A flicker paradigm for inducing change blindness reveals alcohol and cannabis information processing biases in social users

ABSTRACT Aim To apply a new paradigm using transient changes to visual scenes to explore information processing biases relating to ‘social’ levels of alcohol and cannabis use. Participants Male and female student volunteers (n = 200) not self‐reporting substance‐related problems. Setting Quiet testing areas throughout the university campus. Design A flicker paradigm, for inducing change blindness with lighter and heavier social users of alcohol (experiment 1, n= 100) and social users and non‐users of cannabis (experiment 2, n= 100), explored the associations between habitual level of use and the latency to detection of a single substance‐related or neutral change made to a scene of grouped substance‐related and neutral objects. Measurements Alcohol use was measured as the number of units of the heaviest drinking day from the previous week; cannabis use as the number of months of use in previous 12. Change–detection latency comparisons were used to evaluate processing biases. Findings In both experiments, (i) heavier social users detected substance‐related changes quicker than lighter and non‐users; (ii) lighter and non‐users detected substance‐neutral changes quicker than heavier users; (iii) heavier social users detected substance‐related quicker than substance‐neutral changes; and (iv) lighter and non‐users detected substance‐neutral changes quicker than substance‐related changes. Conclusions Alcohol and cannabis processing biases are found at levels of social use, have the potential to influence future consumption and for this reason merit further research.