Small Grants 2016-17

Sex Differences in Cross-Priming for Gambling among Stimulant Users (S43)

Project Approved 2016-17

Dr. Daniel McGrath (Principal Investigator)
Department of Psychology, University of Calgary
Google Scholar Profile

Dr. Sherry Stewart (Co-Investigator)
Department of Psychiatry & Psychology, Dalhousie University
Google Scholar Profile | ResearcherID: F-4088-2011


The proposed study is a dual-site project between Dr. McGrath’s Substance Use and Gambling Laboratory at the University of Calgary and Dr. Sherry Stewart’s Addictions Laboratory at Dalhousie University. Recruitment is already underway at the Dalhousie site and has been funded through a small grant from the Nova Scotia Health Research Foundation. However, in order to achieve a sufficient sample size, the investigators have deemed that a second testing site in Calgary is required. The proposed study will employ a single between-subjects experimental session. The experiment itself is a 2 Group [stimulant user (SU) vs. healthy control (HC)] x 2 Sex (male vs. female) design. All participants will first be phone screened for inclusion and exclusion criteria and then asked to attend their laboratory session. A total of 80 participants (40 at each site) will be recruited in Calgary and Halifax via newspaper and Internet bulletin boards. Of the 80 participants, 40 will be current stimulant users and 40 will be healthy controls (with 20 males and 20 females in each group).

Attainment of objectives: We were able to accomplish the main objectives of the proposed project, despite substantial recruitment challenges. Recruitment proved difficult due to the small population base for our original testing site in Halifax. To increase feasibility of completing the project, we made two main modifications. First, using these AGRI funds, we added an additional site for data collection in Calgary at the University of Calgary. Second, we recruited stimulant users (and controls) only rather than both stimulant users and opiate users (and controls) as recruiting both groups would have been too time consuming and costly.

For the modified project, we were able to recruit 63 participants in total from Halifax and Calgary which allowed us to compare the differences between stimulant users and stimulant non-user controls in gambling cue reactivity using both self-report craving measures and physiological measures (heart rate and blood pressure). The study was concluded with a paper submitted to a peer reviewed journal and 2 conference presentations.

For the modified project, were able to transfer expertise in cross-priming methodology from CAMH to Dalhousie and the University of Calgary, strengthen collaborations between the three partner institutions, and use pilot data as part of an application for a CIHR Foundation Grant. Overall, the project objectives were met despite a modest budget at both sites.

The goal of the study was to assess the extent to which a gambling challenge (i.e., playing a video lottery terminal) would selectively cross-prime motivation for stimulant use via stimulant-related semantic memory networks. It is has been suggested in previous research that these memory networks undergo incentive sensitization in response to pairing of stimulant-like cues with repeated stimulant use. Furthermore, based on evidence of sex differences in the reinforcing effects of stimulants, we hypothesized that male stimulant users would exhibit greater gambling-stimulant cross-priming than female stimulant users (or healthy controls of either sex). Our initial analyses on subjective craving for stimulants indicated a significant effect for time; however, the interaction of time x group (stimulant vs. non-stimulant) was not significant. Yet, the interaction of time x gender was significant. Similarly, the 3-way interaction of time x group x gender was also significant. This result indicates that women stimulant users in particular displayed an increase in stimulant craving following the gambling challenge. Interestingly, this finding is in the opposite direction of what was initially predicted. Ultimately, these results are intriguing and warrant further elaboration as to the mechanisms driving these effects.

Al-Hamdani, M., McGrath D., Zack M., Ghaferi Z., Collins, P. & Stewart, S. H. Gambling-induced craving and arousal in cocaine users and stimulant non-users: A test of cross-priming. Paper currently in preparation.

Scholarly Conference Papers:

Stewart, H.S., Ghaferi, Z. Collins, P., Cowie, M., Romanow, N., Boothby, C. , Horiachka, B., Zack, M., & McGrath, D.S. (2017, June). Gambling-induced stimulant craving in regular stimulant users: A cross-priming study. Poster presented at the 2017 NIDA International Forum, Montreal, Quebec, Canada.

Horiachka, B., McGrath, D.S., Ghaferi, Z., Cowie, M., Collins, P., Zack, M., & Stewart, H.S. (2017, April). Gambling-induced stimulant craving in a regular stimulant users: A cross-priming study. Poster presented at the Alberta Gambling Research lnstitute's (AGRI) 16th Annual Conference, Banff, Alberta, Canada.

A Comparison of Attentional Biases by Preferred Gambling Activity: An Eye-Tracking Study (S42)

Project Approved 2016-17

Dr. Daniel McGrath (Principal Investigator)
Department of Psychology, University of Calgary


The primary goal of the proposed study is to examine the extent to which attentional bias (AB) is associated with preferred gambling activities. A sample of 90 young adults will be recruited from the University of Calgary and surrounding area for a single eye-gaze tracking session in Dr. McGrath’s Substance Use and Gambling Laboratory. Specifically, we will recruit 30 ‘poker players’, 30 ‘VLT/slot players’ and 30 healthy non-gambling controls. These two forms of gambling were chosen as they are commonly endorsed in the general population and are representative of ‘strategic’ and ‘non-strategic’ forms of gambling respectively.

We were able to recruit a sufficient number of participants for data analyses. The data from this project was used for a student independent studies research project. The results were also presented at the 2017 AGRI Banff conference. Finally, a manuscript is currently in preparation and will be submitted to PlosOne in June 2017.

The goal of the this project was to investigate the specificity of attentional biases in gambling. Specifically, we wanted to test whether attention to gambling related images would align with preferred gambling activity (e.g., Poker and VLTs). We found very strong effects supporting the initial hypotheses. VLT gamblers preferentially attended to slot machine stimuli, poker players attended to poker stimuli, and non-gamblers did not preferentially attend to gambling stimuli. These findings will be especially informative for the design of future eye-gaze tracking experiments.

This project was the first formal collaboration between the Substance Use and Gambling Laboratory and the Cognition Laboratory headed by Dr. Chris Sears. This was a very fruitful collaboration and allowed for substantial knowledge acquisition on eye-tracking methodology for my lab. Furthermore, Amadeus Meitner, a student in lab, worked on this project and completed an independent studies course using this data.

Collaborative elements

As mentioned in point 3, this project served as the basis for collaboration between myself and Chris Sears.

McGrath, D. S., Meitner, A., & Sears, C. R. (2018). The specificity of attentional biases by type of gambling: An eye-tracking study. PLOS ONE, 13(1), e0190614.

Scholarly Conference Presentations & Posters:

McGrath, D.S. (2017, April). The influence of image content, colour, and type of gambling activity on attentional bias toward gambling stimuli. Presentation at the Alberta Gambling Research Institute’s (AGRI) 16th Annual Conference, Banff, Alberta, Canada.