Lecture Overview The Nature of Memory Forgetting Biological Bases of Memory ©John Wiley & Sons, Inc. 2010

The Nature of Memory Memory: internal record or representation of some prior event or experience Memory is also a constructive process, in which we actively organize & shape information as it is processed, stored, & retrieved. ©John Wiley & Sons, Inc. 2010

Nature of Memory: Memory Models ©John Wiley & Sons, Inc. 2010

Information Processing Model ©John Wiley & Sons, Inc. 2010

Information Processing Model— Important Definitions Encoding: processing information into the memory system (acoustic, visual, semantic) selective attention divided attention levels of processing automatic vs controlled processing ©John Wiley & Sons, Inc. 2010

Information Processing Model— Important Definitions Storage: retaining information over time Sensory Short term Memory Long term Memory Retrieval: recovering stored information (recall, recognition, priming; serial position effect) ©John Wiley & Sons, Inc. 2010

Types of Long-term Memory Episodic memory (specific events: did I use cream rinse this morning?) Semantic memory (knowledge of the world: what is cream rinse, why use it?) Procedural memory (skill memory, specific tasks: how do I wash my hair?) ©John Wiley & Sons, Inc. 2010

Types of memory (cont.) Explicit memory: deliberately try to remember something *Implicit memory: unintentional influence of remembered stimuli ©John Wiley & Sons, Inc. 2010

Three-Stage Memory Model ©John Wiley & Sons, Inc. 2010

The Nature of Memory— Three Stage Memory Model Sensory Memory: first memory stage, which briefly preserves a relatively exact replica of sensory information – Sensory memory has a large capacity but information only lasts a few seconds. – Selected information is sent on to short-term memory (STM). ©John Wiley & Sons, Inc. 2010

Two Forms of Sensory Memory ©John Wiley & Sons, Inc. 2010

Short-Term Memory (STM) Short-Term Memory (STM): second memory stage, which temporarily stores sensory information & decides whether to send it on to long-term memory (LTM) – Holds 5-9 items for about 30 seconds, but duration improves with maintenance rehearsal (repeat the item over and over) – Capacity increased with chunking ©John Wiley & Sons, Inc. 2010

Three Stage Memory Model: STM: also called working memory, reflecting that it’s more than just a passive, temporary holding area Three parts of working memory: Visuo-spatial sketchpad central executive phonological loop ©John Wiley & Sons, Inc. 2010

Long-Term Memory (LTM) Long-Term Memory (LTM): third stage of memory with relatively permanent memory storage & a virtually limitless capacity ©John Wiley & Sons, Inc. 2010

Systems and Subsystems of LTM ©John Wiley & Sons, Inc. 2010

Improving LTM: Overcoming the Serial- Position Effect Serial-Position Effect: remembering material at the beginning & end of a list better than material in the middle ©John Wiley & Sons, Inc. 2010

Improving LTM: Understanding Recognition Vs. Recall Research shows people are better at recognizing photos of previous high school classmates than recalling their names. ©John Wiley & Sons, Inc. 2010

A Test for Recall: Can You Name Santa’s Eight Reindeers? ©John Wiley & Sons, Inc. 2010

Now Try Recognizing the Names (Need Help? Answers Appear on Next Slide) A) Rudolph B) Dancer C) Cupid D) Lancer E) Comet F) Vixen G) Blitzen H) Crasher I) Donner J) Prancer K) Sunder L) Thunder M) Dasher N) Donder ©John Wiley & Sons, Inc. 2010

Night Before Christmas To the top of the porch! to the top of the wall! Now dash away! dash away! dash away all!" ©John Wiley & Sons, Inc. 2010

Eight Reindeers Prancer Dancer Cupid Comet Vixen Donder Blitzen Dasher ©John Wiley & Sons, Inc. 2010

Forgetting: How Quickly Do We Forget? Ebbinghaus found: – forgetting occurs most rapidly immediately after learning. – But relearning takes less time than initial learning. ©John Wiley & Sons, Inc. 2010

Why Do We Forget? Five Key Theories Decay Interference Motivated Forgetting Encoding Failure Retrieval Failure ©John Wiley & Sons, Inc. 2010

Five Theories of Forgetting (Continued) 1. Decay Theory: memory degrades with time 2. Interference Theory: one memory competes (interferes) with another – Retroactive Interference (new information interferes with recall of old) – Proactive Interference (old information interferes with recall of new) i.e. when learning a third language your second interferes. ©John Wiley & Sons, Inc. 2010

Examples of the Two Forms of Interference ©John Wiley & Sons, Inc. 2010

Five Theories of Forgetting (Continued) 3. Motivated Forgetting: motivation to forget unpleasant, painful, threatening, or embarrassing memories 4. Encoding Failure: information in STM is not encoded in LTM 5. Retrieval Failure: memories stored in LTM are momentarily inaccessible (tip-of-the- tongue phenomenon) ©John Wiley & Sons, Inc. 2010

Four Key Factors in Forgetting Misinformation Effect: memory distortion from misleading post-event information (Eyewitness testimony) Source Amnesia: forgetting the true source of a memory Sleeper Effect: information from an unreliable source, which was initially discounted, later gains credibility because source is forgotten Information Overload: distributed practice is better than massed practice ©John Wiley & Sons, Inc. 2010

Biological Bases of Memory Biology affects memory in at least two ways: 1. Synaptic changes occur underlying memory 2.Physiological changes influence memory ©John Wiley & Sons, Inc. 2010

Neuronal and Synaptic Changes Long-term potentiation (LTP) = “ Neurons That Fire Together Wire Together” repeated simultaneous stimulation of a pre- and postsynaptic neuron strengthens connection Neurotransmitter release is increased or decreased c i

Biological Bases of Memory (Continued) Physiological changes also affect memory (e.g., flashbulb memories--vivid & lasting images associated with surprising or strongly emotional events). ©John Wiley & Sons, Inc. 2010

Where Are Memories Located? Memory tends to be localized & distributed throughout the brain--not just the cortex. ©John Wiley & Sons, Inc. 2010

Biology & Memory Loss: Injury & Disease Amnesia: memory loss from brain injury or trauma Retrograde amnesia: old memories lost, partially due to lack of consolidation Anterograde amnesia: new memories lost ©John Wiley & Sons, Inc. 2010