Extended exposure paradigms and alcohol-related attentional bias in light and heavy social drinkers and in problem drinkers.
PhD thesis, University of Glasgow.
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It is well-established that the attention of alcoholics (as compared to non-alcoholics, or social drinkers) is captured more by alcohol-related than by neutral stimuli. This phenomenon is called an alcohol-related attentional bias (AAB).
The traditional paradigms for measuring AAB have been the modified Stroop and visual dot-probe paradigms. I have adapted the flicker paradigm for induced change blindness paradigm (flicker ICB paradigm) from visual cognition. In the traditional use of the flicker ICB paradigm a singe change is implemented in a visual scene and then removed. If the change process is masked and the implementation/removal of the change is cycled, the change takes a surprisingly long time to spot. The theoretical underpinning of this phenomenon implies that the change is not detected unless attention is directed to the object carrying the change.
In my own modification of this paradigm, two (not one) changes are simultaneously made and instructions to detect “the change” are given. In this way an alcohol-related and a neutral change are made to compete for attention. Using this paradigm the AAB hypothesis is that those detecting the alcohol-related change will have higher usual consumption that those detecting the neutral change.
In a series of 12 studies, I have shown that social drinkers detecting the alcohol-related change have consumption levels above those detecting the neutral change: a differential AAB within social drinkers. Further, when the object carrying the alcohol-related change is embedded in the neutral group and the neutral object carrying the change is embedded in the alcohol group, the direction of the AAB is reversed. This suggests that the group of objects in which the changing object is embedded drives the change detection rather than the changing object, itself. A similar conclusion is reached when both changing objects are identically-alcohol or identically-neutral. Finally, the role of the context or group in driving change detection was confirmed by embedding the alcohol-changing and neutral-changing objects in groups that did not provide differential alcohol-related and neutral information. Under these latter conditions of test, the AAB disappeared.
In the penultimate experiment reported in this thesis continuous eye-movement monitoring over 30 seconds to the same stimuli as described above (but not incorporating changes or masks) was used to measure attention towards alcohol-related objects even more directly. Using this method a differential AAB within social drinkers was shown.
In a final experiment the more traditional version of the flicker ICB paradigm (containing a single change) was used to explore AAB in drinkers in treatment in which for the first time it was shown that AAB increased with alcohol problem severity.
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