![]() Trackball motion is often measured using motion sensors repurposed from computer mice (CM Clark et al., 2011 Takalo et al., 2012 Paulk et al., 2014), which optically measure changes in ball position by acquiring sequential images of the ball's surface and calculating the direction and magnitude of visual movement in the images ( Avago Technologies, 2009). A useful experimental paradigm to study the behaviour of walking animals is to place them on an air-supported trackball, where the ball's movements in reaction to an animal's leg movements are measured and used to change its sensory environment ( Harvey et al., 2009 Seelig et al., 2010 Takalo et al., 2012). Closed-loop paradigms, which simulate free untethered motion, measure the tethered animal's motor output and concurrently use this to update the animal's sensory environment, permitting a careful study of the interaction of the animal with its environment ( Taylor et al., 2008). By fixing an animal in place, tethered experiments allow measurement of the animal's reaction to precisely controlled stimuli. Virtual reality enables tight control of the sensory stimuli to which animals are exposed, and detailed observation of behavioural responses from them as they interact with the stimuli ( Dombeck and Reiser, 2012). To understand how animals use sensory information, researchers have designed virtual-reality paradigms for tethered animals. ![]() Further, our findings show that caution is required when designing virtual-reality experiments, as animals can potentially respond to the artificial scenario in unexpected and unintended ways. This study suggests that bees are capable of fine-tuning their motor control to improve the outcome of the task they are performing. Although the large perceived inertia and mass of the trackball relative to the honeybee is a limitation of tethered walking paradigms, observing differences depending on the sensor system used to measure bee behaviour was not expected. This behavioural change appears to be a response to a systematic error in the computer mouse sensor that reduces the sensitivity of this sensor system under certain conditions. When computer mouse sensors were used to measure bees' behaviour, the bees modified their behaviour and achieved improved control of the stimulus. Bees walked faster and along straighter paths when the motion of the trackball was measured in the classical fashion – using optical motion sensors repurposed from computer mice – than when measured more accurately using a computer vision algorithm called ‘FicTrac’. To investigate this issue, we conducted experiments with tethered honeybees walking on an air-supported trackball and fixating a visual object in closed-loop. Many different sensor types have been used to measure aspects of behaviour, and although some sensors may be more accurate than others, few studies have examined whether, and how, such differences affect an animal's behaviour in a closed-loop experiment. This is particularly relevant in closed-loop experiments where the animal interacts with a stimulus. When using virtual-reality paradigms to study animal behaviour, careful attention must be paid to how the animal's actions are detected.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |