Made available in DSpace on 2014-12-17T15:36:38Z (GMT). No. of bitstreams: 1 SergioAMR_TESE_1-152.pdf: 4687573 bytes, checksum: d13791598d6a440077f9a5703901fe3b (MD5) Previous issue date: 2012-06-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Lucid dreaming (LD) is a mental state in which the subject is aware of being dreaming while dreaming. The prevalence of LD among Europeans, North Americans and Asians is quite variable (between 26 and 92%) (Stepansky et al., 1998; Schredl & Erlacher, 2011; Yu, 2008); in Latin Americans it is yet to be investigated. Furthermore, the neural bases of LD remain controversial. Different studies have observed that LD presents power increases in the alpha frequency band (Tyson et al., 1984), in beta oscillations recorded from the parietal cortex (Holzinger et al., 2006) and in gamma rhythm recorded from the frontal cortex (Voss et al., 2009), in comparison with non-lucid dreaming. In this thesis we report epidemiological and neurophysiological investigations of LD. To investigate the epidemiology of LD (Study 1), we developed an online questionnaire about dreams that was answered by 3,427 volunteers. In this sample, 56% were women, 24% were men and 20% did not inform their gender (the median age was 25 years). A total of 76.5% of the subjects reported recalling dreams at least once a week, and about two-thirds of them reported dreaming always in the first person, i.e. when the dreamer observes the dream from within itself, not as another dream character. Dream reports typically depicted actions (93.3%), known people (92.9%), sounds/voices (78.5%), and colored images (76.3%). The oneiric content was related to plans for upcoming days (37.8%), and memories of the previous day (13.8%). Nightmares were characterized by general anxiety/fear (65.5%), feeling of being chased (48.5%), and non-painful unpleasant sensations (47.6%). With regard to LD, 77.2% of the subjects reported having experienced LD at least once in their lifetime (44.9% reported up to 10 episodes ever). LD frequency was weakly correlated with dream recall frequency (r = 0.20, p <0.001) and was higher in men (?2=10.2, p=0.001). The control of LD was rare (29.7%) and inversely correlated with LD duration (r=-0.38, p <0.001), which is usually short: to 48.5% of the subjects, LD takes less than 1 minute. LD occurrence is mainly associated with having sleep without a fixed time to wake up (38.3%), which increases the chance of having REM sleep (REMS). LD is also associated with stress (30.1%), which increases REMS transitions into wakefulness. Overall, the data suggest that dreams and nightmares can be evolutionarily understood as a simulation of the common situations that happen in life, and that are related to our social, psychological and biological integrity. The results also indicate that LD is a relatively common experience (but not recurrent), often elusive and difficult to control, suggesting that LD is an incomplete stationary stage (or phase transition) between REMS and wake state. Moreover, despite the variability of LD prevalence among North Americans, Europeans and Asians, our data from Latin Americans strengthens the notion that LD is a general phenomenon of the human species. To further investigate the neural bases of LD (Study 2), we performed sleep recordings of 32 non-frequent lucid dreamers (sample 1) and 6 frequent lucid dreamers (sample 2). In sample 1, we applied two cognitive-behavioral techniques to induce LD: presleep LD suggestion (n=8) and light pulses applied during REMS (n=8); in a control group we made no attempt to influence dreaming (n=16). The results indicate that it is quite difficult but still possible to induce LD, since we could induce LD in a single subject, using the suggestion technique. EEG signals from this one subject exhibited alpha (7-14 Hz) bursts prior to LD. These bursts were brief (about 3s), without significant change in muscle tone, and independent of the presence of rapid eye movements. No such bursts were observed in the remaining 31 subjects. In addition, LD exhibited significantly higher occipital alpha and right temporo-parietal gamma (30-50 Hz) power, in comparison with non-lucid REMS. In sample 2, LD presented increased frontal high-gamma (50-100 Hz) power on average, in comparison with non-lucid REMS; however, this was not