival's managing organization since 1997 allowed him to observe internal decisionmaking processes, and gain an inside understanding of its functioning. His position also facilitated access to archival material and to key actors involved in its history, which allowed him to constitute a unique database, and develop a detailed historical narrative about the event's development over time. As a research-trained organizational and strategy scholar, he was always aware of the risk of insider bias, and constantly sought to challenge and to corroborate his views by exposing them to different data sources and perspectives. The other two authors, who both had prior experience in studying the historical development of FCEs, acted as "outsider researchers", analyzing the historical narrative in detail from an FCE perspective and developing the study's main theoretical contributions. Following the recommendation of [START_REF] Gioia | Forging an Identity: An Insider -Outsider Study of Processes Involved in the Formation of Organizational Identity[END_REF], the three authors discussed their emergent understandings together throughout the entire data analysis process in order to both challenge and to corroborate their understanding of the case.

Data Collection and Analysis

The main difficulty encountered in data collection was the dispersion of the event's archives. The festival archives did not hold documents about the event organization's history, so we relied on municipal and departmental archives, as well as on the personal archives of several former festival board members, to collect administrative documents, official correspondence, minutes, statistical reports as well as trade press articles about the festival (a detailed list of all archival sources is available from the authors).

To include the perspective of actors who had taken part in the organization's historical decision-making processes, the insider-researcher conducted interviews with 14 individuals; many of them former members of the festival's board members or its organization team (see Appendix Table A1 for a list of interviewees). The interviews lasted about 1 h, and were video recorded and transcribed (interview recordings are available on the following website: http://histoire.annecy.org). We selected at least three individuals from each decade of the event's development since 1960 and-whenever possible-who had been involved in the organization's most important historical decisions.

We combined multiple data sources during the analytic process. For instance, to understand the debate about the festival's internationalization, we analyzed a decisive meeting between the festival organizers, the international animation film association (ASIFA), and the French national film board (CNC), drawing on the official minutes edited by the Paris-based festival director, on notes taken by the head of the Annecy municipal commission for cultural affairs, and on personal correspondence between the festival director and the mayor of Annecy. We also corroborated our interpretation of this episode by addressing it specifically in our interview with a participant at the original meeting.

Data analysis comprised two main stages. The initial stage followed a historiographical approach [START_REF] Ventresca | Archival Research Methods[END_REF], aiming to develop a "detailed story from the raw data" (Langley 1999, 695), retracing the development of the festival and its management organization from the mid-1950s until today. This historical narrative (written in French, and about 50,000 words in length) was crafted by the insider-researcher on the basis of the archival material and the interviews, and then reviewed by nine interview participants from all periods of the festival's development, as well as by a French film historian. In the second analysis stage, the two outsider-researchers adopted a temporal bracketing strategy, seeking to identify periods of continuity and discontinuity in the event's organization [START_REF] Langley | Strategies for Theorizing from Process Data[END_REF], in order to identify and analyze key moments at which the dominant position of the event was questioned and reestablished.

For this paper, we decided to focus on three moments in the event's development that we identified as constituting "critical transitions", in the sense that they occurred over relatively short time periods and involved "fundamental and comprehensive changes introduced to the formal and informal rules of the game" (Peng 2003, 275). As we argue in more detail below, each of these three transitions resulted in shifts in characteristic features of the event, as well as in modifications of the managing organization. These changes modified the event's trajectory to realign it with the evolution of its field. The three critical transitions that we identified were: (1) its transfer from its original location in Cannes to Annecy (1958Annecy ( -1960)), (2) the opening up of the festival to commercial animation (1981 -1983) and (3) the event's shift from a biennale to an annual cycle (1997 -1998).

Findings

The overall development of the Annecy festival can be described as shifting from serving as a prestige showcase in the late 1950s, toward functioning as an artistic gathering dedicated to auteur animation in the 1960s and 1970s, toward a broad film festival and market open to commercial animation in the 1980s and 1990s, and eventually, since the late 1990s, to a more broad-spectrum industry event serving as a creative marketplace for animation industry products and projects. Each of these forms catered to specific audiences and was connected to a particular type of internal organization, as summarized in Figure 1. During the first transition (1958)(1959)(1960), the festival organization shifted from a small group of Paris-based curators toward a more complex, hybrid organization composed of a Paris-based festival management and a local, Annecy-based volunteer organization. The second critical transition (1981)(1982)(1983) was marked by the disruption of ties with the Paris-based festival managers and the creation of a small, purely local organization based in the city of Annecy with strong volunteer support. The third transition (1997)(1998) saw this local organization grow into a larger, more professional entity that served as a hub for industry-level exchanges beyond the festival itself.

In the following subsections, we present a narrative account for each of these three transitions, focusing on the environmental conditions, actors and decision processes involved, and their outcomes in terms of event characteristics and internal organization.

Shift in Location: From Cannes to Annecy (1958Annecy ( -1960) ) In the 1950s, the general public mainly considered animation as a form of children's and family entertainment, epitomized by Disney movies, which had defined animation as a 'cartoon' medium since the late 1920s [START_REF] Wells | Animation: Genre and Authorship[END_REF]. To present a more artistic perspective on animation, the French film critic and animation director Andre ´Martin organized a week of artistic animated short films as a side event at the 9th Cannes International Film Festival in 1956, with the help of the national association for the promotion of cinema (Association pour la diffusion du cine ´ma, AFCD), and the support of the French national film board (Centre national de la cine ´matographie, CNC). For the first time, this event convened a large number of highly respected animation artists (e.g. Norman McLaren, Jiri Trnka, Alexandre Alexeieff, Paul Grimault and John Hubley) to take stock of the varied artistic creation in the animation field, and presented a program of animated films from such artists. Following its initial success, the Cannes 'animation days' were repeated in 1958, aiming to unite the world's 'animation legends' (inscription on a photograph of 1958 participants) and showcase prestigious animation from the classic animation regions of Eastern and Western Europe, and North America.

