Contexte et objectif : La pleine conscience et l’hypnose sont deux moyens non pharmacologiques de réduire la douleur. La combinaison de ces deux outils a montré des effets synergiques dans certains contextes cliniques, mais n’a pas encore était étudié dans un contexte de modulation de la douleur. L’objectif de ce travail est d'évaluer les réponses du système nerveux autonome (SNA) par ses manifestations physiologiques - variabilité du rythme cardiaque (VRC) et activité électrodermale (AED) ainsi que les réponses réflexes de retrait nociceptif (RIII), à des stimuli électriques nociceptifs en contexte hypnotique de pleine conscience et de dissociation chez des participants sains. Méthode : 48 individus (13 pilotes et 35 participants) ont été conviés à 2 sessions pour évaluer les prédispositions individuelles à l’hypnose (échelle SHSS) et la pleine conscience (questionnaire FFMQ) (session 1) puis pour l'expérience principale évaluant la modulation de la douleur (session 2). L'expérience principale comprenait 4 conditions expérimentales administrées chez tous les participants (devis intrasujet) : (1) contrôle passif de repos (baseline) (2) contrôle hypnotique avec suggestions neutres, (3) hypnose avec suggestions de dissociation, et (4) hypnose avec suggestions de pleine conscience. Chaque condition est subdivisée en 2 blocs pendant lesquels les suggestions verbales sont données (bloc 1), puis pendant l’administration des stimuli électriques nociceptifs (bloc 2)). Les données physiologiques ont été enregistrées en continu et la douleur perçue a été rapportée après chaque stimulus nociceptif. Des modèles linéaires mixtes multiniveaux et des tests de corrélation permettent respectivement d’évaluer les contrastes entre les conditions et évaluer les relations entre la modulation des réponses à la douleur et les prédispositions individuelles à l’hypnose et à la pleine conscience. Résultats : Nos résultats confirment que plusieurs indices de la VRC et de l’AED permettent de mesurer les réponses autonomes à la douleur (MeanNN, LFn, HFn, SCL, SCR : p<.001, SD1/SD2 : p<.005, RMSSS p<.05). Toutes les conditions hypnotiques ont permis de diminuer les scores de douleur (p<.05) et ont montré des différences de VRC (RMSSD, SD1 SD2 : p<.05) comparativement à la condition baseline. La condition de dissociation a permis la plus grande diminution des scores de douleurs ainsi que des réponses réflexes diminuées (p<.001). Les participants avec un score SHSS plus élevé ont montré une plus grande diminution du RIII durant les conditions hypnotiques (neutre : p<.05, dissociation et pleine conscience : p<.005). Discussion : Nos résultats fournissent des preuves supplémentaires en faveur de la capacité des suggestions hypnotiques à moduler l’activité physiologique. Les suggestions hypnotiques de dissociation et de pleine conscience ont montré un effet antinociceptif mesuré par les scores de douleur, par une réactivité autonome modifiée et par des réponses réflexes diminuées comparativement à la condition baseline. Toutefois, les réponses autonomes à la douleur et le RIII n’ont pas été significativement différentes entre les conditions hypnotiques. Les personnes hautement susceptibles à l’hypnose pourraient bénéficier d’un effet antinociceptif plus important lors d’interventions hypnoanalgésiques. / Background and objectives: Mindfulness and hypnosis are two non-pharmacological means of reducing pain. The combination of these tools has shown synergistic effects in certain clinical contexts but has not yet been studied in the context of pain modulation. The aim of the present study was to evaluate autonomic nervous system (ANS) responses through physiological manifestations - heart rate variability (HRV) and electrodermal activity (EDA) - as well as nociceptive withdrawal reflex responses (RIII), to nociceptive electrical stimuli in a hypnotic context of mindfulness and dissociation in healthy participants. Method: 48 individuals (13 pilots and 35 participants) were invited to 2 sessions to assess individual predispositions to hypnosis (SHSS scale) and mindfulness (FFMQ questionnaire) (session 1) and then for the main experiment assessing pain modulation (session 2). The main experiment comprised 4 experimental conditions administered to all participants (within-subjects design): (1) passive resting control (baseline) (2) hypnotic control with neutral suggestions, (3) hypnosis with dissociation suggestions, and (4) hypnosis with mindfulness suggestions. Each condition was subdivided into 2 blocks during which verbal suggestions were given (block 1), then during the administration of nociceptive electrical stimuli (block 2)). Physiological data were recorded continuously, and perceived pain was reported after each nociceptive stimulus. Multilevel linear mixed models and correlation tests were respectively used to assess contrasts between conditions, and to evaluate relationships between modulation of pain responses and individual predispositions to hypnosis and mindfulness. Results: Our results confirm that several HRV and EDA indices measure autonomic responses to pain (MeanNN, LFn, HFn, SCL, SCR: p<.001, SD1/SD2: p<.005, RMSSS p<.05). All hypnotic conditions decreased pain scores (p<.05) and showed differences in HRV (RMSSD, SD1 SD2: p<.05) compared with the baseline condition. The dissociation condition resulted in the greatest decrease in pain scores as well as diminished reflex responses (p<.001). Participants with a higher SHSS score showed a greater decrease in RIII during the hypnotic conditions (neutral: p<.05, dissociation and mindfulness: p<.005). Discussion: Our results provide further evidence in favor of the ability of hypnotic suggestions to modulate physiological activity. Hypnotic dissociation and mindfulness suggestions showed an antinociceptive effect measured by pain scores, altered autonomic reactivity, and decreased reflex responses compared to the baseline condition. However, autonomic pain responses and RIII were not significantly different between hypnotic conditions. People who are highly susceptible to hypnosis may benefit from a greater antinociceptive effect during hypnoanalgesic interventions.

