Week 9

Executive Functions

Executive functions are generally explained as a set of abilities within the human frontal lobe that help us to guide our behaviour, particularly in unknown situations. These functions include processes like prioritizing and sequencing of behaviour, inhibiting impulsive behaviour, planning, mental flexibility, and decision-making. Due to the wide rage of processes involved, impairments are difficult to be diagnosed through the assesment of a single test. It is therefore suggested to use different tasks to examine different facets.

Most scientists share the assumption of executive functions to effortfully guide goal-directed behaviour. Psychological and neurobiological models however differ highly. Banich, 2011 proposes that different parts of the frontal lobe create a pathway of information to achieve the correct response. Explaining her model however, it can be criticized that alternative explanations have not been taken into account but just briefly overviewed. It is claimed that the posterior part of the dorsolateral prefrontal cortex (DLPFC) first gives notice on the top-down attention, deciding where to focus attention. The mid-DLPFC then decides which of the perceived representations is more relevant for the task. The posterior dorsal anterior cingulate cortex (ACC) determines which response to exhibit and passes the decision on to the dorsal ACC where the final evaluation takes place. If the dorsal ACC accepts the response it will be executed (216 words). If it gets disapproved, a signal gets send back to the Prefrontal cortex to start the process over again.

The intensity of each mechanism increases with the decrease of previous mechanisms in the pathway, and therefore can differ highly in each individual. Moreover the level or activation of certain mechanisms is highly associated with the age of the individual.