While the animation week could have continued to exist as a side event to the Cannes festival, its success-paradoxically-gave rise to deep apprehension among the participating animation artists about the Cannes festival's environment, with its emphasis on stars and the media, and to a sense of the need for an event and a venue dedicated specifically to animation. As Pierre Barbin, one of the main organizers of the Cannes animation days, noted:

In the middle of the Cannes festivities, this artistic, cultural, and serious gathering seemed a little out of place, and did not receive all the attention it deserved. [START_REF] Barbin | Rapport sur les IIIe `mes Journe ´es Internationales du Cine ´ma d'Animation[END_REF] Encouraged by the CNC, the animation day's organizers began looking for a place to set up a dedicated animation event. Two of the co-organizers of the Cannes week, who were also board members of the Annecy film club, suggested their home city, a small scenic conurbation in the French Alps. The idea of a dedicated animation event in Annecy coincided with local politician's search for projects that could distinguish the city from the more prestigious neighboring thermal resorts of Evian and Aix-les-Bains. So, in spring 1959, the Annecy city council agreed funding for an international animation festival, and its mayor actively lobbied the French minister of culture for match funding and official patronage.

According to official reports, the first Annecy event was characterized by a marked sense of exchange and interest in artistic animation between the participants [START_REF] Barbin | Rapport sur les IIIe `mes Journe ´es Internationales du Cine ´ma d'Animation[END_REF]. As a direct outcome of the first Annecy festival, an international animation film society, ASIFA (Association internationale du film d'animation), was created to facilitate international exchanges and, during the second Annecy festival in 1962, it established an international animation film festival calendar, determining that the Annecy event should take place in odd years, leaving the even years for the development of other ASIFA-accredited international festivals such as Mamaia (1966 -1970), Zagreb (since 1972), Ottawa (since 1976), Hiroshima (since 1984(since ) and Cardiff (1992(since -1996)).

Its first five editions (1960 -1967) established Annecy as an internationally reputed and increasingly attractive competitive artistic animation festival [START_REF] Barbin | Lettre de Pierre Barbin a `Dominique Puthod[END_REF], with rigorous selection, international participation and engaging social events that connected established and young animation artists from the East and the West. Thus, the shift in place from Cannes to Annecy remodeled what had been a showcase event into a competitive festival, changing it from a high-prestige curated program toward one that presented a "severe selection" of contemporary animation films [START_REF] Barbin | Rapport sur les IIIe `mes Journe ´es Internationales du Cine ´ma d'Animation[END_REF]. As Table 1 shows, the festival received a stable number of submissions and had a rejection rate of about 50 per cent throughout the 1960s.

In terms of internal organization, the Annecy festival was managed from 1960 to 1982 by a hybrid organization comprising a Paris-based festival director and team responsible for film selection and programming, and for administrative and financial control, and a local , 1956 -1981 1956 a 1958 a 1960 1962 1963 1965 1967 1971 1973 1975 1977 1979

Animated Times

team in Annecy in charge of logistics, organized as a dedicated nonprofit association with strong ties to its film club, and chaired by the city's mayor.

Shift in Scope: From Auteur-Based to Commercial Animation (1981 -1983) With the move from Cannes to Annecy, and throughout the event's steady growth and institutionalization during the 1960s and 1970s, its Paris-based programmers continued to privilege artistic over commercial animation, an orientation which was further reinforced when Raymond Maillet, a well-known French journalist and film critic was appointed festival director in 1971 with the declared ambition of improving the recognition of animation as an art form.

However, as time went on, the promotion of a traditional program of artistic animation with the emphasis on the work of auteurs became more and more misaligned with the global realities of animation. From the late 1970s, this field was increasingly marked by the growth of 'new' animation countries (such as Japan), the beginning of the development of cable television networks and private TV channels, and the resulting demand for commercial animation production for children's programs and music videos, together with the emergence of various forms of computer-based animation. As Pierre Jacquier, an Annecy-based board member (1980 -1984) and Annecy city representative, later recalled:

The festival . . . was becoming a sanctuary for artistic films with a tendency towards academism, ignoring the new uses of animation, new forms of cinematography, new technologies, and economic issues. (Jacquier 1991, 3) The consequences of this growing misalignment impacted several stakeholder groups. First, consequences became visible in the festival's attendance numbers. Although participation in terms of numbers of films submitted had increased in the first half of the 1970s, submissions declined by more than 60 per cent between 1975 and 1979, and-most noticeably-the number of animation professionals attending the festival dropped from more than 1,000 in 1975 to 765 in 1979 (see Table 1 above). While submissions grew again in 1981, the festival board was alarmed when professional attendances fell by 10 per cent and ticket sales by almost 18 per cent, resulting in a significant financial deficit. Second, professional associations and animation directors began to criticize the tight control the festival director Raymond Maillet exercised over the selection committee, which seemed reluctant to accept films from non-traditional animation countries, to recognize computer-generated animation, or to acknowledge animated films produced for television. And third, the Annecy municipality became increasingly critical of the festival's direction, as they felt it had no real influence on its scope, even though it was investing increasing financial resources, and had begun constructing a large new cultural facility that could host much larger events.

After the 1981 deficit, and confronted by festival director Raymond Maillet's refusal to redefine the festival's scope, the president of the local non-profit association in charge of the festival sought advice from an international media journalist and writer-Henry R. Cassirer-to develop options for the event's future development. In his response letter, [START_REF] Cassirer | Lettre de Henry R. Cassirer a[END_REF] recommended that the entire festival organization-and in particular the financial control-should be handed over to the Annecy team. He also suggested opening the festival to computer-generated animation and video, and proposed the creation of an international animation film market.

At the organizational level, Raymond Maillet's ongoing resistance to calls for change was made possible by his executive roles on three different Paris-based professional animation associations that held seats on the Annecy festival board. But, after the Cassirer report, the local Annecy organizers and the city authorities succeeded in mobilizing the support of several important stakeholders: notably the French national film board-which saw an economic development opportunity for the French animation industry and promised financial support for a purely Annecy-based festival and market-and of ASIFA, which had a strong interest in the event's growth and internationalization.

In 1982, after Maillet made an unsuccessful attempt to enroll more than 30 acquaintances as members of the local association in order to elect a new board, the board decided to terminate his contract as festival director, to localize the entire organization of the festival in Annecy, and to appoint Annecy-based community organizer and theatre director Jean-Luc Xiberras as the new festival director.

In 1983, the new director and the local organizing team tripled the number of screenings in Annecy's newly inaugurated cultural center, which provided more seats and better screening conditions, appointed an international selection committee, and explicitly invited computer-animated films. The new festival program included more resource-intensive (and commercially oriented) feature-length animated movies, and also showcased films from emerging animation countries. The subsequent (1985) edition of the festival event was marked by the creation of an international animation film market which paralleled with the festival. This initiative positioned Annecy as the only animation event in the world that combined both a film competition and a marketplace, and attracting additional actors from the emerging commercial animation economy (e.g. television channels, animation software studios and training institutions).

