Study of the electroencephalographic correlates of mind wandering and meditation. Etude des corrélats électroencéphalographiques de la dérive attentionnelle et de la méditation

Si l'on essaye de concentrer notre attention sur un objet physique ou mental donné, on s'aperçoit vite qu'elle ne peut pas rester indéfiniment fixée sur l'objet en question mais se ré-oriente rapidement vers d'autres pensées ou sensations, un phénomène appelé dérive attentionnelle. Fait intéressant, les anciennes traditions de pratiques de méditation ont développé une grande variété de méthodes visant à développer la prise de conscience des épisodes de dérive attentionnelle et à entraîner l'esprit à rester concentré. Il est important de souligner que la connaissance du contenu de l'attention est une information qui est personnelle au sujet et qui ne peut être évaluée qu'à l'aide de méthode prennant en compte la perspective à la première personne. Au cours de ma thèse, j'ai étudié à la fois la dérive attentionnelle et les états de méditation dans un effort pour mieux comprendre ce qui se passe dans le cerveau quand quelqu'un médite. Quelle que soit la tradition de méditation, les dérives attentionnelles sont omniprésentes pendant la méditation. Ce sujet constitue donc un point de départ idéal pour l'étude de la méditation. Ce phénomène de dérive attentionnelle n'est pas unique à la méditation mais est présent dès qu'une personne se concentre sur une tâche à l'exclusion de toute autre. En utilisant un protocole nouveau, nous montrons que les épisodes de dérive attentionnelle sont accompagnés par une amplitude accrue des basses fréquences EEG 1-3Hz delta et 4-7Hz theta ainsi qu'une réduction du traitement sensoriel pré-attentif, comme le montre l'analyse de potentiels évoqués. Ces résultats indiquent que la dérive attentionnelle est associée à un niveau réduit de vigilance, similaire aux premiers stades de la somnolence. Ceci est cohérent avec certains textes bouddhistes sur la méditation, qui représentent la dérive attentionelle comme un état de sommeil par rapport aux périodes où l'esprit est concentré. Puis, nous avons réalisé une étude comparative de l'activité EEG au cours de la méditation pour tenter de déterminer l'origine des résultats divergents de la littérature. Nous avons enregistré l'activité spontanée EEG de 3 groupes de méditants de 3 différentes traditions de méditation et d'un groupe de non-méditants en utilisant le même protocole. Nous avons montré que tous les groupes de méditants avaient une amplitude de fréquence gamma 60-110Hz plus élevée par rapport aux contrôles pendant la méditation, indiquant peut-être des processus attentionnels différents chez les méditants. Aucune différence n'a été trouvée entre l'état mental contrôle et l'état méditatif chez les méditants, ce qui suggère que les modifications dues à la pratique longue de la méditation sont plus robustes que les effets de l'état mental de méditation par rapport à un état contrôle. Dans l'ensemble, notre étude souligne la nécessité de mieux définir ce que pourrait être le meilleur état de contrôle mental pour la méditation. Au cours de ce travail j'ai également exploré les méthodologies pour recueillir des informations subjectives pertinentes. Notre travail apporte de nouvelles perspectives pour l'étude la conscience humaine, mais la route reste longue avant que nous ne comprenions parfaitement les mécanismes sous-jacents de notre vie intérieure.Trying to focus our attention on any given physical or mental object, we soon realize it cannot be kept indefinitely focused and soon drifts towards other thoughts or sensations, a phenomenon called mind wandering. Interestingly, ancient traditions of meditation practices have developed a large variety of methods aiming at developing the awareness of mind wandering episodes and training the mind to remain focused. It is important to point out that the knowledge of the focus of attention is a type of information that is private to the subject and that can only be assessed using methods that take into account first-person perspectives. During my thesis, I studied both the mind wandering and the meditation mental states in an effort to better understand what is happening in the brain when someone meditates. First, regardless of the meditation tradition, mind wandering is ever present during meditation and it seemed like an ideal starting point for studying meditation. It is also a phenomenon that is not unique to meditation and is present whenever a person attempts to focus. Using a novel EEG protocol, we show that mind wandering episodes are accompanied by increased amplitude at low frequencies in the delta (1-3Hz) and theta (4-7Hz) frequency bands as well as a reduction of pre-attentive sensory processing as shown by the analysis event-related potentials. These results indicate that mind wandering is associated with a lower vigilance level, resembling early stages of drowsiness. These results are consistent with some Buddhist texts on meditation, in which mind wandering is considered to be a state of relative sleep where the mind is not aware. Then, we realized a comparative study of EEG activity during meditation to attempt to sort out the origin of the divergent results found in the literature. We recorded the spontaneous EEG activity of 3 groups of meditators from 3 different meditation traditions in addition to a non-meditator group using the same protocol and equipment. We showed that all groups of meditators had higher 60-110Hz gamma amplitude when compared to the controls during meditation, possibly indicating different attentional processes in meditators. No differences were found between the mental control state and the meditative state in meditators, suggesting that we were observing trait rather than state effects of meditation. Overall, our study emphasizes the need to better define what could be the best control mental state for meditation. During this work, I also explored the methodologies allowing the collection of accurate subjective data. Our work brings new data in the field of consciousness, mind wandering and meditation study, but the road will be long before we fully understand the mechanisms underlying our inner life

