Biology subjects

Grigg, M.

Publications and source records attributed to Grigg, M..

3 recordsLinked to original sources

bioRxiv2026

Linking reaction time variability to physiological markers of arousal across timescales

Reaction time is a measure of the speed of our response to stimuli in the environment. Even for a well-trained task, a subjects reaction time varies. One source of this variability is internal state fluctuations (such as changes in arousal). There are few studies that systematically quantify the extent to which reaction time varies across different timescales and link this to measures of systemic physiology associated with arousal. In much of the literature, it is assumed but not demonstrated that behavioral and systemic measurements associated with arousal will be consistently linked because both estimate a common underlying arousal process. In this work, we examined this assumption by simultaneously measuring reaction time, heart rate, and pupil diameter in rhesus macaque monkeys performing several visual tasks over hours and across hundreds of sessions. We found a portion of the variability in reaction time could be linked to systemic physiological signatures of arousal on fast timescales from second to second and slower timescales from minute to minute. This link between reaction time and systemic physiology was also present for different biomarkers of arousal (heart rate and pupil). However, the strength of this relationship varied depending on the arousal biomarker. Our findings support the conclusion that there are multiple arousal mechanisms that act simultaneously to influence behavior and multiple timescales at which they operate.

neuroscience↗

bioRxiv2026

From Breath to Behavior: Respiratory Features Predict Visual Detection Performance

Breathing is a continuous bodily rhythm that not only sustains physiology but also shapes brain function and behavior. Here we investigated how respiration interacts with perceptual performance in nonhuman primates performing a visual detection task. Using continuous recordings, we extracted detailed features from each respiratory cycle including timing, duration, phase, depth, and volume, aligned to trial onset. Analyses revealed that timing-related features, such as inhalation onset and the respiration length, were the most reliable markers of trial outcome, whereas amplitude-based measures contributed less consistently. These findings demonstrate that the temporal structure of breathing, rather than its magnitude, plays a dominant role in shaping behavior on a moment-to-moment basis. By uncovering how fine-grained features of respiration align with perceptual success, our work highlights respiration as a strong correlate of cognition and highlights the value of feature-based approaches for linking interoceptive rhythms to behavior.

animal behavior and cognition↗

bioRxiv2024

Age is an intrinsic driver of inflammatory responses to malaria

Age is a critical factor influencing the host immune response to infection and disease pathogenesis. In malaria, the risk of severe disease increases with age in non-immune individuals. Malaria severity is in part driven by inflammation, but the specific cells and mechanisms contributing to age-dependent disease risk are incompletely understood. Here, we assessed inflammatory cytokines in non-immune children and adults with clinical malaria, and the phenotypic, functional and transcriptional differences of in vitro innate cell responders to malaria parasites in naive children and adults. During naturally acquired malaria, age was associated with increased plasma levels of inflammatory chemokines CCL2, CCL3, CXCL8, CXLC9, along with CRP, and IDO, which were associated with clinical symptoms. In malaria naive individuals, classical monocyte and V{delta}2+ {gamma}{delta} T cell responses from adults were characterized by higher inflammatory cytokine production, and transcriptional activation following stimulation with malaria parasites. Classical monocyte responses in adults were dominated by CCL2 production, while in children the response had increased IL10 production and enrichment in IL10 signaling pathways upon parasite stimulation. This heightened inflammatory response in adults was not mitigated by parasite induced Tregs. Taken together, these findings identify cellular mechanisms of age-dependent host responses that play crucial roles in driving inflammatory responses in malaria.

immunology↗