Hi Everyone,
I just wanted to let you know that I have recently had my viva, which I passed. So I wanted to thank you all, again(!), for supporting my study into the effects of chronic ketamine use on semantic memory (which is like general knowledge) and subjective experiences.
Below is a copy of the abstract, which I hope will make sense to some of you. Please feel free to ask questions.
In a few days time I’m off on a long holiday to Thailand, which means that I won’t be checking these websites/email, so please don’t be offended if you contact me and I don’t respond for a while.
Once again, thank you, and best wishes,
Justin
Abstract
Background: There has been an increase in the prevalence of recreational ketamine use over the past five years. Due to ketamine’s cognitive and psychotomimetic effects it is being investigated as a pharmacological model for psychosis.
Problem under investigation: To investigate the long-term effects of chronic recreational ketamine use on indirect and direct semantic priming, general semantic processing and subjective experiences.
Participants: Forty-six participants, aged 18 to 46 years, completed the study, 24 male and 22 female.
Design: An independent groups design was used to compare three groups: 16 ketamine users (people who use ketamine and other recreational drugs), 14 poly-drug users (people who use recreational drugs, but not ketamine) and 16 non-drug users (people who have not and do not use illicit drugs). Participants completed computer tasks which assessed semantic memory and pen and paper questionnaires that assessed subjective experiences.
Results: The ketamine group scored higher than the non-drug group on a measure of schizotypy. Semantic processing was found to be similar across the groups, although the ketamine group had significantly longer reaction times to high frequency words than to low frequency words on the direct semantic priming task, whereas the two control groups showed no significant differences.
Conclusions: The ketamine group were impaired relative to the other two groups in their processing of high frequency words compared to low frequency words, and were higher in schizotypy than non-drug users. However, the absence of indirect priming effects across the three groups limits the conclusions that can be drawn and methodological reasons for this are discussed.
