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The Cognitive Neuroscience of Memory and its Relevance to Meme Research Morris Moscovitch Rotman Research Institute and Department of Psychology Baycrest Centre for Geriatric Care University of Toronto. Memory, Social Networks, and Language: Probing the Meme Hypothesis II May 15-17
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The Cognitive Neuroscience of Memory and its Relevance to Meme ResearchMorris MoscovitchRotman Research Institute andDepartment of Psychology Baycrest Centre for Geriatric Care University of Toronto Memory, Social Networks, and Language: Probing the Meme Hypothesis II May 15-17 Victoria College, University of Toronto U of T
Collaborators • Gordon Winocur – Rotman Research Inst., Trent U. • Lynn Nadel – U of Arizona • Carlo Umiltà – U of Padova • Cheryl Grady - Rotman Research Inst. • Brian Levine - Rotman Research Inst. • Morris Freedman – Rotman Research Inst. • Mary Pat McAndrews - Toronto Western • Sandra Black – Sunnybrook • Fuqiang Gao – Sunnybrook • Marilyne Ziegler- University of Toronto • Baycrest Psychologists – Baycrest Psychology
Collaborators • Robyn Westmacott – Hospital for Sick Children • Shayna Rosenbaum – York University and Rotman Research Inst. • Asaf Gilboa – Haifa University • Donna Addis – Harvard University • Lillian Park – Rotman Research Institute • Signy Sheldon – University of Toronto
Meme – A unit of cultural information that can be transmitted and replicated, but also altered in the process.
Memory would seem to be crucial to meme formation and transmission. But what kind of memory? And what kind of memory processes?
Types of Memory: Human Explicit Implicit Episodic Perceptual Conceptual Semantic Motor (procedural)
Dissociation between Episodic and Semantic Memory: Comparison of Two Patients
Remote Memory in Amnesia Patient K.C. • right-handed man with bilateral hippocampal damage from head injury that occurred in 1981, when he was 31 years old • preserved remote semantic memory • cursory evidence of impaired autobiographical episodic memory for all times in his life
A B C KC’s MTL lesions
Mediodorsal thalamic nucleus Cingulate Gyrus Anterior thalamic nucleus Fornix Precommissural Fornix Corpus Callosum Postcommissural Fornix Anterior commissure Septal nuclei Mammillary bodies Alveus of the hippocampus Subiculum Parahippocampal Gyrus Dentate gyrus Pes Hippocampi Amygdala MTL & Related Structures
Semantic Dementia Patient E.L. 65 year-old man, originally from England who worked as a graphic artist at the CBC.
Video of EL being interviewed by Morris Freedman and Morris Moscovitch
Robyn WestmacottShayna RosenbaumSandra BlackMorris FreedmanPeter GaoStefan KohlerLarry LeachSandra PriselacJill RichShayna RosenbaumKathy Stokes Westmacott et al., Neurocase, 2001; Cog. Neuropsychol., 2002, 2004; Neuropsychologia, 2004; Rosenbaum et al, Neuropsychologia, 2005.
Asaf GilboawithShayna Rosenbaumand Amir Poreh and Gordon Winocur Poreh, et al, Neuropsychologia, 2006; Gilboa et al, Hippocampus, 2006.
Mediodorsal thalamic nucleus Cingulate Gyrus Anterior thalamic nucleus Fornix Precommissural Fornix Corpus Callosum Postcommissural Fornix Anterior commissure Septal nuclei Mammillary bodies Alveus of the hippocampus Subiculum Parahippocampal Gyrus Dentate gyrus Pes Hippocampi Amygdala MTL & Related Structures
Patients with fornix lesion • Fornix lesions prevent major hippocampal output while leaving the hippocampus, the rest of MTL, and neocortex intact. • According to our hypothesis that the hippocampus is necessary for recollection, autobiographical memories, whether recent or remote, should be impaired in people with fornix lesions.
The Case of D.A. p.s. • An educated 45-year-old right-handed male. Arrived with a one-month history of excruciating headaches. • Continued working up to the time of his surgery. • An MRI T1 revealed a typical colloid-cyst situated in the anterior part of the IIIrd ventricle, with a mild degree of obstructive hydrocephalus. Colloid cyst
ADF’s Fornix lesions Age-matched control ADF
Other memory-related lesions Basal forebrain Basal ganglia Control ADF Control ADF
Famous Faces and Events TASK YEARS % Correct Famous Faces 1970-80 95 1981-90 96 1991-99 99 Famous Events 1970-80 100 1981-90 95 1991-99 90 Personal Episodes 1970-80 50 1981-90 50 1991-99 40
Reaction to Photos from Significant Personal Events • His Photograph of an Army Camp 73 • Army base, these are T. type tanks. When was the picture taken? Why was it taken? I don’t know. • Group photograph of a graduation ceremony in 1984 • This is the graduation ceremony of some kind of training. I can't remember the ceremony. • Photograph of the circumcision of his son 1987 • Looks at the picture for 5min: This is a circumcision rite. I can see the baby. He didn’t identify his son. • A picture from a trip to Greece 97 • A trip to Turkey (Wife =No). Rhodes? (wife =no) …we went on a train (wife= by a boat).
