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 gain some experience in calibration or making sure the stimulus works the way your think it does
    3. to develop some understanding of what is an experiment
    4. To begin to learn how to design an experiment to answer a question
    5. to compare data to hypothesis
    6. To expand our understanding of Acuity

The Experiment:

  1. Design:
    1. Stimulus Type: Vernier
    2. Number of Positions: Same as for Acuity
    3. Upper limit of staircase: leave as default but record (the unit is in pixels)
  2. Method (Method of Limits):
    1. Number of Levels to Test: Same as last time
    2. Number of staircases: 9-15 (same as last time)
    3. Type of MOL: Traditional
  3. Procedure:
    1. Place your head centered on the screen 24" from the monitor surface.
    2. Fixate on the red fixation mark.  Do not move your eyes from that spot.
    3. Line will be presented 
    4. If you see it, press the yes button or the z key.
    5. If you do not see it, press the no button or the / key.
    6. The computer will track the staircases and when each position is done it will move to the next position.
    7. The threshold are calculated and a summary of the results will be displayed at the end of the experiment.
    8. Press the Show Data button and record your results
    9. Here is the link to the lab.
  4. Write-up: (Method, Results, Summary)
    1. Week 1:
      1. Do a graph of your results to hand in. 
      2. Your graph should be and x-y scatter plot with points connected by straight line connectors
      3. Put error bars around mean values. See this document by Dr. Darrin Rubino to see how to add error bars.
      4. Include a paragraph describing why you graphed the data the way you did.
    2. Week 2: 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