Brain case study: Patient HM

Fundamental learnings from HM cases study --> The memory systems in the brain constitute a highly specialized and complex system. --> The hippocampus and the parahippocampal areas play a critical role in converting memories of experiences from short-term memory to .

Henry Gustav Molaison — known through most of his life only as H. It is a highly precise surgical procedure, informed by advanced brain imaging and a detailed knowledge of the brain. Regarding the underlying neural structures, Corkin argues that Molaison's ability to acquire the floor plan is due to partly intact structures of his spatial processing network e. On December 4, , Annese's group acquired brain slices, with only two damaged slices and 16 potentially problematic slices.

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Over 55 years he became the most studied medical case in history, and on death his brain was dissected into slices and digitized as a three-dimensional brain map, preserving his tragically.
View our selection of latest mobile accessories. Choose from colourful cases, stylish headphones and playful mobile covers. Shop your mobile cases online.
Patient HM was an important case study for neurological research in the 20th century. Holly Story discovers how his life and his unique condition helped scientists to understand the brain Henry Gustav Molaison, known to the world as ‘Patient HM’, has been called .
Over 55 years he became the most studied medical case in history, and on death his brain was dissected into slices and digitized as a three-dimensional brain map, preserving his tragically.

Over 55 years he became the most studied medical case in history, and on death his brain was dissected into slices and digitized as a three-dimensional brain map, preserving his tragically.

It was also well-suited to research: In Dr Milner published the first results of her formal testing. This paper became one of the most cited papers in neuroscience. The fact that Henry suffered one kind of amnesia so acutely as a result of damage to one part of his brain, and yet retained his intellectual abilities, prompted researchers to reassess this assumption.

It was clear that the temporal lobe must be vital for memory function. It would take years of study using animal models and great advancements in technology before the medial lobe memory system was fully understood, but Patient HM helped to lay the foundations of this vital research.

In Milner published the results of a series of trials that she had conducted with Henry, which revealed one of her most notable discoveries. In the trials she had asked Patient HM to draw a line between two outlines of a five-pointed star while watching his hand and the page in a mirror. Milner asked Henry to repeat this task several times on several different occasions. Each time Henry did not remember having completed the task before, yet his performance improved.

This demonstrated that, although he was not conscious of it, Henry was able to learn new motor skills by repeated practice. From these trials Milner was able to conclude that this form of memory, called motor learning, must be distinct from the system of memory that records new facts, faces and experiences. Henry was always supportive of the research that he enabled and said he was glad that he could be of help to others.

In he gave his consent for his brain to be used in further research after his death, and this led to the establishment of Project HM. When Henry died in , his brain was removed and scanned repeatedly using MRI.

It was then sent to the Brain Observatory at the University of California. In scientists sliced the brain into 2, pieces, each just 70 micrometres millionths of a metre thick. Their aim was to create stained histological slides that would enable researchers to map the brain in new ways and connect individual anatomical structures with specific functions. The dissection took 53 hours to complete and five blades were used in the process. Each slice was photographed and the images were posted online, and the whole procedure was streamed live on the internet.

Henry and his doctors could not have imagined the technology that would eventually be used to preserve his brain, nor could they have predicted the advances in neuroscience that would result from his operation, his condition and his generosity.

To read about how resection operations are done today and to hear a surgeon talk about how technology helps him operate, read our interview with Conor Mallucci. This is a false-colour PET scan highlighting the limbic areas of the brain. The highlighted area shows the location of receptors for a certain type of neurotransmitter that is involved in memory, learning, emotional processes and addiction. This image is looking down on the top of the head with the eyes facing the bottom edge.

This finding provides evidence that working memory does not rely on medial temporal structures. It further supports the general distinction between short-term and long-term stores of memory. Molaison's largely intact word retrieval provides evidence that lexical memory is independent of the medial temporal structures.

In addition to his intact working memory and intellectual abilities, studies of Molaison's ability to acquire new motor skills contributed to a demonstrated preserved motor learning Corkin, In a study conducted by Milner in the early s, Molaison acquired the new skill of drawing a figure by looking at its reflection in a mirror Corkin, Further evidence for intact motor learning was provided in a study carried out by Corkin In this study, Molaison was tested on three motor learning tasks and demonstrated full motor learning abilities in all of them.