Over the following years, the size of the event increased steadily (see Figure 2 for the development of submissions between 1983 and 1997), and the Annecy festival and market developed into a highly reputed international biennale for all forms of artistic and commercial animation, positioning itself-in the words of its new festival director-as a "meeting place for all those who have a professional activity related to the production of animated film" [START_REF] Xiberras | Rapport d'activite ´[END_REF]. In terms of internal organization, the former hybrid formwith its separation between the Paris-based festival office and the local volunteer organization-shifted in favor of a single, small, permanent organization, located close to the Annecy municipality, which could mobilize a large local volunteer base during festival weeks.

Shift in Calendar: From Biennial to Annual Event (1997)(1998) During the 1980s and 1990s, global animation production exploded in terms of volume, and relied increasingly on international cooperation (Yoon and Malecki 2010), and growing numbers of new events were created in order to facilitate industry actors' relationships in this increasingly global field. As a biennale, organized in accordance with the 1962 ASIFA agreement only every other year, the Annecy festival was at odds with these developments, as its director, Jean-Luc Xiberras, highlighted as early as 1989: Isn't now the time to re-adapt [the festival] to the inflationary rhythm of animation production in the 1980s? [START_REF] Xiberras | Editorial[END_REF] However, the Annecy event kept to its biennale schedule until 1997, even though it faced growing problems related to the increase of submissions and the potential loss of its market's relevance. Submission numbers increased from 385 in 1983 to 1,271 in 1997 but, as the number of possible screenings was limited, the festival's rejection rate reached almost 80 per cent in 1997 (see Figure 2). Growing submissions created logistic problems for the three selection committees, and the high rejection numbers ran contrary to its mission of presenting a comprehensive overview of international animation production. On the market side, stakeholders began to worry that the Annecy animation film market would lose its relevance in the context of the developing annual 'industry event circuit' that began to emerge in the mid-1980s around a set of major television and licensing fairs such as the MIPTV in Cannes, or the New York Licensing Expo (Ru ¨ling 2011). The biennale format was also starting to cause problems for developing long-term relationships with sponsors, and made it difficult to persuade experienced staff to commit from one biennale festival to the next.

The festival director and the CNC, who sought to develop Annecy into an "essential rendezvous on the international animation agenda" (Xiberras 1997), favored annualizing the festival. But a number of well-known artistically oriented animation directors strongly disapproved this suggestion, fearing a further shift toward commercialization, and ASIFA, the international animation film association created in Annecy in 1961, was also against the idea, insisting on maintaining its historical festival calendar with different ASIFA-accredited events in odd and even years. The French filmmaker and ASIFA president Michel Ocelot, for instance, reminded the 1997 board meeting that "Annecy had initially demanded the twoyear schedule . . . in order to avoid direct competition". He warned that annualizing Annecy would "condemn the Zagreb Festival to death", and announced that ASIFA would refuse further accreditation if the event moved to an annual cycle. Other opponents reminded Annecy that ASIFA had supported it in the successful shift toward a local festival organization in 1983. , 1983 -1997 But, after succeeding in mobilizing the main public policy stakeholders at municipal, regional, national and European levels to increase their financial contribution-and despite the opposition of ASIFA and parts of the French cultural establishment-the local festival board voted to move the Festival to an annual cycle in August 1997, and the Annecy municipal council confirmed the shift a month later. In reaction, ASIFA officially denounced the unilateral decision of the Annecy board to violate rules that had initially been created at its own demand, and stressed its disrespect of other festivals that had been its long standing partners. It widely circulated a petition to boycott the 1998 festival, which was prominently relayed by some of its most visible members.

The first annual Annecy festival and market took place in June 1998. The event saw a 20 per cent decline in professionals' attendance at the festival (3,451 accreditations compared to 4,307 in 1997), which some commentators saw as a consequence of the ASIFA-led boycott. Despite increased overall public funding, moving to an annual schedule resulted in a 25 per cent reduction of public subsidies on an annual basis, and forced the festival organizers to develop new ties with corporate sponsors. However, the shift to an annual cycle eventually strengthened the festival's orientation toward commercial animation, and led to the development of new partnerships with software producers and animation service providers. On the market side, the new format was successful and the first annual edition in 1998 even generated a significant positive financial result, which helped stabilize the newly recruited permanent organizing team, which had grown from 4 to 15 people.

Table 2 summarizes our findings, and provides an overview of the three critical transitions which marked the historical development of the Annecy festival. It highlights the industry conditions, event format and deinstitutionalization challenges for each transition, as well as the key actors, and the characteristics of the transition process. In terms of the deinstitutionalization challenges outlined in previous research-event fragmentation, closure to innovation, and competing events (see above)-the transitions posed different challenges. The first two transitions were both marked by a risk of closure to innovation, whereas the third was characterized by the development of competing events and facing the challenge of potential fragmentation by including a wider range of animation productions. In all three cases, the critical transition occurred after periods of relative stability and success for the event (although the first transition happened after only two events in Cannes), but in situations where the event's current format appeared to risk losing its relevance for the developing animation field it. In all transitions, the initiative for change originated from actors that were strongly locally embedded, but that, at the same time, succeeded in mobilizing support from larger, field-level organizations: in the cases of transitions 2 and 3, this support allowed the festival to overcome resistance from actors opposed to the format change. The discussion section below develops these observations further, and sets them in the wider context of FCE literature.

Discussion and Conclusion

This paper has intended to gain a better understanding of how an organization in charge of a series of field-configuring events can renew them so they retain their dominant place in their field. Our inductive case study suggests three important factors that contributed to such event renewal. First, it highlights the role of "critical transitions" as points when new directions are set for an FCE-in our case, ensuring it remains open to innovations and (1958 -1960) Transition 2 [START_REF] Cassirer | Lettre de Henry R. Cassirer a[END_REF][START_REF] Xiberras | Rapport d'activite ´[END_REF]( ) Transition 3 (1997( -1998) ) Environmental movements in its field. Second, it points out that recurrent FCEs located in specific places are embedded in both their organizational fields and their local environments, and emphasizes the influence of both field members and local stakeholders in their renewal. Finally, our analysis points to the role of the event's governance structure in managing the tensions involved in the FCE's evolution.

