Case Studies Ramachandran and his research on Phantom Limbs. The case of HM and his 30 second memory

Introduction to phantom limb Ramachandran Who is he? Introduction to phantom limb How does it work?

Phantom Limb People lose body parts and still feel a sensation in the missing limb Chronic phantom pain happens to 2/3 of the patients Can be dangerous because patients commit to extreme methods to remove the pain

The Phantom Limb study Ramachandran had a theory about the so called phantom pain or sensation the missing limb could feel Based the study believing there was a map connected to each body part Once a body part was amputated the sensory inputs where removed Meaning that touching the same side of the face as the missing limb could give sensations or in some cases pain in the missing limb

The Experiment Tested his theory by blindfolding his patients in this case a mid 40’s man whom lost an arm Poked the patient with a stick on various body parts Poked the man in the stomach Poked the man in the cheek , the same side of the face as the missing limb is Absence of the limb the brain rewrote the map previously linked to the arm

Penfield Homunculus

Why did he feel a sensation in his missing arm when he was being touched in his face?

Solution to phantom limb sensation Put the patients in front of a mirror

30 second memory The case of patient HM, one of the most important case studies for the study of memory

Patient HM Suffered from a brain injury at a young age which caused him to have epileptic seizures. Had an operation at age 27 which left him with severe damage to his brain. After that, HM almost completely lost the ability to create new memories, and he was forever stuck as a 27 year old.

A comparison between HM and a normal brain Temporal lobe injury. Medial temporal lobes practically gone. Damaged hippocampus & amygdala. A comparison between HM and a normal brain

Could still remember certain things, with the help of association. Could not create new vivid memories.