He was widely studied from late 1957 until his death in 2008. The brain atlas constructed was made publicly available in 2014. This accident was initially reported to have occurred at age nine, but was corrected by the patient’s mother at a later stage. On September 1, 1953, at cognitive psychology smith kosslyn pdf age of 27, Molaison’s bilateral medial temporal lobe resection included the removal of the hippocampal formation and adjacent structures, including most of the amygdaloid complex and entorhinal cortex.
11 years before, meaning that his amnesia was temporally graded. Near the end of his life, Molaison regularly filled in crossword puzzles. He was able to fill in answers to clues that referred to pre-1953 knowledge. For post-1953 information he was able to modify old memories with new information. He died on December 2, 2008.
Molaison was influential not only for the knowledge he provided about memory impairment and amnesia, but also because it was thought his exact brain surgery allowed a good understanding of how particular areas of the brain may be linked to specific processes hypothesized to occur in memory formation. Similarly, his ability to recall long-term memories that existed well before his surgery, but inability to create new long-term memories, suggests that encoding and retrieval of long-term memory information may also be mediated by distinct systems. Nevertheless, imaging of Molaison’s brain in the late 1990s revealed the extent of damage was more widespread than previous theories had accounted for, making it very hard to identify any one particular region or even isolated set of regions that were responsible for HM’s deficits. The study of Molaison revolutionized the understanding of the organization of human memory. In the following, some of the major insights are outlined. Molaison’s historical memory impairment at cellular resolution. On December 4, 2009, Annese’s group acquired 2401 brain slices with only two damaged slices and 16 potentially problematic slices.
The digital 3D reconstruction of his brain was finished at the beginning of 2014. The researchers found, to their surprise, that half of H. 1953 surgery, which has deep implications on past and future interpretations of H. These findings suggest revisiting raw data from behavioral testing. A discrete lesion was discovered in the pre-frontal cortex that was never suspected. The 3D virtual model of the brain allowed the dynamics of the surgery to be reconstructed, and found that the brain damage above the left orbit could well have been created by Dr. Scoville when he lifted the frontal lobe to reach into the medial temporal lobes.
The article also describes the general neuropathological state of the brain via multiple imaging modalities. Since HM did not show any memory impairment before the surgery, the removal of the medial temporal lobes can be held responsible for his memory disorder. However, for sentence-level language comprehension and production, Molaison exhibited the same deficits and sparing as in memory. Molaison was able to remember information over short intervals of time. This finding provides evidence that working memory does not rely on medial temporal structures. Molaison’s largely intact word retrieval provides evidence that lexical memory is independent of the medial temporal structures . In this study, Molaison was tested on three motor learning tasks and demonstrated full motor learning abilities in all of them.