Cognitive Psychology

1. Chapter 2
Cognitive Psychology
Memory

2. Memory and Its Processes
• Memory: an active system that receives information
from the senses, organizes and alters that information
as it stores it away, and then retrieves the information
from storage

3. Models of Memory
• Parallel distributed processing (PDP) model:
memory processes are proposed to take
place at the same time over a large network
of neural connections

4. Models of Memory
Levels-of-processing model: assumes that
information that is more“deeply processed” or
processed according to its meaning, rather than just
the sound or physical characteristics of the word or
words—will be remembered more efficiently and for
a longer period of time

5. Models of Memory
Information-processing model: assumes that the
processing of information for memory storage is
similar to the way a computer processes memory - in
a series of three stages
Precursor: Multi-store model: Atkinson and Shiffrin's (1968) original
model of memory, consisting of the sensory register, short-term store, and
long-term store.

6. Memory and Its Processes
• Processes of memory
1. encoding: the set of mental operations that
people perform on sensory information to
convert that information into a form that is
usable in the brain’s storage systems
2. storage: holding onto information for some
period of time
3. retrieval: getting information that is in
storage into a form that can be used

7. Three-Stage Process of Memory
Information enters through the sensory system, briefly registering in sensory memory. Selective
attention filters the information into short-term memory, where it is held while attention (rehearsal)
continues. If the information receives enough rehearsal (maintenance or elaborative), it will enter and
be stored in long-term memory.
encode
Information-processing
model

8. Sensory Memory
• Sensory memory: the very first stage of memory
– the point at which information enters the nervous
system through the sensory systems
– The nervous system has a specific sensory system or
organ, dedicated to each sense. Humans have a multitude
of senses. Sight, hearing, taste, smell, and touch are the
five traditionally recognized senses.

9. Sensory Memory
• Iconic memory: visual sensory memory,
lasting only a fraction of a second
– capacity: everything that can be seen at one
time
– duration: information that has just entered
iconic memory will be pushed out very quickly
by new information (within a second or so), a
process called masking
• Eidetic imagery: the (rare) ability to access
a visual memory for thirty seconds or more

10. Sensory Memory
• Echoic memory: the brief memory of
something a person has just heard
– capacity: limited to what can be heard at any
one moment; smaller than the capacity of
iconic memory
– duration: lasts longer than iconic; about two to
four seconds
fyi: The sensory memory for touch stimuli is
sometimes known as the haptic memory. Smell
and taste memories are not named.

11. Short-Term Memory
• Short-term memory (STM; working
memory): the memory system in which
information is held for brief periods of time
while being used
– selective attention: the ability to focus on only
one stimulus from among all sensory input

12. Short-Term (working) Memory
• Digit-span test: a series of numbers is
read to subjects who are then asked to
recall the numbers in order
– conclusion: capacity of STM is about seven
items or pieces of information, plus or minus
two items—or from five to nine bits of
information.
– “magical number” = 7 Traditional theory!
– Note: New research indicates as few as one item at a time

13. Short-Term (working)Memory
• Chunking: bits of information are
combined into meaningful units, or chunks,
so that more information can be held in
STM
• Maintenance rehearsal: saying bits of
information to be remembered over and
over in one’s head in order to maintain it
in short-term memory (STMs tend to be
encoded in auditory form)

14. Short-Term (working)Memory
• STM lasts from about twelve to thirty
seconds without rehearsal
• STM is susceptible to interference
– e.g., if counting is interrupted, one will have to
start over

15. Long-Term Memory
Long-term memory
(LTM): the memory
system into which all
the information is
placed to be kept
more or less
permanently

16. Long-Term Memory
• Elaborative rehearsal: a method of transferring
information from STM into LTM by making that
information meaningful in some way, as opposed to
simply repeating the word to yourself over and over.

