Executive Decisions

The executive control mechanism in our brains refers to our ability to switch tasks and adapt to immediate demands stemming from our environment and our needs. Good executive control means that we are flexible in that we can switch very rapidly from working on one thing to working on something else with minimal general cost.  By general cost we mean loss in response time for that task and increase in error rate.

When it comes to cognitive tasks, we may often claim to be multi-tasking, but we aren’t really doing that. We are just breaking the tasks in small chunks and switching back and forth between them in an effort to keep them all moving. The general cost can be high as switching occurs frequently, adding to the costs each time.

Many jobs involve us doing repetitive things, but with making decisions on taking one action or another depending on what appears in front of us. This can be as simple as rejecting unsatisfactory items on a production line or as serious as counting votes in an election. How often have we heard the comment that “they could train monkey to do this?” While complaining that we’re being paid peanuts for the work, we miss the irony.

This is meat and drink to the cognitive neuroscientists who will quickly ask “do monkeys make model human beings?” Caselli and Chelazzi of the Us of Verona and Parma have waded into the discussion with a comparison of task switching costs between a pair of macaques and eight young people. Only one of the eight humans was recorded as male – does that mean that jobs that demand frequent switching from one repetitive task to another are mainly done by women in their neck of the woods?

Down to the experiments. A lever had to be pushed to the right or left depending on the color and orientation of an image of a stripe. The participants, willing and coerced, were given a visual clue as to whether they had to choose between color or orientation as the instruction, just prior to seeing the image for a second. There was verbal feed back about the correctness of choice for each of the participants and, in addition, the two monkeys got a shot of juice if they were correct.

Results are everything when it comes to executive decisions.

Monkey One was more thoughtful and so slower to respond than the humans or his friend. Monkey Two was eager to get juiced up with his next shot and beat all the humans to it. Unfortunately his error rate was four and a half times as high as the humans as he only got an 82% test score, while his thoughtful friend was down to three times as wrong with an 88% score. People weren’t perfect though, with only a 96% correct rate. Good you may say, as long as it not about decisions into whose bank account to deposit your paycheck.

The authors come to the conclusion that “monkeys appear to be less competent than humans in managing task-switching-situations.” However they do propose monkeys as a good model for studying human executive decision making. While watching some of the decisions being made by the good and the great, I suspect that they may be right.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021489

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