Introduction to Psychology Essay Example | Topics and Well Written Essays - 1500 words

Introduction to Psychology - Essay Example In the quest then for accurate psychic measurement, methods beyond the law must be considered in the interests of more accurate, useful and meaningful psychic measurement. (Fechner, 1912) Psychophysics: It’s Roots in Fechner and Weber As stated, quantitative scientific study of the relation between stimulus and sensation is, more to the point, the manual manipulation of stimulus properties for the purpose of analyzing perceptual processes of reaction to stimuli. Today, the area of modern psychophysics is seen as applying a whole class of methods evolved over time to the empirical study. Methods, for instance, such as absolute threshold can measure such sensory reactions as a subject’s ability to perceive a dim light in a dark room by manipulating the intensity of the dim light. (Zimbardo et al, 2010). While Gescheider (1997) found that modern applications tend to rely heavily on ideal observer analysis and signal detection theory, the work of Ernst Heinrich Weber and Gu stav Theodor Fechner, particularly Fechner as described in his 1912 treatise, Elemente der Psychophysik, remain the basis of new developmental processes. The classical techniques and theory of psychophysics were formulated by Fechner. Applying laws of physics and mathematics, he took Weber’s basic law of measuring the proportional aspects of stimuli a step further, using logarithmic relation between physical and psychological (or perceived) magnitudes—measuring statistically how individuals actually perceived stimuli, or understood it, in relationship to behavior. In considering the significance and practical consequences of access to such information, Zimbardo et al (2010) offer the example of the usefulness of knowing how loud a fire alarm must be for those inside a building to hear it. This particular example speaks to the importance of the hearing system in determining the impact of stimuli; the former example of perceiving a dim light in a dark room speaks to the visual system, which we focus on for the purpose of analyzing its importance to the measurement of stimuli and its effect. The Visual System The visual system as related to sensory reception is perhaps the most studied of all methods. Simplified, the eye gathers light, focuses it, and sends signals to the brain. For instance, Zimbardo et al (2010) found that color is literally created through neural processes of the brain as it interprets information from the original source. Hecht (1924) in his study of visual discrimination similarly found that sensory determination in changes of brightness and in discriminatory thresholds versus original light intensity can be calculated by mathematical formulas. These formulas over time, evolved and were incorporated into the Weber-Fechner law, combining â€Å"Weber’s Law that over a large dynamic range, and for many parameters, the threshold of discrimination between two stimuli increases linearly with stimulus intensity...[and Fechnerà ¢â‚¬â„¢s work] showed [ing] how Weber’s law could be accounted for by postulating that the external stimulus is scaled into a logarithmic internal representation of sensation† (Dehaene, 2003:146). Using information on the magnitude of star light and its ratio to intensity, Fechner (1860) was able to determine the relation between the two, and as suggested by Hecht (1924), thus developed the idea that this relationship produces a human threshold sensation leading to the perception of varying degrees of light.