COGNITIVE SCIENCE 17 Can You Remember My Name? Part 1 Jaime A. Pineda, Ph.D.

The Persistence of Memory Dali, 1931

Nature of Learning (synaptic plasticity) Experiences produce changes in the brain (learning) –Perceptual: the ability to identify and categorize objects through our senses (knowing about things); takes place in sensory systems –Motor: the ability to identify and categorize things through our motor systems (knowing what to do) –Stimulus-response: establishing an association between a stimulus perception and a motor response Classical and instrumental conditioning (Hebbian rules/LTP and LTD) –Relational: the relationships among individual stimuli Spatial Episodic Observational

Nature of Memory –Changes in the brain as a result of experiences are retained for a period of time (memories) –How and where are memories stored? Karl Lashley – “memory is not possible” Memories are highly distributed

Memory Organization of experience….what would you do without it? The ability to retain learned information and knowledge of past events and experiences and to be able to retrieve that information. Learn ---- Retain ---- Retrieve Encoding ---- Maintenance ---- Retrieval

Brain Research In the Media…

Common Model of Memory Processes

Time Course of Memory Processes

Memory Processes Sensory Holds information for a fraction of a second Perception and attention Short Term Information remains for about seconds Chunking Rehearsal: Rote and Elaborative Long Term Information remains for days, months, and years Retrieval: More frequent activation of neuron patterns leads to more efficiency

Memory Dichotomies working (short-term) vs. long-term episodic vs. generic explicit vs. implicit procedural (riding a bike) vs. declarative

Types of Memory Working memory: An active system for temporarily storing and manipulating information needed in the execution of complex cognitive tasks (e.g., learning, reasoning, and comprehension) (Baddeley 1986)Baddeley 1986 –The “magic number” (+ 7) for digit span, and more. –Sets a limit on performance, good thing? –“Loading platform” for long term memory

Memory Processes How do memories get from working memory to long term memory storage? –consolidation How do we get them back? –Retrieval –Indexing

What Facilitates Encoding, Consolidation, and Maintenance? Time spent in working memory? rehearsal? Attention and engagement Connection to what we already know Depth of processing (typeface vs. meaning)

What Facilitates Retrieval? Memory cues & context Depth of processing, easier to find Retrieval failure or memory loss? Or forgetting vs. misplacement?

Forgetting We are forgetting all the time. Decay-- metabolic processes undo “memory traces” Displacement-- awake vs. asleep during recall interval, interference

ta-da!

Long Term Memory

Squire & Zola, PNAS, 1996 Squire’s Taxonomy of Memory

Memory Disorders Two main types of Amnesia: Anterograde (“forward”) Amnesia Retrograde (“backwards”) Amnesia

Memory Disorders Anterograde Amnesia Problem: forming new memories post- injury/operation Korsikoff’s Syndrome (chronic alcoholics), Alzheimer’s, patients like H.M. with hippocampal/thalamus damage Can read, write, converse, remember life until damage was done

“Right now, I’m wondering, Have I done or said anything amiss? You see, at this moment everything looks clear to me, but what happened just before? That’s what worries me. It’s like waking from a dream; I just don’t remember.” “…Every day is alone in itself, whatever enjoyment I’ve had, and whatever sorrow I’ve had.” H.M.:

Memory Disorders Retrograde Amnesia: Problem: loss of memory for some period before brain injury ECT and head traumas “Trace consolidation theory” -- memory hasn’t had time to become firmly established, but... several years? Sometimes memories do come back gradually

Memory Disorders What amnesiacs can do: procedural memory tasks (mirror tracing) implicit memory tasks behavioral conditioning

Squire & Zola, PNAS, 1996 Squire’s Taxonomy of Memory

Memory in the Brain Other important brain areas and functions: Pre-frontal cortex—retrieval, working memory Hippocampus & other parts of Thalamus-- consolidation Amygdala--emotional events, fear conditioning Occipital & Temporal Lobes— visual/auditory memories