Executive functions are a set of high-level cognitive processes which allow us to adapt to our environment, they become active when action routines are no more sufficient. Executive functions are the subject of Fabienne Collette’s work group which is devoting particular attention to the former, particularly in the context of normal or pathological ageing.

Most of the time, we act in accordance with automatic procedures, “overlearned” cognitive skills which are mainly unconscious. In this way, we can focus our attention on other targets – in particular - on what can be perceived as complex, new or dangerous. It is at this stage that “executive functions”, a set of high-level cognitive processes that allow us to adapt to our environment when action routines are no longer sufficient, become active.

The action of driving a car illustrates the idea perfectly. During good weather, when the road is clear, a driver arrives at his destination having driven there in automatic mode. Generally speaking, he will not be able to give a detailed account of his journey because he will barely remember passing one place or another, or stopping at a given red light. Let us imagine that the road is slippery and plunged into semi-darkness. The driver will then have to be much more attentive in order to be able to break from his routine actions in the event that a problem occurs. Therefore, if he sees that a child is about to run out to cross the road even though there is a green light for traffic, he will take conscious control of his vehicle and will press the brake pedal to ensure that he can safely stop. In this way he will have switched from automatic mode (I press the accelerator when the lights are green) to call upon the executive system or more particularly upon flexibility, one of the functions that the executive system is composed of, which in this case is translated by a change of action plan.


Professor Fabienne Collette, Director of Research at the FNRS in the Cyclotron Research Center (CRC) and the Neuropsychology Unit of the University of Liege (ULg), gives us another example of a situation where the executive system becomes active: Inhibition. “Let us suppose that you park your car in a no-parking zone for two minutes in order to deliver a parcel. When you return to your car a policeman is giving you a fine. Your first instinct might be to argue aggressively with him because you feel that you are the victim of an injustice. In general, you are more likely to inhibit this inappropriate behavior, to explain the situation calmly and apologize in the hope that you will not have to pay a fine”.

Intelligent behaviors

Executive functions are very varied, as illustrated by Patrick Rabbit in 1997, at the University of Manchester, in his theoretical approach to the question. Sometimes they combine for the purpose of formulating a goal, for planning and the choice of behavioral sequences to be adopted in order to achieve the goal, the comparison of the efficiency of the different strategies, the implementation of the plan selected until its final accomplishment and its later alteration in case of failure. Sometimes executive functions participate in the conscious search for specific information in the memory or in the allocation of attentional resources enabling an individual to switch from a particular behavioral sequence to a better one according to environmental requirements. Sometimes they coordinate the simultaneous realization of two tasks, block inappropriate behaviors and detect errors in order to correct them.

According to Rabbit, executive functions also contribute to the maintenance of attention over long periods of time. In this way they make it possible to exercise high-level control of the occurrence of prolonged behavioral sequences.

Executive functions can probably not be likened to “intelligence”, all the more so because the definition of intelligence remains a vague concept with an uncertain definition, but they certainly constitute the essential background to behaviors that are described as intelligent to the extent that certain authors liken them to the g factor which is a sort of common denominator, whether real or artificial (opinions about this vary), applicable to all these behaviors. “The cerebral networks involved in the completion of I.Q. tests or the accomplishment of tasks that solicit the executive functions overlap to a large extent. There is clearly a common biological substrate”, comments Fabienne Collette.