The hippocampal formation has been implicated in spatial formation for many decades. The hippocampus proper has received the most attention but other regions of the hippocampal formation contribute largely to spatial cognition. This thesis concentrated on one such region, the postsubiculum. The postsubiculum is considered important because it contains head direction cells and because it thought to be a major input to the hippocampus, via the entorhinal cortex. This thesis aims to test the functional role of the rat postsubiculum under two types of situation: one where the rat must rely on idiothetic cues for navigation, and another where the rat has visual cues present and can rely on these for orientation. The thesis also investigates hippocampal place cells and their stability over time after short exposures to novel environments. Chapter 3 of this thesis aimed to test whether the postsubiculum is necessary for path integration during a homing task. Rats were trained on a homing task on a circular platform maze. Once the task was acquired, rats were given lesions of the postsubiculum or sham lesions and then re-tested on the path integration task. The homing performance of rats with lesions of the postsubiculum was as good as that of the sham rats. A series of manipulations suggests that the rats were homing by path integration, confirmed by probe tests. The rats were then tested on a forced-choice delayed alternation T-maze task that revealed a significant impairment in alternation with delays of 5, 30, and 60 seconds. This suggests that the postsubiculum is not necessary for path integration in a homing task but is necessary for avoiding previously visited locations as is necessary in an alternation task. The experiments in Chapters 4 and 5 of this thesis aimed to investigate the effects of postsubiculum pharmacological inactivation on hippocampal CA1 place cells when rats were introduced to a novel environment with visual cues. A necessary first step was to assess place cells without any manipulation of the postsubiculum (Chapter 4) and then use information gained from this in the design of experiments in Chapter 5. Rats chronically implanted with recording electrodes in the CA1 region of the hippocampus were exposed to novel cue-rich environments whilst place fields were recorded. Following delays of 3, 6, or 24 hours, the same cells were recorded again in the same environment but with the cues rotated by 90°. Pixel-by-pixel correlations of the place fields show that stability of the place fields was significantly lower at 24 hours than at 3 hours. Stability after 6 hours was not significantly different from 3 hours. In the third set of experiments, rats were implanted with drug infusion cannulae in the postsubiculum and recording electrodes in CA1. Following infusions of either the AMPA receptor antagonist CXQX, the NMDA receptor antagonist D-AP5 or a control infusion of ACSF, place field stability was assessed as rats were exposed to a cylindrical environment with a single polarising cue card for 3 x 10 minute sessions and then again 6 hours later. There were no differences in place field correlations between the 3 drug conditions, although there was evidence of larger changes in spatial information content between cells in the CNQX and AP5 drug condition, but not the ACSF condition. The results suggest that, under the present testing conditions, place fields stability did not depend upon AMPA receptor-mediated transmission nor did it depend on NMDA receptor-mediated synaptic plasticity.

This work has been motivated by the desire to enhance our knowledge about specific cognitive requirements of navigation in multiple reference frames environments and to understand the roles of the hippocampus and posterior parietal cortex in this behavior. The main conclusions of this thesis are: (a) We have developed a novel behavioral test called the Enemy Avoidance Task. The initial set of experiments has shown that laboratory rats are able to plan their movement with respect to a to-be-avoided moving object. Behavioral performance in the task may be quantitatively evaluated. (b) The aforementioned ability is crucially dependent on the functional integrity of the dorsal hippocampus. To the contrary, functional inactivation of the dorsal hippocampi by local infusion of tetrodotoxin did not cause any impairment in the ability of the animal to estimate its distance from a non-moving object. The finding suggests a specific role of the hippocampus in dynamic cognitive processes required for flexible navigation strategies such as continuous updating of information about the position of a moving stimulus. These results are at odds with the two major theories of hippocampal function (Cognitive map theory and Declarative memory theory) and therefore suggest that revision of the theories is necessary. (c)...