consistent across all subjects, being a clear phenomenon in just one subject. We also observed that four of these volunteers showed an increase in alpha rhythm power over the occipital region, immediately before or during LD. Altogether, our preliminary results suggest that LD presents neurophysiological characteristics that make it different from both waking and the typical REMS. To the extent that the right temporo-parietal and frontal regions are related to the formation of selfconsciousness and body internal image, we suggest that an increased activity in these regions during sleep may be the neurobiological mechanism underlying LD. The alpha rhythm bursts, as well as the alpha power increase over the occipital region, may represent micro-arousals, which facilitate the contact of the brain during sleep with the external environment, favoring the occurrence of LD. This also strengthens the notion that LD is an intermediary state between sleep and wakefulness / O sonho l?cido (SL) ? um estado mental no qual o sujeito est? consciente de estar sonhando durante o sonho. A preval?ncia do SL em Europeus, Norte-Americanos e Asi?ticos ? bastante vari?vel (entre 26 e 92%) (Stepansky et al., 1998; Erlacher & Schredl, 2011; Yu, 2008) e em Latino-Americanos ainda n?o foi investigada. Al?m disso, as bases neurais do SL permanecem controversas. Diferentes estudos observaram um aumento da pot?ncia na frequ?ncia alfa (Tyson et al., 1984), na oscila??o beta na ?rea parietal (Holzinger et al., 2006) e no ritmo gama na regi?o frontal (Voss et al., 2009) durante o SL em rela??o ao n?o l?cido. Assim, para investigar a quest?o epidemiol?gica (Estudo 1), elaboramos um question?rio online sobre sonhos que foi respondido por 3427 volunt?rios. Em nossa amostra, 56% s?o mulheres, 24% s?o homens e 20% n?o responderam o g?nero; a mediana de idade foi de 25 anos. Um total de 76,5% dos indiv?duos refere que lembra dos sonhos pelo menos uma vez por semana. Cerca de dois ter?os dos sujeitos observam o sonho em primeira pessoa, ou seja, vendo o sonho da pr?pria perspectiva e n?o como mais um dos personagens do sonho. Os elementos mais comuns nos sonhos s?o movimentos/a??es (93,3%), pessoas conhecidas (92,9%), sons/vozes (78,5%) e imagens coloridas (76,3%). O conte?do on?rico se relaciona principalmente com planos para o dia seguinte (37,8%) e mem?rias do dia anterior (13,8%). Os pesadelos apresentam principalmente ansiedade/medo (65,5%), ser perseguido (48,5%) e sensa??es desagrad?veis que n?o envolvem dor (47,6%). Assim, sonhos e pesadelos podem ser evolutivamente entendidos como uma simula??o das situa??es frequentes que acontecem na vida e que se relacionam com a nossa integridade social, psicol?gica e biol?gica. Observamos tamb?m que a maioria dos indiv?duos (77,2%) relata ter tido pelo menos um SL, tendo experimentado na sua maior parte at? 10 epis?dios (44,9%). A frequ?ncia do SL foi fracamente correlacionada com a frequ?ncia de lembran?a dos sonhos (r=0,20, p<0,001) e foi tamb?m maior em homens (?2=10,2, p= 0,001). O controle do SL ? raro (29,7%) e inversamente correlacionado com o tempo de dura??o do SL (r=- 0,38, p<0,001), que normalmente ? curto: para 48,5% dos sujeitos o SL dura menos que 1 minuto. A ocorr?ncia do SL ? principalmente facilitada pela possibilidade de dormir sem hora para acordar (38,3%) que aumenta a chance de ter sono REM (SREM), e estresse (30,1%) que aumenta tamb?m as transi??es do SREM para a vig?lia. Como conclus?o, nossos resultados indicam que o SL ? uma experi?ncia relativamente comum (mas n?o recorrente), geralmente fugaz e dif?cil de controlar, o que sugere que o SL ? um est?gio intermedi?rio, incompleto e estacion?rio (ou fase de transi??o) entre o SREM e a vig?lia. Al?m disso, apesar das popula??es Europeias, Norte-Americanas e Asi?ticas terem uma preval?ncia de SL bastante vari?vel, nossos dados de uma amostra de Latino-Americanos fortalecem a no??o de que o SL ? um fen?meno universal da esp?cie humana. Para investigar as bases neurais do SL (Estudo 2), realizamos registros de sono em 32 sujeitos que n?o apresentam SL de forma frequente, e investigamos 6 sujeitos que apresentam SL recorrentemente. A primeira amostra foi submetida a duas t?cnicas cognitivo-comportamentais para induzir o SL: sugest?o pr?