Installation¶

1. Download and place the pylinkwrapper folder somewhere you can easily reach in the file system.
2. Add the folder to Psychopy’s python path as detailed here: http://www.psychopy.org/recipes/addCustomModules.html

That’s it! Here’s a quick demo of getting connected to the Eyelink:

import pylinkwrapper

win = visual.window(monitor='nickMon', fullScr=True, allowGUI=False, color=-1)
tracker = pylinkwrapper.connect(win, '1_nd')

Check out the documentation for the Connector Class class to see what functions are available.

Connector Class¶

This class provides methods for interacting with the Eyelink from psychopy.

class pylinkwrapper.connect(window, edfname)¶

Provides functions for interacting with the EyeLink via Pylink.

Parameters:	window – Psychopy window object. edfname – Desired name of the EDF file.

calibrate(cnum=13, paval=1000)¶

Calibrates eye-tracker using psychopy stimuli.

Parameters:	cnum (int) – Number of points to use for calibration. Options are 3, 5, 9, 13. paval (int) – Pacing of calibration, i.e. how long you have to fixate each target.

drawIA(x, y, size, index, color, name)¶

Draws square interest area in EDF and a corresponding filled box on eye-tracker display.

Parameters:	x (float or int) – X coordinate in degrees visual angle for center of check area. y (float or int) – Y coordinate in degrees visual angle for center of check area. size (float or int) – length of one edge of square in degrees visual angle. index (int) – number to assign interest area in EDF color (int) – color of box drawn on eye-tracker display (0 - 15) name (str) – Name interest area in EDF

drawText(msg)¶

Draws text on eye-tracker screen.

Parameters:	msg (str) – Text to draw.

endExperiment(spath)¶

Closes and transfers the EDF file.

Parameters:	spath (str) – File path of where to save EDF file. Include trailing slash.

fixCheck(size, ftime, button)¶

Checks that fixation is maintained for certain time.

Parameters:	size (float or int) – Length of one side of box in degrees visual angle. ftime (int) – Length of time to check for fixation in seconds. button (char) – Key to press to recalibrate eye-tracker.

recordOFF()¶

Stops recording.

recordON(sendlink=False)¶

Starts recording. Waits 50ms to allow eyelink to prepare.

Parameters:	sendlink (bool) – Toggle for sending eye data over the link to the display computer during recording.

sendCommand(cmd)¶

Sends a command to the Eyelink.

Parameters:	cmd (str) – Command to send.

sendMessage(txt)¶

Sends a message to the tracker that is recorded in the EDF.

Parameters:	txt (str) – Message to send.

sendVar(name, value)¶

Sends a trial variable to the EDF file.

Parameters:	name (str) – Name of variable. value (float, str, or int) – Value of variable.

setStatus(message)¶

Sets status message to appear while recording.

Parameters:	message (str) – Text object to send, must be < 80 char

setTrialID(idval=1)¶

Sends message that indicates start of trial in EDF.

Parameters:	idval – Values to set TRIALID.

setTrialResult(rval=0, scrcol=0)¶

Sends trial result to indiciate trial end in EDF and clears screen on EyeLink Display.

Parameters:	rval (float, str, or int) – Value to set for TRIAL_RESULT. scrcol – Color to clear screen to. Defaults to black.

Sample Experiment¶

This is a very simple experiment that demonstrates use of pylinkwrapper. It can be found in the sample folder.

'''
Pylink Wrapper test experiment
N. DiQuattro - January 2015

This is a simple experiment where a circle appears randomly on the screen. It's
purpose is to provide examples of how to use the pylink wrapper with a psychopy
experiment.

There's help documentaiton available for each of the functions that show the
available parameters. 
'''

# Import modules
from psychopy import visual
from psychopy import core, event
import numpy as np

import pylinkwrapper# Here's the special one

# Window set-up
win = visual.Window(monitor = 'nickMon', units = 'deg', fullscr = True,
                    allowGUI = False, color = 0)

# Initiate eye-tracker link and open EDF
tracker = pylinkwrapper.connect(win, '1_test') 

# Calibrate eye-tracker
tracker.calibrate()

# Stimulus
fix = visual.Circle(win, radius = 1, pos = (0, 0), fillColor = [1, 0, 0],
                    lineColor = [1, 0, 0])
                    
cfix = visual.Circle(win, radius = .15, fillColor = -1, lineColor = -1)

# Display stimulus 5 times
for t in range(5):

    # Find random coordinates and set them
    fx = np.random.randint(-10, 10)
    fy = np.random.randint(-10, 10)
    fix.setPos((fx, fy))
   
    # Eye tracker trial set-up
    stxt = 'Trial %d' % t
    tracker.setStatus(stxt)  #  Define status message that appears on eye-link
                             #  display
                             
    tracker.setTrialID()  # Sends trial start message for EDF
    tracker.sendMessage('Circle Trial')
    
    # Draw IA
    tracker.drawIA(fx, fy, 1, 1, 5, 'circle')  # Draw interest area and box
     
    # Start recording
    tracker.recordON()

    # Draw and display circle
    cfix.draw()
    fix.draw()
    win.flip()
   
    # Wait for response 
    keyp = event.waitKeys()
    
    # Stop Recording
    tracker.recordOFF()
    
    # Send response key to EDF file
    tracker.sendVar('response', keyp[0][0])

    # End trial for EDF
    tracker.setTrialResult()
    
    # ISI with fixation check
    cfix.draw()
    win.flip()
    tracker.fixCheck(2, 1, 'z')

# Retrieve EDF
tracker.endExperiment('C:\\edfs\\')  # Closes and retrieves EDF file to
                                     # specified path