Durch dynamische Aktivität im Gehirn kann ein Organismus auf seine Umwelt reagieren. Der Parietallappen spielt zwar in vielen Anforderungsbereichen eine Rolle, soll sich jedoch auf bestimmte Merkmale beschränken. Dieser Widerspruch könnte in Annahmen über Aufgabencharakteristika und deren Verbindung zu parietaler Aktivität begründet sein. Viele kognitive Modellen klammern die Konnektivität des Gehirns aus, zulasten ihrer biologischen Plausibilität. Die vorliegende kumulative Dissertation umfasst drei Manuskripte, die einige dieser Probleme ansprechen. Symbolische (arabische Zahlen) und nichtsymbolische (Punktewolken) Multiplikation und Division wurden zur Validierung des experimentellen Paradigmas sowie zur Untersuchung von Antwortverzerrungen (Operational Momentum) benutzt. Aufgrund der besseren Leistung in symbolischen Aufgaben, wurden aufgabenbezogene Konnektivitätsveränderungen in zerebralen und parietalen Seed-Regionen mit psychophysiologischer Interaktionsanalyse (gPPI) bei symbolischer Multiplikation geprüft. Zudem wurden bildgebende Daten einer nichtsymbolischen Schätzaufgabe sowie in unabhängigen funktionellen Lokalisieraufgaben erhoben. Parietale und sensorische Regionen wurden mittels multivariater Verfahren (multivoxel pattern analysis) analysiert. Die Ergebnisse dieser drei Studien legen nahe, dass parietale Aktivität eine wichtige bereichsübergreifende Bedeutung besitzt, die eventuell mit Aufgabenschwierigkeit und kognitiver Anforderung zusammenhängt. Der Beitrag sensorischer Regionen zu bereichsspezifischen Leistungen scheint bedeutender als bislang angenommen. Der Parietallappen interagiert mit dem Zerebellum und beide reagieren auf Schwierigkeit. Die abnehmende Konnektivität bei zunehmend komplexen Multiplikationen legt nahe, dass eine komplexitätsabhängige Modulation der Konnektivität wichtig für eine bedarfsabhängig adäquate Reaktion ist. Zusammen zeigen diese Ergebnisse wie verschiedene Gehirnregionen auf Umweltanforderungen reagieren. / The brain’s dynamic activity allows an organism to respond to its environment. The parietal lobe plays a role in responding to demands in many domains. However, it is also claimed to be specific to many task features. One reason for this contradiction may be assumptions about task features and their link to parietal activity. The connectivity within the brain has also been overlooked in many cognitive models, making them less biologically plausible. This cumulative dissertation presents three manuscripts that address some of these issues. Symbolic (Arabic digits) and non-symbolic (dot-arrays) multiplication and division were used to behaviorally validate an experimental paradigm as well as test response bias (operational momentum). Subjects accurately responded to symbolic problems, therefore symbolic multiplication problems were used to examine task-related connectivity changes from cerebellar and parietal seed regions using psycho-physiological interactions analysis (gPPI). Finally, brain imaging data from a non-symbolic estimation task and an independent functional localizer was collected. Parietal and sensory regions were analyzed using multi-voxel pattern analysis (MVPA). The results of the three studies suggest that parietal activity may reflect a more domain-general role, possibly related to task complexity and cognitive demand. Additional sensory regions also seem to play a larger role in domain specific task performance than previously assumed. Furthermore, the parietal lobe interacts with the cerebellum and both regions are involved in responding to task complexity. Cerebellar-parietal connectivity decreased during more complex multiplication, suggesting that increased connectivity during simple tasks and/or decreased connectivity during complex tasks, may be important for response to task demands. Together, these findings demonstrate the roles of multiple brain regions in responding to environmental demands.

