On the measurement of the effects of alcohol and illicit substances on inhibition of return.
Inhibition of return (IOR) refers to the delayed orienting of attention to previously inspected locations in favour of novel locations. Given its implications for visual attention and search, researchers have begun to investigate whether IOR may be impaired by the use of alcohol or illicit substances (e.g. d-amphetamine). The present paper reviews the existing literature exploring the impact of alcohol and other drugs on IOR through the use of the model spatial cueing task developed by Posner. Studies were located that investigated IOR paradigm with respect to either (a) acute effects of alcohol or other psychoactive substances and (b) hallucinogenic drug states as models for psychosis. Findings suggest that alcohol, d-amphetamine and some hallucinogens may alter the timecourse of IOR. This review also yields a critical qualitative analysis of the methodology of studies in this field of research and the implications of particular methodological features for interpreting previous findings. The importance of using multiple stimulus onset asynchronies, employing a cue-back to centre paradigm and distinguishing between acute and chronic substance use are emphasized. Furthermore, questions are raised as to whether findings suggest an impact of psychoactive substances on the subcortical mechanisms that play a critical role in the generation of IOR or are an indirect effect resulting from impairment of the cortical mechanisms responsible for voluntary disengagement of attention. Directions for future research and particular methodological approaches are highlighted.