The structure of long-term memory – Taxonomy of content – Semantic coding – Serial position effect Memory consolidation – How are memories formed – Transfer of information from STM to LTM How can we probe long-term memory? – Explicit memory tests – Implicit memory tests
Specific memories – Autobiographical memory – Mnemonists – Eye-witness testimony – Flashbulb memories Neuroscience of long-term memory – The role of different brain centers for the formation and storage of human memories – What kind of neural processes are the basis for memories
Declarative memory – Things we remember and can talk about – Semantic memory: factual knowledge – Episodic memory: memories of personal experience Non-declarative memory – Procedural memory: How to do things (motor skills, perceptual learning) – Associations (priming, conditioning)
Primacy effect – Less influenced by proactive interference – First items are consolidated into LTM Recency effect – Less influenced by retroactive interference – Items still in WM / STM Modifications of the shape of the curve – Delays in recall will reduce recency effect – Fast presentation rate might interfere with consolidation and reduce primacy effect – Amnestics might show selective impairment of primacy effect
Take 3 minutes and … – Write down the names of all the animals you know – Time yourself and stick to three minutes – Make a mark every 30 seconds so you know how far you have gotten for each half minute
Multimodal storage – LTM by definition stores information in many specialized forms, e.g., visual information, auditory information, procedural information Semantic code – LTM relies heavily on meaning of material – Formation of associations between items in LTM – Higher false alarm rate for semantically related words in recognition tasks – Categorical structure of recall - grouping of similar objects into categories
Ability to think about our cognitive processes – We generally know whether we know something or not, even before we can answer the question – We can think about strategies to get to a particular memory content – We can use memory or mnemonic strategies to remember more information The tip-of-the-tongue phenomenon – Sometimes, we know that we know something, but we cannot get there all the way – Ability to describe the content (e.g., long vs. short name, “sounds like”, associations) – Ability to predict time it will take to retrieve knowledge University of Idaho
General principle – Not all information is retained in LTM – Information has to be consolidated – Integration with existing memories strengthens memory trace Multiple pathways – Content of memories is stored in different locations all across the brain, depending on modality and type of memory – Declarative: stored in cerebral cortex; important role of hippocampus in consolidation – Procedural: Role of cerebellum and basal ganglia
Levels of Processing Theory (Craik & Lockheart, 1972)
Memory storage varies by the type of encoding – The type of processing of to be remembered material determines how much of the material is later recalled – Information that is processed shallowly is not retained as well as information that is processed more deeply Examples – Processing of physical features of words (capitalized?) – Phonological processing (rhyming) – Semantic processing (what is the meaning of word?) – Self-referential processing (how does it related to me?)
Memories are integrated – Memories are integrated into larger structures (schemata) reflecting expectations / beliefs – Memory for meaningful material is best – Memory is biased by expectations and “fills in” missing pieces Examples – Bartlett’s experiments on Schemata (1932) – Cultural framework of autobiographical memories Memory for text – Schemata relevant for construction of understanding in text comprehension University of Idaho
Retrograde amnesia – Loss of memory for events prior to a trauma – Mild retrograde amnesia occurs frequently (e.g., after a concussion) – Retrograde amnesia can diminish over time Anterograde amnesia – Loss of memory for events after a trauma – Best known case: H.M. Effects of amnesia – Affects declarative memory (explicit memory) – Procedural memory and implicit memory can still be intact