BACKGROUND: Social cognitive ability is a significant determinant of functional outcome and deficits in social cognition are a disabling symptom of psychotic disorders. The neurobiological underpinnings of social cognition are not well understood, hampering our ability to ameliorate these deficits. Using ‘resting-state’ fMRI (functional magnetic resonance imaging) and a trans-diagnostic, data-driven analytic strategy, we sought to identify the brain network basis of emotional intelligence, a key domain of social cognition. METHODS: Subjects included 60 participants with a diagnosis of schizophrenia or schizoaffective disorder and 46 healthy comparison participants from three different sites: Beth Israel Deaconess Medical Center, Boston, MA, McLean Hospital, Belmont, MA, and University of Pittsburgh, Pittsburgh, PA. All participants underwent a structural T1/MPRAGE and resting-state fMRI scan. Emotional Intelligence was measured using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). A connectome-wide analysis of brain connectivity examined how each individual brain voxel’s connectivity correlated with emotional intelligence using multivariate distance matrix regression (MDMR). RESULTS: We identified a region in the left superior parietal lobule (SPL) where individual network topology predicted emotional intelligence. Specifically, the association of this region with the Default Mode Network (DMN) predicted higher emotional intelligence (r = 0.424, p < 0.001) and association with the Dorsal Attention Network (DAN) predicted lower emotional intelligence (r = -0.504, p < 0.001). This correlation was observed in both schizophrenia and healthy comparison participants. These results held true despite corrections for sex, age, race, medication dosage (chlorpromazine equivalents), and full scale IQ (FSIQ), and was replicable per site. Post-hoc analyses showed that membership of the left SPL was entirely within the DMN in high scorers and within the DAN in low scorers. This relationship was also shown to be specific to the identified left SPL region when compared to adjacent regions. Sulcal depth analysis of the left SPL revealed a correlation to emotional intelligence (r = 0.269, p = 0.0075). CONCLUSIONS: Previous studies have demonstrated individual variance in brain network topology but the cognitive or behavioral relevance of these differences was undetermined. We observe that the left SPL, a region of high individual variance at the cytoarchitectonic level, also demonstrates individual variance in its association with large scale brain networks and that network topology predicts emotional intelligence. This is the first demonstration of a clinical phenotype in individual brain network topology. / 2019-07-03T00:00:00Z

Cette thèse a pour thème l'étude les mécanismes neurocognitifs impliqués dans la détermination de la latéralité intrinsèque d'objets. Dans une première étude, nous avons montré qu'une projection de son propre schéma corporel sur un objet est nécessaire pour en différencier la gauche de la droite. Cette inscription corporelle fut observée aussi bien pour des stimuli humains que non humains, suggérant que la présence d'axes intrinsèques à l'objet est suffisante pour y permettre la projection du corps. Une seconde étude nous a permis de mieux comprendre les mécanismes neuronaux de l'inscription corporelle, en utilisant une tâche de comparaison de formes identiques ou miroir différemment orientées. Les stimuli étaient soit des corps humains, soit des assemblages de cubes. La magnetoencephalographie (MEG) révéla une implication du lobe pariétal supérieur gauche dans l'incarnation et la transformation spatiale des deux stimuli. Par ailleurs, une contribution de l'aire motrice supplémentaire fut observée dans le cas des cubes. Ainsi, nous proposons de considérer le lobe pariétal supérieur comme le substrat neural d'un émulateur utilisant le schéma corporel afin d'encoder la latéralité d'un objet et de prédire les conséquences visuelles d'une transformation spatiale. La contribution additionnelle de l'aire motrice supplémentaire a probablement facilité la transformation de formes non familières, par l'envoi d'une commande motrice à l'émulateur visant à accroître la cohérence de l'objet tourné mentalement. Ces interprétations supportent l'idée d'une cognition incarnée dans les actions corporelles. / The aim of this thesis was to study the neurocognitive mechanisms implicated in the determination of objects intrinsic handedness. In a first study, we evidenced that distinguishing the left from the right of an object requires a mental projection of the body schema onto the stimulus. This embodiment process occured for human and non human stimuli as well, suggesting that the mere presence of intrinsic axes on stimulus enables the bodily projection. In a second study, we explored the neural mechanisms underlying embodiment in a handedness shape matching task, using human bodies and cubes assemblies as stimuli with different orientations. Magnetoencephalography (MEG) revealed that the left superior parietal lobe participated in the embodiment and spatial transformation of both stimuli. In addition, we observed a contribution of the supplementary motor area for cube assemblies specifically. Therefore, we consider the superior parietal lobe as the neural substrate of an emulator processing the body schema to encode handedness and to predict the visual consequences of a spatial transformation. Besides, the additional contribution of the supplementary motor area probably helped the spatial transformation of unfamiliar shapes by backpropagating a motor command to the emulator to increase cohesiveness of the mentally rotated object. These interpretations support the grounding of cognition in bodily actions.

