# name
Reconstruction of EEG alpha band sources during a working memory task

# metadata.dc.description[].value
Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2021-2022. Director: Albert Compte. Tutora: Roser Sala.

# metadata.dc.description.abstract[].value
Working memory denotes the temporary retention of a small amount of information in a readily accessible
form for subsequent action. It facilitates planning, comprehension, reasoning, and problem-solving.
Although there is still some debate, working memory has been specifically associated with the prefrontal
cortex based on animal intracranial recordings. On the other hand, recent scientific evidence indicates
that the alpha frequency range of the electroencephalogram (EEG) is related with working memory
storage, but the anatomical sources of these signals are still unknown. The goal of this project is to
determine the brain regions involved in generating stimulus-selective alpha-band EEG signals during a
working memory task, using a source reconstruction approach. To this end, I compared activity currents
estimated in three regions of interest (ROIs), the prefrontal cortex, the posterior parietal, and the visual
cortex, during a visuospatial working memory task in 5 subjects. Structural Magnetic Resonance Imaging
(MRI) was obtained for each subject and EEG was acquired during the performance of the task. I applied
previously defined source reconstruction algorithms to the EEG filtered signal – in alpha waves – to data
extracted during the task for each of these 5 subjects. The method used to perform the source
reconstruction – to solve the inverse problem - was LORETA. To assess stimulus selectivity, I compared
sources in the two brain hemispheres in two different conditions during the task, when memorized stimuli
were presented either in the left or the right hemifields and considering the three ROIs of interest. We
found that prefrontal cortex and posterior parietal regions showed more selectivity for the stimulus and
had more activity during the delay of the working memory task than the visual cortex. This result validates
my approach to estimate the anatomical sources of stimulus-selective alpha-band EEG signals in
cognitive tasks.

# metadata.dc.rights[].value
cc-by-nc-nd (c) Ferrer Raventós, Anna, 2022

# metadata.dc.source[].value
Treballs Finals de Grau (TFG) - Enginyeria Biomèdica

# metadata.dc.title[].value
Reconstruction of EEG alpha band sources during a working memory task