Measures and materials

Cravings were measured using the Alcohol Urge Questionnaire (AUQ; Bohn et al., 1995) and the Food Cravings Questionnaire-State (FCQ-S; Cepeda-Benito et al., 2001). The AUQ and the FCQ-S were calculated as a summed value and a mean value, respectively, with higher values indicating higher cravings. Cravings were measured once at baseline and after each trial. Internal consistency coefficients were comparable across baseline and all trials for alcohol (α’s = 0.86 to 0.93) and food cravings (α’s = 0.92 to 0.95). Of note, food cravings can be considered one of two primary outcome variables in the present study, while alcohol cravings were included only as a manipulation check.

Attentional biases were measured using the visual probe task and an eye-tracking device (Castellanos et al., 2009; Field & Eastwood, 2005). We examined the effect of alcohol odors on both food attentional biases and alcohol attentional biases, with the latter analysis being included as a manipulation check. Three forms of attentional biases were assessed. First, using the visual probe task, participants were presented with alcohol pictures (alcohol visual probe task) or food pictures (food visual probe task) paired with matched control pictures side-by-side, with each presentation lasting 1 second; afterward, they saw a visual probe (right or left arrow). They were instructed to press the left and right mouse button when they see a left and right arrow, respectively. Faster average reaction time (in milliseconds) toward probes replacing food or alcohol pictures versus matched control pictures is indicative of greater cognitive attentional biases. Second, eye-tracking measured visual fixation during the visual probe task, which is defined as the maintenance of visual gaze on a picture. Greater average gaze duration (in milliseconds) on food or alcohol pictures versus matched control pictures is indicative of greater duration attentional biases. Third, greater proportion of initial fixations on food or alcohol pictures versus matched control pictures is indicative of greater direction attentional biases. All pictures used in the visual probe task came from previous attentional biases studies (see Castellanos et al., 2009; Field et al., 2004). Importantly, separate forms of attentional biases reflect differing attentional processes. Notably, duration and cognitive attentional biases reflect biases in maintained selective attention due to pictures being presented for a prolonged period of time (i.e., 1000ms). In assessing cognitive and duration attentional biases, individuals are able to shift attention freely between food or alcohol pictures and control pictures, with longer attention paid to and faster reaction times toward alcohol or food pictures indicating a bias in maintained selective attention. In contrast, direction attentional biases reflect biases in automatic selective attention (Castellanos et al., 2009; Ceballos et al., 2009; Field & Cox, 2008; Schoenmakers et al., 2008). Direction attentional biases assess immediate initial orientation toward either food/alcohol pictures or control pictures, with more frequent immediate initial orientation toward food/alcohol pictures reflecting a bias in automatic selective attention.

Beer and water odors were delivered to participants via an 8-channel air dilution olfactometer (Bragulat et al., 2008; Kareken et al., 2004), which was controlled using the Dasylab software and a Personal Daq/56 module (IO-Tech, Inc., Cleveland, OH). Small polytetrafluoroethylene tubes were used to deliver air to the participants’ nose at 2.0 liters per minute (lpm), which consists of a constant 1.0 lpm stream and a 1.0 lpm stream of an odorant. The primary manipulation condition involves exposure to beer odorant (Bud Light, 4.20% ABV), while the control condition involves exposure to water odorant.

Problematic food consumption was assessed using the Three Factor Eating Questionnaire-R18 (TFEQ-R18; Karlsson et al., 2000). The TFEQ-R18 (α = 0.83) was calculated as a mean value, with higher values indicating higher problematic food consumption.