Le contrôle cognitif est défini comme l'ensemble des processus guidant la sélection de nos actions en fonction de nos buts et des événements externes. Ce travail étudie les bases neurales du contrôle cognitif chez l'humain au moyen de l'imagerie par résonnance magnétique fonctionnelle (IRMf). Dans une première étude, nous montrons qu'il existe trois niveaux hiérarchiques du contrôle cognitif : le contrôle sensoriel, exercé par le cortex prémoteur, sélectionne les actions en fonction des stimuli ; le contrôle contextuel, exercé par le cortex préfrontal latéral (CPFL) postérieur, sélectionne les associations sensorimotrices (les tâches) en fonction du contexte immédiat des stimuli ; le contrôle épisodique, exercé par le CPFL antérieur, sélectionne les tâches et les réponses en fonction des événements passés. Dans une deuxième étude, nous montrons que les contrôles sensoriel, contextuel et épisodique interviennent également dans la sélection préparatoire des actions, et engagent alors respectivement les mêmes régions qui sont engagées au moment de l'exécution. Dans une troisième étude, nous montrons que chaque région du cortex frontal latéral possède une homologue fonctionnelle dans le cortex pariétal. La réciproque n'est toutefois pas vérifiée : nous révélons une région pariétale spécifique qui serait impliquée dans le calcul, et non dans la sélection des réponses possibles associées aux stimuli perçus. En outre, alors que les régions frontales présentent une organisation hiérarchique, les régions pariétales présentent une architecture parallèle. Nos résultats expérimentaux supportent ainsi un modèle global de l'organisation du contrôle cognitif dans le cortex cérébral.

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Submitted by Marta Toyoda (1144061@mackenzie.br) on 2017-01-11T16:07:37Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Patricia Aparecida Dall'Agnol.pdf: 1602930 bytes, checksum: 8098731b4aaab3d45152553a6766f941 (MD5) / Approved for entry into archive by Eliezer Santos (eliezer.santos@mackenzie.br) on 2017-02-01T20:03:08Z (GMT) No. of bitstreams: 2 Patricia Aparecida Dall'Agnol.pdf: 1602930 bytes, checksum: 8098731b4aaab3d45152553a6766f941 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-02-01T20:03:08Z (GMT). No. of bitstreams: 2 Patricia Aparecida Dall'Agnol.pdf: 1602930 bytes, checksum: 8098731b4aaab3d45152553a6766f941 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Rubber Hand Illusion (RHI) is generated by the conflict between synchronized visual and tactile stimuli delivered at the same time in the participant’s hand, occluded from the vision, and in a visible rubber prosthesis. Such conflict generates the sensation of incorporation of the extra limb in the participant. This illusion enable evaluate body awareness and how we perceive our body and single parts of it. Neuroimaging studies show that during the RHI the main cortical areas activated are the Premotor Cortex (PMC) and the Posterial Parietal Cortex (PPC). The knowledge of this areas playing an important role of multisensory integration that underlies the generation of the illusion and that the transcranial direct current stimulation (tDCS) technique has the ability of interfere on cortical activity, this study aimed to investigate possible neuromodulatory effects during the perception of the RHI. Specifically, we investigated effects of tDCS over PMC and PPC over i) time to perceive the RHI, ii) proprioceptive shift and iii) intensity of the illusion, measured via questionary. We evaluated 36 volunteers divided in 2 groups. The group 1 received tDCS over the PMC and the group 2 received tDCS over the PPC. The applied montages to both groups were: i anodal current at right hemisphere and cathodal current at left hemisphere; ii. anodal current at left hemisphere and cathodal current at right hemisphere; and iii. Sham condition.We verify that when tDCS was applied over the PMC using anodal current on the right hemisphere and cathodal current on the left hemisphere there is a significant effect on the proprioceptive shift task. Specifically, the volunteers had a greater shift towards the extra limb when compared to sham condition. However