for a comparison between Panksepp's Seeking System and Freud's definition of the drive.

Repression as the Condition for Consciousness

Ariane Bazan, Brussels, Belgium 1 abstract Solms makes a convincing case for the subcortical structures as conciousnessinducing instances and the audacious logical consequence, that the Freudian Id, therefore, is conscious, makes sense. However, in his understanding of this conscious Id, affect and drive are conceptually confused and a brain-based view of affect, drive and pleasure altogether is defended. My first aim is to stress the importance of understanding the drivethe vector between an internal body regulatory imbalance and an external body motor responseas an acquired link, for which the criterion is first given by the pleasure, produced by a release of tension when an internal body need is alleviated. Moreover, I question the representational nature of this primary subjective consciousness and I propose that the constitutive contribution of the neocortex to consciousness is not so much memory space, than it is the process of inhibitionor repressionwhich enables the distinction between a mental and a perceived object and consequent action-selection, and in the process of doing so generates representations and "solidifies" objects.

key-words: driveaffectpleasurerepressioninhibitionrepresentation

This paper has the great merit to put a range of empirical observations together and to point out the "obvious" (but nobody has done so before), that "cortical varieties of consciousness actually depend upon the integrity of subcortical structures, not the other way round" (p. 13). Moreover, it makes sense to me to understand these subcortical structures, and the consciousness they generate, as of an inherent drivenature and therefore all the more closer to the concept of the Freudian "Id".

My first aim is to defend a conceptual distinction between an affect and a drive (or "instinct"), in the Solms-Panksepp notion of the conscious "Id" while both concepts are often equated or conflated in this paper 2 . I understand that one of the pillars of the conceptual framework presented by Solms is [START_REF] Panksepp | Affective Neuroscience[END_REF] ground-breaking notion of affective neuroscience, implying that there are distinct subcortical brain circuits, which seem conserved over species and which, when activated, give rise to the behavioural expressions of the different affects and therefore, as the result of the feeling of these motor discharges, to the different emotions. [START_REF] Panksepp | Affective Neuroscience[END_REF] regards these emotional operating systems not as drives but as regulatory mechanisms emerging from the intrinsic potentials of the nervous system. Solms (p. 4) also considers the brain as the emergence site of affect: "Affect is an intrinsic property of the brain.", of the affect-as-the-drive: "They [the various instinctual motivational circuits] are intrinsic to the brain" and of the (un-)pleasure feelings: "Feelings of pleasure-unpleasure (…) are readily generated by stimulating a region of the ERTAS knows as periaqueductal grey.". This suggests an all-brain organisation for affect, drive and pleasure. Therefore, it is as if an organism comes to organise itself as an intentional entity as the result of a causal chain emerging from the brain, from its "intrinsic potentials", and, by consequence, eventually from the innate structure of the brain3 . Flexibility and learning are understood as mere ways to fine-tune the system to changing environments but the major impulse comes from the nervous system, be it from the subcortical and brain stem structures. Now, it is difficult to understand intentionality itself as emerging from the brain. My fundamental point is that we can not do away with the body as a site of originin contrast to a brain-based site of originif we want to end up with directed, oriented behaviour, i.e. with an intentional system. Going back to Freud's (1895) concept of the "experience of satisfaction" a possible chain of event might go as follows. The main regulatory systems (respiration, digestion, sudation, excretion, circulation, copulation etc.) are taken care of by the viscera of the internal body. Suppose that there is a depletion of nutrients in the tissues of the internal body; this lack is translated in an afferent stimulation, which is "achieved through a network of upper brainstem, diencephalic and basal forebrain 'arousal' structures (…) known (…) as the extended reticulo-thalamic activating system" (p.3). This arousal stimulation will probably set off the SEEKING system. Panksepp (1998: 194) indicates: "The speciestypical expressions of this system lead to foraging in some species and predatory stalking in others.". But even in animals, only in the case foraging or predator stalking leads to food coming in, will the depletion, from which the urge to act first emerged, get replenished. This replenishing is a release of tension, which Freud (1895) qualifies as "pleasure". In other words, the pleasure criterion is given by the (internal) bodynot by the brain. Only if the motor pattern chosen is successful will there be pleasure, a pleasure given by (the release of tension in) the body.

This pleasure has to be distinguished from another kind of gratification. The behaviour which has delivered this pleasure, because it has delivered this pleasure, will get tagged physiologically as a salient behaviour. This is what neuroscience tells us (e.g. [START_REF] Berridge | Liking' and 'wanting' food rewards: Brain substrates and roles in eating disorders[END_REF] but also what Freud (1905: 182) suggested: "This satisfaction must have been previously experienced in order to have left behind a need for its repetition; and we may expect that Nature will have made safe provisions so that this experience of satisfaction shall not be left to chance.". As a result, once this tagging happened, acting out the behaviour, delivers a gratification subserved by the dopamine circuitry 4 . Say that due to changed circumstances (e.g. captivity) some other motor pattern (e.g. pushing a button) leads to food coming in, than it is that motor pattern which will become gratifying. In other words, the link between the internal body's need status and the external body's behaviour pattern responding to that need, has to be physiologically registered, by the internal body's signal of pleasure when the need is effectively alleviated; even in animals, therefore, this link is acquired and not innate.

But there is more. In animals the "translation gap" between internal and external body is small: there is almost always immediate efficient adjustment between the internal regulatory systems and the external behaviours, which are even qualified as "associated peremptory" actions (p. 4). However, in humans, due to the large helplessness of the newborn, that translation gap becomes an unavoidable reality. For example, the kind of behaviour induced by the human SEEKING system in a newborn when activated by an internal body need signal, is far less specific than the complex stereotyped behaviour of newborn animals: when it comes to "seeking", the human baby will cry and wriggle. Nonetheless, this behaviour may be effective. Indeed, a mother may come along, hear the baby cry, interpret the behaviour and feed the baby. In the end, as the milk alleviates the hunger and thereby brings pleasure, the cry was an adequate act and gets physiologically tagged as such, i.e. the motor activity of crying and sucking become gratifying, which ensures that they will in the future be readily repeated when a new hunger signal arises. In other words, humans, far more than animals, need the internal body tissues based pleasure criterion to connect afferent brain stem stimulation with "associated" motor expression patterns, which are much less a-priori associated (as might confusingly be understood from e.g. p. 6 "[instincts] are intrinsic affective-motor stereotypes").

For these reasons, we can not do away with the body as a site of origin for the constitution of an organism, and eventually of a mental system. As the notion of "drive" supposes this bodily site of origin in its definition, while an affect may arise from the encounter with an external stimulus, it is important not to conflate affects and drives. It is important to remember that Freud (1915a) called the drive the vector between the biological and the mental.

Second, what kind of consciousness is generated by the subcortical structures? Solms indicates that in the Libet experiment the "primary subjective" or the "affective (volitional)" self actually initiates the movement and that it is only to the "representational 'declarative'" self that awareness of the movement comes with some delay. This makes sense, but I don't think that this primary subjective self is the self that generates the kind of consciousness which gives us the (illusory) idea of free will, and therefore, the Libet results remain: the awareness of having decided to move comes after the decision to move. What is more, e.g. [START_REF] Haggard | On the relation between brain potentials and the awareness of voluntary movements[END_REF] show that this awareness may come as the result of the decision to move, and more precisely, as the result of the movement selection, i.e. the inhibition of non-chosen alternatives.

disconnection between pleasure and gratification happens far more in a human than in animal life, due to the large "translation gap" between internal and external body, which induces a large variability in the range of possible adequate actions, many of them which may become later on in life inadequate, while still gratifying. This then may result in the typical suffering which is induced by the persistence of behaviours which the subjects themselves do no find pleasurable, i.e. it is one of the major causes of human distress.

