Faasimuutuse uurimine inimajus ärkamismomendil

Abstract

Küsimus selle kohta, mis toimub meie ajus sel hetkel, kui ärkame üles uneseisundist, puudutab meid kõiki. Käesolevas interdistsiplinaarses töös kasutati kaasaegseid arvutuslikke meetodeid uurimaks aju elektrilist aktiivsust üleminekul unefaasist ärkvelolekusse. Töö raames arendati välja uudne algoritm eemaldamaks ajuandmetest mitte ajuga seotud signaale. Ärkamismomendi kirjeldamiseks kasutati nii mitmeid üldtuntud kvantitatiivseid meetodeid kui ka inimaju elektriliste signaalide kujutust dünaamilisse olekute ruumi. Ärkamishetkega seostati aeglaseid ajupotentsiaale, üle kõikide ajusageduste ilmnevat võimsuse tõusu, gamma sagedusriba jõudluse esilekerkimist ja ajusignaalide karakteristikute olulist asukoha muutust olekute ruumis.

We take granted the ability to fall asleep or snap out of sleep into wakefulness, yet these transitions change our mental state completely and sometimes (e.g. fire alarm) very quickly. In this interdisciplinary study, modern computational techniques were applied to a relatively unique set of human brain data recorded from the scalp while the subjects were repeatedly woken up from asleep. A novel algorithm was built to automate the phase of cleaning the recordings from non-brain-related signals. With the aim to characterize the transition from sleep to wake state, many quantitative approaches were used and a state space technique was developed to examine these brain recordings. The awakening was associated with slow cortical potentials, an increase in power of a broad range of frequencies, emergence of gamma power, and a transpose in the state space.