SennsLab: Understanding the Experiment Structure

Guide to SennsLab experiment structure for different templates and devices


The possible blocks that make up experiment protocols include:

  • Familiarization (F)
    • This is a block of stimuli chosen to familiarize the participant with the content of the test and the overall test protocol.  Familiarization blocks are not analyzed and no data is collected.  In some templates, familiarization content is automatically added by SennsLab - in addition to any you add yourself. 
  • Washout 1 (W1)
    • The participants are instructed to close their eyes and enter a resting state.  The washout block is meant to de-couple the emotional response from one block to the next and to establish a null baseline for EEG and biosensing data.  This is a break where the participant clears their emotional response.  W1 is positioned between the familiarization tasks and the rest of the study.
  • Washout 2 (W2)
    • The second washout block is the same as the first, except it is positioned between the calibration and the actual test block. 
  • Eyes open (OA)
    • The participant is instructed to enter a rest state with eyes open, used to establish a baseline measurement in EEG and biosensing. 
  • Calibration (C)
    • This block displays built-in stimuli to the participant as a method of determining the range of physiological responses for the individual, and normalizing across all participants.  This is required for all biosensing and EEG tests.  It is not to be confused with eye tracking calibration, which is done during test setup.  Images and videos in this step are built into SennsLab and can not be changed. 
    • For more information about EEG and biosensing calibration in SennsLab, see the entry:  SennsLab Emotional-Cognitive Calibration
  • Test (T)
    • This is the actual stimuli for evaluation and analysis
  • Test survey (ST)
    • This is a survey to have the participant evaluate the test images displayed as "Negative", "Neutral" and "Positive" in order to calibrate the valence calculation.
  • Calibration survey (TC)
    • This is a survey to have the participant evaluate the calibration images displayed as "Negative", "Neutral" and "Positive" in order to calibrate the valence calculation.

The sequence and total number of test blocks depends on the template and the devices used.  Here are some possible experiment layouts: 

Solo Eye Tracker
F - T

Ring - Biosensing
F - W1 - C - W2 - T

Diadem - Dry EEG
F - W1 - OA - C - W2 - T - ST* - TC*

*Passive Image Template Only


Useful Links relating to SennsLab and SennsMetrics: