: WHEN MEMORY LAPSES HUH?

EBBINGHAUS’S FORGETTING CURVE Hermann Ebbinghaus tested memory Created Forgetting Curve: graphs retention and forgetting over time Showed steep drop in retention within hours of learning

MEASURING FORGETTINGFORGETTING Retention: proportion of material retained 3 principle methods for measuring forgetting: recall, recognition, and relearning

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

RECOGNITION DEF: requires subjects to select previously learned info from any array of options Yield higher scores than recall

RELEARNING DEF: requires a subject to memorize info a 2nd time to determine how much time or effort is saved by having learned it before Compare time spent learning the 1st time with time spent learning same material a 2nd time

WHY WE FORGET Pseudoforgetting—due to ineffective 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 info 2) proactive interference: when previously learned info interferes w/retention of new info

WHY WE FORGET CONTINUED Retrieval failure Encoding specificity principle: our ability to remember a stimulus depends on the similarity between the way the stimulus is processed at encoding and the way it is processed at retrieval Transfer appropriate processing: processing at encoding is most effective to the extent that that processing overlaps with the processing to be performed at retrieval 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

IN SEARCH OF THE MEMORY TRACE: THE PHYSIOLOGY OF MEMORY

BIOCHEMISTRY OF MEMORY Specific memories may depend on biochemical changes at specific synapses (alterations in synaptic transmission) Neurotransmitters may help with storage of new info

NEURAL CIRCUITRY OF MEMORY Memories may create unique, reusable neural pathways Long-term potentiation: a long lasting increase in neural excitability at synapses along a specific neural pathway

ANATOMY OF MEMORY Studies in organic amnesia give clues 2 basic types of amnesia: 1)Retrograde: loss of memories for events that occurred prior to the onset of amnesia 2)Anterograde: loss of memories for events that occur after the onset of amnesia Studies 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

ARE THERE MULTIPLE MEMORY SYSTEMS?

IMPLICIT VS. EXPLICIT MEMORY Implicit 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

DECLARATIVE VS. PROCEDURAL MEMORY Declarative memory system: handles factual information Procedural memory system: houses memory for actions, skills, operations, and conditioned responses

SEMANTIC VS. EPISODIC 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

PROSPECTIVE VS. RETROSPECTIVE MEMORY Prospective memory: involves remembering to perform actions in the future Retrospective memory: remembering events from the past or previously learned info