Experiments involving repetition priming underscored Molaison's ability to acquire implicit non-conscious memories, in contrast to his inability to acquire new explicit semantic and episodic memories Corkin, These findings provide evidence that memory of skills and repetition priming rely on different neural structures than memories of episodes and facts; whereas procedural memory and repetition priming do not rely on the medial temporal structures removed from Molaison, semantic and episodic memory do cf.

The dissociation of Molaison's implicit and explicit learning abilities along their underlying neural structures has served as an important contribution to our understanding of human memory: According to Corkin , studies of Molaison's memory abilities have also provided insights regarding the neural structures responsible for spatial memory and processing of spatial information. Despite his general inability to form new episodic or factual long-term memories, as well as his heavy impairment on certain spatial memory tests, Molaison was able to draw a quite detailed map of the topographical layout of his residence.

This finding is remarkable since Molaison had moved to the house five years after his surgery and hence, given his severe anterograde amnesia and insights from other cases, the common expectation was that the acquisition of topographical memories would have been impaired as well. Regarding the underlying neural structures, Corkin argues that Molaison's ability to acquire the floor plan is due to partly intact structures of his spatial processing network e.

In addition to his topographical memory , Molaison showed some learning in a picture memorization-recognition task, as well as in a famous faces recognition test, but in the latter only when he was provided with a phonemic cue. Molaison's positive performance in the picture recognition task might be due to spared parts of his ventral perirhinal cortex. Furthermore, Corkin argues that despite Molaison's general inability to form new declarative memories, he seemed to be able to acquire small and impoverished pieces of information regarding public life e.

These findings underscore the importance of Molaison's spared extrahippocampal sites in semantic and recognition memory and enhance our understanding of the interrelations between the different medial temporal lobe structures.

This is evidence that the older childhood memories do not rely on the medial temporal lobe , whereas the more recent long-term memories seem to do so [16]. On August 7, , a New York Times article written by Luke Dittrich raised a number of concerns about how Molaison's data and consent process had been conducted by the primary scientist investigating him, Suzanne Corkin. The article suggested that Dr. Corkin had destroyed research documents and data, and failed to obtain consent from Molaison's closest living kin.

Corkin, where she said she had destroyed large amounts of data. From Wikipedia, the free encyclopedia. Redirected from HM patient. Henry Molaison Molaison in before his surgery. Henry Gustav Molaison — known through most of his life only as H. After repeated trials on the same puzzles, the man who lost his memory learned to fill in the right answers. In , he underwent an experimental brain operation in Hartford to correct a seizure disorder, only to emerge from it fundamentally and irreparably changed.

He developed a syndrome neurologists call profound amnesia. He had lost the ability to form new declarative memories. Archived from the original on The New York Times. Retrieved August 4, Retrieved 25 August The Institute for Brain and Society. Atlas available without charge on request. Clinical course and experimental findings in H. Journal of Neurology, Neurosurgery, and Psychiatry. Near the end of his life he kept a crossword book and pen with him always, in a basket attached to his walker.

Gilberto; Johnson, Keith A. Findings from Magnetic Resonance Imaging". The Journal of Neuroscience. Interview with Jacopo Annese". Upper Saddle River, NJ: Retrieved March 26, Department of Brain and Cognitive Sciences. Brain and Cognitive Sciences. Retrieved 12 August Archived from the original PDF on Systems versus binding theory accounts". Language and Cognitive Processes. Findings from magnetic resonance imaging". The Journal of Neuroscience Textbooks [ edit ] M. Mind and Brain 1st ed.

Fundamentals of human neuropsychology 4th ed.

Henry Gustav Molaison (February 26, – December 2, ), known widely as H.M., was an American memory disorder patient who had a bilateral medial temporal lobectomy to surgically resect the anterior two thirds of his hippocampi, parahippocampal cortices, entorhinal cortices, piriform cortices, and amygdalae in an attempt to cure his. View our selection of latest mobile accessories. Choose from colourful cases, stylish headphones and playful mobile covers. Shop your mobile cases online. Patient HM was an important case study for neurological research in the 20th century. Holly Story discovers how his life and his unique condition helped scientists to understand the brain Henry Gustav Molaison, known to the world as ‘Patient HM’, has been called .