Michael Tsangaris

Unauthorized Outdoor Graphics as Urban Expressions in the Time of the Crisis

Keywords: graffiti, wall slogans, street art, social protest, Athens, alternative media

When economic crisis emerges and at the same time the refugee problem takes great dimensions, society is prone to unrest and people that cannot reach the mainstream media turn to easy and practical ways to communicate their protest. As Greek economy struggles to recover, civil disturbance can be detected even in brief political statements written on the walls. In any case, Metropolitan walls were always convenient grounds for the 'public sphere'. Wall graffiti and slogans consist alternative media that communicate the social bitterness and discontent. By occupying public space these unconventional forms of political activism are considered by the authorities as acts of civil disobedience that belong to the sphere of contentious politics. Investigating the centre of Athens this paper explores the ways in which these genuine expressions represent the people's resistance against the crisis on the symbolic level. A wide range of opinions can be detected through these channels, illustrating the diversity and the variety of reactions to social tension. Using simple semiotic approach we attempt to decode the texts and clarify the political reasoning of the performers.

INTRODUCTION

Cities are platforms where cultures, technologies and people perform interactively a variety of communicative actions. [START_REF] Park | The City: Suggestions for the Investigation of Human Behavior in the Urban Environment[END_REF] argued that big cities are not just artificial constructions such as buildings, roads and transformational networks, they also involve all the vital processes of the people who compose them. Besides, urban space is not an abstract technical conception invented by the civil engineers and architects far distant from ideology and politics. [START_REF] Lefebvre | Reflections on the politics of space[END_REF] believed that urban space always has been a political arena. In the age of platform capitalism public space is not as neutral as it seems, it is historically and socially determined and constructed. Historical light helps to understand this development as open spaces and public or private buildings have been very often occupied and used by people whose motives were purely political. [START_REF] Foucault | Space, knowledge and power[END_REF][START_REF] Foucault | Security, territory, population: lectures at the Collège de France[END_REF] elaborated this concept considering the effects and the importance of urban space and urban planning over life in 'biopolitics'. Without any question the state uses the urban space to apply governance technologies that are directed to manage and control the citizens. Additionally according to [START_REF] Negri | On Rem Koolhaas[END_REF] the current industry of architecture along with the fashion and the film industries plot to discourage any possible resistance of people, dazzling everything with 'artificial lights' so the rate of exploitation cannot be determined. However, as Harvey acclaimed all people have 'the right to the city'. Urban world can be re-imagined and re-made humanly, as we are all architects, individually and collectively and we can re-shape the city 'through our daily actions and our political, intellectual and economic engagements' (Harvey, 2003: 939).

In order to achieve their objectives social movements sometimes employ unconventional methods that can be contrary to the law. [START_REF] Tarrow | Social movements in contentious politics: A review article[END_REF] defined contentious politics in a broad sense as the collective actions of claimers or those who assert to represent them that rely at least in part on non-institutional forms of interaction with the elites, the opponents or the state. In this respect, contentious politics can be considered that involve also all unauthorised and illegal techniques that the opposing social groups use against the power structure and the status quo to achieve their political goals.

Atton (2001) argues that 'alternative media' are actually all those channels that offer the means for democratic communication to anyone who is normally excluded from the mainstream media production. In his work on alternative media Downing often considers as 'radical media' the media of the social movements 1 . Further, he unfolds his theory to all media conducts including artistic production and cultural practices such as tattoos, street theatre, clothing and graffiti [START_REF] Downing | Radical media: Rebellious communication and social movements[END_REF][START_REF] Downing | Social movement theories and alternative media[END_REF]. In the same direction Fuchs (2010) considers art murals, stickers, posters and graffiti as 'critical media' and outlines that their content reveals the suppressed possibilities of existence, the realities and the potentialities for transformation that the oppressed and dominated groups express, struggling for the advancement of a co-operative society.

Without any doubt urban space has become an all-inclusive platform that carries graphics communicating various messages from commercial promotions to public debates which often draw our attention and invite us to make a break out of everyday routine. Under the title urban outdoor graphics we can include actually all kinds of graphic messages and open exposures, legally or illegally constructed and positioned at the urban environment, including roughly everything, from state and municipal instructions to commercial and political advertising, as well as all unauthorized outdoor graphical expressions of the social activists or the spontaneous reactionary writings from individuals.

The exaggerated use of space by the outdoor graphic representations in big cities all over the world increases steadily the academic discourse and the intellectual reflections concerning this complication throughout multiple perspectives and diverse disciplines such as architecture, ecology, political science, communications studies, 1 John [START_REF] Downing | Radical media: Rebellious communication and social movements[END_REF] argued that the term alternative media is 'oxymoronic' if we consider that everything is an alternative to something else, thus occasionally media scholars instead of using the term alternative media have proposed different adjectives such as activist media [START_REF] Waltz | Alternative and activist media[END_REF], citizens media [START_REF] Rodriguez | Civil Society and Citizens Media[END_REF][START_REF] Pettit | Citizens' media and communication[END_REF], tactical media [START_REF] Lovink | Dark Fiber: Tracking Critical Internet Culture[END_REF][START_REF] Raley | Tactical media 28[END_REF], autonomous media [START_REF] Langlois | Autonomous media: Activating resistance and dissent[END_REF], counter-information media (Baldelli 1977, Vitelli andRodríguez 2004), radical media [START_REF] Downing | Radical media: Rebellious communication and social movements[END_REF], participatory media [START_REF] Rheingold | Using participatory media and public voice to encourage civic engagement[END_REF], social movement media [START_REF] Downing | Social movement theories and alternative media[END_REF], community media [START_REF] Rennie | Community Media[END_REF] or nano-media [START_REF] Downing | Nanomedia: Community media, network media, social movement media: Why do they matter? And what's in a name[END_REF] by using each time unique emphasis on different aspects of their approaches. Nevertheless most of them argue that those terms are not static, sometimes overlap and retain subjective flexibilities. psychology, sociology, history, fine arts, geography, anthropology, cultural studies, business administration and so on.

