You can see executive function as being the central processor or managing director of the brain. Cognitive psychologists have theorised that the executive function system is a network that controls other areas of cognitive functioning, which is why some people call it cognitive control. It’s like a supervisory system overseeing all other functions, directing resources to the most appropriate cognition and inhibiting competing signals. It’s vital for survival in an ever-changing world.
Developing executive functions
Unsurprisingly, given the importance of executive function, it develops late in your life. Most executive functions evolve in adolescence or even early adulthood. The ability to focus attention and inhibit irrelevant information and behaviours take time to grow. Indeed, the brain network thought to be responsible for executive function isn’t fully developed until adulthood.
Understanding executive functions
Executive functions cover a wide range of abilities, which we categorise broadly into three components:
Updating: Monitoring the contents of working memory and altering it as the environmental demands require.
Inhibiting: Preventing an automated behaviour and ignoring unwanted information.
Shifting: Moving between different tasks, cognitive tasks or behaviours.
Although these categories are apparent, subcategories of each also exist.
Measuring executive function
Psychologists have developed hundreds of different tests of executive function. Here are several of the most widely used tasks, some with more exotic names than others:
Continuous performance task: Involves presenting participants with a sequence of letters. They’re asked to respond whenever they see a particular letter or a particular combination of letters. This task measures the monitoring ability of executive functions.
Stroop task: Involves participants naming the ink colour of words. They’re slower when the word is a colour and doesn’t match the ink colour, because participants have to inhibit the automatic process of reading.
Iowa gambling task: Involves the presentation of four decks of cards. Participants must draw cards, which can be rewards or penalties. Some decks contain more rewards and some decks contain more penalties. This task tests participants ability to change goals (updating) and identify strategies for success (attend to which decks are producing good rewards and problem solve).
Tower of Hanoi: Involves participants moving rings of different sizes from one peg to another. One key rule exists: they can’t place a larger ring on top of a smaller ring. Again, this task measures updating.
Wisconsin card sorting task: Tests a measure of set-shifting. Participants are presented with a number of cards and told to match them (but not given the rule). Participants are simply told whether they’re right or wrong and must work out the rule.
Flanker task: Involves participants responding to the direction of a central arrow that’s surrounded by arrows that point in the same or a different direction. Participants must inhibit the direction of the surrounding arrows. This measures the ability to inhibit distracting information.