17. Types of LTM
• Nondeclarative (implicit) memory: type of
long-term memory including memory for
skills, procedures, habits, and conditioned
responses
– Procedural memories are not conscious, but
their existence is implied because they affect
conscious behavior
– also include emotional associations, habits,
and simple conditioned reflexes that may or
may not be in conscious awareness

18. Nondeclarative (Implicit) LTM
Procedural
memory (often
called implicit
memory):
memory that is
not easily
brought into
conscious
awareness

19. Nondeclarative (Implicit) LTM
• Anterograde amnesia: loss of memory
from the point of injury or trauma forward,
or the inability to form new long-term
memories
– usually does NOT affect procedural LTM

20. Types of LTM
Declarative
(explicit) memory:
type of long-term
memory containing
information that is
conscious and
known.
a memory for facts
Semantic: Of or relating to
meaning or the study of
meaning

21. Declarative (Explicit) LTM
• All the things that people know
• Semantic memory: declarative memory
containing general knowledge
– knowledge of language, information learned in
formal education
• Episodic memory: declarative memory
containing personal information not readily
available to others
– daily activities and events

22. Declarative (Explicit) LTM
• Semantic and episodic memories are forms of
explicit memory - memory that is consciously known.

23. Types of Long-Term Memories
Long-term memory can be divided into declarative memories, which are factual and
typically conscious (explicit) memories, and Nondeclarative memories, which are skills,
habits, and conditioned responses that are typically unconscious (implicit). Declarative
memories are further divided into episodic memories (personal experiences) and
semantic memories (general knowledge).

24. Organization of Memory
• LTM is organized in terms of related meanings and
concepts
• Semantic network model: assumes that information
is stored in the brain in a connected fashion
– concepts that are related stored physically closer to each
other than to unrelated concepts
A semantic network, or frame network, is a
network that represents semantic relations
between concepts. This is often used as a
form of knowledge representation. It is a
directed or undirected graph consisting of
vertices, which represent concepts, and edges,
which represent semantic relations between
concepts.

25. An Example of a Semantic Network
In the semantic network model of memory, concepts that are related in meaning are
thought to be stored physically near each other in the brain. In this example, canary and
ostrich are stored near the concept node for “bird,” whereas shark and salmon are
stored near “fish.” But the fact that a canary is yellow is stored directly with that concept.

26. Declarative (Explicit) LTM
• Semantic and episodic memories are forms of
explicit memory - memory that is consciously known.

27. Cues to Help You Remember
• Retrieval cue: stimulus for remembering
• Priming can occur where experience with
information or concepts can improve later
performance
• Priming is a nonconscious (implicit) form of human
memory concerned with perceptual identification of words
and objects. It refers to activating particular representations
or associations in memory just before carrying out an
action or task. For example, a person who sees the word
"yellow" will be slightly faster to recognize the word
"banana." This happens because yellow and banana are
closely associated in memory

28. Cues to Help You Remember
Encoding specificity: tendency for memory of
information to be improved if related information
(e.g., surroundings or physiological state)
available when the memory was first formed is
also available when the memory is being
retrieved
Encoding Specificity is state-dependent learning:
memories formed during a particular physiological
or psychological (affective /emotional ) state will
be easier to recall while in a similar state.

29. Recall
• Recall: memory retrieval in which the
information to be retrieved must be
“pulled” from memory with very few
external cues
• Retrieval failure: recall has failed (at least
temporarily)
– tip of the tongue (TOT) phenomenon

30. Recall
• Serial position effect: information at the
beginning and the end of a body of
information more accurately remembered
than the information in the middle
– primacy effect: tendency to remember
information at the beginning of a body of
information better than what follows
– recency effect: tendency to remember
information at the end of a body of information
better than the information ahead of it

31. Serial Position Effect
In the serial position effect, information at the beginning of a list will be recalled at a higher
rate than information in the middle of the list (primacy effect), because the beginning
information receives more rehearsal and may enter LTM. Information at the end of a list is also
retrieved at a higher rate (recency effect), because the end of the list is still in STM, with no
information coming after it to interfere with retrieval.

