Tara Patale – Intro Psych Blog (F19)

Blog 3: Classical Conditioning and Taste Aversion

Classical conditioning is a type of learning in which an organism learns to associate two stimuli together. A response that usually results from the second stimuli usually also results from the first. An example of classical conditioning is Pavlov’s experiments. Pavlov’s experiments analyzed the response of a dog when the dog would see food. In this example, the unconditioned stimulus is the food because it naturally elicits a response from the dog. The dog’s response of salivation is the unconditioned response which is a naturally occurring response. However, Pavlov would begin ringing a bell before presenting the food and eventually the dog would salivate upon hearing the bell. In this case, the sound of the bell and food became a paired stimulus. The sound of the bell is the conditioned stimulus which was initially an irrelevant stimulus but became associated with the unconditioned stimulus to trigger a conditioned response. The conditioned response was the learned response.

Many people believed that any association between two stimuli could be learned equally. In response, John Garcia conducted an experiment where he paired taste, sound and sight with radiation that would elicit the response of nausea in mice. He concluded that taste was strongly associated with the nausea. In this case, taste was the conditioned stimulus, radiation was the unconditioned stimulus, and nausea was the conditioned response. This experiment concluded that some things are easier to associate than others. This experiment also demonstrated the idea of taste aversion where humans are apt to have an aversion to foods if they become sick afterwards. For example, when I was in seventh grade, I went to a Mexican styled restaurant with family friends and ordered a chicken quesadilla. The family friends I went to the restaurant were recovering from the stomach flu and ordered chicken quesadillas. After enjoying my meal, I went home and went to bed. I woke up in the middle of night with abdominal pain and began to throw up. Reflecting on that night today, it was likely that I had caught the stomach flu and my nausea and uneasiness resulted from it. However, from that day, I could not eat any styled of Mexican food for two years; the thought of any Mexican styled food made me nauseous. Only recently have I been able to enjoy Mexican styled food. This is the perfect example of classical conditioning and how taste aversion works. The stomach flu was the unconditioned stimulus and nausea was the unconditioned response. Because of my pairing of the stomach flu and Mexican styled food, Mexican styled food was the conditioned stimulus and nausea became the conditioned response. Classical conditioning results from pairing any two stimuli; the pairing of some stimuli is stronger (like taste) than others.

Picture: https://www.psychestudy.com/behavioral/learning-memory/classical-conditioning/pavlov

Blog Post 2: Schemas

Schemas are essential for a person’s cognitive development and plays a major role in children, as they are developing through childhood, and plays a large role in adults. The idea of schemas stems from Swiss psychologist Jean Piaget who studied how development of the mind occurs in stages as children experience different schemas. Schemas are aspects of the world. These aspects of the world are learned and developed by children and adults through experience. As children and adults learn new things every day from the environment, experiences are developed, which leads to the development of different schemas. There are schemas for everything we experience in the world. For example, according the picture below, social schemas include not eating garlic when on a date. Many people share the common respect of not eating garlic when going on a date because garlic smells and can create an awkward situation when intimacy occurs. Because many people have experienced the smell of garlic or have experienced being on a date when they or their partner has eaten garlic, that experience develops into schema of avoiding garlic before a date.

As experiences continually occur, new schemas are developed and can modify or change old schemas. For example, growing up, my neighbor owned a Maltese puppy with whom I played with every day. This puppy had soft and white fur which I was obsessed with. Every time I held this puppy, I would embrace it and cherish its warm, fluffy fur. The puppy made me feel safe and secure because of how friendly and cute it was. However, one day when I was playing with the puppy, it became agitated and bit my leg. I was shocked that it bit me and began crying in pain; my parents rushed me to the doctor to make sure that I was safe. That moment changed my perception of my neighbor’s puppy and I no longer felt comfortable being around the puppy or any puppy that was of the same breed. This experience is a great example of how new experiences can change our schemas. Before the puppy bit me, my schema of Maltese puppies was that they were friendly, adorable, and gentle animals because of how positive my experience was with the puppy. However, my schema of Maltese puppies changed after experiencing a traumatic event at a young age. Suddenly, my schema of Maltese puppies was that they were dangerous and were not as cute and friendly as they appeared to be. My initial experience with the Maltese puppy and my new experience with the Maltese puppy caused my initial schema to be replaced with a newer schema. Schemas are created through experience and can change depending on the experience one has had.

How Drugs Influence Our Neurotransmitters – Psychology 100

The nervous system is made up of the central and peripheral nervous system. While the central nervous system is made up of the brain and spinal cord, the peripheral system is made up of the sensory and motor neurons that connect the central system to the rest of the body. In our discussion of drugs and their effects on neurons and neurotransmitters, we will focus on the peripheral nervous system. Neurons are interconnected cells that supports out body’s information system; it is made up of dendrites, the cell body, the axon, and the terminal branches. The dendrites of a neuron receive the information from other neurons, which travels to the axon from the cell body (soma). The axon speeds the information through the neuron, which ultimately reach the terminal branches. The terminal branches then proceed to transmit the messages to other neurons through their respective dendrites. If the input to a neuron’s dendrites is strong enough, the cell “fires” or transmits the message through an action potential- a brief electrical charge that travels down the axon of the neuron and is generated by movement of charged ions in the axon’s membrane. This voltage is responsible for sending information from one neuron (presynaptic neuron) to another neuron (postsynaptic neuron). (Below is a link of a picture of a neuron and the direction of the action potential).

The message is transmitted between two neurons (the presynaptic neuron and the postsynaptic neuron) in a region called the synapse- a junction between the axon tip and the dendrite. When the information travels from the axon to the terminal branch, the message is contained in neurotransmitters that are carried in vesicles. These neurotransmitters travel from the pre synapse of a neuron to the post synapse of another neuron. The neurotransmitters bind to the receptors of the post synapse and then the postsynaptic neuron can carry the information. Neurotransmitters’ effects are heavily influenced by drugs which could enhance or reduce the effect of a certain neurotransmitter. While agonists enhance the effect of a neurotransmitter, antagonists reduce the effect of the neurotransmitter.

Over this past summer of shadowing my pediatrician, I met a patient who had been suffering with a post-traumatic stress disorder. This patient had decreased levels of appetite, depression, and severe anxiety. My doctor sent the individual to a psychiatrist for further help. When my doctor and I saw the patient after a two-month follow-up, we observed that the patient had regained more appetite and had been feeling less depressed and had less anxiety. The patient had been sleeping better with no awakenings in the middle of the night and had also been eating at least two to three meals a day instead of none to one meal a day. We learned from the patient that the psychiatrist had prescribed Prozac. Reflecting upon this now, serotonin is a neurotransmitter that regulates mood, but also plays a role in regulating sleep, appetite, and digestion, among other physiological processes. It is usually taken up by the presynaptic neuron and reused later or broken down. This patient may have had decreased levels of serotonin, resulting in less receptors bound to serotonin. However, the patient began improving with Prozac which is known to be a selective serotonin re-uptake inhibitor. Instead of being taken up the neuron, the neurotransmitter is bound to a receptor for a longer period by Prozac, increasing the effect it has. Consequently, one would expect that mood, among other physiological processes, would improve based on the enhanced effect of serotonin. Prozac is most commonly prescribed to treat depression and plays a major role in enhancing the effect of serotonin.

Links:

https://courses.lumenlearning.com/wm-biology1/chapter/reading-types-of-signals/

https://www.healthline.com/health/serotonin-deficiency

https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/a/action-potential-velocity