Sensory Adaptation Experiments
Task 1
Experiment 1: The sandpaper felt very coarse after rubbing my index fingers on it for the first time. I rated the coarseness at 6. The sandpaper feels less coarse after allowing my fingers to rest for two minutes and I rated the coarseness at 3.
Experiment 2: The sugar water became less sweet after swishing it around my mouth for several seconds. The taste of the fresh water surprised me because it tasted salty.
Experiment 3: I dipped my right hand in cold water and my left hand in hot water. At first the water in the bowl 1 felt very hot while the water in bowl 2 felt very cold. After a few seconds, the water temperatures felt normal. When I dipped my hands in the lukewarm water, I felt like I had dipped my right hand in hot water and my left hand in cold water.
Task 2 I chose three experiments to demonstrate the concept of sensory adaptation. In the first experiment, I rubbed my index fingers over sandpaper for several times and rated its coarseness on a scale of 1-7. I allowed my fingers to rest for two minutes before rubbing them on the same sandpaper for the second time. The first time I rubbed the sandpaper, it felt very coarse, and I rated its coarseness at 6. However, the sandpaper felt less coarse the second time, and I rated its coarseness at 3. In the second experiment, I sipped sugar water and swished it in my mouth for several seconds before disposing it. The sugar water tasted less sweet as I swished it in my mouth. I immediately tasted fresh water, which tasted salty. In the final experiment, I filled three bowls with water at different temperatures. Bowl 1 had hot water bowl 2 had cold water and bowl 3 had a mixture of cold and hot water (lukewarm water). I dipped my left hand in the bowl with hot water and my right hand in the bowl with cold water simultaneously. I allowed the hands to stay in the bowls for 3 minutes. At first the temperatures felt extreme, but after several seconds, the temperatures felt normal. After three minutes, I dipped my hands in the lukewarm water. I felt as if I had reversed my hands such that my right hand was dipped in hot water, and my left hand in cold water. Sensory adaptation is a characteristic of human senses that enables them to decrease their responsiveness to continuous or persistent stimuli. Sensory receptors respond better to changing stimulation than to the same level of stimulation (Coon & Mitterer, 2008, p. 142; Nevid, 2012, p. 94). Sensory adaptation is involuntary and can only be reversed by either eliminating or changing the stimuli. Sensory adaptation occurs because nerve cells fire less frequent signals to the brain at high levels of stimulation than when a stimulus is introduced. Adaptation to sounds or noise is slower than the adaptation to smells, skin sensations, and tastes. Sensory adaptation enables living things to find balance with their environment and respond to changes in their environment (Franzoi, 2010, p. 97; Butler & Hodos, 2005, p. 30). Sensory adaptation was evident in the three experiments. In the first experiment, the sandpaper felt less coarse when I rubbed my fingers on it for the second time. When I rubbed the sandpaper for the first time, my receptors sent frequent neural signals to the brain. The receptors on my fingertips sent neural signals through my spinal cord to the somatosensory cortex in my brain. The somatosensory cortex transformed the neural signals into touch sensations and hence, I could feel the coarseness of the sandpaper. As I continued to rub the sandpaper, the signals to my brain became less frequent. The receptors on my fingertips had already adapted to the coarseness of the sandpaper. Consequently, the sandpaper felt less coarse when I rubbed it for the second time. In the second experiment, the sugar water in my mouth tasted less sweet after swishing it for several seconds. My taste receptor was adapting to the new stimuli. The fresh water tasted salty because it had a greater effect on my receptors than the sugar water. My senses sent frequent neural signals to my brain after tasting the fresh water because the stimuli had changed. Sensory adaptation was also evident in the third experiment because of the reversed sensation. The left hand that was in previously dipped in hot water felt cold in lukewarm water. The right hand that was previously dipped in cold water felt hot in the lukewarm water. The receptors in my hands had adapted to the water temperatures in the first and second bowls. When I dipped my hands in lukewarm water, the receptors sent immediate neural signals to the brain of the change in stimulation. The brain transformed the signals and hence the reversed sensations. Adaptation is a fundamental aspect of the human evolution theories. The evolution perspective outlines that through adaptation; species can survive in changing environmental conditions and reproduce. Adaptation is a trait that can be inherited, and this trait enables species to survive and reproduce in any environment (Miller & Spoolman, 2008, p. 82).

References
Butler, A, B., & Hodos, W. (2005). Comparative Vertebrate Neuroanatomy: Evolution and Adaptation. New Jersey: John Wiley & Sons
Coon, D., & Mitterer, J, O. (2008). Introduction to Psychology: Gateways to Mind and Behavior. Connecticut: Cengage Learning
Franzoi, S, L. (2010). Psychology: A Discovery Experience. Connecticut: Cengage Learning
Miller, G, T., & Spoolman, S. (2008). Living in the Environment: Principles, Connections, and Solutions. Connecticut: Cengage Learning
Nevid, J, S. (2012). Psychology: Concepts and Applications. Connecticut: Cengage Learning