# Automatic Clustering of Students by Level of Situational Interest Based on Their EEG Features
## 2 Related Work  
A suggested technique to evaluate the student's situational interest is by assessing their attention when the teachers or educators delivered their presentation. A study from [PERSON] et al. [25] showed that EEG beta and theta power ratios were used to distinguish attentive and non-attentive students. Across students and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and a decrease in the beta power over the occipital and temporal regions. Meanwhile, [PERSON] [26] reported that attention was indicated by attenuation or reduction of alpha frequency. Since the EEG features for detecting situational interest during learning have not been well studied, our study stands with the hypothesis on inhibition of alpha frequency as an indication for attention. Besides, the delta band was discovered to be useful in assessing students' situational attention during learning in classrooms [27]. [PERSON] et al. [28] found the beta power is manifested in healthy students during focused attention and [PERSON] [25] reported a decrease in beta power during sustained attention. However, these authors set up their experiment by giving the students a visual cognition task and instructing them to stay alert and press the button corresponding to the given stimuli. It contrasts with our study, where the students were instructed to act normally as they were in the real classroom. Therefore, the later analysis will only be focused on the delta and alpha power. In terms of a brain region, the activities in frontal lobes were found to be significant for the recognition of interest and numerical operations [29; 30] and arithmetic tasks [31]. By referring to the EEG electrode's location, [PERSON] et al. [32] and [PERSON] et al. [33] suggested that F3 was one of the ideal locations to gauge the inhibition of alpha frequency during attentional tasks, compared to the relaxation state. Since our aim is to explore the attentional reaction aspect in situational interest, we narrowed down our focus onto the frontal area, represented by the electrode channels of F3 and F4. In addition, frontal EEG asymmetry has frequently been studied concerning the motivational or emotional states. Early research by [PERSON] et al. [34] using the Frontal Alpha Asymmetry (FAA) analysis focused on effective manipulations within the stimulus material, reporting negative FAA metrics (interpreted as larger relative left-hemispheric activation) for positive stimuli, while reporting positive FAA metrics for negative stimuli. However, the use of FAA analysis as a predictor tool, which would be desirable for applied contexts such as marketing research, product design, or brain-computer- interfacing (BCI) is inadequate [35]. In the context of learning, [PERSON] et al. [36] have applied FAA as an index of approach/withdrawal motivation, during the natural reading of a newspaper on the traditional print medium and a tablet computer. A review from [PERSON] [37] reported that there was a relationship between the ability of focus attention and screen-out emotional distractions. The more unfocused we are, the more the prefrontal cortex inhibits a phase-locking response to external stimuli. In his book, [PERSON] [17] had concluded that emotion regulation was dependent on the interaction of frontal cortical structures and subcortical brain regions. Based on the literatures that describe the emotion, which integrated into cognitive control, occurring at prefrontal and frontal area of the brain [17; 37], we further examined the alpha asymmetry in this region. We hypothesize the increases in delta and alpha power in the frontal brain region are correlated to the reduction of cognitive attention and low situational interest in learning the topics. We hypothesized negative alpha asymmetry metric at the frontal region as being associated with positive emotion that increased the interest in learning.