SUMMARYStudies on gaze analysis have revealed some of the relationships between viewers' gaze and their internal states (e.g., interests and intentions). However, understanding content browsing behavior in uncontrolled environments is still challenging because human gaze can be very complex; it is affected not only by viewers' states but also by the spatiosemantic structures of visual content. This study proposes a novel gaze analysis framework which introduces the content creators' point of view to understand the meaning of browsing behavior. Visual content such as web pages, digital articles and catalogs are comprised of structures intentionally designed by content creators, which we refer to as designed structure. This paper focuses on two design factors of designed structure: spatial structure of content elements (content layout), and their relationships such as "being in the same group". The framework was evaluated with an experiment involving 12 participants, wherein the participant's state was estimated from their gaze behavior. The results from the experiment show that the use of design structure improved estimation accuracies of user states compared to other baseline methods.

Structure-activity relationship studies of maitotoxin (MTX), a marine natural product produced by an epiphytic dinoflagellate, were conducted using chemically synthesized model compounds corresponding to the partial structures of MTX. Both enantiomers of the LMNO ring system were synthesized via aldol reaction of the LM ring aldehyde and the NO ring ketone. These fragments were derived from a common cis-fused pyranopyran intermediate prepared through a sequence involving Nozaki-Hiyama-Kishi reaction, intramolecular oxa-Michael addition, and Pummerer rearrangement. The NOPQR(S) ring system, in which the original seven-membered S ring was substituted with a six-membered ring, was also synthesized through the coupling of the QR(S) ring alkyne and the NO ring aldehyde and the construction of the P ring via 1,4-reduction, dehydration, and hydroboration. The inhibitory activities of the synthetic specimens against MTX-induced Ca influx were evaluated. The LMNO ring system and its enantiomer induced 36 and 18% inhibition, respectively, at 300 μM, whereas the NOPQR(S) ring system elicited no inhibitory activity.

This paper presents a novel framework to interpret eye movements using semantic relations and spatial layouts of displayed contents, i.e., the designed structure. We represent eye movements in a multi-scale, interval-based manner and associate them with various semantic relations derived from the designed structure. In preliminary experiments, we apply the proposed framework to the eye movements when browsing catalog contents, and confirm the effectiveness of the framework via user-state estimation.

This paper presents a probabilistic framework to model the gaze generative process when a user is browsing a content consisting of multiple regions. The model enables us to learn multiple aspects of interest from gaze data, to represent and estimate user's interest as a mixture of aspects, and to predict gaze behavior in a unified framework. We recorded gaze data of subjects when they were browsing a digital pictorial book, and confirmed the effectiveness of the proposed model in terms of predicting the gaze target.

Gaze behavior is one of crucial clues to understand human mental states. The goal of this study is to build a probabilistic model that represents relationships between users' gaze behavior and user states while catalog browsing. In the proposed model, users' gaze behavior is interpreted based on semantic and spatial relationships among objects constituting displayed contents, which is referred to as designed structures. Moreover, a method for estimating users' mental states is also proposed based on the model to evaluate the model by measuring the performance of user state estimation. The results from preliminary experiments show that the proposed model improved estimation accuracies of user states compared to other baseline methods.