Memory Flashcards
Explain the Atkinson-Shiffrin model.
Sensory store - modality specific info, help for a few ms.
Short-term store - info held for a few secs. Can be extended via rehearsal. Limited capacity.
Long-term store - nearly limitless in duration + capacity. Includes; semantic, episodic, procedural and prospective memory.
Explain Baddeley’s working memory model (STM).
All info processed by the central executive.
Visuospatial sketchpad, episodic buffer, phonological loop - fluid systems.
Visual semantics, episodic LTM, language - crystallised systems.
What is the average visual and digit span STM capacity?
Visual: 4 items. Limit to storage capacity. When adding more items - capacity doesn’t increase.
Digit span: 7 ±2 items.
Where do neurons spike during retention of spatial locations (STM)? What about during a delay phase of a delayed match-to-sample task?
Retention - Parietal cortex.
Spike - increased number of APs.
Delay - Prefrontal.
What are the neural bases of visual-spatial STM?
Intraparietal sulcus - transient storage of visuospatial information.
Inferior-occipital areas - visual processing. Not storage.
Medial frontal brain areas - monitoring of task. Not storage.
What are the neural bases of verbal STM?
Large LH activity.
Broca’s area - rehearsal.
BA 40 - storage.
Where does chunking take place?
Prefrontal cortex.
What is the role of the prefrontal cortex?
Chunking.
Lie (2006) - Wisconsin car sorting test, fMRI study.
Medial + dorsolateral prefrontal cortex. Increasing activity with increasing task difficulty.
Central executive in PFC.
STM + CE = working memory.
PFC involved in working memory.
Where is STM mostly stored?
Posterior areas.
What is non-declarative memory (LTM)?
Procedural + classical conditioning.
What does declarative memory split into (LTM)?
Semantic (facts) + episodic (events).
Where are declarative memories stored?
Volume of brain tissue destroyed correlated with memory performance - independent of location.
Lashley - no specific memory area. Whole brain involve in learning + memory. Study invalid.
Conclusion: memory not unitary. Different types of memory = different brain structures. Heterogenous memory. Memories are likely to be stored in brain areas involved in original sensory processing. What pathway + where pathway.
Which case study goes against Lashley’s principle?
Philipp - RH removed. Normal life - no memory deficits.
Lashley’s study - used worst possible laboratory task to study memory. Maze running involves many senses. Lashley only eliminated one sense.
Where are memories stored?
Inferior temporal cortex. Hippocampus.
Neurons in ITC can become tuned to a certain face! Spiking neurons correlates with memory trace.
Single neurons develops a preference to a particular object.
People with expertise in a certain area = stronger ITC response. Is this correlate of memory traces or visual perception though?
Explain the relationship between the hippocampus and episodic memory.
Stronger activity of hippo and parahippocampal gyrus when recollecting material.
If remembered correctly = higher activity.