psyc304 week 5 discussion
Color is all around us, but just how deeply integrated is the phenomenon of color into our senses and neural pathways? Describe trichromatic theory and opponent-process theory of color vision, including the observations on which it is based and the physiological basis of each theory. Lastly, watch the video on synaethesia below, and discuss what it means to say that color is created by the nervous system. Explain what everyday life would be like for an individual with the disorder, including its impact on occupation, relationships, and leisure time. Be sure to include how the disorder might affect the person’s behaviors and experiences in these settings.
https://www.youtube.com/watch?v=qiN5kSRxcqM
https://apus.brightspace.com/shared/elf/psyc304/le…
Minimum 300 words answer
Classmate #1:
Hi class,
Two major theories explain and guide research on color vision and the perception of color: the trichromatic theory, also known as the Young-Helmholtz theory, and the opponent-process theory by Ewald Hering. The two approaches are necessary to explain the complexity of the color vision system. Both methods are complementary and apply to different levels of the visual process. For example, the trichromatic theory suggests the operation of color vision at the receptor level. In contrast, the opponent-process theory indicates the operation of color vision at the neural level.
In the mid-1800s, the Young-Helmholtz theory suggests three photoreceptors located in the retina are responsible for achieving the perception of color. Researcher Thomas Young believed the eye’s photoreceptors, cones, were sensitive to “…different wavelengths of light in the visible spectrumâ€. Researcher Hermann von Helmholtz added to Young’s theory that cones were short, medium, or long wavelengths. For example, three photoreceptors are sensitive to certain colors: one is sensitive to blue (short-wavelength), a second is sensitive to green (medium-wavelength), and a third is sensitive to red (long-wavelength). The intensity of the signal detected by the photoreceptors determined the color that was interpreted by the brain. Furthermore, Helmholtz proposed the intensity of the signals detected by the cones determined how colors interpret in the brain. It was discovered later that the brain needs signals from two different kinds of cones for the brain to perceive color. Equally important, through a series of experiments, color-matching studies did discover normal color vision requires three wavelengths of light to produce different colors.
Overall, the trichromatic theory helped explain one part of the process of color vision and perception: both involve the use of the eyes and brain. Also, the theory highlighted the process of how photoreceptors in the eye send signals to the brain. It allows a better understanding of how people perceive things about his or her environment through sight.
According to the opponent-process theory, the perception of color is controlled by the cone receptors to the neural inputs to the brain linked together to form three opposing color pairs: blue-yellow, red-green, and black-white. Due to the colors opposing one another, the cones can detect only one color at a given time. For example, an individual does “…not see greenish-red because the opponent cells only detect one of these colors at a timeâ€. Opponent process theory suggests that the activity of two opponent systems control color perception: a blue-yellow mechanism and a red-green mechanism.
Both theories are necessary to define the complexities of color vision in humans. The trichromatic theory helps to describe how each type of cone receptor senses different wavelengths in illumination. On the other hand, the opponent-process theory helps describe how cones connect to the nerve cells that determines how individuals perceive color in the brain. To put it another way, the trichromatic theory explains how color vision occurs at the receptors, while the opponent-process theory interprets how color vision happens at a neural level. The two theories are applied to different levels of the nervous system.
Lastly, synaesthesia is a neurological disorder which causes the stimulation of one sensory pathway involuntarily leading to the stimulation of another. In other words, the brain processes information in the form of multiple senses at one time. Synaesthesia is a condition many neuroscientists are still studying; therefore, there are many competing theories to explain its causes. After reviewing the video for the forum, it encouraged me to continue researching about the condition to see if any new news has been brought to lights since Jamie Ward was interviewed in 2012. Over 60 types of synaesthesia have been reported since first discovered in the late 19thcentury. For example, I came across a TED Talk explaining a type of synaesthesia: chromesthesia. It is a sound-to-color synaesthesia, and individuals perceive color by nonvisual stimuli. Annie Dickinson stated that “colors cause me to hear sound, and sound cause me to see colorsâ€. Her color that appears while hearing the sound of her own voice is purple. It is like a cloud of color just above her peripheral view. As other people talk, each pitch and tone of voice generates a different color for her. Additionally, objects that make a noise, such as a finger snap, generate a color that comes and goes as quickly as the snap did. Equally important, pitches have similar if not the same colors for her; however, she says the timbre of the sound create different color and intensity.
