o Three key processes involved in memory are encoding (getting information in),
storage (maintaining it), and retrieval (getting it out).
o Encoding involves forming a memory code
o Encoding usually requires attention
o Storage involves maintaining encoding information in memory over time
o Retrieval involves recovering information from memory stores
o Just as memory involves more than storage, forgetting involves more than
“losing” something from the memory store
o Forgetting may be due to deficiencies in encoding, storage, or retrieval
Encoding: Getting Information into Memory
o Like the problem of forgetting people’s names just after you’ve met them, the
next-in-line effect illustrates that active encoding is a crucial process in memory
The Role of Attention
o Attention involves focusing awareness on a narrowed range of stimuli or events.
o Attention is often likened to a filter that screens out most potential stimuli while
allowing a select few to pass thorough into conscious awareness.
o There is debate weather stimuli are screened out early, during sensory input, or
late, after the brain has processed the meaning or significance of the input
o Attention involves late selection, based on the meaning of input.
o However scientific evidence has found evidence on both early selection and late
selection along with intermediate selection o Theorists conclude that the location of the attention filter may be flexible rather
o Studies indicate that when participants are forced to divide their attention between
memory encoding and some other task, large reductions in memory performance are seen
Levels of Processing
o Attention is critical to the encoding of memories, but not all attention is created
o Different rates of forgetting occur because some methods of encoding create more
durable memory codes than others
o Structural encoding is relatively shallow processing that emphasizes the physical
structure of the stimulus
o Phonemic encoding emphasizes what a word sounds like.
o Semantic encoding emphasizes the meaning of verbal input; it involves thinking
about the objects and the actions the words represent
o Levels-of processing theory proposes that deeper levels of processing result in
longer-lasting memory codes
o The hypothesis that deeper processing leads to enhanced memory has been
replicated in many studies
o Semantic encoding can often be enhanced through a process called elaboration
o Elaboration is linking a stimulus to other information at the time of encoding
o Elaboration often consists of thinking of examples that illustrate an idea
o Additional examples led to better memory Visual Imagery
o imagery (the creation of visual images to represent the words to be remembered)
can also be used to enrich encoding
o easier to form images of concrete objects (the word Juggler) than abstract
concepts than abstract concepts (the word truth)
o high imagery words are easier to remember than low-imagery words.
o Imagery facilitates memory because it provides a second kind of memory code
(two codes are better than one)
o Dual coding theory holds that memory is enhanced by forming semantic and
visual codes, since either can lead to recall.
o making material personally meaningful can also enrich encoding
o People’s recall of information tends to be slanted in favor of material that is
o Self-referent encoding involves deciding how or whether information is
o Self-referent encoding appears to enhance recall by promoting additional
elaboration and better organization of information
Storage: Maintaining Information in Memory
o incoming information passes through two temporary storage buffers- the sensory
store and the short-term store- before it is transferred into a long-term store.
o The three memory stores are not viewed as anatomical structures in the brain but
rather as functionally distinct types of memory. Sensory memory
o The sensory memory preserves information in its original sensory form for a brief
time, usually only a fraction of a second.
o Sensory memory allows the sensation of a visual pattern, sound, or touch to linger
for a brief moment after the sensory stimulation is over
o The brief preservation of sensations in sensory memory gives you additional time
to try to recognize stimuli
o short-term memory (STM) is a limited-capacity store that can maintain
unrehearsed information for up to about 20 seconds
o can enhance short term memory by rehearsal0 the process of repetitively
verbalizing or thinking about the information.
o Rehearsal keeps recycling the information through your short-term memory
Durability of Storage
o Without rehearsal, information in short-term memory is lost in less than 20
o Loss of information from short-term memory was due purely to time-related
decay of memory traces, but follow-up research showed that interference from competing
material also contributes.
Capacity of Storage
o Short-term memory is limited in the number of items it can hold
o Miller noticed that people could recall only about seven items in tasks that require
them to remember unfamiliar material. o Limited capacity of STM constrains people’s ability to perform tasks in which
they need to mentally juggle various pieces of f information
o Combining stimuli into larger, possibly higher-order units, called chunks can
increase the capacity of short term memory
o Achunk is a group of familiar stimuli stored as a single unit
o People routinely draw information out of their long-term memory banks to
evaluate and understand information that they are working with in short-term memory.