Il lavoro di tesi si è focalizzato sullo studio dell’arousal come indice psicofisiologico di attivazione e sull’applicazione della metodica di stimolazione elettrica transcranica (tES) non invasiva con lo scopo di modulare tale indice. L’obiettivo è stato quello di indagare se, applicando la tES, fosse possibile migliorare la performance di soggetti giovani sani in compiti di tipo cognitivo. Il progetto di ricerca si è sviluppato in 2 studi principali per un totale di 4 esperimenti. Tali studi hanno previsto l’acquisizione e la successiva analisi sia di dati comportamentali (tempi di reazione, accuratezza), che di indici psicofisiologici (conduttanza cutanea, diametro pupillare). I risultati hanno evidenziato che è possibile modulare l’arousal con dei “bursts” di stimolazione elettrica transcranica, somministrati in concomitanza di stimoli salienti per il soggetto. Tale modulazione si è manifestata con una riduzione dei tempi di reazione ed un contemporaneo aumento della risposta di conduttanza cutanea. Questi dati supportano la possibilità di utilizzare questo protocollo in pazienti con difficoltà di attenzione o altri problemi cognitivi per aumentare l’efficacia di interventi di riabilitazione. / The thesis analyzed the role of the arousal as a psychophysiological index of activation, and the application of non-invasive transcranial electrical stimulation (tES) technique with the aim to modulate this index. In this work we investigated if the application of tES could increase the performance of healthy young subjects during cognitive tasks. The thesis is based on 2 main studies for a total of 4 experiments with the recording of behavioural (reaction times, accuracy) and psychophysiological (skin conductance, pupil diameter) indeces. The results showed that it is possible to modulate arousal with bursts of tES, administered during the presentation of salient stimuli for the subject. This modulation resulted in a reduction of reaction times and an increase of the skin conductance response. These data support the possibility to use this protocol of stimulation with patients with attentional and other cognitive deficits in a rehabilitative context.