Critical Transitions as Moments of Direction Setting

Existing research on the evolution of recurrent FCEs documents cases of incremental evolution, suggesting that they tend to evolve in linear ways (e.g. Delacour and Leca 2011a; Schu ¨ßler and Sydow in press). In contrast, our study suggests another type of development over time-of relatively long periods of incremental evolution, during which routines evolved only marginally, interspersed by relatively short moments of upheaval, during which the FCE's organization changed and the event took a new direction.

Based on these findings, we argue that, during critical transitions, the inertial forces that maintain organizational routine patterns are overcome, so that stakeholders have a larger range of options than usual, and can engage in actively reorienting the FCE. Once a critical transition has passed, institutionalization of new routines occurs, inertial forces reassert themselves, and the FCE again evolves incrementally.

Critical transitions are triggered by conditions which disrupt existing routines. In the Annecy case, they did not automatically occur with environmental evolutions: although the external field environment evolved constantly, major changes to the festival only occurred when tensions between stakeholders reached such levels that new solutions had to be found. In the early 1980s, for instance, important stakeholders became increasingly frustrated with decisions made by the festival director which they judged as being misaligned with both the field's evolution, and the festival's potential for development. Eventually, these tensions led the stakeholders into open conflict to provoke change. The reason why internal tensions prevailed over external pressures and provoked disruptive change might be that no external forces directly threatened the existence of the FCE. While critical transitions mirrored developments in the field, they were clearly facilitated by evolutions in the internal politics of the organization managing the FCE.

Yet this does not suggest that the relationship between field evolutions and those of the FCE is unimportant. Disruptive changes in the FCE series were not the direct result of changes in the field, but the relation between the event and the field in which it operates was nevertheless crucial in our case. Indeed, the Annecy case suggests that FCEs must co evolve with their fields. This co-evolution may not have to be particularly tight as, by definition, FCEs must offer opportunities not otherwise available to field members. For instance, the introduction of Annecy's commercially oriented film market meant that field members could not only be recognized by festival selection and awards-which the festival already offered (cf. Anand and Jones 2008)-but could also encounter new opportunities for funding, distribution, technology sourcing, etc.

The Embeddedness of Recurrent FCEs

Our research also points to the need to consider both field and local dynamics to understand the evolution of FCEs that take place recurrently in the same location. The organizations that stage such FCEs need to consider their double embeddedness-in both the field the FCE contributes to configure and in its local environment. Institutional literature has longexamined embeddedness within organizational fields (DiMaggio and Powell 1983) and, more recently, the work of Marquis and his colleagues (e.g. [START_REF] Marquis | Acting Globally But Thinking Locally? The Enduring Influence of Local Communities on Organizations[END_REF][START_REF] Marquis | Community Isomorphism and Corporate Social Action[END_REF][START_REF] Marquis | Communities and Organizations[END_REF], has considered embeddedness within local communities. Our research contributes both to our understanding of FCEs' local embeddedness, and to the articulation between their local environments and the events' fields.

While existing research on recurring FCEs has considered issues of location, it has mainly looked at cases of events (such as the Olympic games; cf. Glynn 2008) that do not recur in the same location, or, where they do has focusing on more traditional issues of their economic impact on local economic actors (e.g., [START_REF] Attanasi | Cultural Investment, Local Development and Instantaneous Social Capital: A Case Study of a Gathering Festival in the South of Italy[END_REF]. Our study enriches existing research by reversing the dominant perspective, and considering the important role of local stakeholders in FCE series' evolution. In other words, whereas research has noted recurrent events such as film festivals and art fairs as important assets for their host cities, our analysis highlights the role of local communities in influencing such events-influence that does not occur 'naturally', but results from the investment and ongoing work of local actors.

Annecy's municipal government and city council have been highly instrumental in the evolution of its animation film festival, first by providing direct funding and helping to secure subsidies from regional and national government, but also by their active involvement in all three critical transitions outlined above. Our study suggests two reasons why local actors would seek to attract and maintain a recurrent FCE. The first concerns the prestige and reputation of being associated with such events, which are likely to increase media coverage of a host location and contribute to its brand image (e.g. [START_REF] Lucarelli | City Branding: A State-of-the-Art Review of the Research Domain[END_REF]. Second, a stable long-term association with a field-configuring event series can contribute to local development in other ways. Over recent decades, for example, Annecy has invested heavily in local initiatives and infrastructure to help ensure the festival's success, so that local actors could benefit from its image and, even more importantly, from the accumulated knowledge of running the key festival in the global animation field (Ru ¨ling 2011). The potential benefits of recurrent events for local actors not only enhanced their willingness to subsidize the festival, but also to engage in its management and to influence strategic decisions about its evolution.

Our study finds that, during the festival's critical transitions, local actors tended to favor change options that benefitted local interests-those that were more inclusive and would appeal to broader audiences, and increase the event's overall reach and visibility (as well as of its location). Initially, as a purely artistic animation festival, the Annecy event catered to a very limited audience. While its early editions were important events for artistically oriented auteur animation, the festival did not reach out to the larger field of more commercial animation and entertainment, and so risked associating its host city with a potentially obscure subgenre and conveying an image of highbrow culture, attracting only limited numbers of participants. In contrast, later editions clearly aspired to being considered the "world capital of animation", attracting more participants with higher purchasing power.

In the early 1980s, the festival began to lose its attractiveness to professional audiences, and the city council representatives pushed toward opening it up to mainstream animation setting up an accompanying film market. Local Annecy promoters also supported options that enhanced the event's prominence within its field-notably the festival's shift toward being an annual event. While this created problems within the field and conflicts between stakeholders, it also contributed to building Annecy's overall recognition and reinforcing the festival's dominant position in the animation industry. Local actors thus supported options that developed the field in ways that served the local economic ecosystem. When confronted with the critical transitions within the festival's management system, they systematically favored options that would reinforce its local embeddedness.