- sono (n = 8) e incuba??o de est?mulos do ambiente (pulsos de luz) no sonho durante o SREM (n = 8). Um grupo controle n?o foi submetido a nenhuma das duas t?cnicas (n = 16). Os resultados indicam que ? muito dif?cil induzir SL em laborat?rio, uma vez que conseguimos obter apenas um SL em um sujeito, que era do grupo em que aplicamos a t?cnica de sugest?o pr?-sono. O sinal eletroencefalogr?fico deste volunt?rio apresentou pulsos de ritmo alfa (7-14Hz) anteriores ao SL, de forma breve (aproximadamente 3s), sem altera??o significativa do t?nus muscular e independente da presen?a de movimentos oculares r?pidos. O SL desse sujeito apresentou tamb?m uma maior pot?ncia do ritmo alfa (7-14Hz) na regi?o occipital e um aumento de atividade gama (20- 50Hz) na regi?o temporo-parietal direita. Nos 6 sujeitos que frequentemente t?m SL, o mesmo apresentou em m?dia um aumento de pot?ncia em gama alto (50-100Hz) na regi?o frontal em compara??o com o SREM n?o-l?cido; no entanto, isso aconteceu de forma clara para apenas um dos indiv?duos. Observamos tamb?m que quatro desses volunt?rios apresentaram um aumento da pot?ncia do ritmo alfa na regi?o occipital, pouco antes do SL, ou durante o mesmo. Dessa forma, nossos resultados preliminares sugerem que o SL apresenta diferentes caracter?sticas neurofisiol?gicas dos estados t?picos de SREM e vig?lia: 1) Os pulsos de ritmo alfa, bem como o aumento da pot?ncia dessa oscila??o na regi?o occipital, podem ser micro-despertares. Estes facilitam o contato do c?rebro durante o sono com o meio externo, favorecendo a ocorr?ncia do SL e fortalecendo a ideia de que o SL seria um estado intermedi?rio entre o sono e a vig?lia. 2) Como as regi?es temporoparietal direita e frontal se relacionam com a forma??o da auto-consci?ncia e da imagem corporal, sugerimos que um aumento de atividade nessas regi?es durante o sono pode ser o mecanismo neurobiol?gico subjacente ao SL

The diagnosis of Parkinson’s disease (PD) follows the UK Brain Bank Criteria, which demands bradykinesia and one additional symptom, i.e. rigidity, resting tremor or postural instability. The latter is not a useful sign for the early diagnosis of PD, because it does not appear before Hoehn and Yahr stage 3. Early symptoms of PD which precede the onset of motor symptoms are hyposmia, REM sleep behavioral disorder, constipation, and depression. In addition, an increasing number of patients whose PD is related to a genetic defect are being described. Thus, genetic testing may eventually develop into a tool to identify at-risk patients. The clinical diagnosis of PD can be supported by levodopa or apomorphine tests. Imaging studies such as cranial CT or MRI are helpful to distinguish idiopathic PD from atypical or secondary PD. SPECT and PET methods are valuable to distinguish PD tremor from essential tremor if this is clinically not possible. Using all of these methods, we may soon be able to make a premotor diagnosis of PD, which will raise the question whether early treatment is possible and ethically and clinically advisable. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

REM sleep behavior disorder: Characteristics of polysomnographic and behavioral manifestations Abstract REM sleep behavior disorder (RBD) is a disease characterized by abnormal motor activity corresponding to the dream content. REM sleep without atonia (RWA) and behavioral manifestations are the main features registered by video-polysomnography (PSG). Because idiopathic RBD (iRBD) is considered as prodromal stage of synucleinopathies, the direction of current research is the search for markers of early conversion. The goal of this study was to observe the group of patients with iRBD with regard to the development of manifest neurodegenerative disease, to find and test a new polysomnographic marker of phenoconversion, to perform analysis of the movements registered by video and to quantify excessive fragmentary myoclonus (EFM), which is a frequent finding in neurodegenerative processes. A total of 55 patients with iRBD were observed for 2.3±0.7 years. The annual conversion rate was 5.5%. Mixed RWA, representing simultaneous occurrence of phasic and tonic RWA, was suggested as a new marker of phenoconversion. Converted patients showed a higher mixed RWA (p=0.009) and the ROC analysis confirmed that mixed RWA is the best predictive marker of conversion among other RWA types (AUC 0.778). An average of...

