Banca de DEFESA: DANIEL SOARES BRANDÃO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DANIEL SOARES BRANDÃO
DATE: 14/12/2022
TIME: 10:00
LOCAL: Google Meet
TITLE:

Investigation of the cognitive functions of sleep and dreams through electroencephalography, verbal reports and electronic games

KEY WORDS:

Sleep, dreams, EEG, slow waves, cortical spindles, microstates, prey, predator

PAGES: 125
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Sleep is an important bodily and mental state for the elimination of toxins generated by metabolism and for the consolidation of memories. It is a very conserved state throughout animal evolution, being present in all species of reptiles, birds and mammals already studied, as well as several invertebrates. Due to its high evolutionary conservation, it is very likely that sleep had a great influence on the constitution of the different behaviors found in animals. The importance of sleep for memory consolidation has established the fundamental role of this phenomenon in improving task performance. Furthermore, it has recently been shown that dreaming is also involved in improving task performance. The Threat Simulation Theory by Revonsuo and Valli (2000) proposed that dreaming would have been selected throughout evolution for its adaptive value, functioning as an alert for the possibility of future threats. Could the evolution of the different habits of prey and predators have been influenced by sleep and/or dreams? The investigation of the role of sleep and dreams in prey versus predator relationships in humans is quite promising, both because humans can communicate the content of dreams they had, and because of the possibility of developing complex tasks using video games that simulate prey versus predator situations that would be difficult to emulate in animal models.
In this context, experiments were carried out with 15 pairs of volunteers, who came together to the laboratory and had their brain activity recorded simultaneously through electroencephalography (EEG). During the recording, each pair engaged in an interactive electronic game for 45 minutes, then laid to sleep for 2 hours and then played again for another 45 minutes. During the game, one of the participants was randomly selected to play the role of prey and the other to play the role of predator. The prey could kill the opponent only by punches, while the predator also had a firearm. Therefore, the predator had a great advantage in the direct dispute with the prey, as it happens in nature. Dream reports were analyzed through the opinion of 4 independent evaluators who reviewed the reports blindly. The evaluators indicated the degree of certainty that the participant actually dreamed and the degree of clarity of this memory; they also defined whether the dreams were related to the game, the laboratory, personal life, being prey and being a predator. The EEG signals were analyzed automatically, through data processing algorithms developed specifically for this study, adapting the sequence of data transformations after visual inspection of the results. The power of oscillations in characteristic frequency bands, the properties of slow oscillations and sleep spindles, the characteristics of sleep stages and sleep scales were evaluated. An analytical technique that searches for recurrent patterns of spatial distribution of electrical activity was also applied to the EEG signal; such microstates are related to the activities of specific neural circuits through the labels “A”, “B”, “C” and “D”.
The results indicate that preys reported dreaming more than predators, and that prey scores were positively correlated with how much the dream report was related to the game. Prey also benefited more than predators from having a deeper sleep, which also correlated with prey score. The prey had higher power in delta (1 to 3 Hz), which also favored the prey score, mainly through the amplitude of the slow oscillations during sleep. No significant effect was found for sleep spindles. The prey's performance was impaired by the number of occurrences of the microstate C, which is associated with neural activations not specifically related to the proposed task.
Taken together, the results suggest that slow waves during sleep and game-related dream content favorably influence participants' performance in the prey role, but not in the predator role. A possible explanation for this dichotomy would be that sleep and dreams are important for adapting to challenging situations, not being so relevant in situations to which the individual is already adapted.

COMMITTEE MEMBERS:
Interno - 3086031 - DANIEL YASUMASA TAKAHASHI
Externo à Instituição - FELIPE BEIJAMINI - UFFS
Externo à Instituição - GUILHERME BROCKINGTON - UFABC
Externo ao Programa - 2998660 - MARIO ANDRE LEOCADIO MIGUEL - nullPresidente - 1660044 - SIDARTA TOLLENDAL GOMES RIBEIRO