Effective connectivity patterns associated with P300 Unmask differences in the level of attention/cognition between normal and disabled subjects

Abstract

Recent findings indicated that both P300 and α-event-related desynchronization (a-ERD) were associated, and similarly involved in cognitive brain functioning, like attention, allocation and memory updating. In a very recent study, the causality between P300 and α-ERD (Event Related Desynchronization) generators was investigated in four sensory modalities, i.e., audition, vision, somatosensory, and pain. In the present study, we investigated the effective connectivity patterns related with P300 during a visual modality protocol with six different flashing images in a normal and a disabled subject (Cerebral Palsy). We constructed effective connectivity graphs (ECGs) with Partial Directed Coherence (PDC) focusing on target trials in the frequency range of 8 - 13 Hz. Adopting a tensorial classification scheme, we succeeded to differentiate the trials related with six different images with classification performance of 100% in both subjects. In addition, we estimated small-worldness as an indicator to quantify the difference in the level of attention/cognition between normal and disabled subject. Finally, small-world index can be used to measure how demanding a task is in terms of attention/cognition especially for disabled subjects. © Springer International Publishing Switzerland 2014.