La présente thèse examine les liens entre le sommeil, la mémoire épisodique et les rêves. Dans une première étude, nous utilisons les technologies de la réalité virtuelle (RV) en liaison avec un paradigme de privation de sommeil paradoxal et de collecte de rêve en vue d'examiner l'hypothèse que le sommeil paradoxal et le rêve sont impliqués dans la consolidation de la mémoire épisodique. Le sommeil paradoxal a été associé au rappel des aspects spatiaux des éléments émotionnels de la tâche RV. De la même façon, l'incorporation de la tâche RV dans les rêves a été associée au rappel des aspects spatiaux de la tâche. De plus, le rappel des aspects factuels et perceptuels de la mémoire épisodique, formé lors de la tâche VR, a été associé au sommeil aux ondes lentes. Une deuxième étude examine l'hypothèse selon laquelle une fonction possible du rêve pourrait être de créer de nouvelles associations entre les éléments de divers souvenirs épisodiques. Un participant a été réveillé 43 fois lors de l'endormissement pour fournir des rapports détaillés de rêves. Les résultats suggèrent qu'un seul rêve peut comporter, dans un même contexte spatiotemporel, divers éléments appartenant aux multiples souvenirs épisodiques. Une troisième étude aborde la question de la cognition lors du sommeil paradoxal, notamment comment les aspects bizarres des rêves, qui sont formés grâce aux nouvelles combinaisons d'éléments de la mémoire épisodique, sont perçus par le rêveur. Les résultats démontrent une dissociation dans les capacités cognitives en sommeil paradoxal caractérisée par un déficit sélectif dans l'appréciation des éléments bizarres des rêves. Les résultats des quatre études suggèrent que le sommeil aux ondes lentes et le sommeil paradoxal sont différemment impliqués dans le traitement de la mémoire épisodique. Le sommeil aux ondes lentes pourrait être implique dans la consolidation de la mémoire épisodique, et le sommeil paradoxal, par l'entremise du rêve, pourrais avoir le rôle d'introduire de la flexibilité dans ce système mnémonique. / The present dissertation examines relationships between sleep, episodic memory and dreaming. In Articles I and II we use a novel virtual reality (VR) task in conjunction with a rapid eye movement (REM) sleep deprivation (REMD) paradigm and dream sampling to examine the hypothesis that REM sleep and dreaming are involved in the consolidation of episodic memory. REM sleep was associated with the successful recall of the spatial aspects of emotionally charged elements of the VR task. Similarly, dreaming was associated with improved performance on the spatial aspects of the recall task. Recall of the factual and perceptual aspects of episodic memories formed with the VR task was associated with increased slow wave sleep (SWS) during the post-exposure night. Overall, the results suggest that SWS is associated with the perceptual and factual aspects of episodic memories while REM sleep is not, a finding which may relate to observations that REM sleep dreaming is composed of deconstructed fragments of loosely associated episodic memories. Study II examines the hypothesis that a function of dreaming may be to create new associations between previously unrelated memory items. A participant, highly trained in introspection and mentation reporting, was awakened 43 times during theta bursts at sleep onset and provided detailed reports of resulting imagery and associated memory sources. This technique provided evidence that elements of distally related memory sources are brought together in temporal and spatial proximity within a novel context provided by the dream, suggesting a role for dreaming in memory processing. To allow for this possibility, we speculate that dreaming experiences may be functionally equivalent to waking experiences in their ability to induce neural plasticity. Study III addresses an aspect of this functional equivalence by examining if dream bizarreness is incompatible with behavioral and cognitive features associated with waking state experience-driven plasticity, i.e., whether the dreamer can act upon, emote and be motivated towards an element of the dream that is bizarre and that violates basic assumptions of physical reality. The results demonstrate a dissociation in cognitive ability during dreaming characterized by a selective