Aligning measures of impulsivity with underlying constructs

Abstract

This study attempts to clarify the dimensionality of impulsivity. Although research has employed the construct of impulsivity to explain normal and pathological behaviors, there have been divergent interpretations. This study is the first in Hong Kong to investigate the construct and dimensionality of impulsivity based on self-report measures and neurocognitive tests. The subjects in this study were people with a history of substance abuse and people living with HIV/AIDS. The Barratt Impulsiveness Scale (BIS) was used for self-reporting and the Stop Signal Task and Matching Familiar Figures Test (MFFT) were the neurocognitive tests used to assess motor impulsivity and cognitive impulsivity, respectively. Two subscores (stop signal delay and stop signal reaction time) from the Stop Signal Task and three subscores (the first response time, total response time, and number of errors) from the MFFT were obtained for analysis. The Iowa Gambling Task was also examined, revealing the uniqueness of its underlying structure. Additionally, the Beck Depression Inventory-II (BDI-II) and Symbol Digit Modalities Test were administered to investigate their relationships to the measures of impulsivity. Exploratory factor analysis identified three fundamental dimensions of the data sample: inhibitory control, reflection impulsivity, and emotion-induced impulsivity. Further analysis suggested that rather than demonstrating linkages with the fundamental dimensions of impulsivity, the first response and total response times of the MFFT were associated with psychomotor speed. Furthermore, the motor and attentional subscales of the BIS related to the BDI-II.