HUH?: WHEN MEMORY

LAPSES

Hermann Ebbinghaus tested memoryCreated Forgetting Curve: graphs retention and

forgetting over timeShowed steep drop in retention within hours of

learning

EBBINGHAUS’S FORGETTING CURVE

Retention: proportion of material retained3 principle methods for measuring forgetting: recall,

recognition, and relearning

MEASURING FORGETTINGFORGETTING

DEF: requires subjects to reproduce info on their own w/o any cues

RECALL

DEF: requires subjects to select previously learned info from any array of options

Yield higher scores than recall

RECOGNITION

DEF: requires a subject to memorize info a 2nd time to determine how much time or eff ort is saved by having learned it before

Compare time spent learning the 1 st time with time spent learning same material a 2nd time

RELEARNING

Pseudoforgetting—due to ineff ective encoding (penny test)

Decay theory: forgetting occurs b/c memory traces fade with time

Interference theory: people forget info b/c of competition from other material

2 types of interference: 1) retroactive interference: when new info impairs

the retention of previously learned info2) proactive interference: when previously learned

info interferes w/retention of new info

WHY WE FORGET

Retrieval failureEncoding specificity principle : the value of a retrieval

cue depends on how well it corresponds to the memory code

Transfer appropriate processing: occurs when the initial processing of info is similar to the type of processing required by the subsequent measure of retention

Motivated forgetting: tendency to forget things one doesn’t want to think about

Freud called this Repression: keeping distressing thoughts and feelings buried in the unconscious

WHY WE FORGET CONTINUED

IN SEARCH OF THE MEMORY TRACE: THE

PHYSIOLOGY OF MEMORY

Specific memories may depend on biochemical changes at specific synapses (alterations in synaptic transmission)

Neurotransmitters may help with storage of new info

BIOCHEMISTRY OF MEMORY

Memories may create unique, reusable neural pathways

Long-term pontentiation: a long lasting increase in neural excitability at synapses along a specific neural pathway

NEURAL CIRCUITRY OF MEMORY

Studies in organic amnesia give clues2 basic types of amnesia:1)Retrograde: loss of memories for events that

occurred prior to the onset of amnesia2)Anterograde: loss of memories for events that

occur after the onset of amnesiaStudies in amnesia have shown the hippocampal

region is critical for LTM and Consolidation: a hypothetical process involving the gradual conversion of info into durable memory codes stored in LTM

ANATOMY OF MEMORY

ARE THERE MULTIPLE MEMORY SYSTEMS?

Implicity memory: type of memory apparent when retention is exhibited on a task that does not require intentional remembering

Explicit memory: intentional recollection of previous experiences

IMPLICIT VS. EXPLICIT MEMORY

Declarative memory system: handles factual information

Procedural memory system: houses memory for actions, skills, operations, and conditioned responses

DECLARATIVE VS. PROCEDURAL MEMORY

Episodic memory system: made up of chronological, or temporally dated, recollections of personal experiences

Semantic memory system: contains general knowledge that is not tied to the time when the info was learned

SEMANTIC VS. EPISODIC MEMORY

Prospective memory: involves remembering to perform actions in the future

Retrospective memory: remembering events from the past or previously learned info

PROSPECTIVE VS. RETROSPECTIVE MEMORY