Event Related Potentials (ERP)

  • Home
  • Event Related Potentials (ERP)
26 Jan

ERP calibration procedure w/ SmartBCI and SmartSYNC module

Calibration procedure for stimuli presentation delays in the ERP studies using the SmartBCI with SmartSYNC synchronization module. When studying Event Related Potentials (ERP or EP), auditory and visual stimuli are presented to the patient, and their reaction is recorded on the patient's EEG. There is a delay between the moment the stimulus is launched in the program and the moment the patient perceives it, due to signal delays in the audio and video channels. These delays can be comparable [...]

Read more...
07 Aug

WinEEG and Psytask setup for ERP

WinEEG and Psytask setup for ERP on Windows 11 machine For ERP recording it is necessary to connect two desktop computer or laptops with Ethernet cable. However some modern laptops do not have LAN port availalbe. We do recommend to use USB-LAN adapter provided by laptop manufacturer. Workgroup setupFirst of all dd both of your computers used for ERP recording in the workgroup with the same name and set them proper names to simplify futher PC identification while ERP [...]

Read more...
20 Mar

What information is in EDF+ annotations?

The EDF+ specification defines additional type of signal, so called "EDF annotations" signal. In EDF+ file exported from WinEEG we have 5 different annotations. EDF specification does not prohibit having several such signals in EDF+ file. Moreover, the Polyman software actually reads EDF+ files with multiple "EDF annotations" signals without any problems. The Polyman simply combines all "EDF annotations" signals into one. You can do it the same way.Labels of the beginning ERP trial with number of trial [...]

Read more...
08 Nov

Independent components (ICA) of ERPs

These independent components of ERP linearly mixed will comprise the original averaged ERP signal. Each component is an independent piece of the ERP signal, representing a stage in the processing of the perception and then the motor aspects and then the cingulate’s self monitoring of the response. Though inter-related, each piece is a separate stage in the sequential process that creates the complexity of the ERP itself. In WInEEG software we apply Infomax ICA algorithm to decompose original ERP into [...]

Read more...
04 Sep

Subject response (patient button) processing setup for ERP analysis.

If you are using WinEEG+Psytask ERP system, the button response processing is programmed in WinEEG. When you record ERP you should connect patient response button to yellow socket of amplifier. You will see two red channel corresponding to clicking left and right button. To process subject respond channel while computing ERPs go to drop down menu Analysis—Compute ERP. Then you should select Digital 1 for left mouse button or Digital 2 for right button as shown below (arrow 1), after this go to next step (“Define” button, [...]

Read more...
28 Aug

WinEEG and e-Prime connection

WinEEG and e-Prime should work on different computers. WinEEG works on WindowXP PC but ePrime works on Windows 98 PC!!! We will call WinEEG computer as recording computer and ePrime computer as presenting computer. The main goal of connection is to synchronize the stimuli presentation process and EEG recording. e-Prime can send codes via COM port and WinEEG can catch this codes and recognize them as stimuli onsets. That is why the next steps should be done to setup this connection. 1.     Connect [...]

Read more...
27 Aug

What labels are exported to EDF+?

WinEEG can export to EDF+ format such markers as: Labels of the beginning ERP trial with number of trial typePatient response (with button) for GO task So you can see it below in Polyman software 3. Moments of the beginning photo-stimulation flash series of one frequency with digital label of this frequency in Hz and it looks like this: Other parameters (as user’s labels, markers of every photo-flash and so on) are not exported to the EDF+ files. Behavioral responses can be calculated [...]

Read more...
27 Aug

ERP dialog window tips

You can control X axis in the right panel as shown on the picture below, choosing the beginning and end of the time interval you want to see on a diagram. Two dashed vertical lines on the ERP plots mean the moments of appearance and disappearance of sound or image stimulus. The structure of a single trial in the task is shown below Pre-stimuli interval and other parameters are defined in Psytask software where you can set or change them. You can measure [...]

Read more...