Psychophysics Cace

Written Assignment 3

Yumiko Cesar

Thomas Edison State College

January, 2015

PSY-101-OL010

Abstract

We will discuss what psychophysics is and who were the people that pioneered this new way of looking at everything in our world. We will also summarize the workings of the visual system, describe the attentional processes, and touch base on classical conditioning.        

Written Assignment 3

When it comes to sensing the world around us, there are many things that are going on in our brains that we are not even conscientiously aware of. Everything that will be elaborated on in the coming paragraphs are all related to each other in the nigger scheme of things, even though they do not appear to be as such. The first topic at hand is what is psychophysics and who came up with the whole idea or concept of it. Secondly, we will elaborate on the visual system. The attentional processes will also be explained and then we will finish everything off with what classical conditioning is.

Psychophysics

Psychophysics. This term sounds a little scary at first, but when it is broken down, it is rather simple to understand and should not be feared, but revered. Psychophysics is defined as the quantitative branch of the study of perception, examining the relations between observed stimuli and responses and the reasons for those relations. Basically, how we perceive what is around us, and the observations of what we physically feel and how we physically respond to it.

One of the major key players of making psychophysics what it is today, was a German physicist named Gustav Theodor Fechner. Despite being educated in biological science, he sought answers in mathematics and physics. It was not until his vision was severely compromised in a way that was painful that he began to really pave the way for psychophysics.  In his work, Elemente der Psychophysik, Fechner hypothesized that both mind and body are different sides of one reality, even though they appear to be completely separate from each other. He also developed experimental procedures, which we still use today, to measure sensations in relation to the physical magnitude of stimuli. He also developed a formula based off the work of our next subject’s main focus of the just noticeable difference. (Gustav Theodor Fechner, 2015)

Our next subject is also a serious contender is psychophysics. His name is Ernst Heinrich Weber. German descent is a common trait between Weber and Fechner, however, Weber was an anatomist and physiologist whose fundamental studies of the sense of touch gave way to the concept of the just noticeable difference JSD). This concept of JSD states that the smallest difference perceivable between two similar stimuli, for example, two straight lines that have a measure of 1mm in difference. The difference is slight, but it is just noticeable. This concept is fundamental in psychology and pshyiology. Weber has been known for many studies, but the most famous of all is for his work on the sensory response to weight, temperature, and pressure. Weber came to the conclusion that there is a certain point of sensation that had to be passed before an increase in the intensity of any stimulus could be noticed, and the amount of increase necessary to create sensation was the JSD. In other words, if someone is pinching you, there is a certain amount of pressure that needs to be applied before your brain gives the signal that it is too much to handle, the difference from a little pinch to an unbearable one, in this case, would be the JSD. Weber’s observations were eventually expressed into an equation formulated by Fechner and is now called “Weber’s Law.” (Gustav Theodor Fechner, 2015)