This weeks lecture was about the hemispheric lateralisation of the human brain. The human brain is divided in two parts, the right and the left hemisphere, connected by the corpus callosum. Both hemisphere structures are identical to each other, however their functions are managed in different terms. It can be identified that the right hemisphere is dealing with judgement and decision making, such as including the age,spatial skills, facial properties and is also involved in contextual language and numerical computation (e.g. estimation and number comparison). Whereas the left hemisphere has been identified as a less inferior part on vocal tasks, on how our speech develops, the processing of speech and grammar/vocabulary. Today knows as Broca's area, that was found in 1861 by Pierre Paul Broca who distinguished after his patients death that because of syphilitic lesions in his left hemisphere the speech production of his patient could never develop. Later theories about the asymmetry of the brain has brought attention towards the brain lateralization that explains why most people are right handed and less are left handed. Studies on split-brain patients have been done which shows that when looking at something, the right hemisphere is active and the information, travels to the left side to pursue language and patients correctly identified what was on the screen. Now when information was presented to the left side of the hemisphere, the information travels to the right side of the brain, which does notch control language, and that proved that patients could not identify the object presented correctly. So it seems like that split-brain patients have two brains, which is for us one brain with both sides different functions, seems for those patients more like two different systems not working together, and can deal with task separately and in different ways.
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| This picture just shows the brain split into two parts and makes clear how the left hand side is responsible for information given on the right and how the right hemisphere deals with processing on the left. |
During the seminar this week we learned about the experiment that was based on Levy, Heller, Banich, & Burton (1983) first experiment, which is now replicated by Rueckert (2005). I did the experiment myself and found that when being presented with the two chimeric faces, i had to press a key for which i thought was younger or older. Without even knowing which one to pick, unconsciously i pressed one key. The truth was that the two chimeric faces were always the identical mirror images of each other. So I gained a 100 % certainty when picking the image, my left hemisphere was working and i am right handed.
