[open] Continuous Flash Supression Experiment.

Comments

• EoinTravers

  October 2013 edited 8:07PM

  Hi,

  This seems an interesting problem.
  Without knowing much about psychophysics myself, I can only make some suggestions:

  • Do the stimuli really need to be generated freshly on each trial?
    If PsychoPy allows this, maybe you could instead generate a number of folders full of .png of .svg images using your script, and then use something like ImageMagick to convert each folder into a video? This would be pretty painless compared to showing a different 100 times a second.

    • Failing this, you may be able to generate a list of canvas objects (or possibly window, or win objects in PsychoPy terminology, I'm not sure) during the prepare phase of your trial, and then display them sequentially using something like

  # prepare phase
  
  list_of_frames = []
  
  for i in range(number_of_frames_needed):
      this_frame = canvas(exp) # Or this_frame = A_New_Psychopy_Window_Instance
      # Your inline script for generating frames here
      list_of_frames.append(this_frame)
  
  # run phase
  for frame in list_of_frames:
      frame.show()
      self.sleep(5)
  

  I hope this helps!

  Eoin
• faedojury

  October 2013 edited 8:07PM

  Thanks a lot for your answer Eoin,

  To add the needed frames in the prepare phase doesn't seems to really improve the situation.
  Still the refresh rate is too slow.

  For the moment i am thinking about 2 options.
  One is to load at the very beginning of the experiment something like 200 configurations of frames and choose randomly 36 on each trial (I need to present 3 secs at a sampling rate of 12 Hz).
  Another is to definitely create in JPG format something like 500 random pics pre-load them to be used during the experiment.

  Do you think any of them is better than the other? Any other idea?
  Thanks in advance to any creative mind there.

  Felipe
• EoinTravers

  October 2013 edited October 2013

  I've just tried the following, and it seems to do what you want on my computer anyway. Maybe you could try this, and let us know how you get on?

  I've made a new experiment, and in it I've placed a single inline_script item.
  In the Prepare Phase tab of this, I've typed:

  import os
  path = '/home/eoin/Pictures/Webcam/'
  # Change this to a folder on your computer containing about 35 images.
  
  images = []
  for img in os.listdir(path):
      image_path = exp.get_file(os.path.join(path, img))
      images.append(image_path)
  self.images = images
  

  Then, in the Run Phase tab, I've typed:

  from openexp.canvas import canvas
  my_canvas = canvas(exp)
  
  for fpath in self.images:
      my_canvas.clear()
      my_canvas.image(fpath)
      my_canvas.show()
      exp.sleep(83) # 12Hz = 83ms between frames
  

  The result for me is a 3 second burst of all 35 images in my Webcam folder.

  If this works on your machine, I would advise simply generating your stimuli as a series of jpgs, saving them to one folder, and then modifying my code so that the prepare phase looks like:

  import os, random
  path = '/home/eoin/Pictures/Webcam/'
  # Change this to a folder on your computer containing about 35 images.
  
  images = []
  # Randomize the stimuli, and pick the first 35.
  list_of_filenames = random.shuffle(os.listdir(path))
  for i in range(35):
      filename = list_of_filenames[i]
      image_path = exp.get_file(os.path.join(path, filename))
      images.append(image_path)
  self.images = images
  

  Edit:
  I've just tried this on a different folder of images, with a higher resolution (2048x1536, from my phone, rather than 640x480, from my webcam), and I do find it lags. You may want to compress your jpgs (again, ImageMagick is your friend here).

  Edit Again:
  For a good laugh, set your image path to a folder of FaceGen stimuli.
• faedojury

  November 2013 edited 8:07PM

  Hi Eoin,

  Thanks a lot again for your help.
  Actually my original idea was trying to generate images on the fly but it seems that any method is definitely too inefficient, since requires the generation of multiple canvas.
  As you proposed i am at the moment creating a pool of 300 images and loading 36 randomly on every trial, it seem to work pretty well.
  I need pictures that are 300*300 px. so there is not any kind of memory overload.

  Thanks again for your advice and help.

  Best,

  Felipe
• faedojury

  November 2013 edited November 2013

  Hi There again... This is maybe a really silly question but I 've been stuck on it for some hours and i cant find a proper solution. In the CFS experiment I have succesfully overcome the problem of multiple pictures presentation thanks to Eoin's idea.
  Nevertheless it is impossible for me to present 2 canvas at the same time (i need to present the flashing mondrian pictures at the same time that a face that is presented during the same period of time). So the code I have so far is:

  Prepare phase:

  import os, random
  path = '/Users/aedo-jury/Documents/FELIPE/Awareness Faces/Experiment /masks'
  # this is the folder on containing mondrian images for the flashing canvas.
  
  images = []
  # Randomize the stimuli, and pick the first 35.
  list_of_filenames = (os.listdir(path))
  random.shuffle(list_of_filenames)
  
  for i in range(24):
      filename = list_of_filenames[i]
      image_path = exp.get_file(os.path.join(path, filename))
      images.append(image_path)
  self.images = images
  
  # Path to the folder containg the faces
  banana=('/Users/aedo-jury/Documents/FELIPE/Awareness Faces/Experiment /pics/{0}.png'.format(picture))
  

  Run Phae: Here comes the tricky thing becasue If i "put my_canvas2.show()" before or after the canvas for the flashing mondrians it will present them before or after and not at the same time. Contrary if i put it inside of the mondrian loop it will flash the pictures.

  from openexp.canvas import canvas
  from psychopy.visual  import GratingStim, event, core,SimpleImageStim,TextStim,  Circle
  
  # im=SimpleImageStim(win,banana, flipHoriz=False, pos=(-400,200), units='pix')
  
  
  my_canvas = canvas(exp)
  my_canvas2 = canvas(exp)
  my_canvas2.image(banana,x=800, y=600, scale=0.5)
  
  
  for fpath in self.images:
      my_canvas.clear()
      my_canvas.image(fpath,x=200, y=200, scale=0.5)
      my_canvas.show()
      my_canvas.set_penwidth(30)
      exp.sleep(83) # 12Hz = 83ms between frames
  
  my_canvas2.show()
  exp.sleep(2000)
  

  Any idea?

  Thanks in advance.

  Felipe
• EoinTravers

  November 2013 edited 8:07PM

  Hi,

  Could you please clarify, are you trying to superimpose the flashing mondrians on top of your static image (the banana, I think), rather than alternating between the two, or showing them side by side?

  If so, I don't think it's possible to superimpose two canvasses in OpenSesame like this. What you could do instead is create .png images where this is already done - i.e. for each target image you want to present, generate a folder of images of it superimposed with each mondrain in advance, and then show the images from each folder, using the code above.

  While this isn't something I've specifically done myself, it should be relatively easy using ImageMagick, especially if you ask on the forums dedicated to the software.

  Not having ImageMagick installed on my office computer, I can only give an untested example, but I think that to superimpose 100 mondrain images, in this case titled mondrain001.png to mondrain100.png, over a target titled target.png in the same folder, a DOS/Unix command along these lines would be appropriate.

  composite -blend 50 target.png mondrain*.png target*.png
  

  creating files titled target001.png to target100.png.

  Eoin
• faedojury

  November 2013 edited 8:07PM

  Hi Eoin,

  Thanks for your reply.
  Sorry I wasnt so clear.

  Actually what I need is to present continuously one picture during 3 secs on one side of the screen (banana) while on the other side of the screen at the same time are flickering the mondrian paterns at 12 hz (the loop canvas).

  I hope now is a bit clearer.

  Thanks a lot,

  Felipe
• EoinTravers

  November 2013 edited 8:07PM

  Ah, ok, that's a lot simpler.
  A Canvas refers to the whole screen, you can't have two canvases side by side, but you can easily draw your mondrains on one side of the canvas, and the target on the other.

  I think the most efficient way of doing this would be to prepare 24(?) canvases like this in advance during the prepare phase:
  canvases

  import os, random
  from openexp.canvas import canvas
  
  path = '/Users/aedo-jury/Documents/FELIPE/Awareness Faces/Experiment /masks'
  # this is the folder on containing mondrian images for the flashing canvas.
  
  # Get the target
  picture = exp.get('picture') # Get the Experiment variable
  banana=('/Users/aedo-jury/Documents/FELIPE/Awareness Faces/Experiment /pics/{0}.png'.format(picture))
  
  # Randomize the mondrains, and pick the first n_of_frames.
  n_of_frames = 24 # Use 24 mondrains
  list_of_filenames = (os.listdir(path))
  random.shuffle(list_of_filenames)
  
  canvases = [] # A list of canvases to show sequentially.
  for i in range(n_of_frames):
      this_canvas = canvas(exp)
      # Get the mondrain and add it to the canvas
      filename = list_of_filenames[i]
      image_path = exp.get_file(os.path.join(path, filename))
      my_canvas.image(image_path, x=200, y=200, scale=0.5)
      # Add the target to the same canvas
      this_canvas.image(banana,x=800, y=600, scale=0.5)
      # Add our canvas to the list
      canvases.append(this_canvas)
  self.canvases= canvases
  

  Then, in the run phase, all you need to do is show this list of canvases sequentially.

  # Show each canvas for 83ms.
  for canvas in self.canvases:
      canvas.show()
      exp.sleep(83) # 12Hz = 83ms between frames
  
  # Clear screen (uncomment to use)
  #canvas.clear()
  #canvas.show()
  
  # Wait two seconds after last frame
  exp.sleep(2000)
  

  I can't test this from this computer, but hopefully this should solve your (interesting!) problem.

  Eoin