The approach and avoidance task (AAT) has turned out as both a promising diagnostic tool as well as treatment add-on in psychological science. The AAT constitutes one form of cognitive bias modification (CBM), which has been shown to be particularly effective in the field of behavioral addictions, such as alcohol addiction (Eberl et al., 2013; Wiers et al., 2011). The general logic underlying the AAT is to carry out actions that are either compatible or incompatible with an individual's action tendencies. For instance, alcohol addicted patients tend to approach alcohol related stimuli faster than control pictures (i.e. soft drink stimuli), when they are instructed to react upon the format of a picture and not to its' content. This tendency of comparatively faster approaching and slower avoiding alcohol-related stimuli than soft drink content has been termed an approach bias for alcohol. The AAT as a therapeutic tool tries to counteract or at least to attenuate approach or avoidance biases by instructing patients to carry out approach and avoidance gestures that are in conflict with an individual's acquired action tendencies.

Whereas the general effectiveness of the AAT as a clinical intervention has been demonstrated several times, little is known about possible mechanisms that might subserve these effects. Therefore, the current study is dedicated to shed some light on one such potential mechanism, i.e. the role of the avoidance gesture within the alcohol-AAT.

As already suggested by the name of the AAT, the avoidance gesture seems to be a key ingredient in bringing about therapeutic effects. However, recent empirical evidence has brought about some interesting findings, giving rise to an alternative explanation.

A study by Kühn et al. (2017), contrary to common-held beliefs, indicated that inhibition capacity can be trained. Inhibition, in turn, consistently has been linked to psychopathology and all kinds of behavioural addictions (Smith, Mattick, Jamadar, \& Iredale, 2014). The game by Kühn et al. (2017) used to train inhibition resembled the AAT in several ways, e.g. certain stimuli appearing on a treadmill had to be collected by swiping towards oneself and others had to be ignored and the objects slowly disappeared. The latter element contrasts with the AAT, since the ignored objects don't have to be pushed away. However, it resembles the AAT in the sense that in both cases stimuli slowly fade out of the screen and eventually disappear. These parallel let to the assumption that a new form of the alcohol AAT training might be equally effective in lowering relapse rates among alcoholic patients. More precisely, within the newly conceptualized AAT training patients are instructed to inhibit the urge to respond in response to alcohol-related content and to observe the stimuli fading out of the screen. In contrast, to the classical AAT training this zooming out of alcoholic stimuli is not conditional on an avoidance gesture, i.e. swiping/pushing away the stimulus.

It is hypothesized that compared to a control group, in which alcohol and soft drink stimuli have to be swiped to the left and right, both the classical AAT-and the inhibition group will show lower relapse rates and approach biases after the intervention, i.e. a training period of three weeks. No intergroup differences in terms of relapse rates and alcohol-related approach bias are expected for the classical AAT group and the inhibition group.