Last modified by Iris Spruit on 2023/12/18 15:11


Actiview is free open source software used for recording with BioSemi (mainly for EEG) equipment. 

Availability, support and advice

Actiview is available for researchers at FSW Leiden and comes preinstalled on all lab computers (see the Software List to check which version).


To analyze EEG data, markers that signal the onset of certain events need to be sent from stimulus presentation pc to the BioSemi device. These markers will be visible during recording in Actiview. See for more information on sending markers the pages Sending Markers in E-Prime and Sending Markers in OpenSesame and the Markers and Events page for more information on markers in general.


2021/10/25Timing difference E-Prime and BiosemiIt is important to know that Biosemi outputs data in number of samples, not in ms. In one case, there seemed to be a timing delay: The time between two markers in E-Prime was 2000 and in Biosemi 2048. Time in E-Prime was given in ms, but in Biosemi in samples. With a sampling rate of 1024, 2048 samples equaled 2000 ms. Always double-check the unit that is outputted.


  • The BioSemi website offers information on BioSemi hard- and software
  • The BioSemi FAQ provides some answers to Actiview related questions
Tags: Physiology EEG
XWiki 14.10.13