We study the effectiveness of adaptive interventions at helping users process textual documents with embedded visualizations, a form of multimodal documents known as Magazine-Style Narrative Visualizations (MSNVs). The interventions are meant to dynamically highlight in the visualization the datapoints that are described in the textual sentence currently being read by the user, as captured by eye-tracking. These interventions were previously evaluated in two user studies that involved 98 participants reading excerpts of real-world MSNVs during a 1-hour session. Participants’ outcomes included their subjective feedback about the guidance, and well as their reading time and score on a set of comprehension questions. Results showed that the interventions can increase comprehension of the MSNV excerpts for users with lower levels of a cognitive skill known as visualization literacy. In this article, we aim to further investigate this result by leveraging eye-tracking to analyze in depth how the participants processed the interventions depending on their levels of visualization literacy. We first analyzed summative gaze metrics that capture how users process and integrate the key components of the narrative visualizations. Second, we mined the salient patterns in the users’ scanpaths to contextualize how users sequentially process these components. Results indicate that the interventions succeed in guiding attention to salient components of the narrative visualizations, especially by generating more transitions between key components of the visualization (i.e., datapoints, labels, and legend), as well as between the two modalities (text and visualization). We also show that the interventions help users with lower levels of visualization literacy to better map datapoints to the legend, which likely contributed to their improved comprehension of the documents. These findings shed light on how adaptive interventions help users with different levels of visualization literacy, informing the design of personalized narrative visualizations.

We leverage eye-tracking data to predict user performance and levels of cognitive abilities while reading magazine-style narrative visualizations (MSNV), a widespread form of multimodal documents that combine text and visualizations. Such predictions are motivated by recent interest in devising user-adaptive MSNVs that can dynamically adapt to a user's needs. Our results provide evidence for the feasibility of real-time user modeling in MSNV, as we are the first to consider eye tracking data for predicting task comprehension and cognitive abilities while processing multimodal documents. We follow with a discussion on the implications to the design of personalized MSNVs.

We study the effectiveness of adaptive guidance at helping users process textual documents with embedded visualizations, known as narrative visualizations. We do so by leveraging eye tracking to analyze in depth the effect that adaptations meant to guide the user's gaze to relevant parts of the visualizations has on users with different levels of visualization literacy. Results indicate that the adaptations succeed in guiding attention to salient components of the narrative visualizations, especially by generating more transitions between key components of the visualization (i.e., datapoints, labels and legend). We also show that the adaptation helps users with lower levels of visualization literacy to better map datapoints to the legend, which leads in part to improved comprehension of the visualization. These findings shed light on how adaptive guidance helps users with different levels of visualization literacy, informing the design of personalized narrative visualizations.

The use of implicit relevance feedback from neurophysiology could deliver effortless information retrieval. However, both computing neurophysiologic responses and retrieving documents are characterized by uncertainty because of noisy signals and incomplete or inconsistent representations of the data. We present the first-of-its-kind, fully integrated information retrieval system that makes use of online implicit relevance feedback generated from brain activity as measured through electroencephalography (EEG), and eye movements. The findings of the evaluation experiment (N = 16) show that we are able to compute online neurophysiology-based relevance feedback with performance significantly better than chance in complex data domains and realistic search tasks. We contribute by demonstrating how to integrate in interactive intent modeling this inherently noisy implicit relevance feedback combined with scarce explicit feedback. Although experimental measures of task performance did not allow us to demonstrate how the classification outcomes translated into search task performance, the experiment proved that our approach is able to generate relevance feedback from brain signals and eye movements in a realistic scenario, thus providing promising implications for future work in neuroadaptive information retrieval (IR).

We explore electroencephalography (EEG), electrodermal activity (EDA), and electrocardiography (ECG) as valid sources to infer humor appraisal in a realistic environment. We report on an experiment in which 25 participants browsed a popular user-generated humorous content website while their physiological responses were recorded. We build predictive models to infer the participants’ appraisal of the humorousness of the content and demonstrate that the fusion of several physiological signals can lead to classification performances up to 0.73 in terms of the area under the ROC curve (AUC). We identify that the most discriminative changes in physiological signals happen at the later stages of the information consumption process, reflected in changes on the upper EEG frequency bands, higher levels of EDA, and heart-rate acceleration. Additionally, we present a comprehensive analysis by benchmarking the predictive power of each of the physiological signals separately, and by comparing them to state-of-the-art facial recognition algorithms based on facial video recordings. The classification performance ranges from 0.88 (in terms of AUC) when combining physiological signals and video recordings, to 0.55 when using ECG signals alone.

Peripheral physiological signals, as obtained using electrodermal activity and facial electromyography over the corrugator supercilii muscle, are explored as indicators of perceived relevance in information retrieval tasks. An experiment with 40 participants is reported, in which these physiological signals are recorded while participants perform information retrieval tasks. Appropriate feature engineering is defined, and the feature space is explored. The results indicate that features in the window of 4 to 6 seconds after the relevance judgment for electrodermal activity, and from 1 second before to 2 seconds after the relevance judgment for corrugator supercilii activity, are associated with the users' perceived relevance of information items. A classifier verified the predictive power of the features and showed up to 14% improvement predicting relevance. Our research can help the design of intelligent user interfaces for information retrieval that can detect the user's perceived relevance from physiological signals and complement or replace conventional relevance feedback.

Term-Relevance Prediction from Brain Signals (TRPB) is proposed to automatically detect relevance of text information directly from brain signals. An experiment with forty participants was conducted to record neural activity of participants while providing relevance judgments to text stimuli for a given topic. High-precision scientific equipment was used to quantify neural activity across 32 electroencephalography (EEG) channels. A classifier based on a multi-view EEG feature representation showed improvement up to 17% in relevance prediction based on brain signals alone. Relevance was also associated with brain activity with significant changes in certain brain areas. Consequently, TRPB is based on changes identified in specific brain areas and does not require user-specific training or calibration. Hence, relevance predictions can be conducted for unseen content and unseen participants. As an application of TRPB we demonstrate a high-precision variant of the classifier that constructs sets of relevant terms for a given unknown topic of interest. Our research shows that detecting relevance from brain signals is possible and allows the acquisition of relevance judgments without a need to observe any other user interaction. This suggests that TRPB could be used in combination or as an alternative for conventional implicit feedback signals, such as dwell time or click-through activity.