Whereas existing research tends to consider the location and organizational field as two separate and largely independent environmental dimensions, this study emphasizes the interactions between local constituents and field members involved in FCEs held recurrently in the same location. While the local level is characterized by geographic proximity (e.g. [START_REF] Marquis | Community Isomorphism and Corporate Social Action[END_REF][START_REF] Schu ¨ßler | Backstage: Organizing Events as Proto-Institutional Work in the Popular Music Industry[END_REF], organizational fields relate to those organizations that interact around common issues [START_REF] Dimaggio | The Iron Cage Revisited: Institutional Isomorphism and Collective Rationality in Organizational Fields[END_REF][START_REF] Hoffman | Institutional Evolution and Change: Environmentalism and the U.S. Chemical Industry[END_REF]. Members of the same organizational fields can be geographically distant, yet share common concerns in relation to particular issues, whereas members of a locality (mainly) share common local interests. The Annecy case documents the interactions of those two sorts of embeddedness and shows how decisions made about changes in an FCE are likely to influence both the local environment and the field concerned. In our case, as the local actors influenced those decisions, based on their local interests, they also influenced the evolution of the field. Whereas the festival initially mainly concerned the limited subfield of artistic, auteur-driven animation, from the 1980s it extended its coordinating and relationship-enabling role to encompass commercial animation. This development and the setting up of the animation market also allowed for a closer combination of concurrent commercial and artistic dimensions, so both symbolically and materially reinforcing the economic dimension as well as traditional artistic animation. While this evolution was strongly driven by local interests-as local actors were keen to generate more economic activity around the festival-these decisions also had important impacts for the animation field as a whole.

The Importance of Governance Mechanisms

Finally, this study highlights the importance of governance mechanisms in enabling organizations behind recurrent FCEs to manage contradictory tensions. The analysis of this case shows that accumulated tensions did not lead to inaction or to ongoing struggles, but resulted in critical transitions in which tensions were solved and clear new directions established. Existing research has so far documented cases where the organization behind these events decided to ignore such tensions and continued to enforce existing routines, and so proved unable to integrate radical field innovations, leading to the FCE's eventual deinstitutionalization (e.g. Delacour and Leca 2011a). What may have been lacking in such cases is the ability to embrace conflict, to allow the event's organization to work less consensually and so create the capacity to challenge the established consensus. Innovations in field-configuring event series can often be heavily conflict-laden. Our empirical findings highlight the role of conflict, and suggest that managing an FCE's renewal and redirection can necessarily involve managing conflict. By this, we mean not so much reducing underlying tensions and contradictions so as to maintain consensus but, rather, surfacing and managing them productively so that critical decisions can be taken, rather than delayed or diluted, and clear new directions can be set.

Our analysis points to the importance of governance in how the event organization in this case faced those conflicts, managed them, and was eventually able to take and implement decisions in spite of strong opposition, accepting that its historical partners would be marginalized in the process, or even excluded from participating in the event's future development. Previous research on FCEs has usually documented cases where governing bodies were composed of actors sharing the same sets of interests, values and agendas, and which eventually proved less resilient and less able to adapt to the demands of their field's changing environments (Delacour and Leca 2011a). In organizations where multiple stakeholders are represented-such as that managing the Annecy festival-conflicts are likely to arise when key decisions relating to critical transitions must be taken. In the Annecy case, this eventually proved to build the FCE's resilience, as the resulting conflicts allowed the managing organization to address field-level evolution rather than ignoring them, as might be the case if governing bodies are too determined to reach consensual decisions. This observation echoes recent research by Stark and colleagues [START_REF] Girard | Distributing Intelligence and Organizing Diversity in New-Media Projects[END_REF][START_REF] Stark | The Sense of Dissonance: Account of Worth in Economic Life[END_REF]) on the notion of 'heterarchy', defined as an organizational form combining both lateral accountability and organizational heterogeneity, and characterized by distributed intelligence and the organization of diverse interests, logics, etc. Drawing from research on high-tech companies, [START_REF] Girard | Distributing Intelligence and Organizing Diversity in New-Media Projects[END_REF] emphasized that such organizations are characterized by their capacity to include and manage contradictory values and interests in flexible, non-conflicting ways. Heterarchies have higher resilience and are more adaptive because their ongoing engagement with multiple interests and values creates multiple forms of interpretation and organization [START_REF] Stark | The Sense of Dissonance: Account of Worth in Economic Life[END_REF]. The organization behind the Annecy festival differs from existing empirical studies of heterarchies where the diversity of logics and interests and their possible tensions are mitigated through internal mechanisms so that they do not lead to open conflict [START_REF] Grabher | Ecologies of Creativity: The Village, the Group, and the Heterarchic Organisation of the British Advertising Industry[END_REF]. The Annecy case suggests another form of heterarchies where the diversity of logics and interests is managed through facing up to conflict. Our research suggests that the capacity to let tensions emerge and to manage conflict between organization members with diverse values, who disagree about what should be done, in productive ways can also serve to increase resilience and adaptability.

In terms of generalizability, we propose, first, that critical transitions generally provide specific moments during which FCE series can change direction. Beyond this overall observation we propose, second, that the Annecy case shows more specifically how locally embedded FCE series can successfully renew themselves and remain dominant in a field. As opposed to itinerant event series such as academic conferences, the Olympic Games or the UN climate summits (e.g. [START_REF] Garud | Conferences as Venues for the Configuration of Emerging Organizational Fields: The Case of Cochlear Implants[END_REF][START_REF] Glynn | Configuring the Field of Play: How Hosting the Olympic Games Impacts Civic Community[END_REF][START_REF] Schu ¨ßler | On Melting Summits: The Limitations of Field-Configuring Events as Catalysts of Change in Transnational Climate Policy[END_REF], FCE series in the cultural industries, for example literary awards, film festivals, or art biennales (e.g., [START_REF] Anand | Tournament Rituals, Category Dynamics, and Field Configuration: The Case of the Booker Prize[END_REF][START_REF] Delacour | L'e ´volution des lieux de la concurrence. Le cas du marche ´de l'art contemporain[END_REF][START_REF] Ru ¨ling | Film Festival Research from an Organizational Studies Perspective[END_REF][START_REF] Tang | Biennalization and Its Discontents[END_REF] are most often strongly connected to specific locations. Such event series are normally characterized by the important role of local stakeholders and their interests, which are often separate from the specific field to which an FCE series caters in the first place, and which allow for the development of more heterarchic governance structures generating the forms of productive conflict that have enabled Annecy to retain its dominant position in the animation field.

