From Scientific American:
Sights and sounds fill the world, presenting a panoply of possible foci for the brain. Yet most animals can hone in on whatever sight most demands interest. Then the sounds associated with that sight–be it a loved one talking or a tasty meal skittering through the undergrowth–become all the clearer. This is attention and new research shows how an owl’s brain establishes the state. It also provides tantalizing evidence that brains from across the animal kingdom work the same way.
Neurologists Daniel Winkowski and Eric Knudsen of Stanford University wired 12 owls with electrodes in the areas of their brains that process either visual or auditory input. Each region literally maps the world of sound or sight, determining whether it comes from up or down, left or right. Sending a small electrical charge into the owl’s visual brain region–the so-called arcopallial gaze fields–caused it to move its head and eyes in a particular direction. When a simultaneous audio stimulus matched that direction, the owl’s brain responded more strongly to that noise. It also blocked out competing noises from other directions. Owls are already extremely gifted at tuning in a particular sound, the authors note in their paper published in the current issue of Nature, but pairing a sound with a sight enhanced that ability even further.