Let's go back to the experience of satisfaction. Say the hungry baby cried and the mother fed him. The whole motor pathway leading to the effective sucking of the breast, the adequate act, gets linked to the hunger drive and becomes physiologically gratifying. Especially the image of the breast in the right angle for effective sucking becomes the wishful image, which serves as the reference for the motor search of the head movements. In first instance, as Solms keenly points out, whenever the hunger stimulus appears, it is that motor image that gets activated and there is a hallucinatory wish fulfilment with a release of the sucking movement. Indeed, in this stage one could say that "biologically valenced (…) objects of past experience are rendered conscious by dint of their 'incentive salience'" (p.15). I agree that this kind of consciousness, characterised by hallucination and acting-out, is played-out through neocortical activation aroused by drive-instigated subcortical activation and that it doesn't entail secondary process cognition. But I think that this "very primitive form" of desinhibited hallucinatory consciousness might not be representational and it might even be question to debate if this state then really qualifies as "conscious" if it is not representational5 . I propose, however, that the state we would readily qualify as conscious emerges, when no breast is present. In that case, releasing the sucking movement not only will not be effective, but will also lead to a loss of energy. The baby would be better off to stop sucking and start crying again. Therefore, it becomes crucial for the baby's survival to be able to distinguish a mental image from a perceived image of a breast. It is there where the ω neuronsthe motor neurons of perceptioncome in (see also footnote 6, p. 8). As soon as there is enough inhibitory weight of the maturing Ego6 , the ω neurons (e.g. oculomotor neurons) -and especially their "messages of discharge" or "indication of reality"7 will enable this distinction, because a movement of the eyes has radically more drastic effects on a perceived than on a mental image of a breast. At this stage, as the internal origin of the mental image is recognised, the sucking movement is withheld. We might say that the sucking action "is not hypercathected, remains thereafter in the Ucs." (Freud, 1915b: 202), that is, we have here a very basic form of repression (namely of the motor act of sucking)8 .

At the same time, if no breast is present, the neuroscientist Jeannerod (1994: 201) suggests that the neurons encoding the final configuration "(of the environment, of the body, of the moving segments, etc.) as they should arise at the end of the action (…) remain active until the requested configuration has been obtained. If the goal [of an action plan] were not reached, the sustained discharge would be interpreted centrally as a pure representational activity and give rise to mental imagery. ». In other words, the baby will still generate an internal image of the breast, but this image will be recognized as a mental image, and is thus no longer a hallucination. This means that it is truly inhibition of action, which generates representations. Moreover, what is called an "object" can only be what is assembled in these representations as a wishful action or a desired goal of that action (i.e. as an object of a drive, ultimately) 9 .

In other words still, the kind of consciousness we experience thanks to the contribution of the neocortex, is the kind of consciousness which we end up with after inhibition has made selection possible, stabilising both the selected and the inhibited actions/objects. Therefore, I don't think it is as much the passive presence of memory space which the cortex contributes to consciousness, as Solms suggests, but I propose that it is the active process of inhibition (or, in psychodynamic terms, of repression; see [START_REF] Bazan | On unconscious inhibition: Instanciating repression in the brain[END_REF][START_REF] Bazan | From sensorimotor inhibition to Freudian repression: insights from psychosis applied to neurosis[END_REF], which is the foundational, constitutive process which the cortex contributes to representational consciousness. And this kind of consciousness, to my view, is truly secondary process-consciousness. For example, the Swiss psychiatrists Saraga and Gasser (2002: 111) indicate that Freud underscored the importance of this inhibition as being the essence of the secondary process, which enables the development of thought itself, the "substitute of the hallucinatory wish fulfillment".

A last point on words and things. I disagree with Solms on understanding "wordpresentations" as re-representations of objects at a higher level in secondary process thinking. Freud (1891), with his model in On aphasia, intended in the first place to stress a certain equivalence between words and objects. Both words and object presentations are defined by the same type of characteristics, namely perceptual and motor characteristics for both. The perceptual characteristics for objects mostly cover the whole spectrum (vision, smell, taste, feeling, sound etc.), while for words the range is more restrained (the graphic image, the word sound). The motor characteristics of objects include the usual way we interact with them, while for words it includes the articulation movement for spoken word and the writing movement for written words. In other words, a word is in the first place an object like another and treated as another. The special faculty which emerges from language only emerges because of the fact that connections are made between specific object representations and specific word representations (the famous double link in his scheme) at a conscious level. But this linkingthe reference capacity of languageis structurally unstable, very much so in the unconscious (where the word presentation is loosely connected to the object presentation) but also consciously, due to language's structural ambiguity. So, even if in some cases word-presentations are rerepresentations of objects at a higher level, they always also are not, i.e. they can induce effects without any connection to their "corresponding" object-presentations 10 (such as in signifier-structured symptoms; [START_REF] Bazan | Des fantômes dans la voix. Une hypothèse neuropsychanalytique sur la structure de l'inconscient[END_REF]Bazan, 2011b). It is precisely because words can navigate on these two hierarchical levels, the primary and the secondary process, that they are effective in the talking cure and not only 9 When does an object become an object to a mental apparatus or a Freudian object presentation, as Solms points out? There is only one criterion possible from within the emerging mental system is: when it becomes a possible object of the drive. This is also what Solms says when he speaks of "objects of desire coming to mind" (p. 15). By trial and error, by learning, through interpretation from others, internal body need states get linked to a range of adequate actions, delivering the objects which can alleviate the depletion at the origin of the drive. This makes each adequate action and its object an entity. We usually think of objects as perceptual entities, while even in Freud's object presentation model, the motor modality, the usual way of motor interaction with that object, its "grasp", is present as an important constitutive component. Likewise, the neuroscientists Grabowski and colleagues (1998) and Grafton and colleagues (1997), propose that objects are encoded as the motor program which we have to mobilise to use these objects. In that sense, there is some neurophysiological equivalence between the adequate act and the adequate object of a drive. 10 For empirical evidence on this point see Villa et al. (2006).

because they are the instruments of rational, contextualized thought capable of representing relations.

To end with, three things with which Solms closes his paper and with which I wholeheartedly agree. First, I completely agree that "it is difficult to imagine how the neuroscience of the future can be anything but psychodynamic"11 . Second, when Solms says that "we are breaking through to a truly mental science" (p. 23), I completely adhere to this view (and I have defended elsewhere that this will be the logical result of the tremendous revolution in the neurosciences; Bazan, 2011a). Let me add, in the same line of thought, that I also adhere to his word choice of "mental solids" and that we are reminded that Freud (1900: 613) spoke about "psychic reality" and not about some metaphorical discursive construction for his understanding of the unconscious. And finally, of course I am encouraged to read that the final word is giving to the clinical expertise. As psychoanalysts, these last decennia, especially in the domain of neuro-psychoanalysis, we have been far too little proud and aware of our precious and unique clinical method. This lengthy, most of the time undirected, often times confusion and ambiguity-inducing therapeutic offer, is so much at the antipode of what has been valued in science, ànd in clinics, these last decennia that many of us have been readily willing to leave it or to undervalue itwhile it actually is the very core of our unique contribution. Villa, K.K., Shevrin, H., Snodgrass, M., Bazan, A., Brakel, L.A.W. (2006). Testing

Freud's hypothesis that word forms and word meanings are functionally distinct in the unconscious: Subliminal primary process cognition and its links to personality. Neuro-Psychoanalysis 8:117-138.

e.g. p. 6-7 "[Feud] no less than Panksepp, recognized that the basic emotions are innate mental organizations." This kind of statements is confusing in the context of this paper, since this might be true for the basic emotions (a motor pattern set off by a stimulation, internal or external; the link is innate or learned; what is innate is the activated pattern of reactions) but this seems to me fundamentally wrong when it comes to drives (which by definition is a vector linking an internal body need state to an external motor behaviour pattern; it is of crucial importance to see that the linking is not innate but acquired; see further).

Note that this distinction between the pleasure given by the consumption of something, the internal body was in need of, and the gratification or the incentive given by the motor activation of the behaviour pattern leading to this consumption, parallels[START_REF] Berridge | Liking' and 'wanting' food rewards: Brain substrates and roles in eating disorders[END_REF] distinction between "liking" and "wanting" (see also[START_REF] Shevrin | The psychoanalytic theory of drive in the light of recent neuroscience findings and theories[END_REF] and the Lacanian distinction between pleasure and jouissance(Lacan, 1959(Lacan, -1960; see alsoBazan et al., 2012; Bazan & Detandt, in press). Also note that the motor behaviour pattern may remain physiologically gratifying, because it is carved as such in the physiology of the subject, even when it no longer brings pleasure, due to changed circumstances. This

Is a hallucination a representation, or should we consider it as an activation or stimulation at the periphery of the mental apparatus, namely at its perceptual periphery, in the same way the acting-out is an activation at the motor periphery of the mental apparatus?

or of the Default Mode Network[START_REF] Carhart-Harris | Free-energy and Freud: An update[END_REF].

