Event-related EDA Analysis

We currently don’t have any event-related designs but an example would be showing pictures of happy vs. sad faces. Each time a new picture appears on the screen, we would call that an event. There would be 2 different conditions; 1) happy and 2) sad and the SCR would be contrasted between these conditions.

The protocol channel (our channel 8 ) would contain the the stimulus onset signals. These can be converted to stimulus events in the global channel in Acqknowledge (this is a white bar above channel 1).

The following EDA preferences are recommended: Analysis → EDA → Preferences:

These images are from an older version of Acqknowledge but still work similarly:

Phasic EDA is our channel 10.

Tonic EDA channel is wherever there is room for a new channel.

This analysis places SCR markers on the peaks.

( = beginning of SCR

droplet = SCR

) = end of SCR

Lightbulbs = stimulus events (happy or sad face images)

Channel 2 signal peaks = stimulus presentation programmed into the protocol

Numbered flag marker = this is when the SCR is within a 10-second epoch (see what we have selected in previous step) of the stimulus presentation. If it’s further away, we assume that the SCR is not triggered by the preceding stimulus.

The Excel Output looks as follows:

If you request graph channels and excel spreadsheet output, you receive one channel per measure.

These are from top to bottom:

SCL

Latency

SCR amplitude

SCR rise time

SCR size

SCR onset

SRR

NS.SRR