08:29
Mr. Asim Rajput
Primates use "orientation saliency" to quickly select items in our surroundings that are new, risky, or don't belong. Basically put, if several objects in your visual field are oriented in direction, your eye will be drawn to the object that goes the opposite way. Because this method might be useful for predatory owls, researchers wondered if barn owls would exhibit orientation saliency as well.
Barn owls have a hard job: in near-darkness, they require to catch at least little critters a day to feed themselves, and about twenty a day in the event that they have offspring. Since the stakes are so high, the selective pressure acting on these birds' vision is intense. Last week's PNAS reports that owls exhibit a number of the same visual recognition patterns that humans do, despite different visual systems.
Each owl was outfitted with the OwlCam and placed on a perch in a room. The room also contained 25 colored bars on the floor, with 24 of them oriented on the same direction. Across 97 experimental trials lasting 120 minutes, the owls' gazes were overwhelmingly drawn to the bar oriented differently from the rest. The owls looked at that bar more quickly, more often, and for longer periods of time than the other bars.
To answer this query, the scientists attached "the OwlCam," a small wireless camera weighing two.5 grams, to the heads of barn owls. Since barn owls don't move their eyes much, in lieu relying on head motion to modify their gaze, researchers watching the footage could receive a nice suggestion of what, exactly, the owl was focusing on in its field of view.
Orientation saliency is a common thread between barn owls and primates, despite massive physiological and organizational differences between these animals' visual systems (interestingly, archerfish also exhibit orientation saliency). It remains to be seen whether a similar method drives this ability across groups, or whether these animals have found different solutions. What is clear is that orientation saliency probably contributes greatly to barn owls' effectiveness in finding prey.
Barn owls have a hard job: in near-darkness, they require to catch at least little critters a day to feed themselves, and about twenty a day in the event that they have offspring. Since the stakes are so high, the selective pressure acting on these birds' vision is intense. Last week's PNAS reports that owls exhibit a number of the same visual recognition patterns that humans do, despite different visual systems.
Each owl was outfitted with the OwlCam and placed on a perch in a room. The room also contained 25 colored bars on the floor, with 24 of them oriented on the same direction. Across 97 experimental trials lasting 120 minutes, the owls' gazes were overwhelmingly drawn to the bar oriented differently from the rest. The owls looked at that bar more quickly, more often, and for longer periods of time than the other bars.
To answer this query, the scientists attached "the OwlCam," a small wireless camera weighing two.5 grams, to the heads of barn owls. Since barn owls don't move their eyes much, in lieu relying on head motion to modify their gaze, researchers watching the footage could receive a nice suggestion of what, exactly, the owl was focusing on in its field of view.
Orientation saliency is a common thread between barn owls and primates, despite massive physiological and organizational differences between these animals' visual systems (interestingly, archerfish also exhibit orientation saliency). It remains to be seen whether a similar method drives this ability across groups, or whether these animals have found different solutions. What is clear is that orientation saliency probably contributes greatly to barn owls' effectiveness in finding prey.
0 comments:
Post a Comment