Biology subjects

Warburton, M.

Publications and source records attributed to Warburton, M..

8 recordsLinked to original sources

bioRxiv2025

An 'Aha!' moment precedes the strategic response to a visuomotor rotation

Strategic behaviour in sensorimotor adaptation tasks is typically described as either a gradual error minimisation process or as a process of learning through trial-and-error. The former predicts a gradual monotonic reduction in error, until some asymptote, while the latter predicts behavioural exploration to discover an efficacious solution. Another explanation is that a sufficiently rich understanding of the task culminates in an "Aha!" moment, and that this richer understanding naturally entails a new strategy. This predicts some period of perseveration in baseline behaviour, followed by an abrupt shift to a new strategic solution. To avoid obfuscation caused by the motor system, we first investigate these hypotheses in a strategy-only aiming game, where participants aim and fire a cannon at targets. Most participants exhibited a period of baseline perseveration followed by a single-trial shift to a distinct strategy. This strategy typically appears to produce the correct compensatory magnitude for a noisily estimated perturbation, but also substantial variability in compensatory sign. We then applied the same analyses to reaching data from a visuomotor rotation task that inhibited implicit adaptation through delaying feedback presentation. Similarly, we found that participants typically perseverated in reaching towards the target before suddenly switching, in a single trial, to good performance in compensatory magnitude. We fit our generative "Aha!" model to 1337 participants across several datasets and show that it faithfully captures these phenomena. Our findings highlight the need to update existing models to account for the abrupt, insight-driven shifts that characterise individual human responses to sensorimotor perturbations.

neuroscience↗

bioRxiv2025

Large Reaching Datasets Quantify the Impact of Age, Sex/Gender, and Experience on Motor Control

As we age, our movements become slower and less precise--but the extent of this decline remains unclear. To address this, we harmonized data from 2,185 participants across four published studies using a standard center-out reaching task. We found that older age was associated with a steady decline in reaction time (- 1.2 ms/year), movement time (-2.3 ms/year), and movement precision (-0.02{o}/year). Although the rate of decline did not differ by sex/gender, females consistently reacted more slowly (-8 ms), moved more slowly (-37 ms), and exhibited greater precision (+0.5{o}) across the adult lifespan. Notably, sex/gender differences attenuated after accounting for experiential factors such as video game use and the amount of sleep per day, whereas age remained a robust and consistent predictor of motor decline. Together, these findings provide a large-scale quantification of age, sex/gender, and experiential effects on motor control, offering a normative benchmark to inform future clinical interventions aimed at preserving motor function across the lifespan.

neuroscience↗

bioRxiv2023

Visuomotor memory is not bound to visual motion

Sensory feedback plays a critical role in motor control and motor learning, with both processes adjusting outgoing motor commands relative to the error between actual sensory feedback and the predictions of a forward model. However, models of motor control rarely specify the exact nature of these predictions. We hypothesized that large differences in low-level perceptual feedback would delineate contextual boundaries for motor memory, as sufficiently different feedback would require a distinct mapping between motor commands and sensory states. We tested this hypothesis by measuring transfer of visuomotor adaptation across contexts where hand movements caused visual motion in opposite directions. Instead of observing that visual feedback is bound to distinct internal models, we found nearly complete transfer of learning across the contexts, with evidence that the motor memory was bound to the planned displacement of the hand, rather than visual features of the task space.

neuroscience↗

bioRxiv2023

Kinematic markers of skill in first-person shooter video games

Video games present a unique opportunity to study motor skill. First-person shooter (FPS) games have particular utility because they require visually-guided hand movements that are similar to widely studied planar reaching tasks. However, there is a need to ensure the tasks are equivalent if FPS games are to yield their potential as a powerful scientific tool for investigating sensorimotor control. Specifically, research is needed to ensure that differences in visual feedback of a movement do not affect motor learning between the two contexts. In traditional tasks, a movement will translate a cursor across a static background, whereas FPS games use movements to pan and tilt the view of the environment. To this end, we designed an online experiment where participants used their mouse or trackpad to shoot targets in both contexts. Kinematic analysis showed player movements were nearly identical between conditions, with highly correlated spatial and temporal metrics. This similarity suggests a shared internal model based on comparing predicted and observed displacement vectors, rather than primary sensory feedback. A second experiment, modelled on FPS-style aim-trainer games, found movements exhibited classic invariant features described within the sensorimotor literature. We found that two measures of mouse control, the mean and variability in distance of the primary sub-movement, were key predictors of overall task success. More broadly, these results show that FPS games offer a novel, engaging, and compelling environment to study sensorimotor skill, providing the same precise kinematic metrics as traditional planar reaching tasks. Significance statementSensorimotor control underpins human behaviour and is a predictor of education, health, and socioemotional wellbeing. First-person shooter (FPS) games hold promise for studying sensorimotor control at scale, but the visual feedback provided differs from traditional laboratory tasks. There is a need to ensure they provide measures that relate to traditional tasks. We designed an experiment where the visual contingency of movements could be varied whilst participants shot targets. Participants movements were similar between contexts, suggesting the use of a common internal model despite the sensory differences. A second experiment observed canonical learning patterns with practice and found two measures of mouse control strongly predicted overall performance. Our results highlight the opportunity offered by FPS games to study situated skilled behaviour.