Elsewhere, we have defended an equivalence between the Freudian "indications of reality" and the "efference copies" of the modern neuroscientific models(Bazan, 2007a;[START_REF] Bazan | On unconscious inhibition: Instanciating repression in the brain[END_REF]; see also[START_REF] Shevrin | Why do we need to be conscious? A psychoanalytic answer[END_REF].

Indeed, the French psychoanalyst LeGuen (2001: 46) underscores that "what has to be inhibited in fact not the object, but truly the motor act, as a function".

"Psychoanalysis is the future of neurosciences" was also the closing sentence of my presentation at the Athens' International Neuropsychoanalysis Congress[START_REF] Bazan | From sensorimotor inhibition to Freudian repression: insights from psychosis applied to neurosis[END_REF].


SMOKING ADDICTION: THE SHIFT FROM HEAD TO HANDS: APPROACH BIAS TOWARDS SMOKING-RELATED CUES IN LOW-DEPENDENT VERSUS DEPENDENT SMOKERS

The dual process theory is central to several models of addiction, implying both an increase of stimulus salience and deficits in inhibitory control. Our major aim is to provide behavioral evidence for an approach bias tendency in smokers and more specifically during smoking cue exposure. The second aim is to examine whether this bias differs in low-dependent versus dependent smokers. Thirty-two smokers (17 low dependent and 15 dependent; cut-off FTND of 4) and 28 non-smokers performed a modified Go/NoGo task using tobaccorelated words and neutral words as stimuli. Smokers generally made more mistakes and tended to be faster for smoking-related cues specifically. Low dependents acknowledged more their dependency in declarative questionnaires while making more errors and being slower specifically on smoking cues; dependent smokers were less prone to indicate their addiction, but were faster and accurate when it came to picking the smoking cues. These results suggest that a shift has operated from a mental preoccupation with smoking in the low-dependent group, to smoking as a motor habit in our dependent group. This finding invites experts to rethink smoking addiction in the light of this crucial moment, namely, the shift "from head to hands".

Introduction

Tobacco smoking is one of the most common health-impairing behaviors, which seems to persist, despite the awareness of its negative consequences on health and intensive prevention and treatment efforts (Le [START_REF] Faou | Epidémiologie du tabac [Epidemiology of tobacco smoking][END_REF]. Indeed, tobacco seems to be the most addictive substance among addictive drugs (32% of users become dependent; Inserm, 2015) and a smoker dies, on average, 15 years earlier than a non-smoker (US Department of Health and Human Services, 2010).

On a cognitive level, addiction is generally considered as an imbalance between two systems, which are both (indirectly) mediated by dopaminergic systems and smoking addiction does not break the rule [START_REF] Bassareo | Modulation of feeding-induced activation of mesolimbic dopamine transmission by appetitive stimuli and its relation to motivational state[END_REF][START_REF] Pontieri | Intravenous cocaine, morphine, and amphetamine preferentially increase extracellular dopamine in the "shell" as compared with the "core" of the rat nucleus accumbens[END_REF][START_REF] Stacy | Implicit cognition and addiction: A tool for explaining paradoxical behavior[END_REF][START_REF] Tanda | Cannabinoid and heroin activation of mesolimbic dopamine transmission by a common μ1 opioid receptormechanism[END_REF]. Several models refer to this dual-process theory as a global explanation for addiction including its development, maintenance, and relapse [START_REF] Goldstein | Drug addiction and its underlying neurobiological basis: Neuroimaging evidence for the involvement of the frontal cortex[END_REF][START_REF] Kornreich | Conditional reasoning difficulties in polysubstance dependence patients[END_REF][START_REF] Kreusch | Response inhibition toward alcohol-related cues using an alcohol Go/NoGo task in problem and non-problem drinkers[END_REF][START_REF] Noël | The influence of alcohol ingestion on cognitive response inhibition and error processing[END_REF][START_REF] Robinson | The neural basis of drug craving: An incentive-sensitization theory of addiction[END_REF][START_REF] Wiers | Automatic and controlled processes and the development of addictive behaviors in adolescents: A review and a model[END_REF]. Indeed, among the strongest clinical evidence for addiction is both the reactivity towards addiction-related stimuli at the one hand, and the inability to refrain from their approach at the other. This perspective thus conceives addiction as mainly dependent on this double process, implying automatic bottom-up activities characterized (a) by an increase of the stimulus salience which is going "to grasp" the attention in an involuntary way (once this system is sensitized, it leads to repeated behaviors towards the object of consumption) and (b) by a lack of resources for the executive inhibition of a dominant drug behavioral response. they are hard to disentangle: disinhibition towards salient cues can either be due to inhibition impairment or to an approach bias related to the concept of "wanting". "Wanting" is defined as the amount of energy an organism is ready to invest in order to obtain a reward and reflects the activation degree of the dopaminergic systems mediating the addictive behavior. Unfortunately, this definition is well operationalized in animal models, but is more difficult to directly translate in human beings. Even if the concept includes an individual's need to use drugs as well as instrumental drug-seeking and -taking behaviors, to the best of our knowledge, Robinson and Berridge never exactly indicated which type of behavioral effect defines "wanting" in humans. [START_REF] Tibboel | Implicit measures of "wanting" and "liking" in humans[END_REF][START_REF] Robinson | The psychology and neurobiology of addiction: An incentivesensitization view[END_REF] consider "wanting" as a preconscious process which, by definition, cannot be recorded with an explicit measure. Therefore, measures of automatic attitudes, which are supposed to capture "wanting" as automatic processes, are most often used to that purpose [START_REF] Tibboel | Implicit measures of "wanting" and "liking" in humans[END_REF][START_REF] Wiers | Implicit and explicit alcohol-related cognitions in heavy and light drinkers[END_REF]. The most commonly used paradigms are the Implicit Association Test (IAT) and the Approach Avoidance Tasks (AAT). In the IAT, the strength of associations between concepts and evaluations (or attributes) are measured. The main idea is that making a response is easier when closely related items share the same response key. The reactions times (RTs) and number of errors for word categories which are congruent versus incongruent with implicit reaction tendencies are indicative of these tendencies [START_REF] Tibboel | Implicit measures of "wanting" and "liking" in humans[END_REF]. Taken together, the results with the IAT support the theory that cigarette-related cues are processed in a relatively automatic way [START_REF] Mogg | Eye movements to smokingrelated pictures in smokers: Relationship between attentional biases and implicit and explicit measures of stimulus valence[END_REF][START_REF] Tibboel | Testing the validity of implicit measures of wanting and liking[END_REF][START_REF] Wiers | Automatic approach bias towards smoking cues is present in smokers but not in ex-smokers[END_REF], as is the case for other substances (e.g. alcohol; [START_REF] Field | A meta-analytic investigation of the relationship between attentional bias and subjective craving in substance abuse[END_REF]. However, these authors also report results, which are in apparent contradiction with IST [START_REF] Tibboel | Implicit measures of "wanting" and "liking" in humans[END_REF][START_REF] Watson | Motivational mechanisms underlying the approach bias to cigarettes[END_REF][START_REF] Wiers | Automatic approach bias towards smoking cues is present in smokers but not in ex-smokers[END_REF] for details, see Discussion). Also, it remains unclear to which extent these tasks really tag automatic processes as they do imply minimal cognitive control [START_REF] Mogg | Attentional and approach biases for smoking cues in smokers: An investigation of competing theoretical views of addiction[END_REF]. Therefore, in the present study, we propose to shift the paradigm to direct measures of motor mobilization linked to the addictive cue, which are probably closer to the original significance of the "wanting" concept. Indeed, given that smoking is a highly rewarding motor skill and smokers show activation in actionrelated brain areas while watching smoking cues [START_REF] Wagner | Spontaneous action representation in smokers when watching movie characters smoke[END_REF], it is surprising that only a few studies have been conducted on automatic action tendencies for smoking cues in cigarette smokers [START_REF] Fleming | Alcohol cues, approach bias, and inhibitory control: Applying a dual process model of addiction to alcohol sensitivity[END_REF]. Targeting the oculomo tor mobilization (as in visual probe tasks) might also put the focus on attentional processes [START_REF] Mogg | Eye movements to smokingrelated pictures in smokers: Relationship between attentional biases and implicit and explicit measures of stimulus valence[END_REF]. This might be more proximal to evaluative mental events than to the motor event directly involved in obtaining the incentive, as is the locomotor activity of the rats [START_REF] Robinson | Distinguishing whether dopamine regulates liking, wanting, and/or learning about rewards[END_REF]. For example, a visual probe task measuring early attentional shifts at the gaze level also delivers inconsistent results. Some studies suggest that the attentional bias is larger in more frequent, heavy smokers (e.g. [START_REF] Mogg | Selective processing of smoking related cues in smokers: Manipulation of deprivation level and comparison of three measures of processing bias[END_REF][START_REF] Zack | Effects of abstinence and smoking on information processing in adolescent smokers[END_REF], whereas in others that was either not the case (e.g. [START_REF] Munafo | Selective processing of smoking-related cues in current smokers, ex-smokers and neversmokers on the modified Stroop task[END_REF][START_REF] Waters | Determinants and effects of attentional bias in smokers[END_REF]Waters et al., 2003a) or the reverse was true, and a larger attentional bias has been found in lighter smokers (Bradley et al., 2004, Experiment 1;Waters et al., 2003b). Therefore, we decided to focus on hand motor mobilization, which on one hand is closer to the locomotor activity measured in mice in the Berridgean paradigm, and on the other is less linked to cognitive deliberation, and therefore more prone to automatization. For all these reasons, in the present study, we used a modified Go/NoGo task in which smoking cues were used as target Go and NoGo cues. Such a task has already shown promising results with other addictions (e.g. alcohol, [START_REF] Kreusch | Response inhibition toward alcohol-related cues using an alcohol Go/NoGo task in problem and non-problem drinkers[END_REF], but was never applied, to our knowledge, to a smoker population.

Accordingly, the first aim of the present study is to clarify whether "wanting" operates in the same way in smokers as it does in other addictions by using a paradigm specifically focusing on approach bias. Indeed, although the classic Go/NoGo task measures response inhibition, recent research has proposed a modified Go/NoGo task as a measure of the approach bias [START_REF] Kreusch | Response inhibition toward alcohol-related cues using an alcohol Go/NoGo task in problem and non-problem drinkers[END_REF]. In this modified Go/NoGo task, non-problem versus problem drinkers had to press a button on a target presentation when the target-word was alcohol-related in the experimental condition and upon neutral words in the control condition. For smoking addiction, we propose to measure the approach bias for pressing the button upon a cigarette-related word as compared to a control word. This could be a better measure of "wanting" [START_REF] Robinson | The neural basis of drug craving: An incentive-sensitization theory of addiction[END_REF] or incentive salience (see [START_REF] Kreusch | Response inhibition toward alcohol-related cues using an alcohol Go/NoGo task in problem and non-problem drinkers[END_REF] as the smoking-related words are incentive stimuli. According to [START_REF] Berridge | Reward learning: Reinforcement, incentives and expectations[END_REF], they are "motivational magnets" by their virtue of eliciting approach actions and consummatory behaviors. Thus, we expect a stronger approach bias specifically for smoking cues in smokers, as evidenced either by shorter reaction times for cigarette Go-stimuli and/or by a higher percentage of commission errors (False Alarms errors: FA) for cigarette NoGo-stimuli.

The second aim will be to investigate whether the dependence status of the smokers influences this approach bias or "wanting". Indeed, even if nicotine has a massive impact on neuronal receptors [START_REF] Henningfield | Nicotine Psychopharmacology[END_REF], to explain and predict societally important outcomes, such as an inability to quit smoking, heavy use, and other problems due to smoking or tobacco use it may be that dependence is a better predictor than simple measures of number of cigarettes smoked or blood levels of nicotine (IARC, 2008;[START_REF] Piper | Assessing tobacco dependence: A guide to measure evaluation and selection[END_REF]US Department of Health and Human Services, 2014). Dependence, in this approach, is a psychological construct, which is only partially based on physiological indications (e.g. number of cigarettes smoked a day) and also weighs heavily upon behaviors, judgments and decisions of the smoker (e.g. if one decides to continue smoking when ill; [START_REF] Ko | Measuring nicotine dependence: A review of the Fagerstrom Tolerance Questionnaire[END_REF]. This type of psychological distinction is not obvious since literature tends to consider smokers as dependent according to the law of all or nothing (if one smokes, he is an addict). Alternatively, the discriminative criteria between low and high dependency are not sensitive enough and light smokers rarely reach the criteria for dependency, as the quantity of cigarettes consumed are considered as simply too low (e.g. [START_REF] Mueller | Cognitive behavioral smoking cessation during alcohol detoxification treatment: A randomized, controlled trial[END_REF][START_REF] Piper | Assessing tobacco dependence: A guide to measure evaluation and selection[END_REF]. In other words, there has rarely been a differentiation within the smokers group on the basis of their level of psychological dependence -even if authors typically concluded by advising to do so in further research [START_REF] Machulska | A cigarette a day keeps the goodies away: smokers show automatic approach tendencies for smoking -but not for food-related stimuli published[END_REF][START_REF] Thewissen | Pavlovian conditioning of an approach bias in low-dependent smokers[END_REF]. Furthermore, growing evidence shows that acute consumption of a drug reinforces not only the strong motivational properties of an addiction-related cue (incentive salience) and the diminution of inhibition abilities, but also that the level of practice leads to a certain degree of automaticity [START_REF] Field | A meta-analytic investigation of the relationship between attentional bias and subjective craving in substance abuse[END_REF][START_REF] Noël | Alcohol cues increase cognitive impulsivity in individuals with alcoholism[END_REF]. Recent neurophysiological research has even shown that the striatum, known to be of crucial interest regarding addiction, is much more complex than previously thought. The ventral striatum would generate new behaviors learning and consequence-oriented behavior, whereas the dorsal striatum would be responsible for the development of habits (recent data even show that the density of neurons in this region would be correlated to motor stereotypy; [START_REF] Canales | A measure of striatal function predicts motor stereotypy[END_REF] and a temporal switch can be seen in individuals who consume a drug to individuals who abuse of the drug [START_REF] Everitt | Neural systems of reinforcement for drug addiction: From actions to habits to compulsion[END_REF][START_REF] Yin | The role of the basal ganglia in habit formation[END_REF]. This switch transition from habit learning to automatic associations will be investigated in our two smoker groups: we hypothesize that the dependent smokers group will manifest more automatic behavior towards smoking-related cues than the lowdependent group. To summarize, the aim of the present study is two-fold: first, to test the prediction that smokers will generally show an approach tendency toward smoking-related cues (measured by both shorter reaction times on Go-Smoke stimuli and by more commission errors on NoGo-Smoke stimuli) and, second, to explore potential differences in the processing of smokingrelated cues between low-dependent and dependent smokers.

Method

Participants Sixty participants (mean age = 30.8 ± 9.7 see Table 1 for demographic data) were recruited via the hospital where the experiment was located (CHU Brugmann), by way of email, through personal contacts and by announcements on social networks. Through a brief phone screening, major medical problems, as well as past or current drug consumption (other than moderate alcohol and cigarette) were excluded. Smokers were urged to an abstinence of 2 h prior to the experiment to avoid floor or ceiling effects of the urge to smoke during the task [START_REF] Thewissen | Pavlovian conditioning of an approach bias in low-dependent smokers[END_REF]. Non-smokers never smoked in the past (10 cigarettes in the whole life was the maximum allowed). Both groups are similar concerning their age and level of education, but there are significantly less women in the smokers group. The local ethics committee of the Brugmann Hospital approved the study.