In the first place, as mainstream media of visual communications in the urban environment can be considered all conventional outdoor advertisements (which include commercial and political posters, wallscapes, billboards, banners, etc) the shopfront signs, the neon signs, the municipal location banners, the road and the traffic symbol signs, the digital billboards of any kind, the authorised graffiti walls, and all the like. On the other hand as the radical media of urban open space we can consider all unauthorized outdoor graphics such as the illegal bill posters, the political wall slogans, the spontaneous individual existential expressions, the marker quotes and the street graffiti 2 . More precisely, when we speak about unauthorized outdoor graphics in this study we will refer to all those unofficial multiple messages of visual communication in any form (words, sketches, drawings, etc) made without permission on the walls, the billboards, the transportations (railroad carriages, buses, trams, cars, etc) the street furniture (benches, bus stops, kiosks, sidewalk posters, traffic lights, pedestrian panels, columns, etc) and so on. Actually bill posters and printed stickers can be also included among all those that we have already noted, although they belong mainly to the domain of printed media.

But what is radical about unauthorized outdoor graphics? Is it the type of the communication process, the performer or the content of the messages? First and foremost, whatever the theme or the motive, the entire process is illegal as the performers without permission sketch graphics on private or public property. The offence may get much more serious if the content outrages public decency or insults a political personality. Jurisdictions vary between countries but there is a typical range of offences linked to this practice including charges such as criminal action, property damage, vandalism, environmental pollution or antisocial behaviour. Unauthorized outdoor graphics as actions challenge the existing power structures and the status quo, thus as communication performances belong evidently to radical media. Actually from a Gramscian point of view, whatever their content might be, just for the reason that the unauthorised outdoor expressions are illegal public announcements they are against the hegemon and thus they belong to the political domain. However the researcher must always take into account the historical period, the geography, the perceptions and representations of the social groups in focus, concerning the situation. In this sense what might be illegal and condemned from the community at particular time, place and point of view could be an act of patriotism if we change the frame of the analysis.

Outdoor graphics by their very nature are available to a local audience and usually they convey tropes over and above the literal meaning of the texts reflecting the ideology of 2 The origins of the word graffiti comes from the ancient Greek verb 'gráphein' (γράφειν) that means to write. However graffiti is the plural of the Italian term 'sgraffito' a technique for decorating surfaces (walls, pottery etc). While authorized and unauthorised drawings and writings stand for centuries on the urban walls the current use of the term 'graffiti' as street expression initiated sometime after the midsixties by street gangs who marked their territory in New York, Los Angeles, Philadelphia, and so on. Famous early prime movers of these spray graffiti forms were Cornbread, Cool Earl, Taki 183 etc [START_REF] Schacter | The world atlas of street art and graffiti[END_REF]. Although most scholars address to graffiti for any outdoor graphics we will use the term to refer only to those peculiar Latin and Afro American cultural forms of urban graphic expressions that became globalized after the seventies. the performers. Additionally, they are considered passive because urban pedestrians do not have a choice to face them or to avoid them. The messages are just there, sometimes holding a dominating power as centres of attraction capable to provoke sharp emotional reactions. Nevertheless, graphics regularly cover central spaces of the urban landscape reaching unconsciously the pedestrians while walking in the city streets absorbed by their own everyday problems. In essence, outdoor exposure requires low active mental processing because people receive all these messages when they are in a passive state of mind. However, in times of crisis the radical messages can induce the people's solidarity and can lead them to a sense of an oppressed alliance. They can suggest ways of action and evoke 'life politics' against the side-effects of this 'reflexive phase of modernity' that we are all going through according to [START_REF] Beck | Reflexive Modernization. Politics, Tradition and Aesthetics in the Modern Social Order[END_REF]. Nevertheless Della Porta and Diani (2009:87) cite that people's 'mobilization does not depend so much on values as on how social actors assign meaning to their experience'. Social movements' cultural production sometimes implies a combination that reflects both conquering and revitalizing aspects of the given traditions of the population. This process can quietly take place on continuing basis within the local community using familiar signification codes by the unauthorized outdoor graphics. The size, the extent, the shape, the position (angle and height in relation to the human body) the location (residential, commercial, public utility area, etc) the proximity of important establishments, such as educational institutions, governmental agencies, office buildings, etc, the type and volume of the traffic, the interference of other graphics or the probability of an immediate erasing, can be very important factors concerning the effectiveness of the unauthorized outdoor graphics.

In any case, platform capitalism and the integration of social media with all other forms of media changed have everything. The visual communication of outdoor graphics no longer depends only on the direct human encounter and the communal cultural codes of the locals. Nowadays, unauthorized outdoor graphics are conceived and designed by the performers having always in the back of their mind the social media conventional requirements. Wall graffiti and slogans can be reproduced and presented globally by the Web 2.0 platforms such as Facebook, Twitter, Instagram and YouTube. Consequently, via those wide distribution channels the socio-political messages of the streets can get global support and move to larger scale politics. It is very interesting to consider the ways in which activists have adapted the practice of radical community media forms so they can be utilized and get interacted with the alternative new media technologies.

The purpose of this paper is to explore all sorts of unconventional wall graphics as forms of the public debate in times of crisis in order to understand the contemporary social conditions in Athens. First we will develop a general review concerning the performance of the unauthorized outdoor graphics of Athens in retrospect. Next we will describe our experimental 'psychogeographical' passage, trying to grasp the sentiments evoked by the specific effects of the urban environment that confront unconsciously every day the inhabitants. Using a simple semiotic approach we will attempt to decode some of the texts3 and clarify the political reasoning of the performers.

A BRIEF REVIEW

Graphic representation as a mode of communication appeared as soon as human symbolic thought begun to evolve. The oldest wall graphics were created by the early human populations just about the same period all around the world that is approximately 39,900 years from today [START_REF] Roebroeks | Archaeology: Art on the move[END_REF]. Since then, graphical human expressions have been evolving to more sophisticated communication forms, changing their features, following the technological progress and reflecting the social reality of their times.

Agora museum of Athens that is located under the Acropolis contains a great collection of exhibits which are closely related to the Athenian Democracy (coins, ostraka-ballots, etc) but also maintains an excellent collection of inscriptions from the 5th century BC. Nowadays in everyday life when we talk about outdoor graphics such as advertising billboards or graffiti we usually have in mind ephemeral signs, however in a broader sense depictions applied on the walls or any other surface have been considered by communications scholars as long lasting and time-based media [START_REF] Innis | A plea for time[END_REF] in comparison to the fluid space-based media4 of contemporary times such as radio, television and the internet (including Web 2.0 technologies etc). Certainly when the scholars talked about long lasting nature in relation to wall graphics they had in mind most probably cases like the ancient Pettakere cave paintings (Aubert, 2014) or Greek and Roman engravings. Thus, eventually at this point we face the first contradiction concerning our inquiry: outdoor graphics can be seen as eternal and at the same time ephemeral in many ways. Unauthorised outdoor graphics can be set down one night and washed up the next morning or they can remain in the walls for months, yet in our days they can be saved reproduced and disseminated by digital technology from the urban platforms to the social media platforms and sometimes they can remain in people's minds as symbols of rebellion for ever.

