Are executive function and impulsivity antipodes? A conceptual reconstruction with special reference to addiction

Abstract

Rationale: Although there is considerable interest in how either executive function (EF) or impulsivity relate to addiction, there is little apparent overlap between these research areas.

Objectives: The present paper aims to determine if components of these two constructs are conceptual antipodes--widely separated on a shared continuum.

Methods: EFs and impulsivities were compared and contrasted. Specifically, the definitions of the components of EF and impulsivity, the methods used to measure the various components, the populations of drug users that show deficits in these components, and the neural substrates of these components were compared and contrasted.

Results: Each component of impulsivity had an antipode in EF. EF, however, covered a wider range of phenomena, including compulsivity.

Conclusions: Impulsivity functions as an antipode of certain components of EF. Recognition of the relationship between EF and impulsivity may inform the scientific inquiry of behavioral problems such as addiction. Other theoretical implications are discussed.

Fig. 1

Venn diagrams demonstrating the paucity of overlap between Executive Function and Impulsivity. Proportional diagrams were created using the number of results from “Web of Science” searches on December 19, 2011 using the following search terms: “Executive Function” (14,516), “Impulsivity” (6,732), “Executive Function” and “Impulsivity” (384) “Executive Function and Drug Abuse” (157) “Impulsivity and Drug Abuse” (433) and “Executive Function and Impulsivity and Drug Abuse” (25). Similar results are obtained when conducting searches with these terms in other academic databases (e.g., Pubmed)

Fig. 2

The top panel shows Brodmann's areas color coded to show areas wherein lower levels of activation are associated with executive dysfunction (blue), impulsivity (red) or both executive dysfunction and impulsivity (purple). The bottom panel shows Brodmann's areas color coded to show areas wherein higher levels of activation are associated with executive dysfunction (blue), impulsivity (red) or both executive dysfunction and impulsivity (purple). Color coding based on studies covered in the text of the EF and impulsivity sections

Fig. 3

Factors influencing the balance of activation between the executive and impulsive systems in drug addiction. The activity of the executive function system and the impulsive system are represented as “Prefrontal” and “Limbic” actions, in balance within the central, receiving component of the model. Five non-feedback factors, three of them independent and two of them in a potential sequence chain, are pictured in the left third of the figure. The rightmost two-thirds of the figure pictures eight independent factors, some of which may interact with each other as feedback mechanisms that result in drug-use-dependent changes in the brain