deficiency in appreciating bizarreness in face of a maintained ability for logical thought. This finding thus addresses the problem of the wake-like mind reflecting upon dream bizarreness and suggests that dreaming is a state in which the cognitive aspects associated with synaptic plasticity (attention, emotion and motivation associated with believing a situation to be reality) are present while allowing for the presentation of memory item combinations which may transcend the limits of physical reality. The results of the four studies are discussed in light of how REM and SWS sleep stages are differentially involved in specific aspects of episodic memory (episodic replay vs. episodic novelty) and the possible role that dreaming, as a driver of synaptic plasticity, may have in these relationships.

La littérature suggère que le sommeil paradoxal joue un rôle dans l'intégration associative de la mémoire émotionnelle. De plus, les rêves en sommeil paradoxal, en particulier leur nature bizarre et émotionnelle, semblent refléter cette fonction associative et émotionnelle du sommeil paradoxal. La conséquence des cauchemars fréquents sur ce processus est inconnue, bien que le réveil provoqué par un cauchemar semble interférer avec les fonctions du sommeil paradoxal. Le premier objectif de cette thèse était de reproduire conceptuellement des recherches antérieures démontrant que le sommeil paradoxal permet un accès hyper-associatif à la mémoire. L'utilisation d'une sieste diurne nous a permis d'évaluer les effets du sommeil paradoxal, comparativement au sommeil lent et à l’éveil, sur la performance des participants à une tâche sémantique mesurant « associational breadth » (AB). Les résultats ont montré que seuls les sujets réveillés en sommeil paradoxal ont répondu avec des associations atypiques, ce qui suggère que le sommeil paradoxal est spécifique dans sa capacité à intégrer les traces de la mémoire émotionnelle (article 1). En outre, les rapports de rêve en sommeil paradoxal étaient plus bizarres que ceux en sommeil lent, et plus intenses émotionnellement ; ces attributs semblent refléter la nature associative et émotionnelle du sommeil paradoxal (article 2). Le deuxième objectif de la thèse était de préciser si et comment le traitement de la mémoire émotionnelle en sommeil paradoxal est altéré dans le Trouble de cauchemars fréquents (NM). En utilisant le même protocole, nos résultats ont montré que les participants NM avaient des résultats plus élevés avant une sieste, ce qui correspond aux observations antérieures voulant que les personnes souffrant de cauchemars soient plus créatives. Après le sommeil paradoxal, les deux groupes, NM et CTL, ont montré des changements similaires dans leur accès associatif, avec des résultats AB-négatif plus bas et AB-positif plus grands. Une semaine plus tard, seul les participants NM a maintenu ce changement dans leur réseau sémantique (article 3). Ces résultats suggèrent qu’au fil du temps, les cauchemars peuvent interférer avec l'intégration de la mémoire émotionnelle pendant le sommeil paradoxal. En ce qui concerne l'imagerie, les participants NM avaient plus de bizarrerie et plus d’émotion positive, mais pas négative, dans leurs rêveries (article 4). Ces attributs intensifiés suggèrent à nouveau que les participants NM sont plus imaginatifs et créatifs à l’éveil. Dans l'ensemble, les résultats confirment le rôle du sommeil paradoxal dans l'intégration associative de la mémoire émotionnelle. Cependant, nos résultats concernant le Trouble de cauchemars ne sont pas entièrement en accord avec les théories suggérant que les cauchemars sont dysfonctionnels. Le groupe NM a montré plus d’associativité émotionnelle, de même que plus d'imagerie positive et bizarre à l’éveil. Nous proposons donc une nouvelle théorie de sensibilité environnementale associée au Trouble de cauchemar, suggérant qu'une sensibilité accrue à une gamme de contextes environnementaux sous-tendrait les symptômes uniques et la richesse imaginative observés chez les personnes souffrant de cauchemars fréquents. Bien que davantage de recherches doivent être faites, il est possible que ces personnes puissent bénéficier e milieux favorables, et qu’elles puissent avoir un avantage adaptatif à l'égard de l'expression créative, ce qui est particulièrement pertinent