Synctime edf eyelink trial#
Synctime edf eyelink Pc#

These messages should generally be sent at the end of each trial, allowing variables that may get updated during the recording, such as response time, accuracy, etc., to be included. One or several '!V TRIAL_VAR' messages should be sent to report the experiment condition(s) of a recording trial.The four integers in the message mark the left, top, right, and bottom of the screen.

This message is used by Data Viewer to figure out the appropriate screen size (in pixels) for visualizing the eye movement data, e.g., 'DISPLAY_COORDS 0 0 1023 767'.

The other critical message that worth noting here is the 'DISPLAY_COORDS' message.

Additional info can be included in the 'TRAIL_RESULT' message, e.g., to indicate the result, for instance 'TRIAL_RESULT 0'. Importantly, the variables that would be used for analysis (i.e., the 'TRIAL_VAR' messages) should be written in the EDF file before the 'TRIAL_RESULT' message.

The 'TRIAL_RESULT' message is sent after the recording ends.

Synctime edf eyelink trial#

It is not mandatory, but it is recommended to include a unique trial identifier in the message, for instance, 'TRIALID 13'.

The 'TRIALID' message is sent at the beginning of a trial, before the start of data recording.

Detailed information about the various standard messages that Data Viewer recognizes can be found in the 'EyeLink Examples of these messages include those that specify the overlay image, the interest areas, and the trial variables. To facilitate data analysis in EyeLink Data Viewer, special messages can be added to the EDF file. Above this rate, some messages may be lost before being written to the EDF file. Be careful not to send messages too quickly: the eye tracker can handle about 20 messages every 10 milliseconds. These messages will be time stamped with an accuracy of 1 millisecond from the time sent, and can be used to mark important events such as display changes.

Synctime edf eyelink Pc#

Text messages can be sent to the EyeLink Host PC and added to the EDF file along with the eye movement data. These messages will facilitate the SR Research viewing and analysis applications (e.g., Data Viewer) to process the EDF files. Some programming standards, such as placement of messages in the EDF file by your experiment, and the use of special data types, have been implemented to allow portability of the development kit across platforms.Д®xperiments should place certain messages into the EDF file, to mark the start and end of trials. The EyeLink Developers Kit library contains a set of functions used to program experiments on a variety of platforms, such as Windows, Linux, and macOS.