The Concept of Sensory Adaptation - Assignment Example

?Task Experiment 1. Yes, the perception of the coarseness changed from having a scale of six to a scale of four. 2. The perception of the coarseness changed by having less feelings of coarseness. The sandpaper felt less coarse the second time around. Experiment 2: 3. Yes, the taste of fresh water was surprising. 4. The fresh water tasted strongly bland, or in other words, very fresh to the mouth. This taste was acquired after swishing sugar water in the mouth. Also, while swishing the sugar water, the sweetness of the water decreased. Experiment 4: 7. The first time that the hands were submerged into hot and cold water, the feelings of hotness and coldness seemed unbearable at first. After two minutes, the cold water felt less cold, while the hot water felt less hot. Then, subsequent to submerging both hands into the lukewarm water, the left hand felt cooler, while the right hand felt hotter. Essentially, it was interesting that while both hands were immersed in the lukewarm bowl, these hands had conflicting sensations to the previous temperatures they were first immersed into. While submerged in lukewarm water, the left hand felt surprisingly cold, while the right hand felt hot. Task 2 Introduction Animals and human beings learn to adapt to changes in their surroundings, in order to feel more comfortable and less stressed. Sensory adaptation is an important ability that allows people to be less sensitive to stimuli that repeatedly assault their senses (Rathus, 2007, p.83). In order to learn more about sensory adaptation, three experiments were conducted. They tested how the senses of taste and touch responded to subsequent exposures to the same or different levels of stimuli. These experiments teach people that sensory adaptation is crucial from an evolutionary perspective, so that people will not be constantly stressed from changing environmental conditions. Furthermore, learning more about sensory systems tell something about how the brain works in order to sustain normal human life. 8. Three experiments were conducted. The first experiment required the rubbing of the index finger on coarse sandpaper and rating the coarseness from 1 to 7, with 7 being the coarsest. The index finger was rubbed on the sandpaper and after one minute of rest, the same action was repeated. The perception of the coarseness changed from having a scale of six to a scale of four. The sandpaper felt less coarse the second time around. The second experiment used two cups of water: one cup of sugar water and one cup of fresh water. The sugar water was swished around the mouth for several seconds and was not swallowed. After that, a sip was taken from the cup of fresh water. The taste of fresh water surprised the experimenter. The fresh water tasted strongly bland, or in other words, very fresh to the mouth. This level of fresh taste was acquired after swishing sugar water in the mouth. The third experiment used three bowls of water with varying temperature levels. Bowl 1 had extremely hot, but not scalding, tap water. Bowl 2 contained extremely cold tap water. Bowl 3 mixed very warm and chilly water. These bowls were arranged, so that the right hand was in front of the cold water, the left hand was in front of the hot water, and Bowl 3 was in the middle. The experimenter submerged hands into the water, with the right hand in Bowl 2 and the left hand in Bowl 1. The hands were submerged for three minutes and then quickly put into the lukewarm bowl. The first time that the hands were submerged into hot and cold water, the feelings of hotness and coldness seemed unbearable at first. After two minutes, the cold water felt less cold, while the hot water felt less hot. While submerged in lukewarm water, the left hand felt surprisingly cold, while the right hand felt hot. 9. These experiments showed the process of sensory adaptation. Sensory adaptation occurs when repeated stimulation of low magnitude reduces the number of sensory messages conveyed to the brain, thereby resulting to lesser feelings of sensation (Carpenter & Huffman, 2008, p.89). Every time the body senses something, its receptors send sensory messages to the brain. Repeated exposures, however, decline the number of messages, and sometimes, they may altogether stop, resulting to complete desensitization to the repetitive stimulus (Kent, 2000, p.197). 