The Visual System in the Blind: A Refined Sensation of Sound and Touch - Term Paper Example

? The Visual System in the Blind: A Refined Sensation of Sound and Touch Blindness is a handicap that can be frightening for some especially for those who are not born with it. Through decades of scholarly research and experiments, several advancements in technology and learning systems has been created and developed to help the blind individuals in living independently. It has been discovered that with absence of vision, the auditory and tactile senses are amplified thus opening a window of opportunity for learning and compensation with the handicap. This study reviews theories and technologies regarding these learning systems that can be utilized in aiding the handicap. It also covers implications of these concepts for psychology. The researcher concluded that selection of mode of instruction or technology must be client based for the learning process to transpire. The Visual System in the Blind: A Refined Sensation of Sound and Touch “Blindness is more feared by the public than any ailment with the exception of cancer and AIDS (Dobelle, 2000).” It is the idea of total darkness, of not being able to see things, and experiencing great difficulty in all activities a man can do that creates a dark cloud of notion on this handicap. Yet this fear has been overcome by the greater population of the blind especially for those who were handicapped earlier in their lives. There are blind individuals who need less or no help from others in performing tasks of daily living and some of them require only the help and companionship of a crane and a dog. It is with ample training that a blind individual acquire the skills in perceiving space and identifying objects (Lessard, et al., 1998). This paper will discuss the theories on the visual system in the blind and the methods or technologies developed based on the cited studies. Perception of space, both physiological and psychological, is one of the main components in independent functioning of a human being. In order generate this perception, the existence of three senses – vision, hearing and touch – are regarded as vital. Absence of one may reduce or diminish one’s physiologic perception of space yet the development of the remaining senses can compensate to create a psychological perception. As Gonzales-Mora (1999) explains: “Vision, hearing, and touch all use comparative processes between the information received in spatially separated sensors, complex neural integration algorithms then allow the three dimensions of our surroundings to be perceived and felt. Therefore, not only light but also sound can be used for carrying spatial information to the brain, and thus, creating the psychological perception of space.” This theory guided experts and researchers to develop and enhance the blind individuals’ sensation of sound and touch in compensation of their vision loss. Since the earlier times, studies were conducted to determine the better way of teaching and create technologies to aid in the blind person’s learning of his surroundings. While engineers and ophthalmologists develop surgical methods and visual prosthesis, psychologists and other scholars focused on the more conservative systems that will aid the handicapped in their daily living. Breakthroughs in Visual Prosthesis In the advent of successful artificial internal organ implants, researchers and experts pave their way in creating a visual prosthesis for the blind. Intracortical microstimulation of the visual cortex was experimented on in 1995 creating some spots of light for the adventitiously blind. They suggest further learning of this modal to prove its feasibility in creating visual prosthesis (Schmidt, et al., 1995). Some experiments have been conducted where digital camera, computer, and associated electronics are connected to the visual cortex of the brain in developing visual prosthesis (Dobelle, 2000). The effectiveness of these optic nerve stimulations were proven in 2005 research of Brelen, et al., where they acclaim the success of the procedure adjunct with ample training. In the present era, several visual prostheses have been developed based on neuronal electrical activity at various locations along the visual nerve pathways within the central nervous system. Prostheses were designed to replace the parts that are damaged and names were coined according to their location such as cortical, subretinal, epiretinal, et cetera. Unfortunately, these have been found reliable only for those who had late blindness such as age-related macular degeneration, tumors, inflammations, ischemia, et cetera but not yet for the congenitally blind (Margalit, et al., 2000). These technological advancements are still at its progressive stage as the perfectness of the procedure and the prosthesis itself are yet to be achieved. Furthermore, as it is a surgical procedure, it poses not only risks for the blind individual but also a favorable expense. Since not all can afford these surgeries and technological advancement, refining of the other senses – hearing and touch – are facilitated instead. Development of Other Senses in the Blind “Visually challenged individuals often compensate for their handicap by developing supra-normal abilities in their remaining