Free It's a Jungle in There: How Competition and Cooperation in the Brain Shape the Mind by David A. Rosenbaum Page A

is to resist the idea that your mind has a single head honcho, a top dog who decides things for you. The problem with postulating such a cognitive captain is that granting his or her existence begs the question of how that chief executive decides what to do. Who tells the CEO what commands to issue? You don’t want to end up with a Russian-doll problem, with beings inside beings endlessly passing the ruble.
    If you deny that an executive decides things for you, you’re left with the question of how you make decisions. You can say your brain holds elections and, as it turns out, that account does a reasonably good job of explaining neural and behavioral data. But if you go with the election view, you’re still left with questions: How are elections set? What issues are worth voting on? How is the collective attention of the electorate directed to one thing or another? How, if at all, is attention managed? What is attention anyway?
    To set sail for explaining attention in Darwinian terms, it helps to think about the problems that are solved by invoking attention. One is filtering. Imagine you’re on a train and you’re trying to read. People in nearby seats are jabbering away, oblivious to your quest for quiet. The topic they’re discussing doesn’t interest you in the least. Who cares if their Aunt Helen smoked more than she should have? Why should it matter if their Uncle Ben knew less about pickles than he claimed? But their chitchat cuts through anyway, leaving you unable to concentrate on the reading you want to do. Try as you might to filter out those other speakers, you can’t help overhearing them. Why can’t you tune them out? At some point you may succeed in doing so, ignoring their chatter to the point you’re no longer aware of doing so. But achieving this state is elusive, like falling asleep or falling in love. It comes unbidden.
    The downside of filtering things out is missing what’s important. You may become so engrossed in your reading that you miss the conductor’s call for your station. Filtering needs to be done at the right level. Otherwise you could end up not where you want to go, but in
Nowheresville
.
The Cocktail Party Phenomenon
    Some of the earliest research on attention posited that the gate to the mind, if there is one, is on the sensory side. A psychologist at Oxford University, Donald Broadbent, was led to this view by focusing on a task similar to the one described above. In that task, people were asked to listen to two messages at once. 1 One message was delivered to one ear. Another message was delivered to the other. When participants were instructed to focus on the message coming to one ear, they successfully recalled much of that message, but they recalled virtually nothing of the other. From that outcome, Broadbent drew a reasonable conclusion: People can attend to what reaches one ear but filter out what comes to the other. 2
    This conclusion makes sense if you try to read a book on a train and people to your right prattle incessantly. Closing your right ear, as it were, keeps your left ear open. That way, if the conductor calls your station and his or her voice comes to your “open” left ear, you can hear the call; the prattle to your right won’t derail you. On the other hand, if the conductor’s call happens to come to your right ear when he or she calls your station, you won’t hear the call and you’ll miss your stop.
    Of course, in a railroad car with ambient noise going to both ears at once, you’d be unlikely to miss a call if you happened to be paying more attention to one side than the other, so I mean this example figuratively, not literally. Still, people do miss their train stops on occasion, often as a result of missing calls for their stations. Perhaps they do so for the reason Broadbent suggested.
    There’s a problem with Broadbent’s filter theory, though, that’s not about the prevalence of ambient noise in the environment. The problem is that the