Karl Lashley Psychology

Karl Lashley is a well know researcher in the field of psychology, and is most famous for his work on the theory of anti-localization. Lashley had performed many interesting experiments in the past with the intention of proving his theory that localization does not exist within the cortex. It is important to note Lashley does not oppose the idea that there are specialized functional areas of the brain, mainly the sensory functions that are localized. The visual cortex it probably the best example of a specialized area of the brain; Damage to the visual cortex produces a direct proportion to the damage of visual ability in an animal. Lashley performed experiments with the intent on proving that a memory trace, which is the basic building block on cognition and learning could not be located in any one single portion of the cerebral cortex. In one experiment Lashley had trained rats to run through a maze without turning down any dead ended isles. He then created lesions in the cortex of the animal, before initial training in some, and after training in others. The rats with lesions showed impaired ability of learning or retention of learning. This proved that the part of the cortex with lesions was responsible for learning or retention of a learned trait. However the animal was capable of relearning the pathway through the previously mentioned maze even with lesions to the cortex. This evidence supports Lashley’s theory of equipoteniality, or the ability of cells within a functional group to create equivalent functions (Lashly, 1930, pp 1-14). This experiment shows strong evidence that the brain does not have specific areas that only allow learning and cognition for a single task. It shows that there are numerous cells in the brain that can adapt to produce similar functions as in other parts of the brain.

In another experiment Lashley had created a lesion in the striate cortex of a rat. This produced an inability to discriminate the brightness of objects.