Harston, J. A. | Search bioRxiv

bioRxiv2020

Linear Embodied Saliency: a Model of Full-Body Kinematics-based Visual Attention

Gaze behaviour and motor actions are fundamentally interlinked in both a spatial and temporal manner. However, the vast majority of gaze behaviour research has focused to date on reductionist head-fixed screen viewing experiments and ignored the motor aspect of visuomotor behaviour, thereby neglecting a critical component of the perception-action loop. We address this with an experimental design to capture, rather than constrain, the full range of simultaneous gaze and motor behaviour in a range of natural daily life tasks. Through building autoregressive models and applying these to our novel datasets we find that beyond simple static regions of interest, we can predict visual attention shifts from freely-moving first person body kinematics, through explaining gaze dynamics in the context of body dynamics, on the timescale of freely moving interactive behaviour in individuals, expanding our understanding of natural visuomotor behaviour.

neuroscience↗

bioRxiv2019

Cerebellar-recipient motor thalamus drives behavioral context-specific movement initiation

To initiate goal-directed behavior, animals must transform sensory cues into motor commands that generate appropriately timed actions. Sensorimotor transformations along the cerebellar-thalamocortical pathway are thought to shape motor cortical output and movement timing, but whether this pathway initiates goal-directed movement remains poorly understood. Here, we recorded and perturbed activity in cerebellar-recipient regions of motor thalamus (dentate / interpositus nucleus-recipient regions, MThDN/IPN) and primary motor cortex (M1) in mice trained to execute a cued forelimb lever push task for reward. MThDN/IPN population responses were dominated by a time-locked increase in activity immediately prior to movement that was temporally uncoupled from cue presentation, providing a fixed latency feedforward motor timing signal to M1FL. Blocking MThDN/IPN output suppressed cued movement initiation. Stimulating the MThDN/IPN thalamocortical pathway in the absence of the cue recapitulated cue-evoked M1 membrane potential dynamics and forelimb behavior in the learned behavioral context, but generated semi-random movements in an altered behavioral context. Thus, cerebellar-recipient motor thalamocortical input to M1 is indispensable for the generation of motor commands that initiate goal-directed movement, refining our understanding of how the cerebellar-thalamocortical pathway contributes to movement timing.

neuroscience↗