Skip to main content
. 2015 May 15;10(5):e0125729. doi: 10.1371/journal.pone.0125729

Fig 2. Fear conditioning procedure in the present study.

Fig 2

The behavioral procedure consisted of three consecutive phases: habituation, acquisition, and extinction. Subjects received three CSs and an aversive US. The habituation phase comprised 6 trials (2 trials of each CS). In the acquisition phase, one CS was randomly selected from those three CSs and the selected CS was then paired with the US at a partial reinforcement rate of 50% (i.e. CS+). Other two CSs were presented without pairing the US during the acquisition phase (i.e. CS-). The acquisition phase included 36 trials (12 trials of each CS). The extinction phase consisted of 18 trials (6 trials of each CS).