Effects of search intent on eye-movement patterns in a change detection task

The goal of the present study was to examine whether intention type affects eye movement patterns in a change detection task In addition, we assessed whether the eye movement index could be used to identify human implicit intent. We attempted to generate three types of intent amongst the study participants, dividing them into one of three conditions; each condition received different information regarding an impending change to the visual stimuli. In the “navigational intent” condition, participants were asked to look for any interesting objects, and were not given any more information about the impending change. In the “low-specific intent” condition, participants were informed that a change would occur. In the “high-specific intent” condition, participants were told that a change would occur, and that an object would disappear. In addition to this main change detection task, participants also had to perform a primary task, in which they were required to name aloud the colors of objects in the pre-change scene. This allowed us to control for the visual searching process during the pre-change scene. The main results were as follows: firstly, the primary task successfully controlled for the visual search process during the pre-change scene, establishing that there were no differences in the patterns of eye movements across all three conditions despite differing intents. Secondly, we observed significantly different patterns of eye movement between the conditions in the post-change scene, suggesting that generating a specific intent for change detection yields a distinctive pattern of eye-movements. Finally, discriminant function analysis showed a reasonable classification rate for identifying a specific intent. Taken together, it was found that both participant intent and the specificity of information provided to the participants affect eye movements in a change detection task

The Association between Excessive Internet Gaming Behavior and Immersive Tendency, Mediated by Attention Deficit/Hyperactivity Disorder Symptoms, in Korean Male University Students

Objective Problematic online gaming (POG) and problematic Internet use (PIU) have become a serious public mental health problem, with Internet gaming disorder (IGD) included in "Conditions for further study" section of DSM-5. Although higher immersive tendency is observed in people affected by POG, little is known about the simultaneous effect of immersive tendency and its highly comorbid mental disorder, attention deficit/hyperactivity disorder (ADHD). This study aimed to assess the relationship between immersive tendency, ADHD, and IGD. Methods Cross-sectional interview study was conducted in Seoul, Korea with 51 male undergraduate students; 23 active garners and 28 controls. Results Current ADHD symptoms showed partial mediation effect on the path of immersive tendency on POG and PIU. The mediation model with inattention explained variance in both POG and PIU better than other current ADHD symptom models (R-2=69.2 in POG; 69.3 in PIU). Childhood ADHD symptoms models demonstrated mediation effect on both POG and PIU which explained less variance than current ADHD symptom models (R-2 =53.7 in POG; 52.1 in PIU). Current ADHD symptoms, especially inattention, appear to mediate the effect of immersive tendency on POG/PIU. Conclusion Immersive tendencies may entail greater susceptibility to IGD, and comorbidity with ADHD may mediate the effect of immersive tendency on IGD

Monitoring Rotation Dynamics of Membrane Protein in Live Cells

Dynamic behavior of membrane protein provides critical information in molecular and cellular mechanisms. To have access to the mobility of a membrane protein, single-particle tracking has been advanced for the microscopic mechanism understandings. Among various molecular motions, however, only the lateral motion of the protein has been monitored due to the lack of in situ imaging tool enabling observation for rotation and vibration. Here, we developed plasmonic nanoparticles which can monitor rotational diffusion dynamics as well as lateral motion. This nanoparticle probe allows direct evidence and quantitative analysis of rotation dynamics, and furthermore, observation of conformation changes of proteins and the protein-protein interactions in live cells. This study provides an insight into the molecular mechanism regarding the intracellular signaling process.1

Single-Molecule Rotation for EGFR Conformational Dynamics in Live Cells

Monitoring the dynamics of proteins in live cells on appropriate spatiotemporal scales may provide key information regarding long-standing questions in molecular and cellular regulatory mechanisms. However, tools capable of imaging the conformational changes over time have been elusive. Here, we present a single-molecule stroboscopic imaging probes by developing gyroscopic plasmonic nanoparticles, allowing for replication of protein-protein interactions and the conformational dynamics based on rotational and lateral velocities. This study fundamentally monitors the rotational motion of a membrane protein, epidermal growth factor receptor (EGFR), to decipher undiscovered structural dynamics in live cells without any molecular perturbations. This method offers a strategy to visualize assemblies and conformational changes, and provides unique insights into the mechanism underlying the molecular dynamics for receptors. © 2018 American Chemical Society.1

Mass spectrometry imaging of untreated wet cell membranes in solution using single-layer graphene

We report a means by which atomic and molecular secondary ions, including cholesterol and fatty acids, can be sputtered through single-layer graphene to enable secondary ion mass spectrometry (SIMS) imaging of untreated wet cell membranes in solution at subcellular spatial resolution. We can observe the intrinsic molecular distribution of lipids, such as cholesterol, phosphoethanolamine and various fatty acids, in untreated wet cell membranes without any labeling. We show that graphene-covered cells prepared on a wet substrate with a cell culture medium reservoir are alive and that their cellular membranes do not disintegrate during SIMS imaging in an ultra-high-vacuum environment. Ab initio molecular dynamics calculations and ion dose-dependence studies suggest that sputtering through single-layer graphene occurs through a transient hole generated in the graphene layer. Cholesterol imaging shows that methyl-β-cyclodextrin preferentially extracts cholesterol molecules from the cholesterol-enriched regions in cell membranes. © 2021, The Author(s), under exclusive licence to Springer Nature America, Inc.1