Declarative encoding
Forming new episodic and semantic traces.
Darker cells mean a higher score for this topic on that metric.
Research80
Awareness55
Complexity60
Clinical weight50
Plasticity45
Live debate40
LessMore
Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
Who was patient H.M. in Milner story?
Henry Molaison (1953 bilateral medial temporal surgery). He lost new episodic memory while retaining skills — the dissociation that remade memory science.
What year marks Scoville and Milner report?
1957. The paper tied hippocampal removal to anterograde amnesia without collapsing language or IQ in the teaching summary.
What did mirror-tracing show?
H.M. improved at mirror-tracing across days without remembering the sessions — procedural skill without episodic recall.
Is this a clinical guide to epilepsy surgery?
No. History of published cognitive neuroscience. Not medical advice, diagnosis, or surgical counsel.
Where did Milner work for decades?
Montreal Neurological Institute — careful testing, frontal-lobe work, and mentorship alongside the H.M. archive.
What atlas regions pair with her lesson?
Hippocampus (memory index) and frontal lobes (control). Use dual-view; do not invent a personal lesion map.
Functionally, Milner’s programme showed how to turn patient performance into theory: match tasks to candidate systems and look for clean dissociations.
Network percentages below are editorial teaching emphasis for systems highlighted by her legacy, not a literal BOLD map of Milner herself.
Processes
Anterograde amnesia testing
Probe failure to retain post-lesion events.
Remote memory sampling
Ask what of the past survives.
Procedural skill acquisition
Measure improvement without episodic recall.
Frontal strategy assessment
Test planning and card-sorting style control.
Dissociation logic
Infer systems when one capacity fails and another holds.
Networks
Medial temporal declarative88
Neocortical remote stores70
Frontostriatal procedural65
Language networks (intact)60
Working-memory buffers45
Medial temporal declarative
Encoding new episodes — H.M.’s core deficit.
Neocortical remote stores
Consolidated past that can outlast MTL surgery.
Frontostriatal procedural
Skill learning preserved in classic demonstrations.
Language networks (intact)
Speech and comprehension largely spared in H.M.
Working-memory buffers
Short spans can remain while long-term encoding fails.
Examples
Meeting someone anew each day
Anterograde gap after MTL resection.
Getting better at mirror drawing
Skill up without episodic session memory.
Recalling childhood scenes
Remote stores can survive when consolidation finished.
Frontal sorting errors
Strategy failures distinct from MTL amnesia.
Compare with Memory, Hippocampus and Plasticity pages.
Sources & research
- Loss of recent memory after bilateral hippocampal lesionsLandmark H.M. memory loss report.DOI
- The legacy of patient H.M. for neuroscienceLegacy review of patient H.M.DOI
- Cognitive neuroscience and the study of memoryCognitive neuroscience of memory synthesis.DOI
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