Alcohol Dot Probe

Background

The Alcohol Dot-Probe Task (Alc-DPT) runs a visual dot probe procedure especially targeting automatic attentional bias towards alcohol. The task was first introduced by Julia Townsend and Theodora Duka in 2001 and further developed by Melissa Miller and Mark Filmore in 2010.

Like all DPT procedures the Alc-DPT runs pairs of stimuli followed by a probe stimulus that requires participants to respond. In contrast to the original MacLeod DPT task, Miller & Filmore (2010) used visual stimuli instead of word pairs and used a simple location-based (left vs. right) probe categorization task that likely increases the stimulus-response compatibility (probe is left -> use left response button) and thus, allows for faster response times and fewer categorization errors.

Specifically, the Alc-DPT tests and compares performance on two categories of image pairs: The first category (the target condition) consists of image pairs that depict one image of an alcoholic drink (e.g. a beer bottle) paired with an image of a non-alcoholic drink (e.g. a soda bottle). The second category (the filler condition) consists of neutral image pairs (e.g. a toy paired with an eraser). The image pairs of either category are presented on the left and right side of a centered fixation stimulus. Once the image pairs are removed, a single probe stimulus (X) appears in the location of one of the images and the participant must decide as fast as possible whether the probe appeared left or right by pressing a left or right response button.

Miller & Fillmore (2010) found that individuals with a history of heavy drinking were significantly faster categorizing probe stimuli that appeared in the position of the alcohol images compared to probes appearing in the position of the non-alcoholic objects, thus showing an attentional bias towards the alcoholic information. It's important to note that only relatively simple images of alcohol (such as a beer bottle) produced the attentional bias effect and that more complex images might be less effective at capturing drinkers’ attention in DPT tasks.

The Alc-DPT procedure can easily be adapted to investigate attentional biases towards other categories, such as drug-related biases or food-related ones.

Task Procedure

After working on ten practice trials with error feedback to familiarize participants to the DPT procedure, participants work on 80 test trials total (40 for the target category and 40 for the filler category). Each category runs ten fixed image pairs that are presented four times each, balancing out the left/right location of the image and whether it's followed by the probe. The order of the 80 trials is randomly determined. There is no more error feedback provided during the test trials. Each trial sequence starts with the presentation of a fixation stimulus (+) in the center of the screen for 500ms. The images appear after 1000ms and stay on screen for another 1000ms followed by the probe that is presented for 1000ms or until a response a made, whichever comes first. Participants are asked to press the left 'N' key for probes appearing left and press the right 'M' key for probes appearing right (left/right positions on QWERTY keyboards).

What it Measures

The Alc-DPT measures implicit attentional bias towards alcoholic information

Psychological domains

• Implicit Cognition: Cognitive Processes not under conscious control
• Selective Attention: Focusing on a specific stimulus or task while filtering out distractions

Main Performance Metrics

• Attention Bias Index: Response Time Measure of Attentional Bias towards Information that captures attention (here: alcoholic information)

Psychiatric Conditions

DPT measures have been successfully used to study the following patient groups (amongst others):

• Anxiety Disorders
• Major Depressive Disorder
• Substance Abuse
• Eating Disorders

References

Search Google Scholar for peer-reviewed, published research using the Inquisit Alcohol Dot Probe.

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Townshend J. M., Duka T. Attentional bias associated with alcohol cues: differences between heavy and occasional social drinkers. Psychopharmacology (Berl) 2001; 157: 67–74.

Field M.,Mogg K., Zetteler J., Bradley B. P. Attentional biases for alcohol cues in heavy and light social drinkers: the roles of initial orienting and maintained attention. Psychopharmacology (Berl) 2004; 73: 88–93.

Duka T., Townshend J. M. The priming effect of alcohol preload on attentional bias to alcohol-related stimuli. Psychopharmacology (Berl) 2004; 176: 353–62.

Field M., Duka T., Eastwood B., Child R., Santarcangelo M., Gayton M. Experimental manipulation of attentional biases in heavy drinkers: do the effects generalize? Psychopharmacology (Berl) 2007; 192: 593–608.

Melissa A. Miller, M.A. & Mark T. Fillmore, M.T (2010). The effect of image complexity on attentional bias towards alcohol-related images in adult drinkers. Addiction, 105, 883–890.