In any case, a significant quantity of old photographs that we trucked down in the course of our research concerning past unauthorized graphics in Greece were framing patriotic slogans written in the Greek language all over the walls of Athens by the Greek resistance against the German occupation in the Second World War [START_REF] Glezos | Εθνική αντίσταση 1940-1945[END_REF]. As a matter of fact, it seems that even in the postwar era the walls of Athens continue to stand also as open discussion boards that communicated messages of resistance and contention for a long period of time. The Greek civil war, the postwar prosecution of the Greek left and the colonels Junta disrupted the Greek society and suppressed civil liberties for a long period of time. Actually, if we examine photographic archives or illustrated historical albums [START_REF] Katsigeras | Ελλάδα, 20ος αιώνας. Οι φωτογραφίες[END_REF], each phase of the contemporary history of Greece can be rendered and promptly documented by the writings on the walls and the brief slogans of resistance that lay behind the action in the background of various photographs. However, after the political change-over and the restoration of the Greek democracy, still the political disputes were marked in the urban environment with slogans. During the seventies the youth wings of all the political parties worked incognito at nights covering the walls with posters and political slogans. At that times wall writing was usually performed with paintbrushes and each color denoted a political party according the visual code of politics. The Greek rightwing was represented with blue color, the left with red, the socialists with green while the anarchists and the nationalists were using black 5 . In 1981 Dimaras published a collection of photographs from the seventies that presented humoristic anti-establishment textslogans written in the walls by the radical youths. He noted that in every click of his camera he was not just immortalizing the slogans but he was actually imprinting suppressed grins and the solace of the heavy-hearted Greeks. In the end of the seventies street performers turned to spray practice as the Greek aerosol paint firms settled production and someone could easily get spray cans in reasonable prices at the market.

The classic graffiti made its appearance in the streets of Athens during the eighties. Performers initially followed the techniques and the conventions of the early generation American graffiti writers, but interacting slowly with international trends and using various aesthetic forms of representation with the collaboration of fine art graduates they initialized a great number of hybrid techniques and combinations (wildstyle sketch, photo-realistic, fat cap tagging, stencil, comic-cartoon, neo-classic Greek, sticker, etc). Although the use of stencil reproduction technique in unauthorized urban graphics is quite old 6 its diffusion at the streets of Athens exploded after the year 2000. Since now a great number of books have been published concerning mostly illustrations of Greek graffiti, stencil and slogans by [START_REF] Iosifidis | Graffiti in Greece[END_REF][START_REF] Iosifidis | Graffiti in Greece 2[END_REF], [START_REF] Andriotakis | Σχέδια πόλης. Ahens: Nefeli[END_REF], [START_REF] Menegos | Το Street Art στην Αθήνα[END_REF], [START_REF] Peponis | Οι τοίχοι ανήκουν στο πλήθος[END_REF], [START_REF] Theodosis | Τοιχοδρομίες το STREET ART στην Αθήνα 1[END_REF], [START_REF] Theodosis | Stencil in Athens, Τοιχοδρομίες 2 Athens: Oxi[END_REF], [START_REF] Pagalos | Η ιστορία των graffiti στην Ελλάδα 1984-1994[END_REF] Avramidis and Tsilimpounidi (2016) and so on.

The content of unauthorized graphics that 'embellish' the city of Athens over the last two decades roughly includes signatures (tagging), socio-political comments, football 'ultras' skirmish-talk, classic graffiti themes, street art creations, individual spontaneous personal citations and so on. Direct socio-political critical comments include all written remarks on governmental policies referring often to Greek economy, the crisis, the Greek foreign affairs, the state authoritarianism, human rights, immigration, gender and race equality, gender identities, religion, etc. Football 'ultras' are regularly using obscene words to insult the rival teams and as spontaneous personal citations can be considered all the existential, humorous and sometimes sexist commentaries noted by individuals. Concerning the form of wall drawings we come across aesthetic works that can be either part of the hip hop culture graffiti or hybrids of all the other types that we have described above. Thus we can bump into political, religious, existential and many other 5 The visual code of the street slogans is not in use anymore as most of the political parties apart from the left and the extremists have abandoned this practice. The socio-political slogans that are made by the counter-globalisation movements and all other radical new social movements' activists today use the full range of colours (although, basically black and red) without the strict political meaning that once those colours connoted. 6 A primordial form of unauthorised stencil graphics that were practiced with paintbrushes can be traced in the late thirties during the Spanish Civil War and in the Italian fascism. Punk groups also used spray stencil reproduction techniques to disseminate anti-establishment slogans in the seventies. The mixing of political messages with the band names on the walls or the t-shirts was actually a part of the punk culture. The Crass since 1978 initiated great stencil anti-establishment campaigns at the London underground stations in such an extent that later on, with the arrival of the information age a stencil type font for text editors was named after the band's name. During the eighties in Paris, graffiti performer Blek le Rat was often using the stencil technique and so he has been characterized as the father of stencil graffiti [START_REF] Manco | History of Stencil Graffiti Stencil Graffiti[END_REF][START_REF] King | Blek le Rat: Getting through the walls[END_REF][START_REF] Berger | The story of Crass London[END_REF]. combinations of aesthetic designs. Undoubtedly wall drawings usually demand artistic skills and knowledge of design techniques. Tagging 7 on the other hand, which is the most common form of unauthorized graphics, usually comes in close relation to graffiti and hip hop culture involving just signing to mark the environment with the performer's identity. The actual purpose of tagging is to 'encroach by signature' as many territories as possible, revealing in this way a kind of détournement 8 performance concerning advertising and the legal practices of copywriting and ownership. While recouperation 9 of the graffiti culture in Greece had initiated since the beginning of the nineties by the mass media and the commercial mainstream fashion, in 1998 the Hellenic American Union organized the Thissio Festival which hosted 'stage-names' from all over the world (SEEN, CES, LOMIT, DAIM etc) promoting graffiti as a social festivity. Additionally other events such as a graffiti project on public transports that was organized by the Goethe Institute of Athens in February of 2001 or the establishment of the Crape Dien 10 group as a 'persona ficta' in 2002 to arrange conventions, educational seminaries and so on, drag graffiti to get ingested by the very socio-economic structures which it sought to challenge. Accordingly, unauthorized graphics begun to consort with the art establishment and the cultural industry, if we consider that some years earlier the Greek society confronted graffiti as a pure underground activity.