Measures

Personality and behavioral questionnaires

Fagerström Test for Nicotine Dependence (FTND) and Tiffany Questionnaire for Smoking Urges (TQSU). The FTND is a six-item questionnaire (with different response types, most of them either binary or four-way), which is a widely used, reliable, and valid [START_REF] Etter | A comparison of the content-, construct-and predictivevalidity of the cigarette dependence scale and the Fagerstrom test for nicotine dependence[END_REF][START_REF] Etter | Associations between the stages of change and the pros and cons of smoking in a longitudinal study of swiss smokers[END_REF]IARC, 2008;[START_REF] Kozlowski | Predicting smoking cessation with self-reported measures of nicotine dependence: FTQ, FTND, and HSI[END_REF][START_REF] Piper | Assessing tobacco dependence: A guide to measure evaluation and selection[END_REF] self-report measure aimed to capture the degree of nicotine dependence. Nevertheless, when focusing on each item of the questionnaire, five of them are behavioral measures (e.g. how long do you wait for your first cigarettes, would you smoke when ill, in places where it is prohibited etc.). Fagerström [START_REF] Heatherton | The Fagerstrom test for nicotine Dependence: a revision of the Fagerstrom tolerance questionnaire[END_REF](Heatherton et al., : 1120) ) himself considers the "time to the first cigarette"-item also as a predictor of biochemical measures, and thus, depending on the weight accorded to this question as a physiological versus a behavioral parameter, one might say that at least half of the weight of a result on an FTND questionnaire is given by psychological rather than by direct physiological parameters. Accordingly, in the present research, we have divided our smoker population in two groups of respectively low-dependent (score from 1 to 4) and dependent smokers (scores of 5 or more) on the basis of their results on the FTND and the standardized nomenclature [START_REF] Heatherton | The Fagerstrom test for nicotine Dependence: a revision of the Fagerstrom tolerance questionnaire[END_REF][START_REF] Pomerleau | Nicotine dependence and the Fagerstrom Tolerance Questionnaire: A brief review[END_REF]. The TQSU is a 12-item questionnaire (with responses on a 7-point Likert scale) as a classic self-report measure of craving (e.g. "I have a desire for a cigarette right now"; "Smoking would make me less depressed").

The Urgency Premeditation Perseverance and Sensation seeking impulsive behavior scale (UPPS).

The UPPS [START_REF] Whiteside | Understanding the role of impulsivity and externalizing psychopathology in alcohol abuse: Application of the UPPS impulsive behavior scale[END_REF] is a well-validated and frequently used self-report questionnaire, composed of 45 items (with responses on a 7-point Likert scale), which describes the difficulty to restrain general behavioral reactions in situations that elicit strong emotion (Urgency), the difficulty to anticipate expected situations (lack of Premeditation), the difficulty to sustain prolonged activity (lack of Perseverance), and the tendency to search for new emotionally arousing situations (Sensation seeking; [START_REF] Cirilli | Individual differences in impulsivity predict anticipatory eye movements[END_REF]. If both the FTND and the TQSU are quick assessments with acceptable psychometric properties of smoking behavior, the UPPS is an elaborate measure of general impulsivity, which thoroughly investigates its different facets and might therefore be more sensitive to how people represent themselves. Links between tobacco dependency and UPPS have been consistently demonstrated [START_REF] Mitchell | Measures of impulsivity in cigarette smokers and non-smokers[END_REF][START_REF] Mitchell | Measuring impulsivity and modeling its association with cigarette smoking[END_REF][START_REF] Reynolds | Laboratory and self-report assessments of impulsive behavior in adolescent daily smokers and non smokers[END_REF].

The Marlowe-Crowne Social Desirability scale (MCSD).

As we wished to give specific importance to the measurement of psychological parameters, we have also included the MCSD [START_REF] Crowne | A new scale of social desirability independent of psychopathology[END_REF]. It is a 33-question scale (with dichotomic responses), which was largely validated [START_REF] Evans | Clinical relevance of the Marlowe-Crowne scale: A review and recommendation[END_REF][START_REF] Johnson | An evaluation of the validity of the Crowne-Marlowe need for approval scale[END_REF][START_REF] Sarbescu | Psychometric properties of the Marlowe-Crowne social desirability scale in a Romanian sample[END_REF]. A high score corresponds to a tendency to conform in a socially desirable way, i.e. to show a behavior, which is thought to conform more to the social expectations, or the expectations of the situation (e.g. "I never hesitate to go out of my way to help someone in trouble"). As the social context of the present research is an explicit invitation based upon the smoking behavior, the wish to be "socially desirable", then, would imply a readiness to speak about, as well as to acknowledge, the proper smoking behavior and dependency as well as the symptoms linked to it.

Go/NoGo modified for smoking.

Approach bias toward cigarette cues was recorded through a modified version of the classical Go/NoGo task. The modification involved the use of cigarette-related and neutral words to specifically test approach tendencies and inhibition capacities toward cigarette-related cues. In this task, four blocks, each including 20 words (15 Gowords,, were presented in a counterbalanced order successively to the participants. The words were selected through an unpublished pilot study. Twenty-five people (age: 37; SD: ±13.78) were asked to report all the words related to tobacco in an online survey (Limesurvey). n total, 478 words were proposed and, after weighing the redundancies, 134 were left. From these, 40 were selected with the following criteria: (a) words were one or two syllables long, (b) they had a high frequency of occurrence, (c) ambiguous words were eliminated. This selection was then proposed to 50 new participants (age: 32.28; SD: 11.29) who had to rate the words both on their tobacco-relatedness and on their emotional level (with the pleasantness and arousal scales of the Self-Assessment Manikin, SAM; [START_REF] Bradley | Measuring emotion: SAM and the semantic differential[END_REF]. This led to the final selection of 20 words, which were both highly related to cigarettes and least emotional. Neutral stimuli were matched for length and familiarity. The words were presented in the center of the screen during 500 milliseconds (ms) with an inter-stimulus interval of 1000 ms. Participants had to respond when a Go stimulus was presented (Go trial) and to refrain from responding when a NoGo stimulus was presented (NoGo trial). A Go trial could either be composed of (a) 15 neutral words and five smoking-related words (Go Neutral) or (b) 15 smoking-related words and five neutral words (Go Smoke). Before the start of each block, an instruction indicated which type of stimulus was the Go stimulus. When a Go stimulus was presented, participants had to press the space bar of a keyboard as fast and accurately as possible. The pictures were presented in the center of the screen during 500 ms, with an interstimulus interval of 1000 ms and the image disappeared either after 500 ms or after the subject response. Participants first completed one trial block, which was similar to the test blocks (20 trials). The whole task took approximately 8 min and was performed with E-Prime software (Psychology software tools, Inc.).

Design and procedure

Participants were tested one by one in a quiet room from the Brugmann Hospital. They signed a consent form and completed a pretest subjective craving (only smokers): participants self-reported their craving of a cigarette by answering in % to the question "how much do you want to have a cigarette right now?". This was followed by the modified Go/NoGo task, the rest of the questionnaires implying an identical posttest craving, FTND, TQSU (only smokers) as well as UPPS and MCSD (all participants) and a debriefing.

Data analysis

Task performance was analyzed twice (depending of the fact we were investigating the differences between (a) no smokers and smokers or (b) no smokers, low-dependent smokers, and dependent smokers) following the same analytical structure depending on the group and type of stimulus. Dependent variables of the study were the mean reaction times (RTs) on Go trials and the percentages of FA, defined as a response on a NoGo trial, on which the participant was instructed to refrain from responding. Participant reaction times on Go trials and percentages of FA were analyzed with 2 (word type) × 2/3 (group) mixed analyses of variance (ANOVA). These ANOVAs used group as betweensubject variable and word stimulus as within-subject variables. A multiple linear regression was finally conducted in order to examine the contribution of the main dependent variables in the definition of the groups. All the statistical analyses were performed using the software package SPSS 23 (IBM, Microsoft).

Results

Table 1 summarizes the demographic and behavioral differences between the smokers, non-smokers, and the subgroups of smokers: low and dependent smokers (see also further, Figures 1234).

Smokers versus non-smokers

Concerning the reaction times on Go trials, there was no group effect (smokers vs nonsmokers) on mean RTs for Go trials nor was there an interaction effect between groups and context (Go Smoke or Go Neutral). Nevertheless, the inter-subject effects revealed a marginal significance depending on the group (F(1, 58) = 3.5; p = 0.07) with smokers tending to be faster than the control group independently of context (see also Figure 1). Concerning the FA errors on the NoGo trials, the ANOVA on the percentage FA revealed a significant main effect of the stimulus (F(1, 58) = 7; p < 0.05), both groups making more errors in the NoGo Smoke (this is the Go Neutral) context. In addition, a significant main effect for the group was found (F(1, 58) = 4.7 p < 0.05) with smokers making more errors whatever the condition. The interaction between group and condition was not statistically significant (see also Figure 3). A mean comparison between groups also revealed a significant difference for the FA in the Go Neutral (NoGo Smoke) with smokers making more errors when they have to refrain themselves from pressing while seeing cigarettes-related words. In addition, there is a significant difference for the UPPS t(58) = -4.48 p < 0.001) with the non-smokers scoring at 78.6 ± 12.1, whereas smokers score at 92.8 ± 12.3.

