Chapter 7: Human Memory
Encoding involves forming a memory code.
• encoding requires attention
Storage involves maintaining encoded information in memory over time.
Retrieval involves recovering information from memory stores.
• our memories change over time and are rough reconstructions rather than exact copies of past events.
• forgetting may be due to deﬁciencies in any of the 3 key processes in memory-encoding,storage,or retrieval.
Encoding: Getting Information into Memory
1. The Role of Attention:
• you generally need to pay attention to information if you intend to remember it.
Attention involves focusing awareness on a narrowed range of stimuli or events.
• selective attention is critical to everyday functioning.
• attention is often likened to a ﬁlter that screens out most potential stimuli while allowing a select few to
pass through into conscious awareness.
• the location of our attention ﬁlter depends on the “cognitive load” of current information processing
- when we are attending to complicated, high-load tasks that consume much of our attentional capacity,
selection tends to occur early.
- when we are involved to simpler, low-load tasks, more attentional capacity is left over to process the
meaning of distractions, allowing for later selection.
• when participants are forced to divide their attention between memory encoding and some other task,
large reductions in memory performance are seen.
• divided attention can have a negative impact on the performance of quite a variety of tasks, especially when
they are complex or unfamiliar.
• when people multitask, they really are switching their attention back and forth among tasks,rather than
processing them simultaneously.
• there are 2 types of information processing:
- eﬀortful processing involves picking up information because you are intentionally attempting to do so.
- other information is picked up automatically, without you intending to do so.
2. Levels of Processing:
• you can attend things in diﬀerent ways, focusing on diﬀerent aspects of the stimulus input. • diﬀerent rates of forgetting occur because some methods of encoding create more durable memory codes
• in dealing with verbal information,people engage in 3 deeper levels of processing:
- Structural encoding is a shallow processing that emphasizes the physical structure of the stimulus(ex. how
many letters does a word contain).
- Phonemic encoding emphasizes what a word sounds like(ex. saying the words out loud).
- Semantic encoding emphasizes the meaning of verbal input; it involves thinking about the objects and
actions the word represent.
Levels-of-processing theory proposes that deeper levels of processing result in longer-lasting memory
3. Enriching Encoding:
a) Elaboration is the linking a stimulus to other information at the time of encoding:
• semantic encoding can be enhanced through elaboration
• it often consists of thinking of examples that illustrates an idea.
b) Visual Imagery:
• imagery can also be used to enhance encoding
• it’s easier to form images of concrete objects(banana) than of abstract concepts(truth).
•imagery facilitates memory because it provides a 2nd kind of memory code.
Dual-coding theory holds that memory is enhanced by forming semantic and visual codes, since either can
lead to recall.
c) Self-Referent Encoding involves deciding how or whether information is personally relevant:
• it appears to enhance recall by promoting additional elaboration and better organization of information.
•depressed people have more negative content as part of their self-prototype.
Storage: Maintaining Information in Memory
•incoming information passes through 2 temporary storage buﬀers-the sensory store and short-term store-
before it’s transferred into a long-term store.
1. Sensory Memory:
It preserves information in its original sensory form for a brief time,usually inly a fraction of a second.
• it allows the sensation of a visual pattern, sound, or touch to linger for a brief moment after the sensory
stimulation is over.
• in the case of vision, people really perceive an afterimage rather than the actual stimulus. • the brief preservation of sensations in sensory memory gives you additional time to try to recognize stimuli.
• sensory storage does not last long.
2. Short-Term Memory:
STM is a limited-capacity store that can maintain unrehearsed information for up to about 20 seconds.
Rehearsal is the process of repetitively verbalizing or thinking about the information.
• 2 types of rehearsal:
- maintenance rehearsal occurs when you are simply maintaining the information in consciousness.
- elaborative rehearsal occurs when you are increasing the probability that you will retain the information in
a) Durability of Storage:
• without rehearsal,information in STM is lost in less than 20 sec.
• loss of information is due to interference from competing material.
b) Capacity of Storage:
• STM is also limited in the number of items it can hold.
• the limited capacity of STM constrains people’s ability to perform tasks in which they need to mentally
juggle various pieces of information.
• you can increase the capacity of your STM by combining stimuli into larger, possibly higher-order units,
called chunks(a group of familiar stimuli stored as a single unit).
• in order to recognize something as a familiar unit, the familiarity has to be stored somewhere in LTM. In
this case information would be transferred from LTM into STM.
c) STM as “Working Memory”:
• STM is not limited to phonemic encoding.
•STM involves more than a simple rehearsal buﬀer
•Baddeley’s model of working memory consists of 4 components:
1. Phonological loop-it’s at work when a person uses recitation to temporarily remember phone number.
2. Visuospatial sketchpad permits people to temporarily hold and manipulate visual images(ex. when you are
trying to mentally rearrange the furniture in your bedroom).