we found no effects for the opposite montage. Regarding the application of tDCS over PPC, we observed that the montage of anodal current on the right hemisphere and cathodal current on the left hemisphere promotes significant effects over the time taken to perceive the RHI. Specifically, this stimulation results in faster appropriation of the extra limb when compared to the opposite montage and to sham conditions. Finally, no effects of tDCS were found at the questionary evaluation in none of the groups. Thus, the study demonstrated that application of anodal right and cathodal left tDCS, in both of the studied areas promotes an increased perception of the RHI. In conclusion, this studiy increases the knowledge of the role of PMC and PPC in the integration of visual and tactile stimuli during the RHI, thus increasing knowledge about the aspects of body ownership. Besided it signals the possibility of tDCS as na useful tool for studies in this área and following from clinical application. / A Ilusão da Mão de Borracha (IMB) é gerada pelo conflito entre estímulos visuais e táteis sincronizados realizados ao mesmo tempo na mão do participante, que é ocluída de sua visão, e em uma prótese de borracha visível. Tal conflito gera a sensação de incorporação do membro extra nos participantes. Dessa forma, tal ilusão possibilita avaliar o domínio da consciência corporal em relação a como percebemos nosso corpo e partes dele. Estudos de neuroimagem mostram que durante a IMB as principais áreas corticais envolvidas são o Córtex Pré-Motor (CPM) e o Córtex Parietal Posterior (CPP). Sabendo que essas áreas desempenham importante papel de integração sensorial para que a ilusão ocorra e que a técnica de Estimulação Transcraniana por Corrente Contínua (ETCC) tem a capacidade de interferir na atividade cortical, o presente estudo objetivou investigar os possíveis efeitos da neuromodulação durante a percepção da IMB. Especificamente, investigamos o efeito das montagens de ETCC aplicadas sobre o CPM e o CPP durante a i) percepção do tempo de início da IMB, ii) o deslocamento proprioceptivo e iii) a intensidade da ilusão medida via questionário. Foram avaliados 40 voluntários divididos em 2 grupos. O grupo 1 recebeu ETCC sobre a área do CPM e o grupo 2 sobre a área do CPP. As montagens realizadas para ambos os grupos foram i. corrente anódica em hemisfério direito e corrente catódica em hemisfério esquerdo, ii. corrente anódica em hemisfério esquerdo e corrente catódica em hemisfério direito, e iii. condição placebo. Verificamos que a ETCC aplicada sobre o CPM com a montagem de corrente anódica sobre o hemisfério direito e corrente catódica sobre o hemisfério esquerdo revelou efeito significativo sobre a tarefa do deslocamento proprioceptivo. Especificamente, os voluntários apresentaram maior deslocamento em direção ao membro extra em comparação com a condição placebo, porém, não observamos efeito significativo em relação a montagem contrária. Em relação à aplicação de ETCC sobre o CPP, foi observado que a montagem corrente anódica sobre o hemisfério direito e corrente catódica sobre o hemisfério esquerdo promoveu efeito significativo sobre a percepção do tempo de início da IMB. Especificamente, a estimulação desta área levou a apropriação mais rápida do membro extra em comparação com a montagem contrária e também com a condição placebo. Por fim, não foram observados efeitos da ETCC nas respostas do questionário para ambos os grupos. Desta forma, o estudo demonstrou que a aplicação de ETCC anódica em hemisfério direito e catódica em hemisfério esquerdo em ambas as áreas estudadas aumenta a percepção da IMB. Nossos resultados sinalizaram pela primeira vez com o uso da ETCC a participação do CPM na percepção da localização proprioceptiva e do CPP na percepção do tempo de início da ilusão durante a indução da IMB. Em conclusão, este estudo amplia a compreensão do papel de CPM e CPP na integração dos estimulos visuo-táteis durante a IMB ampliando os conhecimentos sobre sobre os aspectos da propriedade corporal, além de apontar a possibilidade da ETCC ser uma ferramenta útil para estudos nesta área e posteriormente para futuras aplicabilidades clínicas.

