Acuity and Retinal Location Lab Part II



  1. Purpose and Goals
    1. to measure and see how acuity deteriorates as the stimulus is moved farther from the fovea
    2. to develop some understanding of what is an experiment
    3. To begin to learn how to design an experiment to answer a question
    4. to compare data to hypothesis
    5. To expand our understanding of Acuity
    6. To develop skills in doing graphs and calculations in Excel

The Experiment:

  1. Stimulus Settings:
    1. Stimulus Type: Choose either: Vernier, Motion Jump, Motion Smooth (just one)
    2. Contrast: Do not change, as last time
    3. Stimulus Positions: Use same as last time
    4. Background Level: Do not Change
  2. Experimental Method Settings:
    1. Number of Levels of Critical Feature Size: Same as last time
    2. Number of staircases: Same as last time
    3. Minimum Value of Critical Feature Size: 0.1
    4. Maximum Value of Critical Feature Size: 10 (Same as last time)
  3. Procedure:
    1. Make the browser fill the screen.
    2. Place your head centered on the screen 24" from the monitor surface.
    3. Fixate on the red fixation mark.  Do not move your eyes from that spot.
    4. The stimulus will be presented at the position you chose for this condition. 
    5. If you see it, press the yes button or the z key.
    6. If you do not see it, press the no button or the / key.
    7. The threshold is calculated at the end of the experiment.
    8. Press the Show Threshold button to display the threshold and then record your results.
      1. Remember how the threshold is calculated
    9. Here is the link to the lab.
  4. Write-up: (Method, Results, Summary)
    1. Week 1:
      1. Nothing Due
    2. Week 2: Graphing Results with Error Bars
      1. Do a graph of your results to hand in on Moodle. 
      2. Your graph should be and x-y scatter plot with points connected by straight line connectors
      3. Put error bars around mean values.
    3. Week 3: Abbreviated Lab Report with the following sections:
      1. Method: Your method must include the following subsections:
        • Participants:  A brief description of who was in your experiment.  You need data from all members of your group
        • Stimulus: A description of all stimuli used and your calibration
        • Equipment: What equipment you used
        • Procedure: How you collected the data
      2. Results: a description of your findings
        • Use your data and the data from the other member(s) of your group.
      3. Summary: Do your results match your expectations, listed at the beginning of this page