Exploring the Neural Processes behind Narrative Engagement: An EEG Study.

Past cognitive neuroscience studies using naturalistic stimuli have considered narratives holistically and focused on cognitive processes. In this study, we incorporated the narrative structure, the dramatic arc, as an object of investigation, to examine how engagement levels fluctuate across a narrative-aligned dramatic arc. We explored the possibility of predicting self-reported engagement ratings from neural activity and investigated the idiosyncratic effects of each phase of the dramatic arc on brain responses as well as the relationship between engagement and brain responses. We presented a movie excerpt following the six-phase narrative arc structure to female and male participants while collecting EEG signals. We then asked this group of participants to recall the excerpt, another group to segment the video based on the dramatic arc model, and a third to rate their engagement levels while watching the movie. The results showed that the self-reported engagement ratings followed the pattern of the narrative dramatic arc. Moreover, while EEG amplitude could not predict group-averaged engagement ratings, other features comprising dynamic intersubject correlation (dISC), including certain frequency bands, dynamic functional connectivity patterns and graph features were able to achieve this. Furthermore, neural activity in the last two phases of the dramatic arc significantly predicted engagement patterns. This study is the first to explore the cognitive processes behind the dramatic arc and its phases. By demonstrating how neural activity predicts self-reported engagement, which itself aligns with the narrative structure, this study provides insights on the interrelationships between narrative structure, neural responses, and viewer engagement.

Higher levels of narrativity lead to similar patterns of posterior EEG activity across individuals.

Introduction: The focus of cognitive and psychological approaches to narrative has not so much been on the elucidation of important aspects of narrative, but rather on using narratives as tools for the investigation of higher order cognitive processes elicited by narratives (e.g., understanding, empathy, etc.). In this study, we work toward a scalar model of narrativity, which can provide testable criteria for selecting and classifying communication forms in their level of narrativity. We investigated whether being exposed to videos with different levels of narrativity modulates shared neural responses, measured by inter-subject correlation, and engagement levels. Methods: Thirty-two participants watched video advertisements with high-level and low-level of narrativity while their neural responses were measured through electroencephalogram. Additionally, participants' engagement levels were calculated based on the composite of their self-reported attention and immersion scores. Results: Results demonstrated that both calculated inter-subject correlation and engagement scores for high-level video ads were significantly higher than those for low-level, suggesting that narrativity levels modulate inter-subject correlation and engagement. Discussion: We believe that these findings are a step toward the elucidation of the viewers' way of processing and understanding a given communication artifact as a function of the narrative qualities expressed by the level of narrativity.

EEG theta and N400 responses to congruent versus incongruent brand logos.

Neuroimaging and behavioral studies have shown that brands convey meaning to consumers. To investigate the immediate reactions of the brain to brand logos, followed either by congruent or incongruent pictorial brand-related cues, can deepen understanding of the semantic processing of brands, and perhaps how consolidated the logo is in consumers' minds. Participants were exposed to different brand-related image sets, that were either congruent (a match between brand-related images and brand logo) or incongruent (a mismatch between brand-related images and brand logo) while having their brain signals recorded. Event-related potential and EEG time-frequency domain features were extracted from the signals of the target image (brand logo). The results showed significantly larger N400 peak and relative theta power increase for incongruent compared to congruent logos, which could be attributed to an error-monitoring process. Thus, we argue that brands are encoded deeply in consumers' minds, and cognitive processing of mismatched (vs matched) brand logos is more difficult, leading to greater error monitoring. The results were mostly consistent with previous studies investigating semantic incongruences in the linguistic field. Therefore, the error-monitoring process could be extended beyond linguistic forms, for example to images and brands.

Purification and characterization of an extracellular beta-glucosidase from Monascus purpureus.

An extracellular beta-glucosidase produced by Monascus purpureus NRRL1992 in submerged cultivation was purified by acetone precipitation, gel filtration, and hydrophobic interaction chromatography, resulting in a purification factor of 92-fold. A 22 central-composite design (CCD) was performed to find the best temperature and pH conditions for enzyme activity. Maximum activity was observed in a wide range of temperature and pH values, with optimal conditions set at 50 degrees and pH 5.5. The beta-glucosidase showed moderate thermostability, was inhibited by HgCl2, K2CrO4, and K2Cr2O7, whereas other reagents including beta- mercaptoethanol, SDS, and EDTA showed no effect. Activity was slightly stimulated by low concentrations of ethanol and methanol. Hydrolysis of p-nitrophenyl-beta-D-glucopyranoside (pNPG), cellobiose, salicin, n-octyl-beta-D-glucopyranoside, and maltose indicates that the beta-glucosidase has broad substrate specificity. Apparently, glucosyl residues were removed from the nonreducing end of p-nitrophenyl-beta-Dcellobiose. beta-Glucosidase affinity and hydrolytic efficiency were higher for pNPG, followed by maltose and cellobiose. Glucose and cellobiose competitively inhibited pNPG hydrolysis.