Memory formation memories. memories. in half. surgery, to learn one of shock. pick up new. The hippocampus helps support the formation of some types of long-term. People with damage to the hippocampus have troubles encoding new. One of the effect treatments for epilepsy is to cut the corpus callosum. A particular individual, hm, had his hippocampus damaged during such a and was unable to learn new memories. However, it was possible for hm how to perform new tasks by rote. He was given the task to pick up two metallic objects, one was electrified and would provide a small. Over the course of several such incidents (month), hm "learned" not the one that would shock him. Hm"s condition is called anterograde amnesia -- the inability to form long-term episodic or factual memories. Retrograde amnesia is of the kind that previous memories are lost. When the motor cortex is stimilated with electrodes, the sensations of limbs being moved results.