Preventing the return of Fear: A pilot study with healthy volunteers

Learning about potential dangers in the environment is critical for adaptive
function, but at times learning can be maladaptive and result in excessive fear
and anxiety. Recent studies of Schiller et al. (2009) and Kindt et al. (2009)
has shown that the return of emotional memories in humans can be prevented
after fear conditioning, which has important implications for the treatment of
anxiety disorders. Kindt et al. shows this by oral administration of the β-
adrenergic receptor antagonist Propanolol given before memory reactivation.
Schiller et al. on the other hand, introduced a non-invasive technique. They
show that it can be prevented that emotional memories return after extinction
training using a simple behavioral intervention. The present study aims at
replicating these findings. In this study we would like to test whether an
exactly timed reminder of an emotional memory can prevent the spontaneous
recovery of the emotional part of this memory in a standard fear conditioning
paradigm.

The present study aims at testing fear conditioning in healthy volunteers. We
want to examine whether behavioural results are comparable to the results
reported in the literature and if they are suitable for use in future studies
with (pharmacological) interventions and different patient groups. In order to
achieve this, we would like to do a pilot fear conditioning experiment. This to
gain expertise in fear measurements for future fear conditioning experiments
and especially test whether the behavioural findings after extinction training
found by Schiller et al., can be replicated in our laboratory. The goal of the
experiment is to replicate the prevention of spontaneous fear recovery when
extinction training is conducted during the time window in which the fear
memory is proposed to be undergoing reconsolidation. Based on the work of Kindt
and Schiller, we would like to combine and compare different methods to measure
fear (fear potentiated eye blink startle with fear relevant stimuli and skin
conductance with neutral stimuli, respectively) to explore the possibilities of
fear conditioning and the effects of these differences. By making different
combinations to the standard fear conditioning paradigm, we hope to find a
strong and suitable method for fear measurement.

Observational study.

Participants have to undergo fear conditioning, extinction training and
re-extinction on three consecutive days. At unexpected moments during these
experiments the participants can receive mild but painless electrical shocks to
the wrist, noises of high intensities through headphones and/or fear-relevant
images on a computer screen. Total duration of the experiment is about 3 hours.
Participants receive 50 euros for their voluntary participation. There are
negligible risks associated with this study.