Vision and Blindsight Essay

Throughout the novel Invisible Man, Ralph Ellison works with many different images of blindness and impaired vision and how it relates to perception. These images prove to be fascinating pieces of symbolism that enhance the themes of impression and vision within the novel. From the beginning of the novel when the narrator is blindfolded during the battle royal to the end where Brother Jack's false eye pops out, images of sight and blindness add to the meaning of many scenes and characters. In many of these situations the characters inability to see outwardly often directly parallels their inability to perceive inwardly what is going on in the world around them. Characters like Homer A. Barbee and Brother Jack believe they are all knowing

Gibson’s and Gregory’s theories of perception both suggest that eye-retina is important for perception. The both believe that without eye-retina, a person will not be able to see. This is a common view of both of the theories of perception. The idea is supported by the case of SB. SB was a man who had been blind from birth due to cataracts. When he was 52, he had an operation which restored his sight and hence he could see. Thus, this case has shown the importance of eye-retina for things to be perceived. And therefore, supports both of theories of perception which eye-retina is essential for perception.

According to research, the earliest experimental change blindness is developed from the phenomena such as eye movements and more on working memory. It depends on the personal attention to the images they perceive (MacWhinney, 2001). Although individual have well informed and good memory on whether or not they have perceived an image, they also have poor recalling ability especially on the smaller details that are presented in that image. This is evidently through presentation of the complex pictures that are stimulated

During their 20-year collaboration, Dr. Wiesel and Dr. Hubel also showed that sensory deprivation early in life can permanently alter the brain’s ability to process images, causing vision impairments. Their work was the first to demonstrate the existence of a “critical period” during which the brain must develop crucial connections to the eye.

In Dretske's paper over "what change blindness teaches about consciousness," I think one of the most important ideas pointed out is that what is in question is not what the person thinks they saw or were aware of, but what they actually were aware of. This is really hard to test and get results on accurately.

Oliver Sacks, “A Neurologist’s Notebook, The Mind’s Eye,” is referring to how the blind see things, while not always visually like you and I. But also how their minds perceive things like sounds, since their senses are heightened from losing one of their senses. Sacks, references several instances of different people and their experiences with being blind, but also being able to visually see or imagine things using their mind. They build their own visuals in their minds, one describes being able to “see” their hands on the keyboard as they are typing, as well as not being comfortable in a new environment unless they have a mental picture of the areas appearance. Another described being able to replace the gutters on his house single-handed

Magician’s manipulation of the attentional and perceptual systems allows them to perform ‘magic’ Inattentional blindness is one such condition born from their manipulation. Inattention blindness refers to a lack of detecting stimuli when paying attention to other stimuli. One of the main reasons inattentional blindness occurs is through priming of certain detectors. For example, Mack and Rock’s study supported this theory. In their study subjects, did not expect the fixation target to change, therefore they did not see it.

The ailment of complete blindness is not one that is hard to understand. In this case, there is some damage to the visual system, the eyes, and therefore a person is left without all or most of their sight varying on the type of damage. However, a condition a little less understood and rather fascinating is blindsight, even the phrase itself sounds intriguing. In this particular case, the damage is not in the eyes, but in the primary visual cortex instead. The primary visual cortex is what converts the information we get from sensory stimuli into mental images that our brain perceives. Blindsight is a phenomenon that states that even though there is damage or complete destruction of the striate cortex, a subject can still respond to stimuli even though the

In the abstract the authors Daniel. J. Simmons and Daniel. T. Levin, document that the aim of the study was to determine the detection of change blindness for objects in still images and motion pictures, but their focus was to use people in the real world. In the abstract it is pointed out that the research was divided into two similar experiments only changing specific details in which the surrounding objects, such as; clothing, accessories and their general approach to the randomly selected subjects were changed or modified slightly. They would then continue by asking the participants whether or not they noticed the swap. If yes, they would follow up with asking about what tipped them off to the change and if no, they would retort to explaining what had just occurred by explaining the experiment.

Many have experiences that seem to contradict the belief that, to one degree or another, we perceive everything in view and that our attention merely permits us to see some things in more detail than others. Almost everyone at one time or another has had the experience of looking without seeing and of seeing what is not there. The experience of looking without seeing is most likely to occur during moments of intense concentration or absorption. During these moments, even though our eyes are open and the objects before us are imaged on our retinas, we seem to perceive very little, if anything.” (Mack & Rock,

Research findings suggest that those who suffer damage to their visual cortex following a stroke or accident and lose some or all visual capacity might be able to unconsciously locate and recognize certain stimuli. Weiskrantz, Warrington, Sanders, and Marshall (1974) were one of the first researchers to examine blindsight with a human subject. The original study conducted by Weiskrantz et al. demonstrated that the patient could correctly guess the location of stimuli via eye fixation or finger pointing, depending on the size or location, in areas of blindness. While Weiskrantz’s research set the foundation to understanding blindsight in humans, more research was needed to understand what areas of the brain process stimuli on an unconscious

Unconscious perceptions do not make it past Prinz’s lower level. Lower level perceptions don’t make it past the first filter. The first filter is loosely explained, but cases studied match Prinz’s requirement for availability to the working memory, which only happens past the first filter. Sensory change alone is not sufficient. One instance studied is ‘inattentional blindness’. In inattentional blindness cases participants cannot report on changes in their visual stimuli. These perceptions, though they are not reportable, still appear on brain imaging studies. For example, when you have participants focus on a particular aspect of their stimuli others go unnoticed. One study had the members count how many times a basketball was passed by people wearing white shirts. Meanwhile an all-black gorilla moves through the scene unnoticed. This study showed brain activity without awareness. Research on unilateral neglect is consistent with inattentional blindness.

William Molyneux was an Irish scientist and politician with an interest in optics. During his first year in marriage his wife, Anne, became sick and went blind. This caused him question some of the most basic concepts in optics that have led to even current studies. William began to formulate a question about whether blind people were capable of recognizing objects without touching them if they happened to regain their sight back. “Suppose a man born blind, and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal and roughly of the same size, so as to tell when he felt each of them which is the cube and which the sphere. Suppose then the cube and sphere placed on a table, and the blind man made to see. Could he, by his sight before he touched them, tell which is the globe and which the cube?” William

Our eyes are vital organs because they help us visualize our surroundings. But are our eyes perfect in seeing what’s right in front of us? Sadly I learned in our evolution, nature messed up at one point and gave us blind spots in our eyes. This project shows why we have these blind spots, how to discover them, and how big they are. I researched on how our eyes see things; why when one eye is closed, the other eye sometimes can’t see what’s in front of it. I also found during my research a formula that is used to estimate the size of a human eye’s blind spot. I performed an experiment using Blind Spot Test card I made to verify the existence of blind spots in my eyes. I also collected data

To test this hypothesis, an experiment was carried out to investigate inattentional blindness in a different setting using a similar method. A person dressed as a white mummy was used in lieu of a gorilla. It was predicted that more participants would report seeing the mummy in the visually similar condition (the white tops) rather than the visually different condition (the black