memory. encoding, retrieval, and recall types of memory (explicit)(implicit)
TRANSCRIPT
Memory
Encoding, Retrieval, and Recall
Types of Memory
(Explicit) (Implicit)
Context-Dependent Memory (based on experience)
Context-Dependent Memory(based on current state)
Emotional Memory
Motor Memory
Neural Control of Memory
The Hippocampus and Related Structures
Parahippocampal Cortex (Green)Entorhinal Cotrex (Blue)Dentate Gyrus (Purple)CA3 (Purple)CA1 (Purple)Subiculum
Principles of Neuroscience (4th Edition): Chapter 59
Neuronal Signaling Within Hippocampus Predicts Recall vs. Forgetting
Hippocampal Morphology as a Result of Experience
Amnesia
• Retrograde: can’t remember (recall) life before injury
• Anterograde: can’t remember (encode) life after injury– All types of memory affected although these two
distinctions largely refer to episodic memory
• Patient HM was the most rigorously studied amnesiac
Patient HM• In the summer of 1953, Henry Gustav Molaison (1926-2008) underwent brain surgery to
contain epileptic seizures that had become critically debilitating. The intervention brought some relief from convulsions, but these positive results were overshadowed by an astonishing and indelible side effect. Soon after the operation, it became apparent that he could no longer recognize hospital staff, he did not remember the way home, he did not remember newspaper articles he had just read, nor the crossword puzzles he had solved; otherwise, he was completely normal. Since the time of the surgery, more than five decades of scrupulous neuropsychological research examined the nature of patient H.M.'s amnesia which proved to be both persistent and remarkably selective.
• The goal of our project is to provide a window into the brain of the man who helped establish the scientific study of memory and unfailingly forgot the enormously generous contribution he made to medical research.
• Check out “Project HM”: http://thebrainobservatory.ucsd.edu/hm
Brain of an Amnesiac (Large Loss of Hippocampus)
Amnesiac Performance on Implicit Memory Tasks
Squire et al. 1987
Amnesiac Performance on Explicit Memory Tasks
This is data from patient HM
Memory Tests in Non-Humans
• Morris Water
Maze
Hippocampal-Lesioned Mice Perform Poorly on MWM
Hippocampal-Lesioned Mice Perform Poorly on MWM
Neural Control of Memory
Medial Temporal Lobe Striatum Neocortex
Dementia
• It’s a syndrome, not a disease
• Multiple types of dementia across a spectrum of severity– Alzheimer’s, HIV-induced,
Parkinson’s, Rasmussen’s encephalitis, chronic traumatic brain injury, to name a few
Alzheimer’s DiseaseNeuronal Identifier #1: Neurofibrillary Tangles
Alzheimer’s DiseaseNeuronal Identifier #2: Beta-amyloid Plaques