Targeted Extinction of Drug Cues During Sleep - Olfactory Cue Reactivity Task

Change in brain activation in the form of BOLD signals within 3 groups of ROIs:

• Memory related ROIs: Hippocampus, Dorsolateral Prefrontal Cortex
• Cognitive Control related ROIs: Anterior Cingulate Cortex, Ventrolateral Prefrontal Cortex
• Reward related ROIs: Striatum (ventral and dorsal) and Insula

A cue reactivity task based on the odours and images of alcoholic and non-alcoholic items. Adapted from Vollstädt-Klein et al., 2011.

Subjects are presented with odours and images of alcoholic (beer, wine, schnapps) and non-alcoholic (odour: 2-Methyltetrahydrofuran-3-one / images: broom, duster, clothing iron, lightbulb, mat, mulch, penlight, rack, rock, kitchen scissors, trough, vent) items during an fMRI session in blocks. For non-alcoholic items, in each block 5 images from the same stimuli group are presented with the non-alcoholic odour. For alcoholic items, in each block there are 5 images from the selected stimuli group with the congruent odour.

After each block subjects are asked to rate their liking and wanting towards the items that have been presented to them in two 1-5 scales. Blocks are pseudorandomised to maximise balance between groups and minimise the effect of habituation.

Minimum 1: "not at all", maximum 5: "very much".

A cue reactivity task based on the images of alcoholic and non-alcoholic items. Adapted from Vollstädt-Klein et al., 2011.

Subjects are presented with images of the alcoholic (beer, wine, schnapps) and the non-alcoholic (broom, duster, clothing iron, lightbulb, mat, mulch, penlight, rack, rock, kitchen scissors, trough, vent) items during an fMRI session in blocks. In each block there are 5 images from the same stimuli group. After each block subjects are asked to rate their liking and wanting towards the items that have been presented to them in two 1-5 scales. Blocks are pseudorandomised to maximise balance between groups and minimise the effect of habituation.

Minimum 1: "not at all", maximum 5: "very much".

A task to invoke reward based activations in the subjects. Adapted from Kirsch et al., 2003.

Subjects are presented 3 different stimulus conditions, each linked either to a positive monetary reward (a vertically oriented arrow pointing upward), a positive verbal feedback (a vertically oriented double-sided arrow) or a neutral no reward or feedback (a horizontally oriented double-sided arrow). After presentation of the two positive stimuli types, a flashing screen is presented and during the flashing screen if the subjects can press the button fast enough they will either win 1€ or they will be shown a positive verbal feedback depending on the positive stimuli type. The negative stimuli is followed by a 3 second black screen to include a control condition. Each stimulus condition is presented 10 times in a pseudorandom schedule with no more than two equal conditions in succession. The inter-trial interval randomly varies between 6-9 seconds.

Task measuring the objective vigilance of subjects. To distinguish vigilance between the wake and the sleep conditions, following measures will be compared: Median reaction speed (1/reaction time) and percentage of lapses (number of lapses divided by the number of all valid stimuli, excluding false starts. Lapse >= 500 ms, false start < 100ms). The task is prepared in JsPsych, and administered with using a tablet connected to internet. Participant data is securely stored in an encrypted server.

Test measuring current level of alertness of subjects on a seven point scale. A high test score indicates a high level of sleepiness and conversely a low test score yields a low level of sleepiness. Test scores will be utilized as a pre-measurement alertness indicator for participants. The task is prepared in JsPsych, and administered with using a tablet connected to internet. Participant data is securely stored in an encrypted server.

Questionnaire on self-assessment of current craving of subjects. Consists of 8 items on a Likert-type scale from 1-7 where higher scores represent stronger alcohol urges. The task is prepared in JsPsych, and administered with using a tablet connected to internet. Participant data is securely stored in an encrypted server.

A psychophysical test that is developed for assessing individuals reactions to the olfactory stimuli (Hummel et al., 1997). The 12-stick test from Burghardt is chosen for the study and it consists of identifying one of the four items that are presented with each of the twelve odourant sticks. At the end, with the aid of the identification score, the participant's olfaction capability is assessed.