Sensory feedback and coordinating asymmetrical landing in toads

Coordinated landing requires anticipating the timing and magnitude of impact, which in turn requires sensory input. To better understand how cane toads, well known for coordinated landing, prioritize visual versus vestibular feedback during hopping, we recorded forelimb joint angle patterns and electromyographic data from five animals hopping under two conditions that were designed to force animals to land with one forelimb well before the other. In one condition, landing asymmetry was due to mid-air rolling, created by an unstable takeoff surface. In this condition, visual, vestibular and proprioceptive information could be used to predict asymmetric landing. In the other, animals took off normally, but landed asymmetrically because of a sloped landing surface. In this condition, sensory feedback provided conflicting information, and only visual feedback could appropriately predict the asymmetrical landing. During the roll treatment, when all sensory feedback could be used to predict an asymmetrical landing, pre-landing forelimb muscle activity and movement began earlier in the limb that landed first. However, no such asymmetries in forelimb preparation were apparent during hops onto sloped landings when only visual information could be used to predict landing asymmetry. These data suggest that toads prioritize vestibular or proprioceptive information over visual feedback to coordinate landing.Kinematic and forleimb EMG data of toads landing asymmetricallyAllRollData-3-30 Nov 2015.csvDigitized points from high speed video of toads landing asymmetricallyRollCSVTrigdata10 Mar 2016.matEMG data from m.anconeus of cane toads during hops with asymmetric landingsComplied EMG data for each toad for each hop from the m. anconeus muscle of the forelimb during hops with asymmetric landings. For further details see the readMeemgdataInt28 Nov 2015.matWhich EMG trace numbers correspond to which musclesMuscleDataRoll.csvMatlab file with gui used to do calculationsMatlab file with gui used to complie data, do calculations and provide a user interface to identify hop eventsViewData6.mMatlab file used to compile data from digitized dataReadCSVsTrig.mR markdown file used to do statistics and generate most of the manuscriptRoll2.Rm