Initially, during the period before the Olympic Games (2002)(2003)(2004) there was a massive graffiti removal from the urban environment of Athens due to the coming event that would attract thousands of tourists. So, there was an exaggerated state opposition against any kind of outdoor unauthorized graphical expressions. However, paradoxically in 2004 the state established the Festival of graffiti in Chromopolis as part of the celebrations for the 'Cultural Olympiad' with the cooperation of Crape Dien group. Sixteen international 'stage-names' were officially invited to Greece, to work on public walls and in this respect to limit a genuine praxis of free social protest into a promotional practice of a popular celebration perpetuating the stability of the state.

The Greek crisis that initiated in 2009 and all the austerity measures that followed caused dramatic shifts to the Greek public attitudes and activities. In April 2017 Greece recorded the highest unemployment rate (23.2%) 11 from all other countries 7 We refer in particular on tagging because although it is considered to be a part of the American graffiti scene, curving initials, names and dates is not something new. It is interesting to note here, that for centuries most reachable parts of the ancient Greek temples marbles were often covered by the names of the foreign tourists and visitors. Even Lord Byron the British Romantic poet of the 18 th century had carved his name among others in one of the marble of Poseidon temple at Sounio that is still visible today. Unfortunately over seventy per cent of the unauthorised outdoor graphics in Athens is tagging with no direct and clear meaning. 8 Détournement can be regarded as a mode of guerrilla communication that was animated by the Letterists International in the 1950s and then used also by the Situationists International aiming to turn expressions and practices of the capitalist system against itself [START_REF] Debord | A user's guide to détournement[END_REF]). 9 The Situationists International regarded recuperation as the general process that integrates subversion and any conception opposed to the 'spectacle' into the general context of capitalism. It neutralizes radical protests and resistance not by conflict but by its commodification and circulation in the society of the spectacle (Knabb, 1981). 10 Carpe Diem: Chromopolis -Greece 2002, Art Crimes The Writing on the Wall, Accessed: 16 June 2017 11 Unemployment statistics, Eurostat statistics explained, Eurostat, Accessed 13 June 2017 of the European Union while according to Bloomberg's misery index12 the country held the top fourth position globally. Young people in particular have been affected greatly by the long-term unemployment. As more and more people became jobless and impoverished a great number of protests, strikes, demonstrations and deeds of civil disobedience come to be activities of everyday life.

Recently, several interesting studies examined the impact of the economic crisis on the Greek society and its further complications in social life (Simiti, 2015a[START_REF] Simiti | Social need'or'choice? Greek civil society during the economic crisis[END_REF][START_REF] Sotirakopoulos | Direct Democracy now!: The Greek indignados and the present cycle of struggles[END_REF][START_REF] Madden | From Athens to Occupy and back. City: analysis of urban trends, culture, theory, policy[END_REF][START_REF] Makridis | Οι Αγανακτισμένοι: ένα κίνημα που συγκλόνισε την Ελλάδα το καλοκαίρι του[END_REF][START_REF] Kornetis | No More Heroes? Rejection and Reverberation of the Past in the 2008 Events in Greece[END_REF]. Additionally, some other articles related to the subject have analysed urban expressions and aspects of social discontent as they were exposed on the walls of the Greek cities [START_REF] Triantafyllou | Increased suicidality amid economic crisis in Greece[END_REF][START_REF] Tsilimpounidi | Painting human rights: Mapping street art in Athens[END_REF][START_REF] Zaimakis | Welcome to the civilization of fear: on political graffiti heterotopias in Greece in times of crisis[END_REF][START_REF] Avramidis | Reading an Instance of Contemporary Urban Iconoclash: A Design Report from Athens[END_REF][START_REF] Alexandrakis | INDIRECT ACTIVISM: Graffiti and Political Possibility in Athens, Greece[END_REF][START_REF] Stampoulidis | Rethinking Athens as Text: The Linguistic Context of Athenian Graffiti during the Crisis[END_REF].

PSYCHOGEOGRAPHIC INQUIRY

The exact geographic location and the position of the unauthorized outdoor graphics are two crucial factors that one must take into account in order to evaluate their impact on the population of Athens. 'Psychogeography' that according to the Debord investigates 'the precise laws and specific effects of the geographical environment, consciously organized or not, on the emotions and behaviour of individuals' (Engel-Di Mauro, 2008:23) can be an instrument of great value for our study. In this respect, for a wider understanding of the situation concerning alternative outdoor graphics of Athens we decided to perform a 'dérive' and then sketch a 'psychogeographical map' (picture 1) to indicate schematically the 'unities of ambiance' and the density of the exposure to those visual messages embedded in the urban environment. Finally, using a simple semiotic approach we attempted to decode visual representations and to clarify the reasoning of the performers.

'Dérive' is considered to be one of the most significant practises of the Situationists. It is actually a drifting technique, a quick walk through varied urban ambiances in a state of mind that requires an attitude withdrawn from daily routines. Throughout 'dérive' participants must let themselves free to be attracted by the sights and the affinities of the terrain, forgetting all aspects of everyday life or any usual motives for movement and action. 'From a dérive point of view cities have psychogeographical contours, with constant currents, fixed points and vortexes that strongly discourage entry into or exit from certain zones' [START_REF] Debord | Theory of the Dérive[END_REF].

The topography of our 'dérive' covered the greater centre of Athens and as the point of departure was selected 'Syntagma' square (a in picture 1) which is the central square of Athens. First we begin to move following a crooked line course, drifting through 'Omonoia' square (b in picture 1), 'Monastiraki' district (c in picture 1), 'Psiri' district (d in picture 1), 'Keramikos' district (e in picture 1), 'Kolonaki' district (f in picture 1), 'Exarcheia' district (g in picture 1) and finally escaped from the concentric zone through '28th Oktovriou' street moving on to the 'Patissia' district (h in picture 1).

Following the lines of our passage we sketched a map that represented the unities of ambiance concerning the analogy of the senses and the emotions that came out related to the interaction of the outdoor graphics and the environment.

