Testing Operant Conditioning on a Golden Doodle

Operant conditioning is when an association is formed between behaviors and resulting actions. Two predominant experiments were conducted that helped to solidify the idea of operant conditioning. Thorndike’s experiment focused on the law of effect. The law of effect is defined as a rewarded behavior is likely to recur. A simple example is with food as the reward for an animal doing a trick. In a similar experiment, it was concluded that animals can be trained to do unnatural behaviors that they would never do in their natural habitat. This was called the Skinner Box or Operant Chamber experiment. In order to prove this experiment true, shaping was used. This term refers to using reinforcers to guide behavior closer towards the desired behavior. This involves giving a reward during each step of a trained behavior which is defined as successive approximations. In many cases, positive reinforcement is used to increase the good behavior when something is added to the environment.

All these different but related points pertaining to operant conditioning can be surmised by training a dog a trick. In my experience, my family got a golden doodle puppy about five years ago. Since the puppy was my idea, I was tasked with training her. An old farmer who has been our family friend since before I was born had a dog that would roll over and play dead when he made a gun shape with his hand and said, “bang!” All our neighbors would laugh every time. When I got a dog, I knew I wanted to train it to do the same trick through operant conditioning. I started off using shaping and successive approximations. I first taught her to sit by holding a treat in my hand and pushing down on her back while saying “sit”. When she sat, I rewarded her with a treat. After a while, Thorndike’s experiment was proven to be correct. Every time I said “sit”, she would sit down because she knew she would get a reward. This also proves positive reinforcement. After this, I taught her how to lay down and roll over using the same technique. When I started to teach her to play dead, I followed the same methodology. I would get her to sit, lay down, and then roll over. However, when she rolled over, I started to say “bang” so that she would associate that word with being upside down. I got her to stay on her back by using the stay command that I had previously taught her. After emptying a treat bag, she would roll over and play dead whenever I said “bang”. This proved the Skinner Box experiment. In a dog’s natural environment, they would never play dead when a human said “bang” to them. Nevertheless, my dog was able to be fairly easily trained to do this unnatural trick. Overall, operant conditioning proved to be very successful in teaching my golden doodle a fun party trick.

Retinal Disparity in Relation to 3-D Movies and Magic Eye

Depth perception is broken up into two different types of cues, monocular and binocular. Monocular only requires one eye where binocular requires both eyes. By definition, “binocular depth cues are depth cues that are created by retinal image disparity—that is, the space between our eyes, and thus which require the coordination of both eyes” (Wede). On each eye, there is a different image that is recognized. The images are combined into one encompassing image in the visual cortex. The overlaying of two images causes us to see depth.

Three-dimensional glasses in conjunction with specifically made three-dimensional movies allow retinal image disparity to be manipulated. The three-dimensional glasses are different colors and the lenses are different to force the wearer to see two different images. In my experience, I went to see a three-dimensional movie. Being the curious kid that I was, I would take the glasses off, keep one eye in the glasses, switch eyes, and then would wear the glasses correctly. The movie had the three-dimensional aspects outlined in blue and red. My glasses were blue and red and therefore each lens picked up the respective color and formed two images. With only one eye looking through the lens, I could not see the three-dimensional effects.

Another example of retinal disparity has to do with Magic Eye pictures. A person can only see the hidden image in a Magic Eye picture by adjusting the focus of their eyes either in front of the picture, or behind it. As with the three-dimensional glasses, the small distance between a person’s eyes and the different images perceived on each eye, allow a person to see the hidden image. On the bus in 9th grade, a girl used to sit next to me on the bus. One day she showed me her Magic Eye book that she had gotten as a gift. She explained to me that I had to look through the book in order to see the image. I spent the next week repeatedly trying to see the image and failing. Finally, I saw the image. I held my figure out and then slowly moved the book in between my eyes and my finger. I was so excited when I finally figured out how to manipulate my eyes so that I could see the image. I can now find the image in almost every Magic Eye I see. Also, because I learned how to do this, I can now dilate and contact my pupils on demand by changing my depth of focus. Because of retinal image disparity and depth perception, I now understand the psychological and scientific reason as to why I can see the image.

 

 Works Cited

Wede, Josh. Introductory Psychology. Pressbooks. Retrieved from  https://psu.pb.unizin.org/intropsych/chapter/chapter-4-sensation-perception-vision/#43

Myelin, Brain Lesions, and MRI’s in Relation to Multiple Sclerosis

The myelin sheath may not seem to be too important in the overall grand scheme of the central nervous system. However, I personally know what damage to this thin layer of protein and fat can cause in a human being. In 1996, two years before I was born, my maternal grandmother was diagnosed with chronic progressive multiple sclerosis. She first noticed that something was awry in 1994. Her leg began to flop when she walked, she had blurred vision, and had very limited strength in her hands. After numerous spinal taps and testing, she was diagnosed after a Magnetic Resonance Imaging (MRI) scan. MRIs are able to image soft tissue very well and are therefore used to see the structure of the brain. The imaging capabilities are expanded when considering the superior spatial resolution. This spacial resolution allows the doctor to see brain details down to the millimeter. All these features were crucial in observing the brain lesions in my grandmother’s brain which ultimately led to her diagnosis. Brain lesions are an area of brain tissue that has been damaged. Brain lesions can be compared to scar tissue except instead of being on the skin, they are located in the brain. Multiple sclerosis has been proven to have a direct correlation to brain lesions.

Multiple sclerosis is an autoimmune disease that results from the immune system attacking the myelin sheath that encapsulates the axons of neurons in the brain and spinal cord. The myelin sheath assists in spreading nerve impulses from the soma, or the cell body, to the terminal branches of the axon. The anatomy can be seen in Figure 1. The myelin sheath also insulates and protects the axon and allows the messages through the neurons to speed up. In the case of multiple sclerosis, the body’s immune system attacks the central nervous system and targets the myelin sheath directly. Also, oligodendrocyctes, the cells that make myelin, are damaged and killed. The amount of damage is indirectly related to the consistency of the signal getting through. That is, the more damage that is inflicted on the myelin sheath, the more damage there is to the axon, and less of the initial signal gets through. This is due to the nature of an action potential. The action potential is a quick charge that travels down the axon. The action potential is created by the movement of charged ions in and out of channels in the axon’s membrane. Therefore, if less charged ions are able to get through to the axon’s membrane, there will not be enough voltage to cause an action potential. A graphical and pictorial representation can be seen in Figure 2. Reaching threshold is required in order for the neuron to fire. Any amount below threshold will not be able to cause the neuron to fire. This progression of less and less action potentials was seen in my grandmother. My grandmother went from completely healthy to not being able to do anything. Her neurons were so badly damaged that she could not voluntarily move any part of her body after only a handful of years. Ultimately, she passed away from the complications of multiple sclerosis in December 2001. From her, I grew up knowing the complications of multiple sclerosis. However, this assignment allowed me to understand more about the disease in connection to the nervous system. I also learned about how the disease progressed and how she was diagnosed by getting information from my mother. Overall, this tiny myelin sheath can have major complications if it is damaged. The myelin sheath has much more importance in the grand scheme of the body as proven by multiple sclerosis.

Figure 1
Figure 2

 

Works Cited

Immune-Mediated Disease. (n.d.). Retrieved from https://www.nationalmssociety.org/What-is-MS/Definition-of-MS/Immune-mediated-disease