SFB TRR 265: Losing and Regaining Control Over Drug Intake Project B03: Role of Pavlovian Mechanisms for Control Over Substance Use Project B09: Maladaptive Context Inference As Key Mechanism Underlying Impaired Control

This project has three research aims:

1. Investigate whether stronger habitual behavior and increased susceptibility to the conflict between habitual and goal-directed control are associated with SUD
2. Investigate whether PIT is more of a habitual or a goal-directed process.
3. Replicate the previous findings that moderate to severely dependent AUD patients show a stronger PIT effect in contrast to the control group The experiment will be conducted in 90 AUD patients and 90 age and gender-matched controls. Participants will perform the AST task over two consecutive days, and during the second day, they will also perform the single-lever PIT task. In the AST, participants need to press four keys according to the cue location; two keys are associated with high reward, while the other two are associated with low reward in case of correct and timely responses. The explicit goal is to maximize the reward. While in half of the trials the cues are presented in a random order, in the other half of the trials, participants repeatedly perform a fixed action sequence of 12 elements (habit condition). The degree of action sequence chunking (i.e. automation) is assessed via the differences in error rates and reaction times between the random and fixed order condition (habit parameter). Importantly, 15% of all trials are dual- target trials. In these, the goal-directed system (press high reward key) and the action sequence (press sequence key) can either be in line (congruent trials) or in conflict (incongruent trials) with each other. Thus, the interference between goal-directed and habitual control can be tested.

The single-lever PIT task consists of four phases. In the instrumental task, participants need to learn which shells to collect or leave in order to gain as much money as possible; the correct choice is probabilistically rewarded in 80% of all times. During the Pavlovian conditioning phase, colorful fractals are presented in the back of the screen, which have been passively paired either with monetary loss, no change or monetary gain, i.e. they act as positively valued, neutral or negatively valued cues. During the transfer phase, participants were instructed to perform the instrumental task as they have done previously. These fractals thus act as independent, Pavlovian conditioned background stimuli and interact with instrumental behavior in the unrelated task to collect the correct shells. To avoid further learning, this transfer part will be conducted under nominal extinction. Finally, query trials, in which one of two pictures will have to be chosen, will be used to assess the relative cue value.

The participants will additionally perform a Counting Stroop task and a No-go Simon task. In the Stroop task, either one, two, three or four identical digits from 1 to 4 are shown. Number and denotation of digits are either congruent (1, 22, 333, 4444; 80 trials) or incongruent (111, 2222, 3, 44; 80 trials). Subjects have to indicate how many digits were shown. In the No-go Simon task, the investigators will show arrows either pointing to the left or right. The arrow can either be shown on the left or the right side of the display. In congruent trials, direction and position are the same, whereas they differ in incongruent trials. Participants have to indicate the direction of the arrow and ignore the position. 20% of trials are No-go trials, indicated by bold arrows. Here subjects have to always withhold a response (inhibition task).

Expected results: