Latent inhibition, aberrant salience, and schizotypy traits in cannabis users

Abstract

Aberrant salience processing may underlie the link between cannabis and psychosis, as posited in individuals with schizophrenia or high schizotypy. We investigated the relative effects of cannabis use, schizotypy status, and self-reported aberrant salience experiences on salience processing, measured using a latent inhibition (LI) task (Granger et al., 2016), in a non-clinical population. A university sample of 346 participants completed the Schizotypal Personality Questionnaire (SPQ), Aberrant Salience Inventory (ASI) the modified Cannabis Experience Questionnaire (CEQmv) and the LI task. Regression models and parallel (Bayesian and frequentist) t -tests or ANOVA (or non-parametric equivalents) examined differences in LI based on lifetime or current cannabis use (frequent use during previous year), as well as frequency of use. Mann-Whitney U tests assessed differences in SPQ and ASI scores based on current cannabis use. Neither lifetime nor current cannabis use was associated with significant change in LI scores. Current cannabis use was associated with both higher ‘Disorganised’ and ‘Cognitive-perceptual’ SPQ dimension scores and higher total and sub-scale ASI scores. No association was observed between LI score and SPQ total and dimension scores. Higher scores on ‘Senses sharpening’ and the ‘Heightened cognition’ ASI subscales predicted decreased LI scores. These data support previous findings of no association between cannabis use and abnormality in other associative learning tasks in young non-clinical populations, and elaborate the previously demonstrated association between self-reported cannabis use, schizotypy and aberrant salience. The association between dimensions of ASI and LI performance suggests this task may have potential as an experimental measure of aberrant salience.

Ultrasound-Induced Prenatal Stress: New Possibilities for Modeling Mental Disorders

“…This set of personality traits can range from minimal disturbances to psychotic disorders in the general human population [ 140 ]. A number of studies have shown that latent inhibition can also be impaired in this disorder [ 141 , 142 ], which allows us to consider the behavioral phenotype of rats after US PS also as a model, reproducing schizotypy symptoms, that may have important practical relevance as schizotypy allows us to explore the etiological pathways underlying schizophrenic spectrum psychopathology [ 139 ].…”

A developmental trajectory of latent inhibition.

“…Latent inhibition has been demonstrated in a variety of species; as already noted, it has been observed in goats and sheep (Lubow & Moore, 1959), but it has also been demonstrated in rats (Kaye & Pearce, 1987), in pigeons (Tranberg & Rilling, 1978), honeybees (Abramson & Bitterman, 1986), and even snails (Loy et al, 2006). While latent inhibition can also be found in humans (e.g., Dawes et al, 2022; Evans et al, 2007; Granger et al, 2016), there has been sustained debate about the extent to which the effect is demonstrable without embedding the exposure within other so-called “masking” tasks (for a review, see Byrom et al, 2018). In addition, there is some suggestion that latent inhibition has a peculiar developmental trajectory, in that it is seemingly evident in younger children, but not older children.…”

“…However, there are sufficient nuances and shortcomings within the study of the development of latent inhibition to warrant further investigation. In the current study, we employed a task used on several occasions to successfully reveal an effect of stimulus preexposure on later learning in young adults (Dawes et al, 2022; Granger et al, 2016). During the preexposure stage of this task, participants are repeatedly presented with a series of individual letters (D, M, T, or V) which are presented on screen for 1,000 ms and separated by an interstimulus interval of 50 ms.…”