Les méthodes non-invasives de neuro-imagerie et de neurostimulation peuvent être combinées pour mieux comprendre les connexions dans le cerveau. Pour la première fois, une étude combine de façon séquentielle l’IRM fonctionnelle (fMRI) et un protocole de TMS associative pairée cortico-corticale (TMS-PAScc) sur le cortex moteur primaire (M1) et sur le lobule pariétal inférieur (LPI) dans l’hémisphère gauche. La TMS module-t-elle le couplage neurovasculaire et permet-elle de renforcer une connexion fonctionnelle qui soit détectable à la fMRI à l’état de repos (RS-fMRI)? 10 sujets droitiers et en santé font une session de TMS-PAScc LPI-M1 de courte durée (180 paires d’impulsions, fréquence de stimulation à 0.02 Hz). Les mêmes sujets font 2 sessions de la RS-fMRI, avant et après le protocole PAScc. Les résultats montrent que la corrélation du signal BOLD entre les régions LPI-M1 avant et après la PAScc ne change pas de façon significative (avant-PAS=0.10±0.07 et après-PAS=0.09±0.07, p=0.64), tout comme l’amplitude des potentiels évoqués moteurs (PEM) des impulsions pairées LPI-M1 ne change pas de façon significative du début de la PAScc à 25 minutes après la PAScc (PASdébut=0.71±0.46mV, PASpost25min=0.72±0.89mV, p=0.338). Toutefois, les PEM des impulsions pairées LPI-M1 sont réduites par rapport aux PEM des impulsions simples M1, avant la PAScc et après la PAScc (PEM simples_pré et PASdébut, réduction de 0.32mV, p=0.05; PEM simples_post et PASpost25min, réduction de 0.39mV p=0.008), illustrant la présence d’un lien fonctionnel de nature inhibitrice entre LPI et M1. Toutefois, l’amplitude de cette inhibition n’est pas modulée de façon significative par la TMS-PAScc (ratio mesures pairées/mesures simples préPAS=0.9 et ratio postPAS=0.6, p=0.257). Dans l’ensemble, la TMS-PAScc ne montre pas d’effet soutenu sur la connectivité cérébrale telle que mesurée par la RS-fMRI et la TMS et ce, bien que le LPI montre un lien inhibiteur sur M1 de façon aigue. Plusieurs hypothèses peuvent expliquer cette absence d’effet soutenu, notamment, il est possible que l’altération de la connectivité ne soit visible que lorsque le réseau LPI-M1 est activement sollicité, comme durant l’exécution d’une tâche motrice. Il est aussi possible que le nombre de pairages soit insuffisant pour induire des changements mesurables, mais que la connectivité fonctionnelle suite à des sessions répétées de protocole PAScc pourrait modifier le couplage neurovasculaire et la plasticité cérébrale. / Abstract : Noninvasive neuroimagery and neurostimulation methods can be combined to further the understanding of the human brain connections. For the first time, resting state functional MRI (RS-fMRI) and paired associative cortico-cortical TMS (TMS-PAScc) of the motor cortex (M1) and the cortex of the inferior parietal lobule (LPI) of the left hemisphere are combined in a serial manner. Is TMS able to modify the neurovascular coupling as to facilitate LPI-M1 functional connectivity and change the fMRI BOLD signal? 10 right-handed and healthy subjects did a LPI-M1 TMS-PAScc session of short duration (180 paired pulses at 0.02 Hz, 15 min total). The same subjects underwent 2 fMRI sessions, before and after TMS-PAScc LPI-M1. Results show that the BOLD signal correlation between LPI-M1 does not change significantly before and after PAS (prePAS=0.10±0.07 et postPAS=0.09±0.07, p=0.64). TMS measures of motor evoked potentials (PEM) were taken before and after PAS LPI-M1. The paired pulse PEM measures did not change significantly from the start of PAScc to 25 minutes postPAS (PASstart=0.71 ± 0.46 mV, PASpost25min=0.72±0.89 mV, p=0.338). Paired PEM measures are statistically reduced from PAS PEM single measures, before and afterPAS (sPEM_pre et PASstart, significant 0.32mV reduction, p=0.05; PEMs_post et PASpost25min, 0.39mV reduction, p=0.008). PAScc did not show any significant neuroplasticity effect after 20 minutes because paired pulses did not change before and after PAScc. The PEM reduction of paired pulses is most likely related to the inhibiting effect of the conditioning stimulus of LPI on the test stimulus of M1 at 8ms. This inhibition is an effect limited to the measure itself and does not increase significantly with time (pairedpulse/singlepulsemeasures prePASratio=0.9 and postPASratio=0.6, p=0.257). TMSPAScc did not show a sustained effect on cerebral connectivity as measured by RS-fMRI although stimulation of LPI showed an acute inhibiting effect on M1 during paired measures. LPI-M1 TMS-PAScc did not show sustained connectivity and it could be because no task was involved in our study to actively solicit both cerebral regions during PAS. It is also possible that the number of paired stimulation was not enough to bring a change of connectivity and that PAS needs to be repeated on different days to eventually have a sustainable effect.

No description available.