Picture 1 -A psychogeographical map of Athens

'Syntagma' square is the central square of the city located in front of the Greek Parliament where most of the protests take place. Despite the fact that it gets rapidly restored and cleaned up after the protests, there are always slogan remains on the walls, marked with permanent ink, capable of provoking sharp emotional reactions. In the surrounding high streets of 'Filellinon', 'Mitropoleos', 'Ermou' and 'Stadiou', emotions increased dramatically as the density of the graphics grows. This area contains merged all forms of unauthorized outdoor graphics: tagging, political quotes ranging from gay rights to political crisis protests, stencils of any kind, football teams emblazoning and artistic graffiti. Apart the numerous graffiti performances a great variety of assorted stencil and free hand spray writing advanced in front of our eyes articulating phrases such as 'Lesbians, fags, priestesses of shame, we are proudly the shame of the nation', 'zona queer feminista', 'religion stinks patriarchy', 'freedom for all that live in cells and cages', 'solidarity with the resistance and self-organization of the Kurds', 'stop all deportations', 'I am tortured', 'total opposition to the structures of culture', 'their own wars, our own dead, the polytechnic school lives, Americans go home', 'on our way home we want to be free, not brave', 'you tube, indignant brainwashing method', 'immigration is not a crime', 'rapists is not a special race, they are ordinary men' 'minister of Unemployment and Social Insecurity', and so on. The sequence of expensive jewellery stores, four star hotels, luxury restaurants and bookstores next to closed or abandoned shops covered by unauthorised graphics evokes a negative mood to the spectator that renders the city centre an atmosphere of frustration. Moving towards 'Stadiou' street we arrived to 'Omonoia' square which is the heart of the city. Nowadays, this square which was always the centre of commerce and transportations has been transformed to a pure multicultural zone and a meeting point for thousands of people. This place is full of vendors, dealers, immigrants, tourists, refugees, businessmen, pocket-pickers, junkies, homeless, rom, retired and so on. Although 'Omonoia' square can be considered as the actual 'plaques tournante' of Athens, that is a point from where someone can take many different directions to various unities of ambience, the climate of frustration remained the same as before and got even worst as the market is poor, common and plain including drifters and other people on the margins of society.

By strolling through 'Monastiraki', 'Psiri' and 'Keramikos' (Gazi) districts we realized that the walls are covered up by a great mixture of all kinds of graphics. However moving around all those areas it is difficult to determine precisely when the state of mind provoked by a peculiar neighborhood gives way for another as they share a 'unity of ambience'. All those places are meeting points for the youth and attract dozens of people especially on the weekend nights, so they actually share a kind of 'mainstream' cultural ambience. There is a large variety of arrangements such as the bazaar of 'Monastiraki', fashion shops, bars, cafes, pubs, clubs, museums, theatres and restaurants offering diverse types of divertissement. Apparently, all those places of leisure activities in combination to the unauthorized expressions on the walls orchestrate a different ambience for the senses and the thoughts of the passengers in comparison to the ones that we investigated before. Here we came across many street art performances, graffiti and stylish slogan expressions such as 'Peas ', 'PANIK-MODA', 'same', 'NETWORK ARTISTIC', 'CINE•SLIM', 'upset', 'love is', 'jumbo', 'music kiosk', 'yo', 'I am tortured', 'wake up', 'riot', 'DEATH OR GLORY', 'punks', 'viners', 'Sabotage on the machines of progress', 'Room', 'free pussy riot', 'memorandum hey!', 'don't be my enemy', 'true blue', 'we did it! run slow united kingdom', 'with pride, the shame of the nation', 'I'm distracting, do you remember?', 'old clown wanted', 'out', 'slaves hit kings' and so on. Certainly, some of the unauthorized outdoor graphics of the area reflect also strong contentious political participation (concerning gender-gay rights, immigrant and crisis issues, etc) however they are implanted to the general commercial environment where it is difficult to distinguish the illegal from the commissioned graffiti. In this area most of the commercial establishments have started using the same aesthetic tactics and forms of expression as shop fronts, sometimes reproducing even the same social and political messages for other reasons much different from the initial objections of the radical performers. Obviously the purpose of those graphs is not to support social struggle against the crisis or to give voice to 'oppressed and dominated' members of the society but to attract customers, to sell products or at least to decorate and make 'fashionable' art. In this sense alternative communication is blocked towards commodification and recuperation, bringing radical debate into the same context together with other practices such as commodities promotion.

Moving all the way up again to 'Kolonaki' district which is located on the southern side of 'Lycabettus' hill, spontaneous emotions started to arise again reacting directly in response to the visuals of the environment. 'Kolonaki' is a rich and expensive neighbourhood that used to quarter a variety of luxury boutiques from the most prestigious labels in haute couture, perfumery and jewellery. After the crisis a great number of shops closed down altering this district which once had a wealthy and cosmopolitan atmosphere to a fragmented, incoherent and discontinuous terrain. Buildings that used to keep luxury shops are now abandoned and turned over to ruins. Most of them are sealed-off with wooden timbers, covered by bill posters and smudged graphics, standing next to the remaining fashion houses and art galleries. Unauthorized outdoor graphics such as stencils and free hand spray writings with pure contentious political comments (anti-crisis slogans, immigrant issues, etc) such as 'mother have you got the tuition fees?', 'militant anti-fascism, my baby', 'no tolerance for the industrial development', 'struggle for the complete freedom of all earth animals', 'revolution', 'I am tortured', 'out of the European Union -abolition of all memorandums and implementing laws' and so on, have a direct impact on the viewer. Our perception regarding the particular district's atmosphere recalled the emotional states that we had when we were in 'Syntagma' and 'Omonoia' squares supplemented with moods of disappointment, depression and upset. Obviously those three areas share the same 'unity of ambiance' predominated by symbolisms that entail frustrating social associations to economic decline, bankruptcy and social suffering.