She stated with accepting humor that at times the disorder makes situations distracting and overwhelming. Some events, such as music concerts, can be relaxing or emotionally powerful; however, other events, such as walking through a loud city, can be extremely stressful. Every day activities such as work, relationships, and leisure time would take some adjustment to get used to seeing colors everywhere, but the disorder is manageable. Once Annie found out not everyone perceives the world in such an extraordinary way, she decided to help others who may be struggling. She is a musician and created music to the colors that are therapeutic to her. The name of the album is titled “Synesthesiaâ€. Lastly, not everyone with this type of synaesthesia see colors the same. In other words, a synesthete sees his or her version of the worlds “truest†colors. I’ve linked the TED talk below.
Cheers,
Kimberly
References
Cafasso, Jacquelyn. (2017, Sept 27). Opponent process theory. Retrieved from https://www.healthline.com/health/opponent-process…
Cherry, Kendra. (2020a). The opponent process theory of color vision: Understanding how we see color. Retrieved from https://www.verywellmind.com/what-is-the-opponent-…
Cherry, Kendra. (2020d). The trichromatic theory of color vision. Retrieved from https://www.verywellmind.com/what-is-the-trichroma…
Classmate #2:
The two major theories that contribute to our understanding of color vision are the trichromatic theory (also known as the Young-Helmholtz theory) and the opponent-process theory. The trichromatic theory was developed based on experiments conducted by Young and Helmholtz where adjustments were made to the intensity of different light sources to determine and gauge the detection of color by the individual eye. Different wavelengths resulted in different colors being identified in the experiment which led to the conclusion that the cones in the eye were responsible for interpreting the wavelength. This theory, however, is unable to explain all components of color vision such as complimentary after images. Opponent-process theory, developed by Ewald Hering, describes a relationship between the cones that allow for the activation of one pair of cones and inhibition of another in order to detect color. What this demonstrates is that no two set of cones will be excited by the same wavelength at the same time to prevent the bleeding of colors such as “reddish greenâ€. This theory is also used to explain the complimentary after image from one color to another. Once a cone in a pair becomes fatigued, the other cone becomes activated resulting in an extension from color to another, for example, from red to yellow. Neither theory fully explains the eye’s ability to process and see color and so it has been suggested that both be used to give a complete and accurate picture of the description of color vision. Synesthesia is when your body perceives multiple sensory perceptions such as upon hearing a person’s name you may also associate a smell or flavor with it. An individual experiencing this disorder would be impacted because they are associating things with multiple senses which may create problematic scenarios. If one of my co-workers or friends cause me to associate the smell of garlic upon seeing them and I do not like garlic, then it would be difficult to interact with them. This would impact and dictate my behavior and dominate my feelings and emotions about an individual.
Classmate #3:
Hi Class,
The senses of animals have evolved to give members of the species an optimum chance for survival.Some animals, such as cats, have a reflective surface on the back of the eye behind the sensory receptors. When light first enters the eye, some light is detected by the sensory receptors. The light not detected by the sensory receptors continues onto the reflective surface at the back of the eye. This light is then reflected outward toward the sensory receptors, providing a second opportunity for detection. This feature produces two results. First, the outward reflection results in the shining of the cat’s eye when a light beam is falls onto it. The second result is that the cat’s night vision efficiency is doubled over that of animals with a nonreflective rear surface, such as humans.
Diurnal animals, such as fish and birds, have all or mostly cones on their retinas. Their superior color vision is a strong advantage during daylight, but they are nearly blind at night. Nocturnal animals, such as rats and bats, have all or mostly rods on their retinas; therefore they have no color vision, but they can see at night. The retinas of humans contain both rods and cones; therefore humans can see things at night and with color during the day.
Most herbivores and prey animals have their eyes placed far to the side of the head to give them a wide range of vision, whereas carnivores, including humans, have their eyes closer together so the overlapping visual fields can provide good depth perception. This is easy to remember using the old saying, “Eyes wide, likes to hide; eyes front, likes to hunt.â€
Inside the Colorful World of Animal Vision
For cat lovers: How Cats See the World
For dog lovers: How Dogs See the World
Minimum 200 words answer