sensory systems (Leclerc, et al., 2000).” During early times, two proposals battled on the approval of this concept. Axelrod (1959) justifies that since vision is vital in the development of spatial concepts, a blind person is in a deep end of impair. While Rice (1970) acclaims that absence of vision triggers compensation of the remaining senses therefore enabling them to cultivate an accurate concept of space. Through decades, researchers aim to prove and disprove there hypotheses through variable experiments. Researchers claim that congenitally blind individuals compensate their lack of vision through recruitment of deafferented posterior visual areas in blind individuals to carry out auditory functions (Leclerc, et al., 2000). Supporting this claim is Lessard, et al.’s (1998) discovery that “early-blind subjects can map the auditory environment with equal or better accuracy than sighted subjects.” Moreover, then can accurately locate the sounds unlike the sighted subjects or even the partially blind individuals. This breakthrough answered the longstanding query and concluded that the totally blind individuals have better auditory ability as compensatory mechanism. With this auditory enhancements were aimed to be developed through training as Arno, et al. (1999) suggests that frequent exposure to a certain sound, such as in the conducted training, creates visual imagery and a blind individual’s perception related to the sound. For example, by tapping of cranes, the blind can identify it the floor is made of wood, cement, or dirt by familiarizing himself with the sound emitted. He then can take necessary precaution in walking through them and prevent accidents or injury. It is believed that all surfaces in the surrounding can emit specific sounds that with enough training in familiarization (Leclerc, et al., 2000) can guide the blind in creating visual imagery. Aside from auditory enhancement, tactile stimulation is also utilized in order to help a blind individual cope with his handicap and be able to read or write. This is through the utilization of Braille writing system created by Louis Braille in late 1800s. In Braille, palpable raised dots are created accordingly in a cell creating a pattern to correspond an alphabetical letter. This system was later on developed into higher grading system where words or phrases were formed with fewer characters for ease of writing. Since then, it has been the universal method of written communication among the blind and this can be seen in books, money, elevators, signs, et cetera (American Printing House for the Blind, 2008). In 2007, the Annual Report from the American Printing House for the Blind (2008) reflected that there are approximately 57,696 legally blind children in the United States yet only ten percent of that population use Braille as their primary reading medium. The decline of Braille usage has been known to be caused by budget constraints and technological advancement. Today, several technologies come handy for the blind individual and have been more attractive for the younger users because it is easier to use they are able to communicate with other people who are not trained with Braille. Sadato, et al. (1998) studied the neural activity of the blind individual and compared it those of a sighted individual who are well adept with Braille. They discovered that in a blind person, tactile processing pathways usually linked in the secondary somatosensory area are rerouted to the ventral occipital cortical regions originally reserved for visual shape discrimination thus explaining how this method helps them in recognizing letters and words. In utilizing visual imagery, it was discovered that it is not a necessary component in mental rotation after conducting series of tests with the congenitally blind population. They further claim that the congenitally blind do not have the ability to visually represent forms even with adequate tactile perception (Marmor and Zaback, 2012). Other scholars query if tactile sensation of the tongue can be utilized in visual imagery (Sampaio, 2001) although there were not much evidence to support this claim. With all these discoveries, engineers develops technologies that aids the blind individual to create a visual imagery or perceive a space through a device that captures the emitted sound of the surrounding and transmits it to a headphone for the individual’s perception. The designers of the prototype aim to improve the individual’s immediate knowledge of his interaction with the current environment thereby enhancing one’s sense of independence in mobility (Gonzales-Mora, et al., 1999). The society nowadays also acknowledges the presence of the handicap in the nation making public places and facilities accessible for their needs. Ramps were made in places with flights of stairs, Braille system are used in elevator buttons and other public facilities, and with technology, most touch screens have voice prompts to assist them. Summary and Implications To sum all that transpired in this paper, it can be stated that human had gone a long way of progress in creating a better system and technology to help the blind population. Visual prosthesis has been developed and proven effective for regaining sight of individuals with late blindness such as elderly with