lorsque l'on considère leur pronostic et les différents types de traitements. / Existing literature suggests that REM sleep plays a role in the associative integration of emotional memory, and that attributes of dreams during REM sleep, particularly their bizarre and emotional nature, either reflect or even influence this associative and emotional function. The consequence of frequent nightmares on this process is unknown, although, the experience of a nightmare suggests an associative restriction imposed by intense negative emotion, consistent with research showing that negative affect tends to restrict cognitive flexibility in wake. This is consistent with existing theories of nightmare function, largely purporting that nightmares reflect temporary failures in emotion regulation. The first objective of the thesis was to conceptually replicate prior research portraying REM sleep as enabling increased associative access to emotional memory. The use of a daytime nap allowed us to assess the effects of REM sleep, compared to both NREM sleep and waking, on participant performance on a novel task measuring Associational Breadth (AB). Results showed that only those subjects awakened from REM sleep responded with atypical emotional word associations, suggesting that REM is specific in its capacity to broadly integrate emotional memory traces (article 1). Further, REM dream reports were more bizarre than both NREM dreams and waking daydreams, and more emotionally intense than NREM dreams; these attributes are thought to reflect the hyper-associative and emotional nature of REM sleep (article 2). The second objective was to clarify whether and how REM sleep-dependent emotional memory processing is altered in frequent nightmares sufferers. Using a similar nap protocol, our results showed that NM participants had higher baseline AB in response to emotional cue-words, contrary to predictions, but nonetheless corresponding with anecdotal reports of heightened creativity. Following REM sleep, both NM and CTL groups showed similar changes in associative access to emotional cue-words, with negative AB being restricted and positive AB being broadened; one week later, the NM group alone maintained this altered pattern of emotional semantic access (article 3). This finding suggests that, over time, nightmares may interfere with REM sleep-dependent emotional memory integration. Regarding imagery, the NM participants had heightened bizarreness, and positive, but not negative, imagery in their daydreams, but not their dreams (article 4), mirroring our AB finding that the NM group had significantly higher emotional associativity in wake, although patterns of associativity following a REM sleep nap did not differ between groups. Overall, findings support a role of REM sleep in the associative integration of emotional memory. However, our findings regarding nightmare sufferers are not entirely consistent with views that nightmares are associated with dysfunctional emotional memory processing. Although they did show a prolonged priming effect suggestive of inadequate emotion regulation, they also showed heightened semantic associativity and vivid positive imagery in wake. We therefore propose a novel Environmental Sensitivity framework for the study of nightmare sufferers, claiming that an increased sensitivity to a range of environmental contexts, not only negative contexts, underlies the unique symptoms and imaginative richness seen in frequent nightmare sufferers. Although further empirical research exploring potentially adaptive traits or sensitivity to positive contexts in nightmare sufferers is needed, the possibility that these individuals may benefit especially from supportive environments, and may have heightened creativity and semantic associativity, is particularly relevant when considering prognosis and treatment approaches.

This work examines sleep apnea syndrome, sleep physiology and self control of respiration during sleep. There is a review of respiration disorders during sleep and methods of monitoring sleep apnea syndrome. In another part the data of monitoration are processed and method of flow, saturation and snoring signal events detection is described, program algorithm is described and results are presented.

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