TY - JOUR
T1 - Directed EEG Functional Connectivity Features to Reveal Different Attention Indexes Using Hierarchical Clustering
AU - Iddas, Hadriana
AU - Iramina, Keiji
N1 - Funding Information:
Furthermore, we also observed significant connectivity from the central to occipital areas in familiar states (Fig. 4b and Fig. 4c). Our results were supported by a previous study of event-related potentials (ERP). This study suggested that the earliest response amplified by attention at 75 ms was recorded from the dorsal occipital areas in a visual task in which a subject was asked to notice the position of a target (vertical or reversed) in flashes that were randomly displayed to each field [53]. Pantazatos et al. found specific interactions between the ventromedial prefrontal cortex (vmPFC) and lateral occipital cortex (LOC) in a natural and complex search task [54]. These results support the notion that the occipital lobe has a primary role in examining visual information and attentional modulation.
Publisher Copyright:
© 2013 IEEE.
PY - 2021
Y1 - 2021
N2 - Functional connectivity related to familiarity has recently been investigated in the context of various stimuli (e.g., words, faces, pictures, music, and video). However, the directed functional connectivity patterns with different attention indexes as a response to familiar/unfamiliar stimuli remain unclear. In the current study, we employed the Directed Transfer Function (DTF) to estimate the information flow between brain areas. This method was reported to be practically robust to volume conduction. Furthermore, the hierarchical clustering approach was utilized to group subjects based on the attention index, i.e., the alpha/theta ratio of fronto-central (frontal to central and central to frontal) features. Three major findings were revealed from this study. First, all subjects had different attention indexes when they watched familiar/unfamiliar videos. Then, subjects were sorted into three groups: low index (LI), middle index (MI), and high index (HI). Second, a competition between two states (familiar/unfamiliar) showed that the information flows of familiar stimuli were greater than unfamiliar stimuli, which involved significant effects in the frontal, temporal, and parietal areas. Third, comparison between groups (LI/MI/HI) demonstrated that the frontal and central regions were the primary sources that distributed information flows to almost the whole brain, particularly during familiar conditions. This result indicates that these two regions may play an important role in attentional processing.
AB - Functional connectivity related to familiarity has recently been investigated in the context of various stimuli (e.g., words, faces, pictures, music, and video). However, the directed functional connectivity patterns with different attention indexes as a response to familiar/unfamiliar stimuli remain unclear. In the current study, we employed the Directed Transfer Function (DTF) to estimate the information flow between brain areas. This method was reported to be practically robust to volume conduction. Furthermore, the hierarchical clustering approach was utilized to group subjects based on the attention index, i.e., the alpha/theta ratio of fronto-central (frontal to central and central to frontal) features. Three major findings were revealed from this study. First, all subjects had different attention indexes when they watched familiar/unfamiliar videos. Then, subjects were sorted into three groups: low index (LI), middle index (MI), and high index (HI). Second, a competition between two states (familiar/unfamiliar) showed that the information flows of familiar stimuli were greater than unfamiliar stimuli, which involved significant effects in the frontal, temporal, and parietal areas. Third, comparison between groups (LI/MI/HI) demonstrated that the frontal and central regions were the primary sources that distributed information flows to almost the whole brain, particularly during familiar conditions. This result indicates that these two regions may play an important role in attentional processing.
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U2 - 10.1109/ACCESS.2021.3072224
DO - 10.1109/ACCESS.2021.3072224
M3 - Article
AN - SCOPUS:85104204549
VL - 9
SP - 59328
EP - 59335
JO - IEEE Access
JF - IEEE Access
SN - 2169-3536
M1 - 9399438
ER -