Transcript Memory Section 2

: WHEN MEMORY
LAPSES
HUH?
EBBINGHAUS’S FORGETTING CURVE
 Hermann Ebbinghaus tested memory
 Created Forgetting Cur ve: 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 2 nd time to
determine how much time or ef fort is saved by having learned
it before
 Compare time spent learning the 1 st time with time spent
learning same material a 2 nd time
WHY WE FORGET
 Pseudoforgetting—due to inef fective encoding (penny test)
 Decay theor y: forgetting occurs b/c memory traces fade with
time
 Interference theor y: 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 : 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
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 pontentiation: 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
 Implicity memor y: type of memory apparent when retention is
exhibited on a task that does not require intentional
remembering
 Explicit memor y: intentional recollection of previous
experiences
DECLARATIVE VS. PROCEDURAL MEMORY
 Declarative memor y system: handles factual information
 Procedural memor y system: houses memory for actions,
skills, operations, and conditioned responses
SEMANTIC VS. EPISODIC MEMORY
 Episodic memor y system: made up of chronological, or
temporally dated, recollections of personal experiences
 Semantic memor y system: contains general knowledge that is
not tied to the time when the info was learned
PROSPECTIVE VS. RETROSPECTIVE
MEMORY
 Prospective memor y: involves remembering to perform
actions in the future
 Retrospective memor y: remembering events from the past or
previously learned info