L VIII, C IX Flashcards
2 subdivisions of episodic memory:
Recollection, familiarity
Familiarity and recollection in:
Dorsal parietal cortex
Ventral parietal cortex
Dorsal parietal cortex = frequent activation for familiarity, low-confidence recognition.
Ventral parietal cortex = frequent activation for recollection, high-confidence recognition.
Attention to memory (AtoM) model extends distinction between dorsal and ventral memory attention systems:
Dorsal parietal cortex = top-down processes, memory search and monitoring.
Ventral parietal cortex = bottom-up processes, recovering salient episodic details.
Developmental amnesia in children due to hypoxia:
Smaller hippocampus (BA34) than healthy controls, semantic memory appears to be intact.
Retrieval of recent memories:
HPC index receives information from sensory cortices, puts it together.
Retrieval of remote memories:
HPC index no longer needed, because stable sensory network connections have been established.
Place cells =
Spatially modulated neurons in HPC (BA34) that fire in specific locations - spatial encoding.
Cognitive map theory (O’Keefe & Nadel) =
Main role HPC (BA34) is mediate memory for spatial relations among objects in environments.
Evidence is place cells in HPC.
Relational memory theory (Eichenbaum & Cohen) =
HPC (BA34) mediates memory for new associations in general, not just spatial.
Episodic memory theory =
HPC (BA34) is critical for episodic memory but not semantic.
Evidence: hippocampal damage affects episodic more than semantic.
Semantic dementia (SD) often caused by…
Damage to anterior temporal lobe (ATL/BA38).
Starts with anomia, later severe loss of knowledge of language.
PFC regions mediate … processes.
Posterior parietal regions mediate … processes.
PFC - semantic/linguistic
Posterior parietal - attentional control
HPC associated with …, not …
Recollection, not familiarity.
Two-process theory =
HPC/BA34 is slow-processing, relational and spatial.
Perirhinal cortex/BA35 is fast-processing, item-based, familiarity.
Three-process theory =
Perirhinal cortex/BA35 for memory of objects.
Parahippocampal cortex/BA27 for memory of spatial layouts.
HPC/BA34 integrates above, domain-general relational memory.
2 distinctions in semantic knowledge:
Sensory/functional
Domain-specific
Sensory/functional theory =
Conceptual knowledge is organized by sensory/functional properties of objects.
Evidence: processing words activates associated sensory regions, e.g., reading ‘kick’ activates motor cortex.
Domain-specific theory =
Conceptual knowledge is organized by semantic categories.
Evidence: brain-damaged patients showed impairment in specific semantic categories.
Amodal =
Can be generated from any modality to generate behavior in any modality.
Convergent architecture =
Hub catches deep structure to generalize conceptually, even if sensory modalities differ.
Distributed-only view =
Abstract semantic knowledge is mediated by the same network as concrete semantic knowledge.
During encoding phase, activation in …
Activation is dependent on whether words are later remembered/forgotten.
… hemisphere more activated when remembered.
This is the…
Inferior frontal gyrus (IFG/BA45)
Left IFG more activated when remembered.
Subsequent memory effect (SME)
SMEs tend to occur in … hemisphere for verbal stimuli, and … for visual stimuli.
Left
Bilateral
SMEs in anterior left IFG
SMEs in posterior left IFG
Anterior left IFG (BA45) - semantic processing
Posterior left IFG (BA45) - phonological processing
Dorsal parietal regions - greater activity in … trials, thus … SME.
Ventral parietal regions - greater activity in … trials, thus … SME.
Remembered/forgotten - positive/negative
Dorsal - remembered, positive
Ventral, forgotten, negative
IFG/BA45:
MFG/BA46
IFG/BA45 - encoding
MFG/BA46 - retrieval
Source error often in…
Frontal lobe
Synaptic consolidation =
Within minutes/hours after encoding - changes in gene expression, protein synthesis, etc.
System consolidation =
Within days/months/years after encoding - changes in neural connectivity, brain regions, etc.
Confabulations are often caused by lesions in … and …
Ventromedial and orbitofrontal cortex
OFC (BA11)
Damage to MTL (BA21/BA37):
Damage to HPC (BA34):
Damage to ATL (BA38):
MTL: declarative memory
HPC: episodic memory
ATL: semantic memory
BA38
Anterior temporal lobe
Temporal pole
BA34
Hippocampus
BA21/BA37
Medial temporal lobe
BA21 = medial temporal gyrus
BA37 = occipital temporal cortex
