Application of directed transfer function and network formalism for the assessment of functional connectivity in working memory task

作者：Blinowska Katarzyna J^*; Kaminski Maciej; Brzezicka Aneta; Kaminski Jan

来源：Philosophical Transactions of the Royal Society A-Mathematical Physical and Engineering Sciences, 2013, 371(1997): UNSP 20110614.

DOI：10.1098/rsta.2011.0614

• functional connectivity
• short-time directed transfer function
• working memory task
• weighted directed networks
• community structure of networks

The dynamic pattern of functional connectivity during a working memory task was investigated by means of the short-time directed transfer function. A clear-cut picture of transmissions was observed with the main centres of propagation located in the frontal and parietal regions, in agreement with imaging studies and neurophysiological hypotheses concerning the mechanisms of working memory. The study of the time evolution revealed that most of the time short-range interactions prevailed, whereas the communication between the main centres of activity occurred more sparsely and changed dynamically in time. The patterns of connectivity were quantified by means of a network formalism based on assortative mixing-an approach novel in the field of brain networks study. By means of application of the above method, we have demonstrated the existence of a modular structure of brain networks. The strength of interaction inside the modules was higher than between modules. The obtained results are compatible with theories concerning metabolic energy saving and efficient wiring in the brain, which showed that preferred organization includes modular structure with dense connectivity inside the modules and more sparse connections between the modules. The presented detailed temporal and spatial patterns of propagation are in line with the neurophysiological hypotheses concerning the role of gamma and theta activity in information processing during a working memory task.

• 出版日期2013-8-28