Damasio(1994)提出軀體標記假說（Somatic Marker Hypothesis）來解釋情緒如何影響行為決策，認為人們在決策前，與過去的情緒經驗關聯的生理反應會再現，幫助人們做出較好的決策判斷。並利用愛荷華賭博作業（Iowa Gambling Task）來模擬日常生活決策情境，並同時紀錄膚電反應(Skin conductance respons)，量測受試者決策前的預期膚電反應（Anticipatory SCR）和結果呈現後的回饋膚電反應(Feedback SCR)，加以佐證其神經生理機制。本研究將從三個方向進一步驗證其假說，分別是風險因素、生理證據和個別差異。在愛荷華賭博作業中，期望值負的牌也是高風險程度的牌，使結果無法清楚解釋是期望值或者風險程度造成的影響。而過去雖然有許多研究也使用膚電反應當做生理指標，但有許多相異的研究結果，並且較少研究利用事件關聯電位瞭解其中樞歷程。再者，過去相關研究發現個別差異的存在，但是缺乏一致的解釋。因此，本研究以修改版愛荷華賭博作業，控制期望值皆為零的狀況下，操弄風險程度，並且利用膚電反應和事件關聯電位當作周邊和和中樞的生理反應指標，探討受試者在單純風險情境，是否也會受到情緒軀體標記影響風險行為偏好，以及各項生理指標和風險行為偏好間的關聯，並瞭解不同風險偏好的受試者生理指標是否有所差異。結果發現，從行為上顯示有風險追逐和風險趨避兩組受試者，不同風險程度的牌損失回饋對受試者的歷程影響也不一樣，額葉的腦部回饋相關負波(Feedback-related Negativity，FRN)結果顯示，風險追逐的受試者對高低風險損失時的FRN沒有差異，風險趨避的受試者看到低風險損失時的FRN大於看到高風險損失時的FRN。此外，看到高風險酬賞比起低風險酬有較大回饋膚電反應的受試者，和看到高風險損失比起低風險損失有較小回饋膚電反應的受試者，接受高風險牌的比率也較高，其它生理變項對風險行為偏好沒有顯著的預測力。並且預期膚電反應並非過去研究認為單純扮演警訊或者誘因，而有更複雜的機制存在，受試者在接受非偏好的牌和拒絕偏好的牌前有較大的預期膚電反應。預期階段N170的結果顯示，受試者看到刺激之後會拒絕的N170會大於之後會接受的N170，顯示接受或拒絕兩種不同情境時受試者對刺激的處理歷程亦相異。 / Somatic Marker Hypothesis was proposed to explain the influence of emotion on decision making. To examine this hypothesis, Damasio and his colleagues designed the Iowa Gambling Task (IGT) and found that the “anticipatory skin conductance responses (SCR)”, i.e. somatic markers, was elevated before selecting from bad decks to serve as alarms and it warned participants not to select “bad deck” which was negative expected value. However, there are three unsolved problem in these IGT researches: the risk factor, inconsistent physiological evidences, and individual differences. In the original IGT, the bad decks are also more risky and that confounds the interpretations of participants’ choice behaviors and related physiological evidences. There are inconsistent evidences of how the anticipatory SCR and feedback SCR related with choice behaviors. Moreover, there are little event-related potential IGT studies. To solve these issues, the primary aim of the present study is to clarify whether decision making is influenced by risk level even when all options have the same expected value. A modified IGT with high risk deck and low risk deck was used and the expected values of two decks were all zero. Moreover, the procedure was different from original IGT. Participants saw a deck with mark first and then decided to accept or reject this deck. Thus, the role of anticipatory SCR could be clarified more clearly. In addition to SCR, ERP was also recorded for further physiological evidences. To elaborately clarify individual differences of choice behavior and physiological evidences, participants would group to risk-seeking (i.e., accepting more high risk deck and rejecting more low risk deck) and risk-aversion (i.e., accepting more low risk deck and rejecting more high risk deck) according their choice behaviors. The result revealed that the participant who accepted more high risk deck, their reward SCR was higher from high risk deck than from low risk decks, and induced lower punishment SCR from high risk deck than from low risk decks. Moreover, the anticipatory SCR was higher both before they decided to reject the liked deck and before they decided to accept the disliked deck. The results of feedback-related negativity (FRN) from ERP data in frontal region showed that the magnitude of FRN was larger under the conflict punishment (the punishment from low risk decks) condition for risk-aversion participants. The results of N170 from ERP data showed that the magnitude of N170 was larger under the reject condition. These results suggest that the SMH could be explained not only with expected value but also with risk preference. In conclusion, the interpretation of anticipatory SCR by previous study was not completed, and it reflected not merely the negative feeling or positive feeling. This strong anticipatory emotion affects people to change the routine behavior about their risk preference, and there exist individual differences of choice behavior and physiological evidences.

The present study examined the ability of a Virtual Reality (VR) public speaking task to elicit physiological arousal in adults with SAD (n=25) and Controls (n=25). A behavioral assessment paradigm was employed to address three study objectives: (a) to determine whether the VR task can elicit significant increases in physiological response over baseline resting conditions (b) to determine if individuals with SAD have a greater increase from baseline levels of physiological and self-reported arousal during the in vivo speech task as opposed to the VR speech task and (c) to determine whether individuals with SAD experience greater changes in physiological and selfreported arousal during each speech task compared to controls. Results demonstrated that the VR task was able to elicit significant increases in heart rate, skin conductance, and respiratory sinus arrhythmia, but did not elicit as much physiological or self-reported arousal as the in vivo speech task. In addition, no differences were found between groups. Clinical implications of these findings are discussed