overheads, intro psych unit 5 - memory
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Unit 5 - Memory
3 key processes involves in memory
1. encoding
2. storage
3. retrieval
Attention: focusing awareness on a narrow range of stimuli or
events.
- filter that screens out most potential stimuli
- where in the sequence is the filter is located? Early or late?
 Craik & Lockhart (1972): different rates of forgetting occur because
some methods of encoding create more durable memory codes
than others.
- with verbal information there are 3 levels of processing:
o Structural encoding
o Phonemic encoding
o Semantic encoding
Craik & Tulving (1975)
- showed subjects a series of 60 words and asked them
questions about them.
- 1/3 of subjects had questions designed to stimulate
structural encoding
- 1/3 had questions designed to stimulate phonemic encoding
- 1/3 had questions designed to stimulate semantic encoding
- then all subjects were tested on recall of the 60 words. They
found that structural encoders remembered the fewest;
phonemic encoders did better; and the best were the
semantic encoders.
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Ways to Enhance Encoding
Elaboration: linking a stimulus to other information at the time of
encoding.
Visual Imagery: creating visual images to represent the words to be
remembered.
- Paivo, Smythe & Yuille (1968).
- dual code theory: memory is enhanced by forming
semantic and visual codes, since either can lead to recall.
Self-Referent Encoding: deciding how or whether information is
personally relevant.
Information processing view: memory can be understood as having
3 different stores: the sensory store, the short-term store, and the
long-term store.
Sensory memory: preserves information in its original sensory form
for a brief time, usually only a fraction of a second.
- lasts only about ¼ of a second
- Sperling (1960)
Short-Term Memory (STM) (a.k.a. working memory): a limitedcapacity store that can maintain unrehearsed information for up to
about 20 seconds
- Rehearsal is the process of repetitively verbalizing or
thinking about the information
- Peterson & Peterson (1959)
- 7 +/- 2 units
- increase the capacity by chunking
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Long term memory: an unlimited capacity store that can hold
information over lengthy periods of time. Is information in there
forever?
- flashbulb memories: unusually vivid and detailed
recollections of momentous events
- reports of exceptional recall through hypnosis, of events
from childhood
- Wilder Penfield’s finding that people reported old memories
on stimulation of certain areas of the cortex
- However, flashbulb memories fade with time and are not as
accurate as once believed; hypnosis-aided recall often turns
out to be incorrect; and Penfield’s “memories” were often
fantasies, dreams, & hallucinations.
Some of the organizational structures of the LTM:
Clustering: the tendency to remember similar or related items in
groups
Conceptual Hierarchy: a multilevel classification system based on
common properties among items
Schemas: organized clusters of knowledge about a particular object
or event abstracted from pervious experience with the object or
event.
Script: a particular kind of schema that organizes what people know
about common activities.
Semantic Network: nodes representing concepts, joined together by
pathways that link related concepts
- Collins & Loftus (1975): when people think about a word,
their thoughts naturally go to related words, in a process
called spreading activation.
- strength decreases as it travels outward
overheads, intro psych unit 5 - memory
retrieval cues: stimuli that help gain access to memories.
Context: being in the same context where information was first
encoded facilitates the retrieval of information.
Memories get distorted and may include details that weren’t actually
there
Loftus (1979, 1992): the misinformation effect in eyewitness
testimony.
- 3 stages:
1) subjects view an event
2) they are exposed to information about this
event, some of which is misleading
3) their recall of the original event is tested to
see if the misleading information has altered
their memory
Loftus & Palmer (1974): car crash study
Source Monitoring and Reality Monitoring:
 the misinformation effect appears to be due in part to the
unreliability of source monitoring: the process of making
attributions about the origins of memories.
 a source monitoring error occurs when a memory derived from
one source is misattributed to another source.
 People often feel quite confident about these attributions,
even when inaccurate
 some subjects in studies have “insisted” they remember
seeing something that was only verbally suggested to them
 “cryptomnesia”: inadvertent plagiarism that occurs when
people come up with an idea they think is original when
actually they were exposed to it earlier.
