Attention verybody !

Each moment that we are awake, our senses are bombarded with stimuli. Focusing our attention on the few stimuli that are important allows us to filter out the ones irrelevant to the task at hand. The first parts of the brain to respond to objects and sounds in the environment are the so-called ‘primary’ visual and auditory cortex, respectively. Paying attention to sounds in one ear enhances the initial response of the primary auditory cortex on the opposite side. But previous studies have not found the same to be true in the primary visual cortex in subjects paying attention to objects in the visual field. Now, Vahe Poghosyan and Andreas A. Ioannides at the RIKEN Brain Science Institute in Wako have found that attention does in fact modulate primary cortical responses to both auditory and visual stimuli¹. The researchers directed five human subjects to pay attention to a pre-determined sound coming into one ear, or to a pre-determined image within a specific part of the visual field. They then presented a variety of auditory and visual stimuli, and asked the subjects to respond only to the pre-determined sound or image by raising their finger, ignoring all of the irrelevant stimuli. For example, a subject may be told to respond only to sound in the right ear, and to ignore sound in the left ear, as well as any presented images. More