Next to 'Kolonaki' stands 'Exarcheia' district which is the centre of political activism. 'Exarcheia' is by tradition a student area. It is located behind the old building of the 'National Technical University of Athens' which played a significant role in the students' movement of 1973 against the colonels junta. 'Exarcheia' district is a highlypopulated zone and very dense concerning unauthorized outdoor graphics. It is famous as the centre of the Greek anti-establishment activists and new social movements supporters. The 'Squats' movement in Athens actually started from this area in 1981 with 'Valtetsiou 42' squat and in 1985 with 'Harilaou Trikoupi 91' squat. Still there are a couple of active squats in the zone. It is also a meeting point for the alternative culture youths and attracts dozens of people especially on the weekend nights. 'Exarcheia' actually is the Mecca of unauthorized outdoor graphics accommodating graffiti, street art, stencils, tagging, football slogans and political quotes of anti-authoritarian, antiestablishment, gay and immigrant rights comments, and so on. Here we get miscellaneous impressive radical quotes such as 'No tolerance in the meat industry', 'I am no one', 'zona queer feminista ', 'dear capitalism, it's not you, it's me. Just kidding, it's you. It's over.' 'Barack, Oh Mama!!!', 'wild spice', 'dedicated to the poor and the homeless here and all around the globe', 'eat meat is fascism', 'stop all deportations', 'pigs sexists', 'feminists', 'I am tortured', 'fight like a girl', 'chaos riots' 'α city that burns… … a flower that blossoms', and so on. In fact, it is very difficult to find uncovered walls in this area. Everything is dynamically smudged and recreated to honour active participation and objection against authoritarianism. There is a tone of explosion in the atmosphere that follows the colours blast on the walls. Drawings and writings of varying colours and shapes sometimes covering the walls from one end to the other, provoked to our senses powerful emotional reactions. All these sensations associated with anger, hope and rebellion can strike the mind like a high voltage sock that may give potentialities for 'situation-making' and mobilizing social activism.

Finally we escaped the central orbit of our stroll moving on through the 'psychogeographic slope' of '28th Oktovriou' street. It is also difficult to determine when the atmosphere actually changed when we entered to those neighbourhoods, however the density and the pugnacity of the graphics faded gradually as we moved away from the centre. 'Patissia' district that during the sixties represented the ideal neighbourhood of middle class, today consists one of the most polluted, poor and highly concentrated ethnic mixed zones. Walking all the way through '28th Oktovriou' street we encounter abandoned buildings that used to keep supermarkets covered with bill posters and unauthorized graphics. The demographics of the district were changing as we moved north to the broadly inhabited immigrant zone. However, while in the midst of our course approximating 'Amerikis' square, the transformation of the ambiance was completed, advancing original sensations that reflected the specific region's atmosphere. Poverty, deprivation, old buildings with high population density and deficits in the public infrastructures were clearly the visible motifs that gave the entire picture. There was an inter-flux of pessimistic and despair impressions asserted on a multicultural 'mise en scène'. A variety of unauthorized outdoor graphics mostly free hand spray writings and stencil seem to reflect this specific region's spirit. There we came across quotes such as 'papers to the immigrants', 'kick the racists', 'the rebels are right from Piraeus to Edomeni', 'what a stinky society', 'Afro" 'wheels, bag, and hit the fascists', 'beat the nazis, smash fascism' and so on.

DECIPHERING THE PULSE OF THE CITY

Beyond any doubt unauthorized outdoor graphics are always in direct interaction with the urban environment. They produce reasonable social meanings and they might raise serious public discourse if they are interpreted by the scholars and the community inside their social context. Most of them are playful and funny producing surprise, questioning and agitation to the viewer, however many others are considered pure gibberish and devoid of meaning for the non-recruited. In any case, verbal or pictorial, the outdoor graphics are stated usually in brief and serve as vehicles of mental schemata that represent respectively ideologies, socio-political struggles, football 'ultras' disputes, names and nicknames etc. The modality and the structure of the texts follow the formal conventions of writing and drawing, however any other code of visual representation can be used since radical media act as dynamic laboratories of intertextuality, experimentation and innovation. In this sense 'encoding' and 'decoding' texts that concern social discourses and problems of everyday life in the local community is a very interesting engagement that can provide useful information about the vitality and the interaction among the local alternative media sign systems as part of the 'semiosphere' [START_REF] Lotman | Universe of the mind: a semiotic theory of culture[END_REF].

In order to present a complete picture of the situation we selected and analysed three clean-cut and widespread texts from those places that we visited. We choose to investigate typical simple statements in written language (slogans), oversimplified occasionally in order to go for a plain analysis. One of the most emblematic expressions that can easily stand as a synopsis for the entire atmosphere of the city can be spotted to an existential slogan that we first confronted in a heaven spot 13 upon a blind wall at 'Stadiou' street: 'I am tortured '[βασανίζομαι] (picture 2). 13 The term heaven spot in the vocabulary of the street performers means unauthorised outdoor graphics located in highly dangerous positions or areas (rooftops, high deck walls, freeway signs etc).

Picture 2 -Stadiou street: 'I am tortured…' [βασανίζομαι…]

This statement is written in Greek 'childish calligraphy' and someone can see it all over Athens in many sizes, in 'hard-to-reach' places, sometimes covering entire walls or in quite small dimensions, inside trains, trams, buses, etc. There are many urban legends concerning this statement. Some say that the slogan was first written by a brokenhearted woman because her lover left her and then it was adopted by all the oppressed people that suffer by the economic crisis, others say that it was a public servant that first wrote it after his salary reduction, some others believe that it is actually the tagging of a graffiti crew that is named after this verb [START_REF] Dimitriou | Βασανίζομαι-Λάθως. BHMagazino[END_REF]. In any case this shared slogan, repeated over and over again on the walls, the rooftops and the street furniture is in itself a characteristic sign that signifies the misfortune, the grief and the everyday struggle of all the people that live in Greece. It communicates a synecdoche that inductively links the part to the whole. 'What is happening to me is happening to all', the text provides an interplay between personal and collective identities. It can be regarded as an emblem of the collective suffering, it is a symbol constructed to inspire social similarity and unity. Certainly in times of crisis symbols like this can generate a sense of shared 'belonging' that can motivate involvement to social movements and community protests. Additionally, we can assume that the skilfully handwritten childish fonts connote people's naivety and innocence regarding the causes of the economic collapse and the crisis. With reference to our everyday experience the statement is far from being a false information, fabrication or deception of a minority group. Without any question it appears realistic and empathetic for most of the local viewers. There are no gender, class or racial associations in the message and in this sense the writers address directly to all the people that live in Athens and generally in Greece, if we consider the interaction that this peculiar expression may have through the social media platforms. last decades, actual gender equality has not been achieved yet and people still face discriminations and hostilities. Additionally sexist language, insults and hate speech are not so rare in the public discourses and sometimes they even originate from the part of the establishment (extreme right political parties, orthodox church, etc). One more symbolic expression often seen in the streets of Athens that challenges the heteronormativity of public space is the phrase 'zona queer feminista' (picture 4). You can get it in many modes as stencil, free hand spray writing or drafted with a marker, usually in English or Italian. By examining the first level of signification the text is directly and architextually 16 [START_REF] Genette | Paratexts: Thresholds of Interpretation[END_REF] addressed at the viewer as an orientation sign, as a territorial indicator following the logic of the civic public signs. Yet, in a second signification level it recalls gender identity politics. As an unauthorised outdoor graphic the messages works out of the dominant codes and materials of the usual municipal regulatory zone signs that are made in aluminium metal labels by the state, determining the name of the territory or the type of zone (eg residential, industrial) where certain uses of the land are permitted and others are prohibited.

Picture 4 -Syntagma sq 'zona queer feminista'

16 Architextuality refers to a relation of inclusion that links a text to 'various kinds of discourse of which it is a representative' (Genette, 1997: xix). In this sense architextuality is about the designation of a text as the part of a general text genre. It deals with the comprehension of the reader in the relation between a text and all the texts of the same general kind. In this case the text is linked morphologically and in relation to its content on a first semiotic level with the greater category of municipal signs.

It works partly as a welcome sign to inform the citizens and the tourists where they are and about the principles of this territory. In the other hand it could also work as warning sign that indicates a hazard ahead for those opposed to gender equality and LGBT rights. 'Zoning' has been often used by the state as a strategic plan to preserve the 'character' of a community or to govern the people, however here we have a détournement, a rerouting of the way the traditional urban topographic code works. The activists perform a hijack of the discourse with the support of alternative media as they take the leading role of the communication process by contextualizing the word 'zone ' [zona] and in this way they themselves determine urban space instead of the state.

CONCLUSIONS

Alternative media are very important for the effective communication of people who are normally excluded from mainstream media production. Unauthorized outdoor graphics as radical media challenge the existing power structures and the Establishment and in this sense they project political discourses. Modern Greek history can be rendered and promptly documented if someone attempts to observe closely the writings and the brief slogans on the walls that lay in the streets of Athens in the background of the old photographs.

It seems that by drifting through the central zones of Athens, guided by the attraction of various outdoor graphics that are embedded in the urban environment we came to realise that certain 'unities of ambiance' turned out to decipher the 'pulse of the city' through different perspectives. In other words, some zones of the town centre share the same endemic powerful atmosphere and transfuse the specific mentality of the inhabitants at the grassroots level. The most prevalent 'psychogeographical' elements common to the greater central area that includes 'Syntagma' square, the high streets and 'Omonoia' square as well as 'Kolonaki' district, echoed clear sentiments of exhaustion, disappointment, popular distrust for the state and eventually communal rage. The notions that came spontaneously to our minds concerning our encounter to outdoor graphics at the youth shopping and nightlife districts like 'Monastiraki', 'Psiri' and 'Keramikos' (Gazi) were associated with a multiple mixture of ideas including teenage rebellion, groovy discontent, self-styled anarchism [START_REF] Bookchin | Social anarchism or lifestyle anarchism: an unbridgeable chasm Edinburgh[END_REF], riot aestheticization, commodification of activism and finally recuperation. On the other hand 'Exarchia' district that stands like a cultural anti-establishment ghetto between all the other central areas vibrated and reflected all the current collective protest tendencies. Further, by entering the inner city of 'Patissia' poverty, alienation and cultural hybridity produced various, strange and depressing sentiments.

The reluctance of mainstream media to defend people against austerity measures and to promote in a honest way the 'human rights' as universal laws has raised radical media representational systems to give voices for those who have been silenced. All those radical graphics that we encounter apart producing effects of pessimistic and rebellious sentiments associated with the debt crisis and the austerity meters in Greece, they also charged certain strong magnetic fields of optimism reflecting the willingness of the people to progress, incorporate and coexist for arriving to more advanced cosmopolitan communities of plural citizenships. In periods of crisis the one dimensional nature of the mainstream media and the 'society of the spectacle' can be easily realised by the people and challenged; thus understanding alternative media power and its potential challenges to the establishment can engage civil society to social struggles developing critical ideas against any tyranny towards a more harmonious and optimistic future.

We will be using the term text with the broad sense to refer to any meaning which can be deciphered as a system of signs.

According to Innis the media that emphasize time are durable in character such as parchment, clay and stone in contrast the media that emphasize space which are apt to be less durable and light in character(Innis, 1950:7).

Saravaia, C. and Jamrisko M. These Economies Are Getting More Miserable This Year, Bloomberg LP, March 3, 2017, Accessed:

June 2017

International organisation for migration, Greece, Retrieved June 20, 2017 https://www.iom.int/countries/greece

The Athens antifa community is a collaboration of anti-fascist communities that live and act in Athens as a part of the international struggle. According to antifa web page they are against all fascism (whether carries the swastika or not) and have nothing to do with any party, the state or the media (αστερισμός).

Another old and emblematic expression that is repeated over and over again on the walls, the rooftops and the street furniture yells: 'papers to the immigrants' [χαρτιά στους μετανάστες] (picture 3). The massive immigration inflow had already started in Greece since the late eighties. This resulted to the accumulation of many undocumented immigrants that were used for many years as a source for low-cost unregistered workers and as a reserve labour force. Nowadays, according the European Agency for the Management of Operational Cooperation at the External Borders of the Member States of the European Union (Frontex), Greece is the major gateway of undocumented immigrants and asylum seekers from Africa and Asia 14 . This statement is written in Greek block capitals next to a punch drawing and is usually signed by antifa community 15 . Within the frameworks of this expression lays an entire system of social relations and social values concerning the human rights protest. It is a calling for the community's attention concerning values such as equality before the law, freedom of movement, right to life and work, religious tolerance and so on, for all the immigrants. Besides, the signing of text and the drawing are directly linked to ideological standpoints, beliefs and appeals that support the anti-racist, anti-fascist, antiimperialist protests and in general all the global justice movements.

