Biology subjects

Yoon, T.

Publications and source records attributed to Yoon, T..

3 recordsLinked to original sources

bioRxiv2026

Confined T cell migration controls programmed cell death 1 expression

T cell immune checkpoint expression and dysfunction are attributed solely to molecular cues. We discover using microphysiological systems and in vivo models that transmigration through confined pores induces acute loss of programmed cell death 1 within minutes of surface immune checkpoint markers on CD8+ T cells through ubiquitin-mediated proteasomal degradation, corresponding with enhanced fitness and function. Such imprints and its underlying mechanism of programmed cell death 1 loss are conserved across species and applicable to human TIL and CAR T cells, and are correlative with disease outcomes in human melanoma. Our findings establish the diverse tissues landscapes that T cells traverse during immunosurveillance, and specifically transmigration, as a form of mechanical immune regulation, and reveal a mechano-modulatory strategy to improve the quality and persistence of engineered or patient-derived T cells for adoptive immunotherapy.

immunology↗

bioRxiv2023

Integrating simultaneous motor imagery and spatial attention for EEG-BCI control

Objective: EEG-based brain-computer interfaces (BCI) are non-invasive approaches for replacing or restoring motor functions in impaired patients, and direct brain-to-device communication in the general population. Motor imagery (MI) is one of the most used BCI paradigms, but its performance varies across individuals and certain users require substantial training to develop control. In this study, we propose to integrate a MI paradigm simultaneously with a recently proposed Overt Spatial Attention (OSA) paradigm, to accomplish BCI control. Methods: We evaluated a cohort of 25 human subjects ability to control a virtual cursor in one- and two-dimensions over 5 BCI sessions. The subjects used 5 different BCI paradigms: MI alone, OSA alone, MI and OSA simultaneously towards the same target (MI+OSA), and MI for one axis while OSA controls the other (MI/OSA and OSA/MI). Results: Our results show that MI+OSA reached the highest average online performance in 2D tasks at 49% Percent Valid Correct (PVC), statistically outperforms MI alone (42%), and was higher, but not statistically significant, than OSA alone (45%). MI+OSA had a similar performance to each subjects best individual method between MI alone and OSA alone (50%) and 9 subjects reached their highest average BCI performance using MI+OSA. Conclusion: Integrating MI and OSA leads to improved performance over MI alone at the group level and is the best BCI paradigm option for some subjects. Significance: This work proposes a new BCI control paradigm that integrates two existing paradigms and demonstrates its value by showing that it can improve users BCI performance.

bioengineering↗

bioRxiv2019

Saccade vigor as an implicit measure of subjective economic value

Decisions are made based on the subjective value that the brain assigns to options. However, subjective value is a mathematical construct that cannot be measured directly, but rather inferred from choices. Recent results have demonstrated that reaction time and velocity of movements are modulated by reward, raising the possibility that there is a link between how the brain evaluates an option, and how it controls movements toward that option. Here, we asked people to choose among risky options represented by abstract stimuli, some associated with gain, others with loss. From their choices in decision trials we estimated the subjective value that they assigned to each stimulus. In probe trials, they were presented with a single stimulus at center and made a saccade to a peripheral location. We found that the reaction time and peak velocity of that saccade varied roughly linearly from loss to gain with the subjective value of the stimulus. Naturally, participants differed in how much they valued a given stimulus. Remarkably, those who valued a stimulus more, as evidenced by their choices in decision trials, tended to move with greater vigor in response to that stimulus in probe trials. Thus, saccade vigor partly reflected the subjective value that the brain assigned the stimulus. However, the influence of subjective value on vigor was only a modest predictor of preference: vigor in probe trials allowed us to predict choice in decision trials with roughly 60% accuracy. New and NoteworthyWe found that saccade vigor tends to vary monotonically with subjective value: smallest for stimuli that predict a loss, and highest for stimuli that predict a gain. Notably, between-subject differences in valuation could be gleaned from the between-subject differences in their patterns of vigor. However, the influence of subjective value on vigor was modest, allowing partial ability to infer subjective value for the purpose of predicting choice in decision trials.

neuroscience↗