neuroscience↗

bioRxiv2022

Measuring motion-to-photon latency for sensorimotor experiments with virtual reality systems

Consumer virtual reality (VR) systems are increasingly being deployed in research to study sensorimotor behaviours, but properties of such systems require verification before being used as scientific tools. The motion-to-photon latency (the lag between a user making a movement and the movement being displayed within the display) is a particularly important metric as temporal delays can degrade sensorimotor performance. Extant approaches to quantifying this measure have involved the use of bespoke software and hardware and produce a single measure of latency and ignore the effect of the motion prediction algorithms used in modern VR systems. This reduces confidence in the generalisability of the results. We developed a novel, system-independent, high-speed camera-based latency measurement technique to co-register real and virtual controller movements, allowing assessment of how latencies change through a movement. We applied this technique to measure the motion-to-photon latency of controller movements in the HTC Vive, Oculus Rift, Oculus Rift S, and Valve Index, using the Unity game engine and SteamVR. For the start of a sudden movement, all measured headsets had mean latencies between 21-42ms. Once motion prediction could account for the inherent delays, the latency was functionally reduced to 2-13ms, and our technique revealed this reduction occurs within [~]25-58ms of movement onset. Our findings indicate that sudden accelerations (e.g. movement onset, impacts and direction changes) will increase latencies and lower spatial accuracy. Our technique allows researchers to measure these factors and determine the impact on their experimental design before collecting sensorimotor data from VR systems.

neuroscience↗

bioRxiv2021

Nucleosomal Asymmetry Shapes Histone Mark Binding and Promotes Poising at Bivalent Domains

Promoters of developmental genes in embryonic stem cells (ESCs) are marked by histone H3 lysine 4 trimethylation (H3K4me3) and H3K27me3 in an asymmetric nucleosomal conformation, with each sister histone H3 carrying only one mark. These bivalent domains are thought to poise genes for timely activation upon differentiation. Here we show that asymmetric bivalent nucleosomes recruit repressive H3K27me3 binders but fail to enrich activating H3K4me3 binders, despite presence of H3K4me3, thereby promoting a poised state. Strikingly, the bivalent mark combination further attracts chromatin proteins that are not recruited by each mark individually, including the histone acetyltransferase complex KAT6B (MORF). Knockout of KAT6B blocks neuronal differentiation, demonstrating that bivalency-specific readers are critical for proper ESC differentiation. These findings reveal how histone mark bivalency directly promotes establishment of a poised state at developmental genes, while highlighting how nucleosomal asymmetry is critical for histone mark readout and function.

molecular biology↗

bioRxiv2020

Getting stuck in a rut as an emergent feature of a dynamic decision-making system

Human sensorimotor decision-making has a tendency to get stuck in a rut, being biased towards selecting a previously implemented action structure ( hysteresis). Existing explanations cannot provide a principled account of when hysteresis will occur. We propose that hysteresis is an emergent property of a dynamical system learning from the consequences of its actions. To examine this, 152 participants moved a cursor to a target on a tablet device whilst avoiding an obstacle. Hysteresis was observed when the obstacle moved sequentially across the screen between trials, but not with random obstacle placement. Two further experiments (n = 20) showed an attenuation when time and resource constraints were eased. We created a simple computational model capturing dynamic probabilistic estimate updating that showed the same patterns of results. This provides the first computational demonstration of how sensorimotor decision-making can get stuck in a rut through the dynamic updating of its probability estimates. Significance StatementHumans show a bias to select the organisational structure of a recently carried out action, even when an alternative option is available with lower costs. This hysteresis is said to be more efficient than creating a new plan and it has been interpreted as a design feature within decision-making systems. We suggest such teleological arguments are redundant, with hysteresis being a naturally emergent property of a dynamic control system that evolved to operate effectively in an uncertain and partially observable world. Empirical experimentation and simulations from a first principle computational model of decision-making were consistent with our hypothesis. The identification of such a mechanism can inform robotics research, suggesting how robotic agents can show human-like flexibility in complex dynamic environments.

neuroscience↗

bioRxiv2018

Studying Human Behaviour with Virtual Reality: The Unity Experiment Framework

Virtual Reality systems offer a powerful tool for human behaviour research. The ability to create three-dimensional visual scenes and measure responses to the visual stimuli enables the behavioural researcher to test hypotheses in a manner and scale that were previously unfeasible. For example, a researcher wanting to understand interceptive timing behaviour might wish to violate Newtonian mechanics, so objects move in novel 3D trajectories. The same researcher may wish to collect such data with hundreds of participants outside the laboratory, and the use of a VR headset makes this a realistic proposition. The difficulty facing the researcher is that sophisticated 3D graphics engines (e.g. Unity) have been created for game designers rather than behavioural scientists. In order to overcome this barrier, we have created a set of tools and programming syntaxes that allow logical encoding of the common experimental features required by the behavioural scientist. The Unity Experiment Framework (UXF) allows the researcher to readily implement several forms of data collection, and provides researchers with the ability to easily modify independent variables. UXF does not offer any stimulus presentation features, so the full power of the Unity game engine can be exploited. We use a case study experiment, measuring postural sway in response to an oscillating virtual room, to show how UXF can replicate and advance upon behavioural research paradigms. We show that UXF can simplify and speed up development of VR experiments created in commercial gaming software and facilitate the efficient acquisition of large quantities of behavioural research data.

neuroscience↗