Short-Term Memory as “working memory”
o short-term memory involves more than a simple rehearsal buffer, as originally
o short term memory characterized as working memory
o 1) phonological rehearsal loop represents all of STM in earlier models
o 2) visuospatial sketchpad permits people to temporarily hold and manipulate
o 3) executive control system controls the deployment of attention, switching the
focus of attention and dividing attention as needed
o 4) Episodic buffer is a temporary, limited capacity store that allows the various
components of working memory to integrate information and that serves as an interface between
working memory and long-term memory.
o long-term memory is an unlimited capacity store that can hold information over
lengthy periods of time
o one point of view that all information stored in long term memory is stored there
o forgetting occurs only because people sometimes cannot retrieve needed
information from LTM o In surgery for epilepsy long-lost memories were unearthed by electrical
stimulation of the brain
o Flashbulb memories, which are unusually vivid and detailed recollections of
o Flashbulb memories represent an instance of permanent storage
o Like other memories, flash bulb memories become less detailed and complete
with time and are often inaccurate.
o Although the possibility cannot be ruled out completely, there is no convincing
evidence that memories are stored away permanently and that forgetting is all a matter of
Are Short-Term Memory and Long-Term Memory Really separate?
o Some theorists have expressed doubts about whether there really are separate
o View of short-term memory and long-term memory as independent systems was
originally based, in part, on the belief that they depended on different types of encoding and were
subject to different mechanisms of forgetting.
o STM was thought to depend on phonemic encoding (based on sound), whereas
LTM encoding was thought to be largely semantic (based on meaning)
How is Knowledge Represented and Organized in Memory
o Most theorists seem to agree that our mental representations probably take a
variety of forms, depending on the nature of the material that needs to be tucked away in
Clustering and Conceptual Hierarchies
o clustering is the tendency to remember similar or related items in groups. o Conceptual hierarchy is a multilevel classification system based on common
properties among items
o Aschema is an organized cluster of knowledge about a particular object or even
abstracted from previous experience with the object or event
o People are more likely to remember things that are consistent with their schemas
than things that are not
o The inverse is also true however; people sometimes exhibit better recall of things
that violate their schema-based expectations
o Asemantic network consists of nodes representing concepts, joined together by
pathways that link related concepts.
Connectionist Networks and Parallel Distributed Processing (PDP) Models
o connectionist, or parallel distributed processing (PDP), models assume that
cognitive processes depend on patterns of activation in a highly interconnected computational
networks that resemble neural networks
o PDP models assert that specific memories correspond to particular patterns of
activation in these networks
o Conceptual hierarchies, schemas, and semantic networks are largely limited to
explaining how factual information might be represented in memory.
Retrieval: Getting Information Out of Memory
Using Cues toAid Retrieval o Tip-of-the-tongue phenomenon is the temporary inability to remember something
you know, accompanied by a feeling that it’s just out of reach.
o Retrieval cues are stimuli that help gain access to memories.
o Partial recollections are often headed in the right direction. (only getting the first
letter of the word you want to say)
o Trying to recall an event by putting yourself back in the context in which it
occurred involves working with context cues to aid retrieval.
Reconstructing memories and the Misinformation Effect
o Memories are sketchy reconstructions of the past that may be distorted and may
include details that did not actually occur
o Part of what people recall about an event is the details of that particular event and
part is a reconstruction of the event based on their schemas.
o “overwriting” explanation is when new misinformation destroys and replaces the
original memory of the event
Source Monitoring and Reality Monitoring
o Source monitoring is the process of making attributions about the origins of
o Source monitoring is a crucial feature of memory retrieval that contributes to
many of the mistakes that people make in reconstructing their experiences
o Asource-monitoring error occurs when a memory derived from one source is
misattributed to another source.
o cryptomnesia is inadvertent plagiarism that occurs when people come up with an
idea that they think is original, when they were actually exposed to it earlier
o Reality monitoring refers to the process of deciding whether memories are based
on external sources (one’s perceptions of actual events) or internal sources (one’s thoughts and
imaginations. o People engage in reality monitoring when they reflect on whether something
actually happened or they only thought about it happening.
o When memories can be retrieved with little effort, one is more likely to infer that
the event really happened
Forgetting: When Memory Lapses
o forgetting can be caused by deficiencies in encoding, storage, retrieval, or some
combination of these processes.
o Aforgetting curve, graphs retention and forgetting over time.
o Most forgetting occurs very rapidly after learning something
o When subjects memorize more meaningful material, such as prose or poetry,
forgetting curves aren’t nearly as steep.