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overheads, intro psych unit 5 - memory
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Reality monitoring: the process of deciding whether memories are
based on external sources (one’s perception of actual events) or
internal ones (one’s thoughts, imagination, dreams)
 when the memory is rich in sensory or contextual information, or it
can be retrieved with little effort, we are likely to infer it is a
memory of a real event.
Forgetting: can be caused by deficiencies in encoding, storage,
retrieval, or some combination of these processes.
Measures of Forgetting
 retention: the proportion of material retained
 a recall measure of retention requires subjects to reproduce
information on their own without any cues
 a recognition measure of retention requires subjects to select
previously learned information from an array of options. These are
generally easier than recall tasks.
 A relearning measure of retention requires subjects to memorize
information a second time to determine how much time or effort is
saved by having learned it before.
- calculate a savings score to indicate how much they had
retained from the first time
Some possible causes of forgetting:
Ineffective encoding:
 maybe the information never got put into memory in the first place,
usually due to a lack of attention (“pseudoforgetting”)
 encoding may be ineffective; some approaches toe encoding lead
to more forgetting than others
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Decay:
 forgetting can be due to memory traces fading with time
 occurs at the site of the physiological mechanisms responsible for
memories
 decay has been shown to contribute to loss of information from the
sensory store and STM but not for LTM
 time going by isn't as important as what happens during that time particularly if learning other information has led to interference.
Interference:
 people forget information because of competition from other
material
 greatest effects when the intervening material is most similar to the
test material
 McGeoch & McDonald (1931)
 2 kinds of interference
- Retroactive interference: when new information impairs the
retention of previously learned information.
- Proactive interference: when previously learned
information interferes with the retention of new information.
Retrieval Failure:
 people often remember something that they couldn’t remember
previously
 may be due to a breakdown in the process of retrieval
 retrieval failures may be more likely when a mismatch occurs
between retrieval cues and the original encoding of the
information.
- encoding specificity principle: the value of a retrieval cue
depends on how well it corresponds to the memory code.
Motivated Forgetting:
 Freud: retrieval is blocked by unconscious avoidance tendencies,
i.e. “repression”.
 some research suggests that people don’t remember anxietyladen material as readily as emotionally-neutral material.
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Recent interest in the issue of repressed memories:
 instances of “recovered” memories of accusations of childhood
abuse
 most allegations do not have independent corroboration
 are these false memories?
Organic amnesia: memory loss due to head injury
 Retrograde amnesia: loss of memories for events that occurred
prior to the onset of amnesia.
 Anterograde amnesia: loss of memories for events that occur
after the onset of amnesia.
 The famous case of H.M.
 the hippocampal region is probably important in the consolidation
of memories: the gradual conversion of information into durable
memory codes stored in long term memory.
Patients with anterograde amnesia appear to have no ability to form
new long-term memories. But certain kinds of testing reveal that this
isn't exactly true.
 implicit memory: when retention is exhibited on a task that does
not require intentional remembering.
 explicit memory: involving intentional recollection of previous
experiences
 Some theorists believe that these 2 kinds of memory are handled
by independent memory systems: declarative and procedural
memory.
Declarative memory: recollections of factual information like words,
definitions, names, dates, faces, events, concepts, ideas
Procedural memory: recollections of actions, skills, operations, and
conditioned responses (e.g. how to ride a bike, tie your shoes, type)
 Maybe implicit memory is a function of the procedural memory
system and explicit memory is a function of the declarative
memory system.
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Tulving (1986; 1993) further subdivided declarative memory into
episodic and semantic memory.
 Episodic memory: like an autobiography, personal events
from your life that are temporally dated
 Semantic memory: like an encyclopedia, contains general
knowledge that is not temporally tagged
Prospective memory: remembering to perform actions in the future
Retrospective memory: remembering events from the past or
previously learned information.
 people vary tremendously in their ability to carry out prospective
memory tasks
 habitual task are easier to remember than infrequent tasks
 event-based tasks are easier to remember than time-based tasks
 the older we are the more vulnerable we become to problems with
prospective memory