Correspondence between Responses on an Internet Purchase Task and a Laboratory Progressive Ratio Task

Problematic internet use (PIU) is of increasing concern to society and is correlated with negative behavioral and health issues. Human laboratory procedures to assess economic demand for internet use may be useful in translational efforts to better understand PIU and to assess potential treatments. One such procedure involves hypothetical purchases of access to internet use. Little is known about how such hypothetical purchases relate to actual behavior. In the current study, we assessed the correlation between measures of demand via an internet purchase task (IPT) and breakpoints on a progressive ratio (PR) schedule ( n = 52). Participants responded on a computer-based task on an escalating work requirement that resulted in 30-s of access to their internet-enabled smartphone. We found a statistically significant correlation between demand intensity ( Q o ) and total responses ( r (29) = .83, p < .001), and between Omax (maximum response expenditure) and total responses ( r (29) = .34, p = .03) on the PR schedule. We did not find a relationship between measures of demand elasticity and measures of PR behavior. Because Omax is reflective of both demand and elasticity and Q 0 is primarily influenced by demand alone, the results of this study indicate that demand intensity of internet use may be a better predictor of real-world behavior than other measures of demand. These results suggest that demand intensity for internet access may be a valuable proxy for behavior-based measures in the assessment and treatment of PIU.