Question

What does it mean to say the left hemisphere is the "Interpreter." Fully describe and explain the study that shows the left hemisphere is the "interpreter" compaired to the right hemisphere. (what are the variables? how is the right hemisphere different than the left?) Trace the path of the information from the stimuli t the hemisphere. How does the study show the left hemisphere is the interpreter?

Answer 1

The left and right hemispheres of the brain may seem like mirror images of each other superficially, however, they are very different in their functioning which is known as lateralization of functions. The two hemispheres perform different functions and together they are capable of executing complex actions. Corpus Callosum, is a band of nerve fibers which connects the two hemispheres of the brain. It passes between the two hemispheres, through which they communicate. If the Corpus Callosum is cut there's no communication between the two hemispheres.

Let us assume that the two hemispheres are no longer connected, and a subject is seated with a special set of glasses and is presented with a visual stimulus on the right visual field which is a picture of a baseball, then, he is verbally going to answer what he sees. The response made by him is that he sees a baseball. The way our visual system is constructed, the right visual field stimulates the left hemisphere, which controls speech. Thus, he was able to answer what he could see, verbally. Also considering if a picture of violin is flashed to the same subject on the left visual field, the subject would not be able to name it. He would instead mimic what he sees through actions or gestures but he would not be able to name it. The left visual field stimulates the right hemisphere, which controls our motor activities. The left hemisphere is the 'interpreter'. However, both the hemispheres need to communicate with each other for a person to perform functions normally. If they were not severed, the subject would have answered what he sees on the screen, a baseball and a violin.

Left Hemisphere of the brain is responsible in producing and comprehending language, which makes it the 'Interpreter'. Different functions are found in different areas of the brain but in order to achieve complex functions like speaking, comprehending or reading, it requires the various areas of the cortex working together. Movements required in speaking or producing a certain language involves the motor cortex which controls the lips, tongue and the jaw to function properly in order to make crisp and proper speech. The Right Hemisphere is responsible for the above motor functioning.

However, from the above experiment it can be concluded that the Left Hemisphere is the 'Interpreter'.