Neurological Evidence for Impairment of Supervisory Attentional System in Impulsive Children

Abstract

Background & Aims: Supervisory Attentional System (SAS) model of information processing (Norman and Shallice, 1980) explains the overall voluntary cognitive control and regulation of mental processes during novel or complex tasks. From a functional point of view, “Impulsivity” is a multidimensional concept that incorporates failure of "response inhibitory control" –a key component in SAS–and other cognition processes. Even aggressive, suicidal, and violent behaviors are associated with impulsivity and difficulty in inhibiting responses. The aim of this descriptive-comparative study was to investigate whether SAS impairments play a role in impulsive behaviors of children. Materials & Methods: Students of 8 to 10 years old were categorized into groups of high impulsivity (1.2 SD higher than the mean (n=25)) and low impulsivity (1.2 SD higher than the mean based on the Conners' Teacher Rating Scale (CTRS-RS)). SAS performance was assessed by Continuous Performance Test (CPT), Go/No Go (GNG), and Tower of London Test (TOL). Results: In CPT, higher commission score (p=0.025, F=5.40); in GNG, lower inhibitory control and omission (p, F=16.27; p0.016, F=6.27; p0.006, F=8.46); and in TOL, higher time test, time total, error, and lower results scores (p0.015, F=6.34; p0.027, F=5.18, p0.001, F13.49; p0.001, F12.50) were obtained by the more impulsive participants. Conclusion: Taken together, a multivariate analysis of variance in all three tests revealed that response inhibitory control is negatively associated with high impulsivity, indicating the correlativity of SAS impairment with impulsivity. This finding introduces quantifiable means of assessing SAS impairment in impulsive children, which can help improve the diagnosis and treatment strategies of impulsivity-related disorders.