Biology subjects

Hung, S.-M.

Publications and source records attributed to Hung, S.-M..

4 recordsLinked to original sources

bioRxiv2024

Individual variability in neural representations of mind-wandering

Mind-wandering is a frequent, daily mental activity, experienced in unique ways in each person. Yet neuroimaging evidence relating mind-wandering to brain activity, for example in the default mode network (DMN), has relied on population-rather than individual-based inferences due to limited within-individual sampling. Here, three densely-sampled individuals each reported hundreds of mind-wandering episodes while undergoing multi-session functional magnetic resonance imaging. We found reliable associations between mind-wandering and DMN activation when estimating brain networks within individuals using precision functional mapping. However, the timing of spontaneous DMN activity relative to subjective reports, and the networks beyond DMN that were activated and deactivated during mind-wandering, were distinct across individuals. Connectome-based predictive modeling further revealed idiosyncratic, whole-brain functional connectivity patterns that consistently predicted mind-wandering within individuals but did not fully generalize across individuals. Predictive models of mind-wandering and attention that were derived from larger-scale neuroimaging datasets largely failed when applied to densely-sampled individuals, further highlighting the need for personalized models. Our work offers novel evidence for both conserved and variable neural representations of self-reported mind-wandering in different individuals. The previously-unrecognized inter-individual variations reported here underscore the broader scientific value and potential clinical utility of idiographic approaches to brain-experience associations.

neuroscience↗

bioRxiv2023

Method for Spatially Confined Stimulation by Retinal Scanning Displays: Are Blind Spots Really Blind?

Conventional displays, such as CRTs and LCDs, are commonly used to present and manipulate visual stimuli in many vision science studies. However, such displays pose difficulties when the goal is to constrain stimulation to specific retinal locations, so as to isolate their contribution to downstream effects. Scattered and refracted light can stimulate unintended areas, contaminating the outcomes. In this investigation, we evaluate a laser-based retinal scanning display for its ability to map and exclusively stimulate the retinal blind spot. This application stimulates melanopsin receptors inside the blind spot, separately from rod and cone photoreceptors, which lie outside the blind spot. This paper covers three experiments: 1. The initial exploratory observations; 2. the examination of pupillary responses, and; 3. the inference of implicit visual perception arising from the blind spot. We aimed to simultaneously validate our technical methods, while increasing our understanding of the role of melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) in vision and implicit visual perception.

neuroscience↗

bioRxiv2023

Practice makes imperfect: stronger implicit interference with practice in individuals at high risk of developing Alzheimer's disease

Early screening to determine patient risk of developing Alzheimers will allow better interventions and planning but necessitates accessible methods such as behavioral biomarkers. Previously, we showed that cognitively healthy older individuals whose cerebrospinal fluid amyloid / tau ratio indicates high risk of cognitive decline experienced implicit interference during a high-effort task, signaling early changes in attention. To further investigate attentions effect on implicit interference, we analyzed two experiments completed sequentially by the same high- and low-risk individuals. We hypothesized that if attention modulates interference, practice would affect the influence of implicit distractors. Indeed, while both groups experienced a strong practice effect, the association between practice and interference effects diverged between groups: stronger practice effects correlated with more implicit interference in high-risk participants, but less interference in low-risk individuals. Furthermore, low-risk individuals showed a positive correlation between implicit interference and EEG low-range alpha event-related desynchronization when switching from high-to low-load tasks. These results demonstrate how attention impacts implicit interference and highlight early differences in cognition between high- and low-risk individuals.

neuroscience↗

bioRxiv2020

Mind Wandering in Sensory Cortices

Mind wandering contains rich phenomenology as we experience moment by moment, however, such linkage between our subjective experiences and the underlying neural mechanism has been missing in the literature. Here we report that the sensory contents of mind wandering recruit corresponding sensory cortices, serving as the neural bases of the sensory contents in mind wandering.

neuroscience↗