JMIR Publications

ABSTRACT

Background:

Considered a facet of behavioural impulsivity, response inhibition facilitates adaptive and goal-directed behaviour. It is often assessed using the Stop-Signal Task (SST), which is presented on stand-alone computers under controlled laboratory conditions. Sample size may consequently be a function of cost/time and sample diversity constrained to those willing/able to attend the lab. Statistical power and generalisability of results might, in turn, be impacted. Such limitations may potentially be overcome via the implementation of online testing.

Objective:

The aim of this study was to investigate if there were differences between variables derived from an online SST when it was undertaken independently – that is, outside the laboratory, on any computer, and in the absence of researchers – versus when it was performed under laboratory conditions.

Methods:

We programmed a web-based SST in HTML and JavaScript and employed a counter-balanced design. A total of 166 individuals (Mage = 19.72, SD = 1.85, range: 18-36, 88% female) were recruited. Of these, n = 79 undertook the independent task prior to visiting the laboratory and n = 78 completed the independent task following their laboratory visit. Average time between SST testing was 3.72 days (SD = 2.86). Dependent samples and Bayesian paired samples t-tests were utilised to examine differences between lab-based and independent SST variables. Correlational analyses were conducted on stop-signal reaction times (SSRT).

Results:

After exclusions, 123 participants (Mage = 19.73, SD = 1.97) completed the SST both in the laboratory and independently. While participants were less accurate on go trials and exhibited reduced inhibitory control when undertaking the independent – as compared to the lab-based – SST, there was a positive association between the SSRT of each condition (r = .48, P < .001, 95% CI [0.33, 0.61]).

Conclusions:

Findings suggest an online SST, which participants undertake on any computer, in any location, and in the absence of the researcher, is a suitable measure of response inhibition.