Plasticity of visual attention in Isha yoga meditation practitioners before and after a 3-month retreat.

Meditation has lately received considerable interest from cognitive neuroscience. Studies suggest that daily meditation leads to long lasting attentional and neuronal plasticity. We present changes related to the attentional systems before and after a 3 month intensive meditation retreat. We used three behavioral psychophysical tests - a Stroop task, an attentional blink task, and a global-local letter task-to assess the effect of Isha yoga meditation on attentional resource allocation. 82 Isha yoga practitioners were tested at the beginning and at the end of the retreat. Our results showed an increase in correct responses specific to incongruent stimuli in the Stroop task. Congruently, a positive correlation between previous meditation experience and accuracy to incongruent Stroop stimuli was also observed at baseline. We also observed a reduction of the attentional blink. Unexpectedly, a negative correlation between previous meditation experience and attentional blink performance at baseline was observed. Regarding spatial attention orientation as assessed using the global-local letter task, participants showed a bias toward local processing. Only slight differences in performance were found pre- vs. post- meditation retreat. Biasing toward the local stimuli in the global-local task and negative correlation of previous meditation experience with attentional blink performance is consistent with Isha practices being focused-attention practices. Given the relatively small effect sizes and the absence of a control group, our results do not allow clear support nor rejection of the hypothesis of meditation-driven neuronal plasticity in the attentional system for Isha yoga practice

The Cognitive Correlates of Anthropomorphism

While anthropomorphism in human-robot interaction is often discussed, it still appears to lack formal grounds. We recently proposed a first model of the dynamics of anthropomorphism that reflects the evolution of anthropomorphism in the human-robot interaction over time. The model also accounts for non-monotonic effects like the so-called novelty effect. This contribution proposes to build upon this model to investigate the cognitive correlates induced by a sustained human-robot interaction and we present here our initial ideas. We propose to distinguish three cognitive phases: pre-cognitive, familiarity-based, and adapted anthropomorphism, and we outline how these phases relate to the phenomenological evolution of anthropomorphism over time

Internet-Based Intervention for Posttraumatic Stress Disorder:Using Remote Imagery Rehearsal Therapy to Treat Nightmares

No abstract availabl

Spontaneous visual imagery during meditation for creating visual art: an EEG and brain stimulation case study

Experienced meditators often report spontaneous visual imagery during deep meditation in the form of lights or other types of visual images. These experiences are usually interpreted as an “encounters with light” and gain mystical meaning. Contrary to the well-studied intentional and controlled visual imagery, spontaneous imagery is poorly understood, yet it plays an important role in creativity of visual artists. The neural correlates of such experiences are indeed hard to capture in laboratory settings. In this case study we aimed to investigate the neural correlates of spontaneous visual imagery in an artist who experiences strong visual imagery during meditation. She uses these images to create visual art. We recorded her EEG during 7 meditation sessions in which she experienced visual imagery episodes (visions). To examine the functional role of the neural oscillations we also conducted 3 separate meditation sessions under different transcranial alternating current (tACS) brain stimulation: alpha (10 Hz), gamma (40 Hz) and sham. We observed a robust increase in occipital gamma power (30-70 Hz) during the deepest stage of meditation across all sessions. This gamma increase was consistent with the experience of spontaneous visual imagery: higher during visions compared to no visions. Alpha tACS was found to affect the contents of her visual imagery, making them sharper, shorter and causing more visions to occur. The artist reported that these sharp images were too detailed to be used in her art. Interestingly, gamma and sham stimulation had no impact on her the visual imagery contents. Our findings raise the hypothesis that occipital gamma might be a neural marker of spontaneous visual imagery, which emerges in certain meditation practices of experienced meditators

