Physiological substrates of executive functioning: a systematic review of the literature.
Executive function (EF) is a multifaceted construct that has been defined as a set of higher-order cognitive processes that allow for flexibility, self-regulation, strategic planning, and goal-directed behaviors. EFs have been studied in numerous clinical disorders using a variety of neuropsychological tasks and, more recently, neuroimaging techniques. The underlying physiological substrates of EF were historically attributed to the frontal lobes; however, recent studies suggest more widespread involvement of additional brain regions. The purpose of the present study was to conduct a systematic review (using PRISMA 2009 guidelines) of neuroimaging studies employing functional magnetic resonance imaging and diffusion tensor imaging methods investigating the physiological substrates of EFs in attention-deficit/hyperactivity disorder compared to other clinical groups and non-clinical participants. Research articles were retrieved using PsycINFO, PsycARTICLES, MEDLINE, and ScienceDirect, beginning February 2015 through May 2016. A total of 42 studies met eligibility. Of those 42 studies, 22 studies included clinical participants and 20 studies included non-clinical participants. Results revealed increased activation of the frontal brain region in the majority of non-clinical studies and approximately 50% of the clinical studies, albeit with some inconsistencies across subregions, tasks, and age groups. Implications, methodological limitations, and suggestions for future research are discussed.
Interdisciplinary Neuroscience Program, University of Rhode Island, Chafee Hall, 10 Chafee Road, Kingston, RI, 02881, USA. bailey_munro@my.uri.edu.
Bailey A
BA
Munro
Interdisciplinary Neuroscience Program, University of Rhode Island, Chafee Hall, 10 Chafee Road, Kingston, RI, 02881, USA.
Lisa L
LL
Weyandt
Department of Psychology, University of Rhode Island, Kingston, RI, USA.
Lily E
LE
Hall
Department of Psychology, University of Rhode Island, Kingston, RI, USA.
Danielle R
DR
Oster
Department of Psychology, University of Rhode Island, Kingston, RI, USA.
Bergljot Gyda
BG
Gudmundsdottir
Department of Psychology, University of Rhode Island, Kingston, RI, USA.
Benjamin G
BG
Kuhar
D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D003863:Depression / Q000503:physiopathology*; D056344:Executive Function / Q000502:physiology*; D006801:Humans; D059906:Neuroimaging; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology*
ADHD; Executive functioning; Neuroimaging; Physiological substrates