We were testing to see if the human mind can be tricked into associating a fake arm with their own body after we establish a connection between sight and touch with the fake arm.
Our hypothesis was that the subjects’ minds will perceive for a short time after the sensory connection is made that the fake arm is attached to the subject’s body and is their real arm.
We asked for volunteers from the classes who were willing to participate and who had not seen this experiment before. We had each individual subject follow us into an isolated room and sit down at the table. The table had a divider set up on one side of the subject. Participants were asked to place each hand on either side of the divider. A rubber arm was placed in front of the subjects on one side of the divider and positioned so that it imitated the subject’s hidden arm. The fake hand and the hidden hand were than brush simultaneously with a paint brush while the participant is instructed to watch the fake hand. This forces the brain to make a connection between what the hidden hand is feeling and the brushing being seen on the fake hand. As subjects were watching the fake hand being brushed we pulled a hammer from under the table and hit the fake hand unexpectedly.
Our subjects consisted of Traverse Bay Area Career Tech students, and a teacher, in Graphic Arts who were willing to participate and had never seen this experiment done before.
Reactions were recorded on video and observed while they answered a few questions about the experiment including, “How did it feel?”, “Did you expect it to hurt when I hit the hand?”, “Did you feel like that was your arm?”, and “Did you try to pull the fake hand away?”.
Materials needed for this experiment included an isolated room to conduct the experiment, a table with a divider, a rubber arm (with a sleeve), a camera, a hammer, and two paint brushes.
Our independent variable was striking the fake hand with a hammer, while the dependent variable was the participant’s reaction. The constant variable was the situation with the rubber arm. This was a laboratory single blind study.
After conducting the experiment and recording our observations 11 of the 19 subjects claimed that they felt no connection to the fake arm. 6 said they felt some sort of connection and 2 were unsure about how they felt. A majority of participant’s did not feel a connection so our hypothesis was wrong. We determined if each individual felt a connection or not based on their reactions and their answers to prompts after the hitting the fake hand with hammer. It should be noted that a few subjects did look away from hand during the experiment after being instructed to keep watching it. This means that they watched the hammer being pulled out and were able to have a reaction prior to contact with the fake hand and this may have influenced the results(cheaters cheaters pumpkin eaters). But based on the 19 subjects we tested, our conclusion is that the majority of people were unable to connect the fake arm to their body even after being primed by the paint brush stimulation.