Memory Models Evaluate two models or theories of

Memory Models Evaluate two models or theories of one cognitive process (memory) with reference to research studies

Traditional Memory Model Focus on three part process 1. Sensory Memory 2. Short Term Memory 3. Long Term Memory

Traditional Memory Model

What is MEMORY? • Memory – internal record of some prior event or experience – a set of mental processes that… • receives, encodes, stores, organizes, alters, and retrieves information over time

Memory: Processes • Encoding – Converting information into a form in which it will be retained in memory • Storage – Holding information in memory for later use • Retrieval – Recovering information from storage in memory Memory can fail at any of these 3 points

Types of Memory Sensory Memory STM LTM

Overview of Memory Model

Three Stages of Memory • Stage 1 - Sensory Memory is a brief representation of a stimulus while being processed in the sensory system • Stage 2 - Short-Term Memory (STM) is working memory – Limited capacity (7 items) – Duration is about 30 seconds • Stage 3 - Long-Term Memory (LTM) is large capacity and long duration

Overview of Memory Model

Are there cultural differences in memory? • Industrial vs. small tribal societies • Cole et al. , 1968 – Individuals do better on memory tasks that relate to their everyday life • I. S. string of numbers • S. T. S. location of edible berries • Deregowski, 1972 (TIME) Zambia Africa – Rural woman vs. Rural School boys • Better at recalling stories related to WHEN things happen

• Important influence on memory that varies across culture literacy – Pre-literate memories based oral communication – Literate store info many ways • Cultural Models of Memory – Shared cultural concepts • Way to organize knowledge and shape the way people think and remember – Example Bartlett, 1932

Short Term Memory

Overview of Memory Model

Short-Term Memory • Duration: <18 seconds (without rehearsal) – Maintenance Rehearsal – Elaborative Rehearsal • Capacity: 7+-2 (Miller, 1956) • Chunking – 8 6 7 5 3 0 9 3 1 2 vs. – 867 5309 312

Digit-span test, George Miller • Test to measure attention and short-term memory – 7 (+/- 2) is the magic number – Called information bits – 7 avg upper limit, 5 avg lower limit

Encoding in STM • Primarily Auditory / Phonological – Sound-based errors in recall of visually presented letters • More words can be recalled if they are short (fast to be pronounced) • Visual – Letter matching: AA faster than Aa

Recoding • Chunking helps – Modifies or reorganizes – Puts information into units that are recognized by LTM

• How long does STM last? – A very short time, unless… – Maintenance rehearsal • Silently repeating it until it is needed • More rehearsal increases chances of it making it to LTM – Research Peterson & Peterson, 1959 – Subject heard XAR and then after a short pause were told to count backwards in threes from 67 • Memory scores fell to zero No rehearsal • The best way to transfer information to LTM… – Elaborative Rehearsal: connect new and old information

Short-Term Memory Decay

Long Term Memory

Long-Term Memory Where the past lives? • Invasive Research – Electrode used during brain Surgery – Produce vivid memories of events in the past – Penfield, 1957 • Conclusion “continuous strip of movie film, complete with sound track” • No evidence that this is true • Is every memory permanently recorded in memory? – Relatively permanent, perfect memories a myth

Overview of Memory Model

Measuring Memory Recall Recognition Relearning Implicit & Explicit Memory Priming

Organization of LTM • Retrieval Cue – a clue or prompt that helps stimulate recall and retrieval of a stored piece of information from longterm memory – 2 types: 1. Recognition 2. Recall

Memory Measures • Recall is when a general cue is used to search memory • Recognition is when a specific cue (face or name) is matched against LTM • Relearning - situation where person learns material a second time. • Quicker to learn material 2 nd time

Neurological Evidence of Memory Model • Case Study of HM – Damage to the hippocampus • STM works, LTM does not • The impact of Alzheimer’s disease on memory

