Estimation of Directed Functional Connectivity in Neurofeedback Training Focusing on the State of Attention

The directed transfer function (DTF) is a measure based on the concept of Granger’s causality, which associated with a neurofeedback system, can represent an important analysis tool to support the treatment of neuropsychiatric disorders. Defined in the structure of the multivariate autoregressive model (MVAR), the DTF provides a spectral estimate of the strength and direction of any causal link between the signals acquired by electroencephalography (EEG). This study aims to estimate the directed functional connectivity related to the attention status of healthy adult individuals during neurofeedback sessions, aiming to better understand how the neuronal regions communicate and influence each other’s activity and study the feasibility of using these algorithms with neurofeedback. Data were collected from 19 individuals, eleven male and eight female, with an average age of 21.21 years, standard deviation of 2.39 and an age range of 18–26 years. As a result, they were able to identify changes in the direction and strength of the interaction flow between certain brain regions that occurred during the sessions, suggesting that the sessions enabled individuals to activate brain regions related to the state of attention. The main contribution presented in the study was the use of the mathematical methods mentioned to identify and analyze brain modulations in individuals who participated in neurofeedback sessions related to the strengthening of the state of attention.