In terms of future research, our study highlights the need for additional work on the relationships between institutional field dynamics and FCE evolution. Field dynamics can take different forms [START_REF] Strang | Institutional Conditions for Diffusion[END_REF][START_REF] Meyer | Organizing Far from Equilibrium: Nonlinear Change in Organizational Fields[END_REF], and a single case study can only provide exploratory insights on the articulation of those between the evolutions of the field and of the FCE in a specific case. In particular, it would be interesting for future research to seek a better understanding of the relations between a field's dynamics and those of its FCEs. The Annecy case suggests that, while field evolution may be constant, the field's FCEs evolve in a pattern of punctuated equilibrium, suggesting relationships between field and event dynamics are complex. In terms of FCEs, our study highlights the need for more research into their organizations and governing bodies, the ways in which they work and the diversity of actors' interests, values and agendas that they reflect.

We acknowledge three main limits in our study. First, as already pointed out, and in common with most studies on FCEs, ours has limitations relating to its reliance on a single, exploratory case study based on archival data and retrospective interviews. However, we are confident that our efforts to combine different data sources, as well as insider and outsider interpretations of the Annecy event's historical development, have allowed us to develop a set of valid contributions to the FCE and associated literatures. In particular, it has let us open the black box of the organizations behind FCE series, and reveal the crucial yet underestimated role they play in the evolution of their FCEs, and of their fields. Second, while our research has focused on three critical transitions, and our contributions are limited to the insights gained from analyzing and contrasting those transitions, we acknowledge that these are steps in a larger process. Further research that considers the process of evolution from other perspectives would be necessary to develop a longitudinal analysis of how organizations maintain an FCE's dominant field position. And third, while our research provides insights on the interactions between local actors and field members around a recurrent FCE organized in a specific location, our results in this regard are certainly specific to our case study. In our case the key element in connecting the two dimensions was the decision to shift the entire management of the FCE to the local level, and the resulting increase of the power of local actors. It would be interesting to explore other cases to explore further interactions between local actors and field members in other configurations where, for instance, organization is not locally based. Combining research on local/field interactions with existing research on industrial districts (e.g. [START_REF] Barabel | Esquisse d'une analyse des strate ´gies locales d'adaptation de l'ordre traditionnel face a `la globalisation: Une approche ne ´o-institutionnaliste[END_REF][START_REF] Boschma | Knowledge Networks and Innovative Performance in an Industrial District: The Case of a Footwear District in the South of Italy[END_REF][START_REF] Niosi | Aerospace Clusters: Local or Global Knowledge Spillovers?[END_REF] might provide useful directions to do so.

Disclosure statement

No potential conflict of interest was reported by the authors.

Figure 1 .

 1 Figure 1. Evolution of the Annecy event through critical transitions

Figure 2 .

 2 Figure 2. Films submitted and selected, 1983 -1997

Table 1 .

 1 Development of the event

Table 2 .

 2 Comparison of critical transitionsTransition 1

APPENDIX


Simon L Gay
email: simon.gay@liris.cnrs.fr

Salima Hassas
email: salima.hassas@univ-lyon1.fr

Autonomous object modeling based on affordances in a dynamic environment

Keywords: Affordances, Autonomous learning, Body schema, Developmental learning, Constructivism learning, Self-motivation, Spatial awareness

We present an architecture for self-motivated agents to generate behaviors in a dynamic environment according to its possibilities of interactions. Some interactions have predefined valences that specify inborn behavioral preferences. Over time, the agent learns to recognize affordances in its surrounding environment under the form of structures called signatures of interactions. The agent keeps track of enacted interactions in a spatial memory to generate a completed context in which it can use signatures to recognize and localize distant possibilities of interactions, and generates behaviors that satisfy its motivation principles.

Introduction

In this paper, we address the problem of the construction, interpretation and exploitation of a short-term representation of a dynamic environment by an artificial agent that initially ignore elements that compose its environment. Our work is based on a model proposed by Georgeon and Aha [START_REF] Olivier | The radical interactionism conceptual commitment[END_REF], called Radical Interactionism, in which actions and perceptions are considered as inseparables and kept embedded within data structures called interactions. Specifically, interactions are used to model Piaget's notion of sensorimotor scheme [START_REF] Piaget | The construction of reality in the child[END_REF].

In previous works [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF][1], we proposed and tested mechanisms that allow an artificial agent to construct and exploit such a structure to generate behaviors adapted to the environmental context of the agent. These mechanisms are inspired from biology: most natural organisms have brain structures that maintains some geometrical correspondences with the animal's surrounding space, such as tectum [START_REF] David | The optic tectum[END_REF] (or colliculus in mammals), or sensorimotors cortices [START_REF] Michael | Complex movements evoked by microstimulation of precentral cortex[END_REF]. These mechanisms are however limited to a static environment. To overcome this limitation, we propose to adapt these mechanisms to consider movements of elements of the environment. This paper focuses on the adaptation of mechanisms that learn to define objects that compose the environment, and mechanisms that generate behaviors. [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF]. A decision cycle begins with an intended interaction i t of the agent, which then experiments a set of enacted interactions E t

Formalization of Parallel Radical Interactionism (PRI)

The PRI model [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF] begins with a set I of primitive interactions. Each primitive interaction i is attributed a valence v i that defines the agent's behavioral preferences. This principle defines a form of intrinsic motivation [START_REF] Oudeyer | Intrinsic motivation systems for autonomous mental development[END_REF], called Interactional Motivation. A PRI decision cycle, illustrated in Figure 1, begins with an intended interaction i t from the agent. At the end of the decision cycle, the agent is informed of interactions that were actually enacted, called Enacted set E t .

We thus consider that the agent receives additional sensory stimuli when an interaction is enacted. These stimuli cannot be considered without the interaction that produce them. We thus propose to construct new interactions by associating an interaction and a stimuli. We call secondary interaction i such an interaction, associated interaction of i the interaction that composes i, and primary interaction an interaction that is not based on another one.

In a preliminary work1 , we have implemented an agent equipped with a sequential RI algorithm that can capture sequential properties of mobile elements. We thus propose that the agent can consider sequences of two enacted interactions. Indeed, a sequence of interactions can carry information about the relative movement of an object detected by these interactions.

The Spatial Memory System

We have proposed a structure, called Space Memory System (SMS) [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF] [START_REF] Gay | Mécanismes d'apprentissage développemental et intrinséquement motivés en intelligence artificielle : étude des mécanismes d'intégration de l'espace environnemental[END_REF], that completes the interactional context E t and helps the agent to generate behaviors adapted to the environment.