Measures of Forgetting
o Measures of forgetting inevitably measures retention as well
o Retention refers to the proportion of material retained or remembered.
o Retention interval is the length of time between the presentation of materials to be
remembered and the measurement of forgetting.
o Three principal methods used to measure forgetting are recall, recognition, and
o Arecall measure of retention requires subjects to reproduce information on their
own with out any cues.
o Arecognition measure of retention requires subjects to select previously learned
information from an array of options.
o Recognition tests are especially sensitive measures of retention
o Recognition tests are excessively easy measures of retention o Arelearning measure of retention requires a subject to memorize information a
second time to determine how much time or how many practice trials are saved by having
learned it before
Why We Forget
o Since you can’t really forget something you never learned this phenomenon is
sometimes called pseudoforgetting.
o Pseudoforgetting is usually due to lack of attention.
o Decay theory proposes that forgetting occurs because memory traces fade with
o The mere passage of time produces forgetting
o Forgetting depends not on the amount of time that has passed since learning but
on the amount, complexity, and type of information that subjects have had to assimilate during
the retention interval
o Interference theory proposes that people forget information because of
competition from other
o There are two kinds of interference; retroactive interference and proactive
o Retroactive interference occurs when new information impairs the retention of
previously learned information.
o Proactive interference occurs when previously learned information interferes with
the retention of new information Retrieval Failure
o Retrieval failures may be more likely when a mismatch occurs between retrieval
cues and the encoding of the information you’re searching for.
o Agood retrieval cue is consistent with the original encoding of the information to
o The encoding specificity principle states that the value of a retrieval cue depends
on how well it corresponds to the memory code.
o Transfer-appropriate processing occurs when the initial processing of information
is similar to the type of processing required by the subsequent measure of retention
o Retrieval failures are more likely when there is a poor fit between the processing
done during encoding and the processing invoked by the measure of retention.
o The tendency to forget things one doesn’t want to think about is called motivated
forgetting, or repression.
o Repression refers to keeping distressing thoughts and feelings buried in the
The Repressed Memories Controversy
o In an effort to make sense of the charges, some accused parents have argued that
their children’s recollections are false memories created inadvertently by well-intentioned
therapists through the power of suggestion.
o There is ample evidence that it is common for people to bury traumatic incidents
in their unconscious.
o Some therapists are overly prone to see signs of abuse where none has occurred
o They are unsophisticated about the extent to which memories can be distorted o They are naïve about how much their expectation and beliefs can influence their
patient’s efforts to achieve self-understanding.
o Many repressed memories of abuse have been recovered under the influence of
o Hypnosis tends to increase memory distortions while paradoxically making
people feel more confident about their recollections
o Many repressed memories of abuse have been recovered through therapists dream
o The imperfections of memory may be adaptive in the long run, but the fact
remains that memory is surprisingly unreliable.
In Search of the Memory Trace: the Physiology of Memory
The Biochemistry of Memory
o Memory formation results in alterations in synaptic transmission at specific sites.
o Durable changes in synaptic transmission may be the neural building blocks of
more complex memories as well
o Manipulations that alter hormone levels shortly after an organism has learned a
new response can affect memory storage in a variety of animals
The Neural Circuitry of Memory
o Specific memories may depend on localized neural circuits in the brain.
o Memories may create unique, reusable pathways in the brain along which signals
o Long-term potentiation is a long lasting increase in neural excitability at synapses
along a specific neural pathway.
o Memory formation may stimulate neural growth and the emergence of new neural
o New neural circuits may reflect the storage of learned information TheAnatomy of Memory
o Cases of organic amnesia- extensive memory loss due to head injury- are another
source of clues about the physiological bases of memory
o Retrograde amnesia involves the loss of memories for events that occurred prior
to the onset of amnesia
o Anterograde amnesia involves the loss of memories for events that occur after the
onset of amnesia
o Scientists now believe that the entire hippocampal region are critical for many
types of long term memory
o Hippocampal region plays a key role in the consolidation of memory
o Consolidation is a hypothetical process involving the gradual conversion of
information into durable memory codes stored in long-term memory.
o Memories are consolidated in the hippocampal region and then stored in diverse
and widely distributed areas of the cortex
o Hippocampal area may play a key role in organizing neural networks that
represent specific memories
Are There Multiple Memory Systems?
o Amnesiacs do remember words from the list. However, when asked, they don’t
even remember having been shown the list
o Implicit memory is apparent when retention is exhibited on a task that does not
require intentional remembering.
o Explicit memory involves intentional recollection of previous experiences.
Declarative Versus Procedural Memory
o The declarative memory system handles factual information o The nondeclarative or procedural memory system houses memory for actions,
skills, operations, and conditioned responses.
o Some theorists believe that an association exists between implicit memory and the
procedural memory system
o Procedural memory system may handle implicit remembering, while the
declarative memory system handles explicit remembering
Semantic Versus Episodic Memory
o declarative memory subdivided into two more parts
o episodic memory contains personal facts and semantic memory contains general
o The episodic memory system is made up of chronological, or temporally dated,
recollections of personal experiences