Non-smokers, low-dependent and dependent smokers

Group demographic characteristics. Our smokers group was divided into two groups (based on the FTND cut-off < 0.05); "Do you smoke even if you are sick in bed?" (t(30) = -2.74; p < 0.05); "Do you smoke more frequently in the morning?" (t(30) = -4.68; p < 0.05). It is interesting to note that the items are not physiological measures. There are significantly less women in the lowdependent group than in the dependent or in the non-smokers group. Personality and declarative behavior characteristics. Counterintuitively, UPPS scores in both dependent smokers and nonsmokers are significantly lower than in low-dependent smokers [t(30) = 2.31; p < 0.05; t(41) = -2.26; p < 0.05] (see Table 1). Likewise, lowdependent smokers reported substantially less time without smoking before the experiment (p < 0.05) and had higher TQSUscores (t(30) = 1.9; p < 0.05). In line with this, they reported higher craving prior to the Detandt, S., Bazan, A., Quertemont, E., & Verbanck, P. (2017). Smoking addiction the shift from head to hands. Approach bias towards smoking-related cues in low dependent versus dependent smokers. Journal of Psychopharmacology. 31(7),[819][820][821][822][823][824][825][826][827][828][829] experiment (precraving: t(30) = 2.79; p < 0.001) as well as after the task (postcraving: t(30) = 4.14; p < 0.001) compared to dependent smokers. Finally, only in ow dependents had the craving scores increased between preand post-experiment measures (t(16) = -3.32; p < 0.05). Pearson the FAs for Go Smoke and Go Neutral and RTs for Go Smoke and Go Neutral as predictors. Interestingly, only the Go Smoke RT was marginally significant (β = -0.24; t(8) = -1.81, p = 0.07), which means that RT for the Go Smoke condition tend to predict the belonging group (non-smokers, low-dependent smokers or dependent smokers) correlations were used to test correlations between MCSD and TQSU, UPPS and craving scores. Interestingly, MCSD correlated positively both with post-craving (r = 0.55; p < 0.05) and UPPS (r = 0.56; p < 0.05) in low-dependent smokers, whereas no correlation was found in dependent smokers. Note that correlations between MCSD and TQSU were not significant (nor between MCSD and FTND).

Hand motor behavior characteristics

Concerning the Go reaction times, the main effect of the group on mean RTs was not statistically significant. However, the interaction between group and condition was marginally significant (F(2, 57) = 2.77; p = 0.07). Dependent smokers were the fastest in the Go smoke (i.e. in the NoGo Neutral) trials, whereas low-dependent smokers and control participants behaved similarly (see Table 1 and Figure 2). Concerning the FA errors on the NoGo trials, the ANOVA on percentage commission errors (or FA) revealed a marginally significant main group effect (F(2, 57) = 2.92; p = 0.06): lowdependent smokers made most FA and control participants least, independent of condition. In addition, a significant main effect for the word type was found (F(1, 57) = 6.9; p = 0.01) with the three groups making more commission errors for smoke cues in the Go Neutral (i.e. NoGo Smoke) condition. The interaction between group and condition was not statistically significant. Interestingly, RTs and FA for smoke cues in the Go Neutral (i.e. NoGo Smoke) condition were correlated (the faster they were, the more errors they made) both in non-smokers (r = -0.39; p < 0.05) and in low-dependent smokers (r = -0.69; p < 0.05) but not in dependent smokers (see Table 1 andFigure 4). Lowdependent smokers also had their RT and FA scores negatively correlated in the Go Smoke (NoGo Neutral) condition. Note that we have also checked the correlations of these (hand) motor results with the MCSD, but no correlations were found.

Predictability of the motor hand behavior characteristics for the dependency group

In order to examine the contribution of the difference between FA and RT rates in the definition of our three groups (non-smokers, low-dependent smokers and dependent smokers), which were originally based on the FTND cut-off, we conducted multiple linear regression analysis with the age, the FAs for Go Smoke and Go Neutral and RTs for Go Smoke and Go Neutral as predictors. Interestingly, only the Go Smoke RT was marginally significant (β = -0.24; t(8) = -1.81, p = 0.07), which means that RT for the Go Smoke condition tend to predict the belonging group (non-smokers, low-dependent smokers or dependent smokers).