The SMS is based on structures that can characterize elements of the environment, called Signatures of Interaction. The principle is based on the assumption that the result of the enaction of an interaction depends on a limited context of elements of the environment, considered as the "objects" that affords this interaction. This definition of objects relates to the concept of affordance proposed by Gibson[4]: an object is a specific spatial configuration of elements in the environment that affords an interaction, and does not require a priori knowledge. A RI agent cannot directly observe these objects, but can "experience" them through interactions. The aim of the signature mechanism is thus to define for each interaction i a set of interactions {j} for which the enaction can characterize the presence of the object that affords i. This mechanism is similar to the mechanism proposed by Ugur et al. [START_REF] Ugur | The learning and use of traversability affordance using range images on a mobile robot[END_REF]. However, the use of interactions rather than actions and perceptions makes it possible to learn spatial properties of space, as interactions carry information about the movements of the agent in space. Our mechanism is adapted from [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF], and extended to sequences of interactions. The mechanism is formalized as a certitude function c that gives the certitude that an interaction or sequence i can be successfully enacted in a context E with an absolute certitude of success when c(i, E) = 1 and of failure when c(i, E) = -1. This function is reinforced at each decision cycle, based on the results of enaction. The parameters of c constitutes the Signatures of interactions. We propose an implementation based on a single layer neuronal network, with a neuron per interaction (1). To this end, the context E t is coded as a binary vector [ 1,t ; ...; n,t ], with n the number of interactions and sequences used by the agent, and k,t = 1 when i k ∈ E t . Each signature of interaction or sequence i is composed of a set W i of n weights w i,k and a bias w i,n+1 .

c(i, E t ) = g   ( k∈[1;n] k,t • w i,k ) + w i,n+1   with g(x) = 2 1 + e -x -1 (1)
A set W i is updated each time the interaction or sequence i is completed as a success or a failure, using the delta rule [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF]. We note r i,t = 1 if i succeeded and r i,t = -1 if i failed.

w t a,k ← w t-1 a,k + α × k,t-1 × (r a,t -c(a, E t-1 )) , ∀k ∈ [1; n + 1], α ∈ [0; 1] the learning rate. (2)
We propose to use a hard-coded structure, called Space Memory [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF], that integrates and tracks detected objects, to study more precisely the modified mechanism of signature of interaction and the exploitation mechanism of the SMS. A space memory M is composed of a set P of position p in egocentric reference. A part of these positions is related to positions that correspond to interactions. This subset of positions constitutes the area of space the agent can observe through interactions, we call Observable Space P O . Any geometrical transformation can be approximated by a function τ : p → p . Moving an element in space thus consists in changing its position according to τ . Each primary interaction i produces a transformation τ i . Note that [START_REF] Gay | Mécanismes d'apprentissage développemental et intrinséquement motivés en intelligence artificielle : étude des mécanismes d'intégration de l'espace environnemental[END_REF] proposes mechanisms to construct such a structure without any preconception.

The selection mechanism is based on two decisional systems. The exploration system leads the agent to try interactions for the sake of learning signatures. As the frequency of the enaction of sequence of interaction is very low, we propose a mechanism that foster the less tested weights. For each weight of each signature, we attribute a counter c i,k that is incremented each time the weight is modified. At each decision cycle t, we compute the relevance of testing an interaction or a sequence in the current context E t , defined by k∈[1:n] c i,k × k,t . An interaction or a sequence is candidate when its certitude of success is smaller (in absolute value) than a threshold, called reliability threshold. The candidate interaction with the lowest relevance is then selected and enacted. If no interaction is candidate, the agent uses the exploitation mechanism.

The exploitation mechanism selects interactions to maximize valence in the short and medium terms. It considers the relative movement of objects generated by the enaction of interactions, and adds a utility value to valence of interactions, that depends on the variation of distance of objects and the valence of interactions afforded by these objects. Closest objects have a greater influence as the agent is more likely to interact with them in the short term. Formally, we note M τ an image of the Spatial Memory M when a transformation τ ∈ T is applied, and E τ the list of interactions stored in M τ , limited to P O . For each transformation τ , a distal object that affords an interaction i is considered as present with a certitude of c(i, E τ ). We note d(τ ) the distance of the object. The utility value ∆ i k , that characterizes the global variation of distance produced by a candidate interaction i k , is computed as follows:

∆ i k = i∈I τ ∈T c(i, E τ +τi k ) × f (d (τ +τi k ) ) - τ ∈T c(i, E τ ) × f (d (τ ) ) × v i (3)
Where f : R + →]0; 1] is a function that characterizes object influence according to their relative distance. In our implementations, we use the function f : x → γ x with γ ∈]0; 1]. The mechanism then selects, among candidates i k , the next intended interaction i t+1 defined by

i t+1 = max i k (v i k + β × ∆ i k ), with β ∈ R + the influence coefficient of the SMS.

Implementation on an artificial agent

We have implemented our mechanisms on an agent moving in a 2-dimensional continuous environment (Figure 2). The agent-environment system defines a set of 7 primary interactions (valence is given in parenthesis): move forward of half the length of the agent (1), bump (-5), move forward and eat something edible (50), turn left of 45 • (-1), turn right of 45 • (-1), turn left of 22.5 • (-1), turn right of 22.5 • (-1). We add a set of visual secondary interactions that consists in seeing an element of a color among {red, green, blue} at a position p (supposed defined by a movement and optic flow), while enacting one of the primary interactions (except for bump that does not produce movement). We discretize observable positions as a regular grid of 30 × 15 positions to simplify movements in space memory.

We define 4 types of elements, characterized by a color that makes them recognizable according to the interactional system of the agent: wall block (green) that affords bump, food and mobile preys (blue) that affords eat, and alga (red) that has no influence on enaction of interactions. Mobile preys move forward at a same speed than the agent. Edible elements are removed when eaten and a same element is added in a randomly selected empty place.

We introduce sequences of interactions to detect relative movements of elements. We only consider relevant sequences. Note that defining relevant sequences is an open question that we intend to address in future works. Primary interactions defines the following sequences: move forward twice

(2), bump (-5), move forward, then eat (52), turn left of 90 • (-2), turn right of 90 • (-2), turn left of 45 • (-2), and turn right of 45 • (-2). A sequence of secondary interactions is composed of a sequence of two secondary interaction. Blue elements can be immobile or move in 8 directions, relative to the agent, as it can rotate of 45 • . The agent can thus experiment, for each position and primary interaction, 9 sequences of secondary interactions. Green and red elements are immobile: the agent can experiment one sequence. We thus define a set of (9 + 1 + 1) × 30 × 15 × 6 = 29700 sequences of secondary interactions.

