Experiment Code:
Per_noCS

Introduction & Research Question:
This study aimed to determine whether the conditioned stimulus (CS) in the electrodermal version of the Perruchet effect is instrumental to the production of said effect. In the Perruchet effect a single stimulus (the CS) is paired with a second stimulus (the unconditioned stimulus, US) on half the trials and on the other half of the trials the US is not presented. Conditioned responding to the CS is typically found to dissociate from conscious expectancy for the US. In this experiment the US is an electric shock and the conditioned response is change in skin conductance response (SCR). Importantly there is no CS in this experiment. If the CS is important in the production of the Perruchet effect then removal of the CS in this experiment should distort SCR, whereas if the CS is not important then a similar SCR pattern should be produced to that seen in previous Perruchet experiments. 

Participants:
24

Experiment Software:
E-Prime, LabChart

Method:
Skin Conductance Response (SCR) calibration procedure: The left hand was cleaned and the SCR electrodes were attached to the medial phalanges of the third and fourth fingers of the left hand. The US in this experiment was an electrical shock, the shock electrodes were attached to the proximal and medial phalanges of the left index finger. Participants set their own shock level in the range of 5-20mA. Participants were required to sit quietly for several minutes to allow SCR to return to baseline. 

Experimental procedure: Participants were instructed that shocks would randomly occur throughout the experiment, unbeknown to the participant the shocks were delivered in a standard Perruchet distribution for comparison with prior Perruchet results. Changes in SCR were continuously monitored throughout the experiment. Participants were also required to make an expectancy rating roughly every 5 seconds about the extent they believed the US would occur at that moment in time. In between the two blocks the participants were given a comfort break and the second block proceeded in the same fashion beginning with SCR calibration. 

Experimenter:
Amy McAndrew

Location:
228-1
Washington Singer Laboratories, University of Exeter

Date:
May – June 2012

Data file format:
.csv

Data file names:
There are 3 files for each participant, a SCR file, an expectancy (EXP) file, and a sequence file. 
Per_noCS_SCR_Px (Contains each SCR response for each trial, for each trial three different values were recorded).
Per_noCS_EXP_Px (Contains each expectancy rating made for each trial).
Per_noCS_Seqs_Px (Contains the sequence of trials for each block in this experiment).