Interpreting EEG alpha activity

Exploring EEG alpha oscillations has generated considerable interest, in particular with regards to the role they play in cognitive, psychomotor, psycho-emotional and physiological aspects of human life. However, there is no clearly agreed upon definition of what constitutes ‘alpha activity’ or which of the many indices should be used to characterize it. To address these issues this review attempts to delineate EEG alpha-activity, its physical, molecular and morphological nature, and examine the following indices: (1) the individual alpha peak frequency; (2) activation magnitude, as measured by alpha amplitude suppression across the individual alpha bandwidth in response to eyes opening, and (3) alpha “auto-rhythmicity” indices: which include intra-spindle amplitude variability, spindle length and steepness. Throughout, the article offers a number of suggestions regarding the mechanism(s) of alpha activity related to inter and intra-individual variability. In addition, it provides some insights into the various psychophysiological indices of alpha activity and highlights their role in optimal functioning and behavior

Mind wandering and task-focused attention: ERP correlates

Previous studies looking at how Mind Wandering (MW) impacts performance in distinct Focused Attention (FA) systems, using the Attention Network Task (ANT), showed that the presence of pure MW thoughts did not impact the overall performance of ANT (alert, orienting and conflict) performance. However, it still remains unclear if the lack of interference of MW in the ANT, reported at the behavioral level, has a neurophysiological correspondence. We hypothesize that a distinct cortical processing may be required to meet attentional demands during MW. The objective of the present study was to test if, given similar levels of ANT performance, individuals predominantly focusing on MW or FA show distinct cortical processing. Thirty-three healthy participants underwent an EEG high-density acquisition while they were performing the ANT. MW was assessed following the ANT using an adapted version of the Resting State Questionnaire (ReSQ). The following ERP's were analyzed: pN1, pP1, P1, N1, pN, and P3. At the behavioral level, participants were slower and less accurate when responding to incongruent than to congruent targets (conflict effect), benefiting from the presentation of the double (alerting effect) and spatial (orienting effect) cues. Consistent with the behavioral data, ERP's waves were discriminative of distinct attentional effects. However, these results remained true irrespective of the MW condition, suggesting that MW imposed no additional cortical demand in alert, orienting, and conflict attention tasks.Acknowledgements Óscar F. Gonçalves was funded by the Brazilian National Counsel for Scientific and Technological Development (CNPq) as a Special Visiting Researcher of the Science Without Borders program (401143/2014-7). Paulo S Boggio was funded by a CNPq researcher fellowship (311641/2015-6). Olivia Morgan Lapenta and Tatiana Conde were supported by two postdoctoral grants from CNPq (150249/2017-9 and 152358/2016-1). Sandra Carvalho was funded by the Portuguese Foundation for Science and Technology (FCT) with the grant IF/00091/2015. Gabriel Rêgo was supported by a PhD grant from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP-2015/18713-9). This work was partially supported by FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE and by national funds through FCT – Fundação para a Ciência e a Tecnologia (P2020-PTDC/MHC-PCN/3950/2014).info:eu-repo/semantics/publishedVersio

Perceived spirituality, mindfulness and quality of life in psychiatric patients

There is some evidence of the relationship between spirituality and quality of life, but there are few bibliographic references on these constructs for patients suffering from mental illness; thus, this study was aimed at revealing the possible role of spiritual outlooks as a protective factor in these individuals. The sample consisted of 96 Portuguese psychiatric patients, selected from a psychiatric hospital and assessed based on parameters for quality of life, spirituality and mindfulness. The data support some theories about the nature of the spirituality. Spiritual beliefs are poorly correlated with the quality of life index, and there is a moderate association between these beliefs and some aspects of mindfulness. It is suggested that a spiritual outlook of psychiatric patients should be taken into account in psychological interventions