Picture 3 -28th Oktovriou' street 'papers to the immigrants' [χαρτιά στους μετανάστες]

There is an intensive frequency in discourses of the outdoor unauthorised graphics concerning gender equality and the 'lesbian, gay, bisexual and transgender' (LGBT) movements. Although in Greece the law has progressed significantly over the


Isa Costantini

Patryk Filipiak

Kostiantyn Maksymenko

Samuel Deslauriers-Gauthier

Rachid Deriche

Rachid De- Riche

Fmri Deconvolution

fMRI Deconvolution via Temporal Regularization using a LASSO model and the LARS algorithm

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

I. INTRODUCTION

Deconvolution methods are used to denoise the blood oxygen level-dependent (BOLD) response, the signal that forms the basis of functional MRI (fMRI) [START_REF] Karahanolu | Total activation: fMRI deconvolution through spatiotemporal regularization[END_REF]. In this work we propose a temporal regularized deconvolution of BOLD fMRI signal with the least absolute shrinkage and selection operator (LASSO) model, solved using the Least-Angle Regression (LARS) algorithm.

II. METHODS

We implemented the deconvolution exploiting the sparsity of the innovation signal s(t) [START_REF] Farouj | Regularized spatiotemporal deconvolution of fMRI data using gray-matter constrained total variation[END_REF], and we built a LASSO model:

where n is the signal length, H represents the hemodynamic response function [START_REF] Khalidov | Activelets: Wavelets for sparse representation of hemodynamic responses[END_REF] and λ is the regularization parameter.

is the exponential accumulation function given by: such that the activity-inducing signal u(t) = * s(t), normalized by the factor S. We chose α = 0.75 experimentally within the range [0,[START_REF] Khalidov | Activelets: Wavelets for sparse representation of hemodynamic responses[END_REF]. We minimized the objective function using LARS [START_REF] Efron | Least angle regression[END_REF], that outputs all λs of interest and their associated solutions. We used the L-curve to estimate the λ * corresponding to the optimal solution . Then, as in [START_REF] Farouj | Regularized spatiotemporal deconvolution of fMRI data using gray-matter constrained total variation[END_REF], we scaled a 3D activation map computed with FSL in the range [0, 3], with a 2-mm isotropic resolution (Fig. 1b).

We multiplied it by two block-type signals of 200s, u(t): A) with 4 onsets, and B) with one long onset. We corrupted the signals with model and block-type noise, we convolved them with H and we added Gaussian noise thus simulating the fMRI time series y(t). We solved the inverse problem and we recovered

(t) = * (t) as described above. Finally, to evaluate the results, we computed the root of the mean square errors (MSE) and standard deviation (STD) between u(t) and u * (t) averaged among the voxels belonging to the grey matter masked activation. We compared our results with those obtained with the temporal regularization implemented in the Total Activation (TA) toolbox [START_REF] Karahanolu | Total activation: fMRI deconvolution through spatiotemporal regularization[END_REF]. We tested the above procedure on the preprocessed task-fMRI image of one subject taken from the Human Connectome Project (HCP) database [START_REF] Van Essen | The WU-Minn HCP[END_REF]. The reconstructed (t) were averaged in a ROI of 6 × 6 × 6 mm 3 centered in the Brodmann Area 4p (MNI coordinates: 62, -14, 30).

III. RESULTS

Table I shows that the MSEs±STDs change for different peak-SNRs (pSNRs) and that they are lower than the ones obtained using the TA toolbox. Fig. 1

.a and c show examples of the reconstructed activity inducing signal using our approach ( ) and the approach in [1] (

). IV. DISCUSSION & CONCLUSION Our findings show that the joint use of LARS and the L-curve for solving our optimization problem allowed us to choose the optimal λ * and related solution among all those outputted by the algorithm. Thus, we decreased the computation time and avoided a need of defining λs a priori, allowing to improve brain dynamics recovery in future clinical application.

fMRI Deconvolution via Temporal Regularization using a LASSO model and the LARS algorithm

Fig. 1 :

 1 Fig. 1: (a) Reconstructed signal u* obtained with our approach (red) and the TA (blue) superimposed on the activation (black) and fMRI signal (green). The plots are related to different activations and pSNRs: activation A, pSNR = 5.17 dB (left); activation B, pSNR = 5.12 dB (right). (b) Activation map. (c) Results of HCP data. Same legend of panel (a); the grey areas represent the duration of the tongue movements.

TABLE I .

 I SUMMARY OF ROOTED MSES AND STDS

	Activation		A			B
	pSNR [dB]	5.17	4	3.98	7.64	5.94	5.12
	OUR	RMSE	0.11	0.22	0.18	0.05	0.19	0.14
	α = 0.75	STD	0.13	0.16	0.14	0.05	0.11	0.08
	TA	RMSE STD	0.24 0.31	0.29 0.32	0.3 0.33	0.19 0.23	0.24 0.24	0.25 0.26


Isa Costantini
email: isa.costantini@inria.fr

Patryk Filipiak

Kostiantyn Maksymenko

Samuel Deslauriers-Gauthier

Rachid Deriche

Rachid De- Riche

L1-Norm

L1-Norm Regularized Deconvolution of Functional MRI BOLD Signal

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Problem

Goal Our method

Recover brain activations and their dynamics without a-priori hypotheses.

Denoise the blood oxygen level dependent (BOLD) functional MRI (fMRI) response.

Temporal regularized deconvolution of the BOLD signal with the least absolute shrinkage and selection operator (LASSO) model, solved using the Least-Angle Regression (LARS) algorithm.

Abstract -Deconvolution methods are used to denoise the blood oxygen level-dependent (BOLD) response, the signal that forms the basis of functional MRI (fMRI). In this work we propose a novel approach based on a temporal regularized deconvolution of the BOLD fMRI signal with the least absolute shrinkage and selection operator (LASSO) model, solved using the angle regression algorithm (LARS). In this way we were able to recover the underlying neurons activations and their dynamics.

Regularization

We exploited the sparsity of the signal s(t) such that:

; λ: regularization parameter; n: signal length.

The joint use of the LARS algorithm and the L-curve allowed us to choose the optimal solution among all those outputted at once. We decreased the computation time and avoided a need of defining λ a priori.

Future works will involve also a spatial regularization.

We improved brain dynamics recovery for future clinical applications.

  signal u(t): activity-inducing signal x(t): activity-related signal ε b : block-type noise ε m : model random gaussian noise ε a : additive random gaussian noise * * activation map b) Activation A; pSNR = 5.17 dB c) Activation B; pSNR = 5.12 dB -Preprocessed HCP motor task-fMRI data. -The reconstructed u*(t) were averaged in a 6×6×6 mm 3 ROI centered in BA4p. -The gray areas represents the duration of the tongue movements.

This work has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC Advanced Grant agreement No 694665 : CoBCoM -Computational Brain Connectivity Mapping).

FSL tool Possum