3. Central executive system controls the deployment of attention,switching the focus of attention and
dividing attention as needed(ex. talking on the phone while watching TV).
- it also coordinates the actions of the other modules
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 LTM.
• working memory capacity plays a fundamental role in complex cognitive processes. 3. Short-Term Memory:
LTM is an unlimited capacity store that can hold information over lengthly periods of time.
Flashbulb memories are unusual vivid and detailed recollections of momentous events.
• although ﬂashbulb memories tend to be strong,vivid,and detailed,studies suggest that they are neither as
accurate nor as special as once believed.Like other memories, they become less detailed and complete with
time and are often inaccurate.
4. Are STM and LTM Really Separate?
• the view of STM and LTM as independent systems was originally based on the belief that they depended
on diﬀerent types of encoding and were subject to diﬀerent mechanisms of forgetting.
• STM was thought to depend on phonemic encoding,whereas LTM encoding was thought to be largely
• information loss from STM was believed to be mostly due to time-related decay,whereas interference was
viewed as the principal mechanism of LTM forgetting.
5. How is Knowledge Represented and Organized in Memory:
a) Clustering and Conceptual Hierarchies:
Clustering is the tendency to remember similar or related items or groups.
Conceptual hierarchy is a multilevel classiﬁcation system based on common properties among items.
• organizing information into a conceptual hierarchy can improve recall dramatically.
b) Schemas- an organized cluster of knowledge about a particular object or event abstracted from previous
experience with the object or event.
• people are more likely to remember things that are consistent with their schemas than things that are not
OR people sometimes exhibit better recall of things that violate their schema-based expectations.
• information stored in memory is often organized around schemas.
• relational schemas are important because they may be related to a variety of disorders.
- these relational schemas aﬀect the way you process information about others and yourself and inﬂuence
your expectations and beliefs about yourself. They may partially underlie low self-esteem and social anxiety.
c) Semantic Networks- consist of nodes representing concepts,joined together by pathways that link related
• semantic networks have proven in explaining why thinking about one word can make a closely related
word easier to remember. • spreading activation within semantic networks-when people think about a word, their thoughts naturally
go to related words.
d) Connectionist Networks and Parallel Distributed Processing(PDP) Models:
PDP models assume that cognitive processes depend on patterns of activation in highly interconnected
computational networks that resemble neural networks.
• a PDP system consists of a large network of interconnected computing units, or nodes, that operate much
• a speciﬁc node’s level of activation reﬂects the weighted balance of excitatory and inhibitory inputs from
many other units.
- PDP models assert that speciﬁc memories correspond to particular patterns of activation in these networks.
• in semantic networks, speciﬁc nodes represent speciﬁc concepts or pieces of knowledge.
• in connectionist networks, a piece of knowledge is represented by a particular pattern of activation across
an entire network.
Retrieval: Getting Information Out of Memory
• understanding retrieval is the key to understanding human memory.
1. Using Cues to Aid Retrieval:
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.
- it constitutes a failure in retrieval.
• memories can often be jogged with retrieval cues-stimuli that help gain access to memories.
2. Reinstating the Context of an Event:
• encoding speciﬁcity principle(Tulving) suggests that your memory for information would be better when
the conditions during encoding and retrieval were similar.
• trying to recall an event by putting yourself back into the context in which it occurred involves working
with context cues to aid retrieval.
• this principle is also true for state- and mood-dependent eﬀects.
- Ex. if you encoded information while intoxicated,you are most likely to remember that information while in
3. Reconstructing Memories and the Misinformation Eﬀect: • your memories are sketchy reconstructions of the past that may be distorted and may include details that
did not actually occur.
• 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.
• reconstructive distortions show up frequently in eyewitness testimony.
Misinformation eﬀect occurs when participants’ recall of an event they witnessed is altered by introducing
misleading post-event information.
Studies of the misinformation eﬀect include 3 stages:
1. Subjects view an event.
2.Subjects are exposed to information about this event,some of which is misleading.
3.Subjects’ recall of the original event is tested to see if the post-event misinformation altered their memory of
the original event.
4. Source Monitoring And Reality Monitoring:
• the misinformation eﬀect appears to be due,in part, to the unreliability of source monitoring.
Source monitoring is the process of making attributions about the origins of memories.
• source monitoring is a crucial facet of memory retrieval that contributes to may of the mistakes that people
make in reconstructing their experiences.
• memories are not tagged with labels that specify their memory sources.Thus, when people pull up speciﬁc
memory records,they have to make decisions at the time of retrieval about where the memories came from.
• Much of the time,these decisions are so easy and automatic,people make them without being consciously
aware of the source-monitoring process.
A source-monitoring error occurs when a memory derived from one sourc