We first test the signature mechanism. We let the agent interacts with its environment, and stop the experiment after 100 000 decision cycles. Figure 3 shows examples of signatures. We can observe that move forward twice is related to the absence of green and blue element in front of the agent (mid-red blob on signature), and bump is related to a green element in front of the agent. We can note that the size of these elements are nearly the size of the agent. The signature of move forward then eat designates a blue element for which the position depends of its movement (and move forward twice is related to their absence): the signature thus integrates dynamic properties of preys. Turn sequences, that cannot fail, are strongly related to the bias. Signatures of visual sequences shows interesting properties: they designate Figure 3: Signatures of sequences of interactions move forward twice, bump, move forward then eat, turn left of 45 • , move forward twice and seeing a blue immobile element, and turning left of 45 • and seeing a blue element with a forward-left movement (at a position designated by a red square), obtained after 100 000 decision cycles. We gather weights related to visual sequences characterized by a same associated sequence (left) and a same color and observed movement (top). Each group is organized to match the topography of the visual field. Weights related to primary interactions and the bias are represented with squares. A black color means a weight of -1 and a white color means a weight of 1. We can observe that move forward is related to the absence of blue and green element in front of the agent, bump is afforded by a green element and eat by a blue element for which the position depends on the movement of preys. Turns sequences are strongly related to the bias as they cannot fail. Signatures of visual sequences designate interactions related to seeing an element of a same color, at a position that correspond to the transformation produced by enacted sequences (orange arrows). elements of a same color than the considered sequence, but at a position that correspond to the position of the sequence, moved by the movement produced by sequences of interactions and the movement of objects. Figure 4 shows examples of these observed movements. In case of sequences of visual interactions related to turns interactions, we also observe a permutation in the movement characterized by sequences designated by signatures. These observations show that signatures integrate spatial and dynamics properties of the environment.

We then add the space memory to test the exploitation mechanism. We propose a simplification of the interactional system: as signatures gather interactions related to a same element, we propose to consider sequences of visual interactions regardless of their associated primary interaction. This simplification decreases the number of sequence and significantly increases the frequency of enaction of these sequences. The downside is that we cannot define signatures of sequences of visual interaction nor enact these sequences. We increase the resolution of the grid that define positions to observe more precisely signatures of interactions.

The experiment is conducted as previously. We let the agent interact with its environment, driven by a curiosity and an exploitation mechanism. We had to reduce the speed of prey to 0.7 times the speed of the agent to allow the agent to reach a prey by approaching it laterally with an angle of 45 • . Figure 5 shows signatures of primary interactions obtained after 25 000 decision cycles. The objects observed by the agent are similar to previously.

We then disable the agent's learning mechanism and observe its behavior in presence of a prey. It appears that the agent "aims" at a point in space in front of a prey (Figure 6). Indeed, the signature of eat interaction considers the movement of preys: the "center" of the object (i.e. the point of space where the interaction can be afforded) is not in front of the prey, but in front of the position of the prey after enacting the interaction. This property is especially visible when we place a wall block in front of the agent (Figure 6 right): as the prey moves left behind the wall block, the agent turns left to reach the prey, although the prey is still in the left side of the agent. This observation shows that the agent considers the future positions of objects rather than their current position.

Conclusion

We proposed an adaptation of mechanisms proposed in [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF] for a dynamic environment, inspired by sequential RI models. We observed that only a few modifications were needed to allow an artificial agent to discover dynamic properties of its environment. The use of sequences of interactions has a little incidence on principles of mechanisms developed for a static environ- Figure 6: Left: the agent is strongly attracted by the prey (1-2), as it affords an interaction with a high valence. The agent is attracted by the future position of the prey: it turns left while the prey is at its right side (2-3), which allows the agent to reach the prey (4). Right: a wall block is added in front of the agent (1). The agent "anticipates" the position of the prey and bypass the wall by its left side [START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF]. Without perceiving the prey anymore, the agent turns left and moves forward to pass ahead the prey and reach it (3). ment. Indeed, a sequence of interaction, like an interaction, can success or fail, which makes it possible to use them as an input of the interactional context to complete or replace interactions without modifying the principle of signatures of interactions. The agent shows that it can learn and integrate elements that afford its interactions and spatial properties of its environment, like with mechanisms developed for static environments. It also learns dynamic regularities of its environment, under the form of sequences of interactions that allow to detect movements of objects and to predict their position. The use of a hard-coded space memory is a strong preconception. However, modifications of mechanisms of constructions of structures to characterize objects and spatial properties of space does not seem to need modifications of mechanisms of construction and exploitation of the agnostic space memory developed previously [START_REF] Gay | Mécanismes d'apprentissage développemental et intrinséquement motivés en intelligence artificielle : étude des mécanismes d'intégration de l'espace environnemental[END_REF]. In future works, we intend to implement our mechanisms in more complex systems, and in particular agents using continuous sets of interaction.

Figure 1 :

 1 Figure 1: Model of the Parallel Radical Interactionism[START_REF] Gay | Autonomous object modeling based on affordances for spatial organization of behavior[END_REF]. A decision cycle begins with an intended interaction i t of the agent, which then experiments a set of enacted interactions E t

Figure 2 :

 2 Figure2: Left: the agent in its environment. The agent is represented as a gray shark, preys as blue fishes and food as blue alga. Right: the interactional context. Inputs are gathered according to properties of related visual sequences of interaction. Input related to primary sequences of interactions are represented with seven squares (here, move forward twice is enacted).

( 1 .

 1 03; 1.08; -0.28°) (-0.05; 0.91; -0.21°) (1.15; 0.94; 0.64°) (-0.86; -0.85; 44.7°) (-0.16; -0.01; 43.9°) (0.58; 0.76; 45.1°)

Figure 4 :

 4 Figure 4: Difference of position between a sequence of visual interaction (black dots) and the barycenter of position of sequences designated by its signature (red circles). Average transformations (x, y, θ) produced by enaction of associated interactions are easily recognizable.

Figure 5 :

 5 Figure5: Signatures of sequences move forward twice, bump and move forward then eat, obtained after 25 000 decision cycles with the simplified interactional system. Object constructed by the agent are similar to that obtained with the complete interactional system.

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