# Overshadowing and salience attribution in relation to cannabis use

## TL;DR

The study finds that regular cannabis use is linked to changes in how people process the importance of cues, which may relate to psychosis risk.

## Contribution

The study introduces new insights into how cannabis use affects cue competition and salience attribution in non-clinical adults.

## Key findings

- Current cannabis users had lower OS scores during testing compared to non-users.
- Cannabis users showed higher implicit aberrant salience in the SAT compared to non-users.
- OS task scores predicted higher explicit and adaptive salience scores in the SAT.

## Abstract

Aberrant attentional salience has been implicated in the cannabis-psychosis association. Here, history and frequency of cannabis use were examined against changes in overshadowing (OS), a cue competition paradigm that involves salience processing. Additionally, we examined the association between OS and alternative measures of aberrant salience, as well as schizotypy, in a non-clinical adult sample.

280 participants completed an online geometry learning-based OS task, while a subset (N = 149) also completed the Salience Attribution Task (SAT) measure of aberrant salience. All completed the Schizotypal Personality Questionnaire (SPQ), Aberrant Salience Inventory (ASI), and the modified Cannabis Experience Questionnaire (CEQmv). Differences across OS and SAT performance stages and between cannabis use groups were assessed using mixed ANOVAs. Multiple regression and correlational analyses assessed the relationships between OS and SAT task metrics and SPQ and ASI subscale scores.

Current cannabis users had significantly lower OS scores during the testing phase relative to those who do not use cannabis, at medium effect sizes. Schizotypy or ASI scores did not mediate this relationship. In the SAT, current cannabis users presented significantly higher implicit aberrant salience relative to non-users. Scores in the first training phase of the OS task significantly predicted higher explicit aberrant and adaptive salience scores in the SAT.

These data indicate an association between regular cannabis use and abnormalities in cue competition effects in a healthy adult sample. Comparisons of OS and SAT cast new light on putative overlapping mechanisms underlying performance across different measures of salience.