10. Adaptation is evident in the experimental results, because the response to the stimuli decreased after subsequent exposures were attained (Kent, 2000, p.197). For instance, in experiment 1, rubbing the index fingers on the same coarseness reduced feelings of coarseness. The sense of touch adapted to the coarse feeling. In experiment 2, swishing sweet water in the mouth soon led to tasting less sweetness. Moreover, it made fresh water tasted fresher to the mouth. In experiment 3, the feelings of hotness or coldness decreased as the minutes went by. At the same time, submerging into lukewarm water affected the sensations for each hand, where the previously hot hand felt cold, while the cold hand felt hot. 11. Human skin is sensitive to changes in temperature, pressure, and pain (Carpenter & Huffman, 2008, p.98). Touch receptors are concentrated on the fingers and face, as well as the back and the legs (Carpenter & Huffman, 2008, p.98). In experiment 1, rubbing the index finger on the coarse sandpaper sent messages to the brain about initial roughness through the touch receptors. At first, the scale of roughness was rated at six. When the same action was repeated, the same stimulus trigged the same touch receptors. This time, however, because the magnitude of the stimulus remained, the touch receptors sent fewer messages to the brain. The result was the feeling of less coarseness, which was rated at four. The index finger experienced desensitization from a low-level stimulus that repeatedly affected the same touch receptors (Carpenter & Huffman, 2008, p.98). The sense of taste is also called gustatory sensation. In experiment 2, the taste receptors in the tongue sent messages to the brain that the water was sweet. Constant stimulus from the sweetness, however, resulted to the taste receptors sending fewer messages to the brain (Schultz, 2008, p.88). This resulted to desensitization to the taste of sweetness. On the contrary, when the taste receptors received the taste of fresh water, the taste became so strong. Fresh water has low magnitude of sweetness that sensitized the taste receptors (Rathus, 2007, p.83). This made the brain sensitive to the freshness and so the unsweetened water tasted surprisingly fresh. The touch receptors were ignited again for Experiment 3, but this time, the entire hand’s wide range of receptors were triggered (Carpenter & Huffman, 2008, p.98). Since the water temperatures were quite extreme, both the left and right hands sent strong signals about the hotness and coldness of the waters. Human skin, however, has more touch receptors for coldness, so the right hand felt very cold at first and for a very long time (Carpenter & Huffman, 2008, p.98). In other words, the left hand felt less hot faster than the right hand feeling less cold. When both hands were submerged into lukewarm water, the water did not feel lukewarm at all, and instead, the right hand felt hot and the left hand felt cold. The brain determined changes in the temperature stimulus, and interpreted it on the basis of the preceding input (Carpenter & Huffman, 2008, p.98). As a result, the hot hand felt cold, while the cold hand felt hot, even when they were submerged into the same lukewarm water. 12. Adaptation is important from an evolutionary perspective because it is critical to comfortable existence and survival (Carpenter & Huffman, 2008, p.89). Because of sensory adaptation, people will not have to waste time on unimportant stimuli changes (Carpenter & Huffman, 2008, p.98). The brain receives overwhelming amount of data everyday and it cannot process all signals from repetitive stimuli without being stressed (Carpenter & Huffman, 2008, p.98). Sensory adaptation makes people feel comfortable to stimuli that they cannot control or do not need to be necessarily controlled all the time. Furthermore, adapting to changing temperatures and other conditions is critical to survival (Carpenter & Huffman, 2008, p.98). People adjust to changing temperatures, for instance, which enable them to survive both warm and cold climates, as long as they are not extreme enough to imperil human life. Hence, sensory adaptation helps people feel comfortable and be adaptive to changes in the environment, thereby ensuring health and survival. Conclusion Sensory adaptation makes life comfortable and bearable. Three experiments were conducted, which gave evidence on how the human body adapts to changing external stimuli through sensory adaptation. Sensory adaptation occurs through touch or taste receptors and their communication with the nervous system. Repetitive stimuli push receptors to send fewer messages to the brain, so the body adjusts to the former. This allows the body to be desensitized to otherwise irritating or distracting stimuli. Hence, sensory adaptation is central from an evolutionary perspective because it is vital to comfortable existence and survival. References Carpenter, S., & Huffman, K. (2008). Visualizing psychology (2nd ed.). New York: Wiley. Kent, M. (2000). Advanced biology. Oxford: Oxford University Press. Rathus, S.A. (2007). Psychology: Concepts & connections, brief version (9th ed.). Belmont, CA: Wadsworth/Cengage. Schultz, M. (2008). Chapter 4: Sensation and perception. In L. Nicholas (Ed.), Introduction to psychology (pp.70-111). Cape Town: UCT Press. Read More