Studying the impact of Lorazepam on approach/avoidance behaviour in healthy individuals

INTERVENTION: A single dose 1 mg of lorazepam or placebo Approach/avoidance behaviour task: We have developed a human approach‐avoidance task that emulates rodent anxiety paradigms such as operant conflict tests, the elevated plus maze (EPM), and the open field test (OT). In this task, presented over successive epochs in the form of a computer game, collection of monetary tokens on a grid provides approach motivation. The possibility that a virtual predator might wake up and remove all tokens harvested during the epoch provides a potential threat, and thus avoidance motivation. In each epoch, one of three predators representing different levels of threat (corresponding either to chase speed or wake‐up probability, in different versions of the task) are present but inactive in a corner of the grid. The grid corner opposite to that of the predator represents a safe place where the predator cannot catch the participant. Participants start either in the same corner as the predator (‘‘active’’ epoch) or from the safe place (‘‘passive’’ epoch). CONDITION: Validation of a human version of the rodent approach/avoidance conflict model ; Mental and Behavioural Disorders PRIMARY OUTCOME: Primary outcome is the overall probability of being in the safe quadrant in the computer game. Probability of being in the safe quadrant will be assessed over all rounds of the experiment and analysed in a time x task x threat level factorial design. Probability of being in the safe quadrant is a surrogate marker for passive avoidance, and was highly sensitive in distinguishing between patients with hippocampal lesions and healthy controls in a previous study.; ; Measured during the entire computer game (average behaviour in the computer game). SECONDARY OUTCOME: Secondary outcomes are distance from threat, distance from walls, probability of being in the threat quadrant, probability of being in the safe place, rate of token collection and speed when on grid, in the computer game. All secondary outcomes will be assessed over all rounds of the experiment and analyzed in a time x task x threat level factorial design. ; ; Measured during the entire computer game (average behaviour in the computer game). INCLUSION CRITERIA: 1. Informed Consent as documented by signature 2. Age 18 – 40 years