Discussion

The first aim of this study was to test the hypothesis that smokers would show an approach tendency towards smoking-related cues in a modified Go-NoGo task. As expected, the smokers generally make more mistakes, whatever the condition (neutral words as cues or smoking-related words as cues) and, specifically, tend to be faster for smoking-related cues. However, contrary to our expectations, there were no differences between groups concerning the FA errors rate in the NoGo Smoke (i.e. the Go Neutral) context. The present results show a significant approach tendency in the treatment of cigarettes cues relative to control stimuli in all participants, including non-smokers. This cognitive bias may be interpreted as an approach tendency due to the fact that smoking-related cues are more easily recognized as they constitute our daily environment, whether one smokes or not, and as the cues Detandt, S., Bazan, A., Quertemont, E., & Verbanck, P. (2017). Smoking addiction the shift from head to hands. Approach bias towards smoking-related cues in low dependent versus dependent smokers. Journal of Psychopharmacology. 31(7),[819][820][821][822][823][824][825][826][827][828][829] belonged to only one semantic category contrary to the neutral cues. Nevertheless, two results are as expected: (a) simple comparisons revealed a significant difference for the FA in the Go Neutral (NoGo Smoke) with smokers making more errors when they have to refrain themselves from pressing upon seeing cigarette-related words and (b) the UPPS scores were significantly different between groups with smokers declaring themselves more impulsive than the control group. In other words, the [START_REF] Kreusch | Response inhibition toward alcohol-related cues using an alcohol Go/NoGo task in problem and non-problem drinkers[END_REF] paradigm, verified with alcohol-dependent individuals, gives results in the expected direction transposed to a nicotine-dependent population, although, disappointingly, results generally remain marginally significant. The second aim was to explore differences between low-and highdependent smokers, in order to develop higher sensitivity and accuracy when describing the wide and heterogeneous group of smokers. Our results show that low-dependent smokers have higher scores for all declarative questionnaires by which they have to position themselves in reference to their addiction: indeed, surprisingly, they consistently declare higher (pre-and post-) craving and they have higher UPSS and higher TQSU scores than dependent smokers. At face value, these elements would be more indicative of high dependency; however, their motor scores betray that this is not the case. Interestingly, their MCSD scores correlate positively with their post-craving as well as with their UPPS scores and this was not the case for the dependent smokers. As indicated, the MCSD measures social desirability, which can be defined as the need to obtain approval by answering in a socially appropriate and accepted way [START_REF] Crowne | A new scale of social desirability independent of psychopathology[END_REF]. The logic behind the development of its items was based on the assumption that a person cannot always behave in a socially desirable manner. The items thus assess daily personal or interpersonal behaviors that are either desirable but not frequent (e.g. "I never hesitate to go out of my way to help someone in trouble"), or conversely, socially disapproved but likely (e.g.: "It is sometimes hard for me to go on with my work if I am not encouraged"). Thus, the more the participant acknowledges respectively denies these behaviors, the more he is thought to act in a socially desired way. As a reminder, there is no difference between the two smoker groups regarding their absolute MCSD scores as such, which means that the correlations we find are not due to a group effect: low-dependent smokers are not more inclined towards socially desirable behavior in general than dependent smokers. But, when it comes to what they say about their smoking behavior specifically, the correlational results show that the low-dependent declarations are sensitive to a concern with social desirability, whereas there is no social desirability sensitivity whatsoever in the declarations of the dependent smokers concerning their smoking behavior. Therefore, one way to interpret these two series of findings together is that, possibly, these low-dependent smokers manage their impression on their smoking behavior by behaving as they think we expect them to do. They volunteered to participate to this research on the basis of an ad which was entitled 'Addiction and Language' and the information on the experiment clearly declared that "the focus of the study addresses the nicotine dependency symptoms and the way one speaks about it". Accordingly, the MCSD-correlation betrays that our low-dependent smokers group readily self-report to be significantly addicted as the experimental set-up expects. In contrast, so-called dependent smokers, have lower (preand post-) craving scores, lower TQSU and UPPS scores than low-dependent smokers, they indicate that they could abstain smoking for a longer time before the experiment and, even if the difference was not significant, also reported lower absolute numbers of cigarettes smoked a day. Why, then, do we persist in thinking that, in accord with the results on the FTND, the first group is the "low dependent" and the second the (really) "dependent" group? Would all results not find an expected interpretation by merely switching around the labels -and to heck with the FTND…? As said, another group of results, however, confirm the FTND-distinctions, namely those concerning the hand motor approach behavior. Indeed, they show that the dependent smokers make less FA than low-dependent smokers in the Go Neutral condition and are the quickest in the Go Smoke condition. Also, there is no correlation whatsoever between their RTs and FAs: going quicker does not make their hands less sure. The low-dependent participants, on the contrary, make more FAs generally and even more commission errors with NoGo Smoke (Go Neutral) stimuli. Also, they are slower than the dependent group when they have to press the keyboard upon seeing tobaccorelated stimuli (Go Smoke condition). Finally, their RTs and FAs score correlate negatively. In other words, the faster they are, the more mistakes they make: this is a logical bias linked to the fact that people tend to make more mistakes when they want to be fast, when prompted to do so. Unlike their declarative results, which show their eagerness to indicate their smoking behavior, the hand motor approach behavior of the low-dependent smokers is substantially slower and more error prone as compared to dependent smokers. In summary, our dependent group has fast hands and sure moves in picking their objects of dependence, whereas the low-dependent participants were slower and clumsier. Taking all this together, we are inclined to conclude that in the low-dependent group the addiction is still very much in the mind and that, when evolving from a recreational to a dependent use of cigarettes, the addiction shifts from mind to hands. Maybe then, dependency is not so much a matter of numbers of cigarettes smoked a day, but may denote a shift from a 'central preoccupation' (including declarative and attentional processes) to 'peripheric automatization'. Likewise, Di [START_REF] Chiara | Role of dopamine in the behavioural actions of nicotine related to addiction[END_REF] proposes that nicotine dependence shifts from an incentive learning process in the early stages to an automatic and habituated treatment of the cues. This implies therefore that smoking cues are either evaluated as motivational, salient, and positive for the first stage or treated automatically in later stages. We might add, in view of the present results, that these "early1" stages involve an evaluative process implying a subjective judgment, whereas a short-cut of this subjective implication may be supposed in the 'automatic and habituated' behavior. Most interestingly, the shift is not simply from declarative behavior to motor behavior as oculomotor results, for example, seem closer to the declarative phenomena (and moreover, "declaration", strictly spoken, is also a motor behavior). For example, [START_REF] Mogg | Attentional and approach biases for smoking cues in smokers: An investigation of competing theoretical views of addiction[END_REF] compared low-nicotine-dependent smokers (Fagerström scores 3) in a visual probe task and found that smokers with low levels of dependence have an enhanced attentional bias for smoking-related cues, as reflected by their longer duration of gaze on such cues. Therefore, it is probably more accurate to describe the shift as a shift from central, cognitive, evaluative processes to peripheric grasping behavior immediately proximal to the target. However, while our results seem to follow the automaticity hypothesis [START_REF] Yin | The role of the basal ganglia in habit formation[END_REF], we would like to stress that they show that dependent smokers are not only faster to grasp smoking-related cues -which would be easily understood as an enhanced automaticity towards these cues -but, remarkably, they also perform better when they have to refrain themselves from pressing in the NoGo. Therefore, we are inclined to think that the results cannot solely be understood through a learning-habits theory of motor stereotypy. Clinically, this might be of crucial interest as it is reflected in what can be seen in addiction (whatever the substance). Indeed, addiction does not simply lead to a passive state of deficiency characterized by a globally hypofunctional inhibitory system or by an overwhelming irrational wanting; paradoxically, consumption might also give advantages and lead individuals to become more effective in certain abilities. Otherwise, the present results show how subjective reports can be influenced by concerns with social desirability, and thereby in apparent contradiction with the motor behavioral results. We propose that the hand motor mobilization proximal to the cigarette stimuli is more closely related to Robinson and Berridge's "wanting" than are the cognitive or declarative questionnaire responses and even more closely related than the oculomotor mobilization as in the visual probe task. The hand motor mobilization in smokers, then, is proposed to be the most comparable to the locomotor mobilization in mice, taken as measure for "wanting" in the Robinson and Berridge-research but also used as a measure for incentive sensitization by others (e.g. [START_REF] Mead | AMPA-receptors are involved in the expression of amphetamineinduced behavioural sensitisation, but not in the expression of amphetamine-induced conditioned activity in mice[END_REF]. Indeed, and importantly, "wanting" is supposed to include pre-or unconscious processes [START_REF] Tibboel | Implicit measures of "wanting" and "liking" in humans[END_REF]. Robinson and Berridge (2000: S105; see also [START_REF] Berridge | Food reward: Brain substrates of wanting and liking[END_REF][START_REF] Berridge | Pleasure, pain, desire, and dread: Hidden core processes of emotion[END_REF] explicitly point out: " the incentive-sensitization theory holds that drugs can activate positive core processes of motivation in the absence of conscious awareness, so that positive effects may not be indicated on any scale of subjective affective intensity. Indeed, the neural system Detandt, S., Bazan, A., Quertemont, E., & Verbanck, P. (2017). Smoking addiction the shift from head to hands. Approach bias towards smoking-related cues in low dependent versus dependent smokers. Journal of Psychopharmacology. 31(7),[819][820][821][822][823][824][825][826][827][828][829] responsible for incentive salience attribution can sometimes produce 'wanting' in the absence of conscious awareness of 'wanting' itself " (our italics). Di [START_REF] Chiara | Role of dopamine in the behavioural actions of nicotine related to addiction[END_REF] reports that in a blind selfadministration of placebo versus nicotine, smokers administrate themselves more nicotine without reporting any change in the subjective measures of craving or satisfaction. In that perspective, we propose that what fundamentally distinguishes the so-called "low dependent" and the "dependent" smokers might be that only in the dependent smokers there is "wanting" in the absence of conscious awareness of/preoccupation with "wanting". In dependency, a shift has operated from a mental preoccupation with smoking, which might still be sensitive to social desirability concerns (i.e. sensitive to others in general), to smoking as a non-negotiable -we might say "intimate" -hand motor habit. Interestingly, though not completely analogous to the present results, Ferguson et al., (2016: 233) found that the smoking behavior of daily smokers was under considerable stimulus control -such as refraining from smoking when prohibited -but this control was weaker at higher smoking rates. In the proposed approach this, then, would indicate that the smoking habit at lower smoking rates is still negotiable in relation to others. In line with the present research they add: "The fact that daily smoking appears to be influenced also by stimulus control would appear at odds with purely pharmacological models in as much as they demonstrate that such models have trouble explaining the range of smoking behaviors observed." and cite Shiffman and colleagues (2015) who had already proposed that smoking patterns can be better explained by a model of smoking that also allows for stimulus control to influence smoking. This approach thereby sheds new light to the earlier reported and seemingly contradictory results. As predicted by IST, several studies show that addicts will approach their addiction-related stimuli faster than controls and independently of the valence they attribute to them [START_REF] Houwer | Do smokers have a negative implicit attitude toward smoking?[END_REF][START_REF] Wiers | Implicit and explicit alcohol-related cognitions in heavy and light drinkers[END_REF]. However, testing smokers in conditions of smoking deprivation did not affect the "wanting" scores on the IAT, whereas, according to the IST, the level of satiation should modify the "wanting" (if the subject is satiated he will experiment less "wanting") [START_REF] Tibboel | Testing the validity of implicit measures of wanting and liking[END_REF]. In the AAT [START_REF] Mogg | Eye movements to smokingrelated pictures in smokers: Relationship between attentional biases and implicit and explicit measures of stimulus valence[END_REF] participants approach or avoid stimuli on the basis of the stimulus dimension that is being assessed (e.g., approach biases for picture depicting either a cigarette or a neutral stimulus). With this test, it has been shown that, as expected, smokers were faster to move a manikin toward cues linked to cigarettes compared to neutral cues and that they maintained their gaze longer on smoking-related pictures [START_REF] Bradley | Attentional and evaluative biases for smoking cues in nicotine dependence: Component processes of biases in visual orienting[END_REF][START_REF] Mogg | Eye movements to smokingrelated pictures in smokers: Relationship between attentional biases and implicit and explicit measures of stimulus valence[END_REF]. Also, AAT scores were correlated with craving when smokers were deprived; however, even if smoking thereupon led to reduced explicit craving it also led to an increase in approach scores [START_REF] Watson | Motivational mechanisms underlying the approach bias to cigarettes[END_REF], which is opposite to IST predictions. To clarify these seemingly incoherent results, we propose, in line with reasoning indicated higher, that incentive salience has to be understood as a motor investment in the 'Berridgean' sense; that is, as a motor trace which, once engraved, operates independently of mental preoccupation and autonomously continues to push forward to grasp for its object. When we propose that it does so with a level of autonomy, we specifically imply that it does so even if that object, which was one day adequate in giving satisfaction (or even "liking"), is no longer doing so, and that a major part of the relief tied to the addictive behavior is now the relief of merely discharging the automatically invested preparation of the addictive behavior (see also [START_REF] Bazan | On the physiology of jouissance: Interpreting the mesolimbic dopaminergic reward functions from a psychoanalytic perspective[END_REF]. In fact, consciously, or we might say rationally, people can report that they crave less for cigarettes after consuming them but on a motor level, reality is different confirming the neurobiological findings which show that "wanting" is located in a system (the NAS-DA) which can work independently of the homeostatic or hedonic processing [START_REF] Berridge | Food reward: Brain substrates of wanting and liking[END_REF][START_REF] Berridge | What is the role of dopamine in reward: Hedonic impact, reward learning, or incentive salience?[END_REF]. As distinguishing dependent from recreational drug use may be a surprisingly difficult task, we propose that the approach bias task might also be a valuable tool in helping to make these distinctions. Indeed, our exploratory linear regression analysis shows that RTs on Go Smoke approach bias task tend to predict the FTND group belonging. Thereby, this measure has been able to make a diagnostic difference between people who seem to be, at the same time, more conscious of their dependence and more disrupted by smoking-related cues and those who treat them more automatically and have less shared preoccupation with their dependence. Inversely, our results also show that the FTND, which does not merely distinguish smoker categories on the basis of the number of cigarettes smoked per day, is able to predict the motor profile towards the addictive stimuli of both groups. This predictive ability of the FTND is all the more interesting, as it has been criticized as a tool to assess tobacco dependence [START_REF] Etter | A comparison of the content-, construct-and predictivevalidity of the cigarette dependence scale and the Fagerstrom test for nicotine dependence[END_REF][START_REF] Etter | Associations between the stages of change and the pros and cons of smoking in a longitudinal study of swiss smokers[END_REF]. What differentiates the FTND from other questionnaires is that it also includes indications of precisely the automaticity and urge to smoke, such as the difficulty to refrain from smoking in forbidden places and the fact of smoking when ill -and in fact it is precisely those two items that are significantly different between our low-dependent and our dependent group. In other words, the FTND scores correlate with the motor parameters, while other current means for identifying substance abuse, whenever they are too direct and/or too cognitive (e.g. our craving scores as well as the TQSU which very much has the same principle as the craving VAS) prove to be inadequate or confusing (see also, [START_REF] Smith | Using a drug-word Stroop task to differentiate recreational from dependent drug use[END_REF].

Limits

First, participants' emotional ratings (both valence and arousal) of the cues have not been assessed in this study, although these data would have been of interest. Indeed, they might have complemented the interpretations regarding the group differences (both for the RT's and errors) as interference from the emotional valence of the cues cannot be excluded. For example, if smokers are less accurate with the neutral cues, it might also be because they allocate less attention to neutral cues. A way to disentangle this issue could be to include an additional stimulus category in the paradigm (see e.g. [START_REF] Noël | Alcohol cues increase cognitive impulsivity in individuals with alcoholism[END_REF]. Second, owing to practical issues, the gender ratio has not been respected and a next study should control whether this variable modifies the tendencies or not. However, one interesting element on a possible bias induced by the gender imbalance in our low-dependent versus dependent population, is that women have generally been shown to be more inclined to socially adapt their behavior to what they suppose is wished for socially than men [START_REF] Eagly | Explaining sex differences in social behavior: A meta-analytic perspective[END_REF]Félonneau and Becker, 2008). However, as our low-dependent population is both the group with the most men and the group who are most inclined to behave in a more socially desirable way when it comes to reporting their smoking behavior, the gender imbalance, if anything, is expected to have handicapped rather than biased the outcome; i.e. with more women in the lowdependent group, logically, we would have expected stronger results in the same direction. Hence, we think the differences between the low-dependent population and the dependent population are genuine.

Conclusion and perspectives

In conclusion, the approach bias paradigm for tobacco addiction, though giving results in the expected direction, remained disappointingly inconclusive and non-significant. However, when distinguishing in our smoker population a low dependent from a dependent group on the basis of the FTND, we were able to show two types of results: it seems low-dependent participants show a mental preoccupation concerning their smoking behavior, are able and willing to 'negotiate' their smoking behavior in function of others and of the social environment and likewise their motor behavior in grasping for a cigarette (stimulus) shows hesitation; the dependent participants, however, seem to be quite unpreoccupied by their smoking behavior as well as unconcerned by social prerogatives, while in parallel their motor cigarette grasping is fast and sure. From these observations different conclusions were drawn. First, the psychological concept of dependency is more suitable to predict the motor smoking habit than the sheer number of cigarettes. Moreover, to our knowledge, no research previously formulated the possibility of a paradox between an automatized motor processing proximal to the stimulus and a metacognitive preoccupation with the dependence (as the behavioral and the MCSD results have allowed us to uncover). This is of crucial interest in addiction in which this paradox is at the very center of the pathology: indeed, it is the mechanism by which a behavior can be maintained without acknowledging it consciously -or even, while claiming one wants to stop. Second, the hand motor mobilization (measured by the approach bias task) is proposed as a parallel of the locomotor activation in the "Robinson and Berridge-mice", i.e. as a measure of "wanting" or of incentive salience. The approach bias paradigm might also be a good complement for clinical use. Third, our research confirms the idea of the independence of the trace as a "peripheric" automatic process from subjective evaluative "central" operations, possibly paralleling the disconnect between "wanting", the amount of motor mobilization which an organism is ready to invest in order to obtain a reward, and "liking" [START_REF] Berridge | Food reward: Brain substrates of wanting and liking[END_REF] or pleasure [START_REF] Bazan | On the physiology of jouissance: Interpreting the mesolimbic dopaminergic reward functions from a psychoanalytic perspective[END_REF] which might also imply evaluative affective, and therefore conscious, effects. Finally, our results suggest that there may be an underlying heightened vulnerability to drug dependence in certain individuals which might take place right into their hand motor mobilization; the addictive abilities of the stimuli not residing solely in the addictive properties of the drug itself nor in the sole evaluative or cognitive processing. It would therefore be interesting to perform these tests in longitudinal studies in order to predict which group might stop more easily. Logically, we expect that the lowdependent group would be prompter to quit and more affected by talking therapy as their addiction is still negotiable. Another possibility would be to perform drug challenge tests, which are frequently used to identify dispositional or acquired differences in neurotransmitter responses [START_REF] Netter | Addictive and nonaddictive smoking as related to responsivity to neurotransmitter systems[END_REF], to compare our two smokers groups. This test might be of particular relevance if it can be shown that there are differences in dopamine levels even if the quantity of cigarettes consumed is not different. In our opinion, this study has contributed to a complementary way of understanding addiction, mainly regarding its behavioral effects. We propose this might be an opportunity to invite experts to rethink smoking habits in the light of this crucial moment, possibly deciding dependency, namely, the shift "from head to hands.