This is a demonstration of what the phase "control of perception" means. It doesn’t mean that what we control is an “illusion” or a “matter of opinion”. It means that we control functions (in the mathematical sense) of our sensory input. The present demonstration lets you control one three different perceptions (functions) of the same sensory input: a rectangular object. This object varies in area, shape and angle (relative to vertical). These three variables – area, shape and angle – are different perceptual aspects (functions) of the same sensory input -- the visual image of the rectangular object. You can control any one of these perceptions by moving the mouse left or right as necessary to compensate for disturbances to that perception.
You start the demonstration by pressing “Run” and moving the cursor into the display screen. (Ignore the blue rectangle in the upper left corner for now). When you press “Run” you will see another blue rectangle, centered in the display, which varies in area, shape and orientation. I suggest that you begin by trying to control the angle of the rectangle. Try to keep the angle at 90 degrees relative to horizontal – that is, keep the rectangle perfectly vertical. You can always start over by pressing “Run” if you are having difficulty doing it. It’s particularly difficult to control just one perceptual aspect of the rectangle because two other perceptual aspects of the rectangle are varying at the same time.
A graph of the results of your controlled is displayed at the end of each 50- second trial. The graph shows the time variations in the value of each of the 3 perceptual variables that you might have controlled during the trial. If you were able to control one of these perceptual variables during the trial then the time variations in that variable will be small relative to the time variations in the other two variables. For example, if you were controlling the angle of the rectangle then the line labeled “Angle” should be nearly flat while the other two lines, for “Shape” and “Area” fluctuate more widely. Such a result would show that you were controlling the perception of angle.
Once you have become skilled at controlling angle you might next try controlling the shape of the rectangle. Try to keep the rectangle’s shape square (like the shape of the rectangle in the upper left). This will require you allowing other aspect of the rectangle to vary; that is, when you try to keep the shape of the rectangle square, the area and orientation (angle) of the rectangle will be changing. Try to ignore these changes in the other perceptual aspects of the rectangle; just try to control the perception of shape. To the extent that you can control just the shape of the rectangle, the graph at the end of a trial will show a relatively flat line for “Shape” (little variation in shape) and much more widely fluctuating lines for “Area” and “Angle”. Such a result would show that you were controlling the perception of shape.
Finally, you can try controlling the area the rectangle. In this case try to keep the total area of the rectangle approximately equal to the area of the rectangle in the upper left. I find “Area” the most difficult aspect of the rectangle to control but do the best you can. Again, to the extent that you can control just the area of the rectangle, the graph at the end of a trial will show a relatively flat line for “Area” and much more widely fluctuating lines for “Shape” and “Angle”. Such a result would show that you were controlling the perception of area.
To the extent that you were able to successfully control the angle, shape and area of the rectangle you demonstrated to yourself the meaning of control of perception. What you control are perceptual aspects of the world as it impinges on your sensory systems – eyes, ears, nose, mouth, skin, proprioceptors. And you can choose which perceptual aspects of the world to control (in this case, area, size or angle) and in what state to keep them controlled (for example, you could have kept the angle at 45 degrees rather than 90 degrees relative to horizontal; the area smaller than that of the rectangle in the upper left; and the shape rectangular rather than square). In other words, you control what you perceive; what you perceive doesn’t control you.