Summary of Studies of Patients with Hippocampal Complex Lesions Autobiographical Memory: Extensive RA, sometimes even without a temporal gradient
Summary of Studies of Patients with Hippocampal Complex Lesions Autobiographical Memory: Extensive RA, sometimes even without a temporal gradient Semantic Memory: Limited RA, most often with a temporal gradient
Two Components of Episodic Memory(Tulving, 1985) • Recollection: Re-experiencing or reliving a past event in the mind; mental time travel. Characterized by recovering and recreating the context in which a stimulus or event occurred. • Familiarity: A stimulus is recognized or experienced as old, but little or no information is associated about the context in which it was encountered. Resembles semantic memory
Two Components of Episodic Memory(Tulving, 1985) • Recollection: re-experiencing or reliving a past event in the mind; mental time travel. Characterized by recovering and recreating the context in which a stimulus or event occurred. • Familiarity: A stimulus is recognized or experienced as old, but little or no information is associated about the context in which it was encountered. Resembles semantic memory.
Carlo Umiltà & Gordon Winocur A component process of memory based on modules and central systems Moscovitch and Umiltà (1990, 1991); Moscovitch and Winocur (1992); Moscovitch (1992)
A B B B C C A C Hi HIPPOCAMPAL COMPLEX B. Cohesion A. Encoding C. Consolidation Remembering Event Event Event A B C A B C B NEOCORTEX A B C A A B C B Hi Hi HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX
The hippocampus is essential for encoding, retaining, and recovering experiences (i.e. recollection).
The hippocampal complex (or medial temporal lobe) is a ‘stupid’ module that automatically encodes all information that is apprehended consciously, and retrieves information obligatorily in response to a proper, proximal cue.
Strategic Memory Processes:The Frontal Lobe as aWorking-with-Memory Structure(Moscovitch & Winocur, 1992, 2002:Moscovitch, 1992)
A B B B C C A C Hi HIPPOCAMPAL COMPLEX B. Cohesion A. Encoding C. Consolidation Remembering Event Event Event A B C A B C B FRONTAL NEOCORTEX FRONTAL A B C A A B C B Hi Hi HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX HIPPOCAMPAL COMPLEX
The hippocampus is essential for encoding, retaining, and recovering experiences (i.e. recollection) which the prefrontal cortex selects, organizes, monitors, and verifies.
Retrieval from the Hippocampus is also ‘stupid’ (automatic and unorganized), needing the prefrontal cortex to make retrieval ‘intelligent’ (goal-directed).
Summary • Memories are not stored as whole representations of events, but as elements of the event which need to be reconstructed into a coherent narrative. Storage is random. • Memories are represented as beads in a jar which need the prefrontal cortex to string into a necklace. • Narratives are better suited than single items for investigations of reconstructive memory.
Memory is reconstructive: Bartlett, Remembering (1932) “The first notion to get rid of is that memory is primarily reduplicative, or reproductive…re-excitement of individual traces did not look to be in the least what was happening... remembering appears to be far more decisively an affair of construction than one of mere reproduction.” pp204-205.
Implications • Recollection: Detailed re-experiencing of a past event always will depend on the hippocampus, no matter when the event occurred. • Automaticity: A proper cue will reactivate “hippocampal” memories automatically and influence performance even on non-episodic tasks. • Random Storage: Allows for recombination of elements needed for construction of scenarios in many domains, from reconstructing the past, imagining the future, and solving problems.
Implications • Recollection: Detailed re-experiencing of a past event always will depend on the hippocampus, no matter when the event occurred. • Automaticity: A proper cue will reactivate “hippocampal” memories automatically and influence performance even on non-episodic tasks. • Random Storage: Allows for recombination of elements needed for construction of scenarios in many domains, from reconstructing the past, imagining the future, and solving problems.
Implications • Recollection: Detailed re-experiencing of a past event always will depend on the hippocampus, no matter when the event occurred. • Automaticity: A proper cue will reactivate “hippocampal” memories automatically and influence performance even on non-episodic tasks. • Random Storage: Allows for recombination of elements needed for construction of scenarios in many domains, from reconstructing the past, imagining the future, and solving problems.
Implications • Recollection: Detailed re-experiencing of a past event always will depend on the hippocampus, no matter when the event occurred. • Automaticity: A proper cue will reactivate “hippocampal” memories automatically and influence performance even on non-episodic tasks. • Random Storage: Allows for recombination of elements needed for construction of scenarios in many domains, from reconstructing the past, imagining the future, and solving problems.
Asaf GilboaCheryl GradyGordon WinocurMorris Moscovitch Gilboa et al., Cerebral Cortex, 2004.
Remote Autobiographical Memory In normal people, the hippocampus should be much more activated for vivid memories (recollection) than for those that are not (familiarity) no matter how long ago the memory occurred.