Protocol for 'Fear Memory - A Neuromodulation Study in Anxiety Disorders' v1

This is a partial-reinforcement auditory fear conditioning protocol, divided in two consecutive days (Day 1 –baseline psychological assessment questionnaires, fear habituation and fear acquisition; Day 2 –tDCS session and fear extinction) plus a follow-up session (Day 3 –fear reinstatement, re-extinction and approach-avoidance task-AAT) one to three months later. On Day 2, there is a 20 min transcranial direct current stimulation (tDCS) session. For the cathodal group extinction was preceded by cathodal tDCS, whereas for the sham group, extinction was preceded by sham tDCS. During the 3 days, fear responses were measured by SCRs (except during tDCS stimulation and AAT), self-report ratings on valence, arousal, contingency and expectancy. On Day 3 implicit approach and avoidance tendencies were measured by reaction times - AAT.