The purpose of this experiment was to determine the effects, if any, certain variables have on the autokinetic effect. The autokinetic effect refers to a perceptual phenomena in which a viewer, who is exposed to a single point of light in a completely dark room, perceives light movement even though the light is stationary. Earlier research done by Ozeki, Takahashi, and Tsuji (1991) suggested a positive correlation between predictions made by the experimenter and movement of light perceived by the observer. Part 1 of our study will examine the effects that predictive instructions have on the perceived light movement. Part 2 examines the effects that internal predictions, made by the observer himself, have on the perception of the light movement.
METHODS: The subject pool consisted of 25 Alma College students. Apparatus used in the experiment included: a writing tablet and pen used to record observations, a small red light to act as the visual stimulus, 3 seperate sets of instructions acting as the source of prediction, and an examination room enclosed by one-way mirrors. Subjects were taken one at a time into the examination room and positioned directly across from the light source. They were each given an instruction sheet predicting 1 of 3 patterns of light movement. The lights were then turned off so that the room was completely dark. The observer was left in the room to record observations for 5 minutes. The subjects involved in part 1 were informed either that they would be viewing a stationary light source or a moving light source. The subjects in part 2 completed Leary's Social Anxiety Scale (1983) and were informed the results of this scale would determine their perception of light movement. Observations collected from all subjects involved in the study, represented by their sketches, were analyzed in terms of line length and number of curves. Line length was measured in cm. using a thin piece of wire to trace the sketch. The number of curves were estimated by the experimenters. Overall light movement was then determined by both line length and number of curves.
RESULTS: In general, the results from part 1 suggested that those who were informed the light would remain stationary perceived less movement than those informed that the light was going to move. On average, those who expected movement recorded longer line lengths containing a greater number of curves. (See Figure Below)
Results from part 2 also suggest a relationship between internal prediction and perception of light movement. Since these subjects were informed that their level of social anxiety would determine their perception of the light movement, each subject formed an internal prediction regarding the type of movement they would experience. (See Figure Below)
DISCUSSION: The difference between the two groups of subjects in part 1 is a difference in external prediction. Half of the subjects expected to view a stationary light decreasing the amount of movement they actually perceived. The other half, who expected to view a moving light, observed more movement than did those who expected to see a stationary light source. As a result, the data collected suggests that external prediction appears to have a psychological influence on the amount of movement perceived by the observer. Results from part 2 of the study suggest that internal prediction can also influence perception of the autokinetic effect. Since the subjects were consciously aware of their level of social anxiety (aided by completing the social anxiety scale), they formed an internal prediction as to how much light movement they were going to see.
REFERENCES:
Burger, Jerry. Personality. Fourth Edition, 1997
Ozeki, Takahashi, & Tsuji. Autokinetic Illusion as Affected by Suggestions of Experimenter and Observer. Perceptual and motor Skills, 1991, 515-526