Organization is the KEY!!! • No specific organization or index • Psychologists theorize about a structure – Memory structure: patterns and association organize memory • Linked ideas help in recall and recognition

Adjustment to the Traditional Memory Model Add different types of Long-Term Memory

SM STM Working Memory LTM Procedural Memory Declarative Memory Semantic Memory Episodic Memory

Skill & Fact Memory • Procedural Memory Skill – Conditioned responses and learned actions – Basic, automatic elements of conditioning, learning and memory • Declarative Memory Fact – Names, faces, words, dates and ideas – Divided into two… • Episodic • Semantic

Semantic Memory • This area almost immune to forgetting – Impersonal facts • Seasons, simple math skills, days of the week • Mental dictionary or encyclopedia

Semantic Memory • Hierarchical Model (Collins & Quillian 1969, 1972) – Hierarchical Organization – Evidence: animal • “A canary is a bird” vs. • “A canary is an animal” – Problem: typicality effects • “A canary is a bird” vs. • “An emu is a bird” emu bird fish canary

Semantic Memory • Spreading Activation Model (Collins & Loftus, 1975) – Modification of Hierarchical Model – Link length = strength animal of association (inverse) bird emu fish canary

Semantic Memory: Schemas o Schema = a model of the world that we use to remember and make sense of things. o an organized unit of knowledge o embodies typical expectations of situations, events, people o has slots that can be filled in with default values • Example: – Stereotypes

• Important influence on memory that varies across culture literacy – Pre-literate memories based oral communication – Literate story info many ways • Cultural Models of Memory – Shared cultural concepts • Way to organize knowledge and shape the way people think and remember – Example Bartlett, 1932

Episodic Memory • Definition – Autobiographical record of personal experiences • Remember – Your last birthday – The first day of school – Homecoming – 9/11

Evaluation of the MSM • Strength – Supported by experimental and neurological studies • But… too simplistic

Limitations 1. Importance of rehearsal is doubted • Just repetition of STM 2. Evidence for a non-linear memory process 3. Evidence that STM has it’s own process and is more complex than just a gateway to LTM 4. LTM has its own types 5. Model does not stress the importance of attention and rehearsal

Memory Models 1. Levels of Processing 2. Loftus’ Reconstructive Model

Levels of Processing Model (LOP) • Craik and Lockhart 1972 – Emphasized the processing NOT the stages • Did not deny the existence – Depth of processing • Three levels of processing – Structural, Phonological, Semantic • Stimuli moves through the levels but can be processed at any level

LOP Questions Answer: Yes Answer: No Level of Processing Is this word upper case? TABLE Table Structural: encodes physical features of stimulus Does this word rhyme with ‘fad’? Mad Train Phonological: delivers information based on how words sound Is salmon a fish? The answer is yes Semantic: extracts meaning of the word salmon

Why is this model important? • Memory is a by-product of perception – Helps us understand perception – Memory is a direct consequence of the way information is perceived and encoded • The deeper level the longer lasting the memory

Craik and Tulving, 1975 • Method: Experiment • Hypothesis: Information processed at a deeper level will be best remembered • Procedure: – Asked participants to answer a number of structural, phonological and semantic questions (not told to memorize) – How did they collect data? • Participants given a list of words (ones they had seen and distracter words) – Memory recogition test

• Results – Words processed at the semantic level were best remembered • Implications – Support LOP – Deeper the processing, the better the memory • Follow-up research found the same for recall tests

Evaluation of LOP 1. No convincing measure of processing depth 2. Theory seems more descriptive than explanatory – EX. Why is semantic better? • • Craik & Tulving said that semantic memory leads to richer memory codes BUT, elaboration is easier in the semantic level

3. Does not address the retrieval stage – Follow-up research Fisher & Craik, 1990 • Information encoded phonologically is easier recalled phonologically but not semantically

Loftus’ Memory Model Theory: Reconstructive Model • Original experience • Experience LTM • New information integrated with original LTM • Recall reconstructive memory