degenerative disease and alike. Although there were not yet successful breakthroughs in prosthesis for the congenitally blind, researches are continuing in search for its fulfillment. Alongside this surgical advancement is the enhancement of the auditory and tactile sense of the blind in creating visual imagery. Theories suggest that to compensate with visual loss, hearing and touch are amplified thus creating a window of opportunity for a better and independent life for the handicapped. Scholars agreed that the surfaces of the surrounding emit specific sounds and with enough training one can determine certain things from the other. Use of cranes in tapping the floor and objects guides the blind on what is ahead or what is surrounding him. Advancement of technologies produced a tool that detects these sounds and transfers them to a set of earphones for the blind’s development of visual imagery. Furthermore, tactile sense was also utilized using the Braille system of reading and writing. Although with technological advancements, this system was left behind by computers, tablets, and other gadgets with speaking interface that allows them to communicate with others even with no proper training of the Braille system. This evolvement of theories and technologies poses great implication in the field of psychology in way that it will serve as guide in developing a teaching plan or choosing a modality of instruction for the blind individuals. Several aspects of the person must be taken into account such as the condition of blindness, learning abilities, other senses available, and financial status. Condition of blindness must be recognized since some are totally blind while the others have partial vision or can still perceive light. Furthermore, the learning needs of the congenitally blind are different from those who were blind later in their years. Learning abilities must be assessed initially before intervention to ensure that learning transpired adequately. As supported by cited studies, the congenitally blind are unable to create visual images unlike those who used to see. It is also important to consider the financial capability of the person to guide on which system or technologies one can afford to use. Blind individuals are just like any other human being. They may lack vision but refined senses of hearing and touch allows them to survive in everyday world. This poses a calling for the society to not just sympathize with the blind population but to create a community that will aid them to live independently. Eradicating the stigma may be a long shot yet recognition of the blind’s capabilities and talents or skills may be a start for their acceptance in the society. Directions for future research This study reflects a review on the advancement in systems and technologies used to aid the blind in coping with vision loss. Further researches may include ways on how these methods will be better utilized by the blind individuals. Teaching methods for psychologists may also be inquired on to further help future scholars to develop strategies and systems in educating the blind. References American Printing House for the Blind. (2008). Braille. Retrieved October 8, 2012 from American Printing House for the Blind website, http://www.afb.org/section. aspx?FolderID=2&SectionID=6 Arno, et al. (1998). "Auditory coding of visual patterns for the blind" Perception 28(8) 1013 – 1029. doi: 10.1068/p2607 Axelrod, S. (1959). Effects of Early Blindness. American Foundation for the Blind. Brelen, M., et al. (2005). Creating a meaningful visual perception in blind volunteers by optic nerve stimulation. Journal of Neural Engineering, 2(1), 22. doi:10.1088/1741-2560/2/1/004 Dobelle, M. (2000). Artificial Vision for the Blind by Connecting a Television Camera to the Visual Cortex. American Society for Artificial Internal Organs, 49(1), 3-9. Gonzales-Mora, J. (1999). Development of a new space perception system for blind people, based on the creation of a virtual acoustic space. Engineering Applications of Bio- inspired Artificial Neural Networks, 1607, 321-330. doi: 10.1007/BFb0100499 Leclerc, et al. (2000). Brain functional reorganization in early blind humans revealed by auditory event-related potentials. Neuroreport: Auditory and Vestibular System, 11(3), 545-550. Lessard, et al. (1998). Early-blind human subjects localize sound sources better than sighted subjects. Nature, 398(17), 278-280. Margalit, E., et al. (2002). Retinal Prosthesis for the Blind. Survey of Opthalmology, 47(4), 335- 356. Marmor and Zaback (2012). Mental rotation by the blind: Does mental rotation depend on visual imagery? Journal of Experimental Psychology: Human Perception and Performance, 2(4), 515-521. doi: 10.1037/0096-1523.2.4.515 Rice, C. (1970). Early blindness, early experience and perceptual enhancement. American Foundation for the Blind, 22, 1–22. Sadato, N. (1998). Neural networks for Braille reading by the blind. Brain, 121(7), 1213- 1229. doi: 10.1093/brain/121.7.1213 Sampaio, E. (2001). Brain plasticity: ‘visual’ acuity of blind persons via the tongue. Brain Research, 902(2), 204–207. Schmidt, E. (1995). Feasibility of a visual prosthesis for the blind based on intracortical micro stimulation of the visual cortex. Brain, 119 (2): 507-522. doi: 10.1093/brain/119.2.507 Read More