32. Recognition
• Recognition: ability to match a piece of
information or a stimulus to a stored image
or fact
• False positive: error of recognition in which
people think that they recognize a stimulus
that is not actually in memory

33. Eyewitness Testimony
• What people see and hear about an event
after the fact can easily affect the accuracy of
their memories of that event
– eyewitness testimony is not always reliable!
– research into this area has found that eyewitness
testimony can be affected by many psychological
factors:
– Anxiety / Stress
– Reconstructive Memory
– Weapon Focus
– Leading Questions (Loftus and Palmer, 1974)

34. Automatic Encoding and Flashbulb Memories
• Automatic encoding: tendency of certain
kinds of information to enter long-term
memory with little or no effortful encoding
• Flashbulb memories: automatic encoding
that occurs because an unexpected event
has strong emotional associations for the
person remembering it

35. How LTMs Are Formed
• Constructive processing: memory retrieval
process in which memories are “built,” or
reconstructed, from information stored
during encoding
– with each retrieval, memories may be altered,
revised, or influenced by newer information

36. How LTMs Are Formed
• Hindsight bias: the tendency to falsely
believe, through revision of older
memories to include newer information,
that one could have correctly predicted the
outcome of an event
– “Monday morning quarterbacking”

37. Memory Retrieval Problems
Misinformation effect: tendency of misleading information
presented after an event to alter the memories of the event
itself

38. Reliability of Memory Retrieval
• False memory syndrome: creation of
inaccurate or false memories through the
suggestion of others, often while the person
is under hypnosis
• Evidence suggests that false memories
cannot be created for just any kind of memory
– memories must at least be plausible.

39. Forgetting: Ebbinghaus
• Curve of forgetting: a graph showing a
distinct pattern in which forgetting is very
fast within the first hour after learning a list
and then tapers off gradually
– distributed practice: spacing one’s study
sessions
 produces better retrieval
– massed practice: studying a complete body of
information all at once

40. Curve of Forgetting
Ebbinghaus found that his recall of words from his memorized word
lists was greatest immediately after learning the list but rapidly
decreased within the first hour. After the first hour, forgetting leveled off.

41. Forgetting: Encoding Failure
• Encoding failure: failure to process
information into memory
Stop!
Many people look at stop signs multiple
times a day. Which of these stop signs is
closest to an actual stop sign?
(The answer can be found in the notes section of this slide.)

42. Forgetting: Memory Trace Theory
• Memory trace: physical change in the brain
that occurs when a memory is formed
– decay: loss of memory due to the passage of
time, during which the memory trace is not used
– disuse: another name for decay, assuming that
memories that are not used will eventually
decay and disappear
– memories recalled after many years are not
explained by memory trace theory

43. Forgetting: Interference Theory
• Proactive interference: memory retrieval
problem that occurs when older information
prevents or interferes with the retrieval of
newer information
• Retroactive interference: memory retrieval
problem that occurs when newer
information prevents or interferes with the
retrieval of older information

44. Proactive and Retroactive Interference
If a student were to study for a French exam and then a Spanish exam, interference could occur in two
directions. When taking the Spanish exam, the French information studied first may proactively interfere with
the learning of the new Spanish information. But when taking the French exam, the more recently studied
Spanish information may retroactively interfere with the retrieval of the French information.

46. Formation of LTMs
• Consolidation: changes that take place in
the structure and functioning of neurons
when a memory is formed
– long-term potentiation: changes in number
and sensitivity of receptor sites/synapses
through repeated stimulation
• Hippocampus: area of brain responsible
for the formation of LTMs

47. Amnesia
• Retrograde amnesia: loss of memory from
the point of some injury or trauma
backwards, or loss of memory for the past
• Anterograde amnesia: loss of memory
from the point of injury or trauma forward,
or the inability to form new long-term
memories
– “senile dementia” (Senile dementia' is a outdated term that used
to be used when it was thought that memory loss and confusion was a normal
part of ageing, rather than being caused by specific diseases like Alzheimer's.
These days, it is more common to refer to dementia, or early-onset dementia if
the person is under 65.)

48. Alzheimer’s Disease
• Alzheimer's disease (AD) is the most common form
of dementia among older people. Dementia is a brain
disorder that seriously affects a person's ability to carry out
daily activities.
• AD begins slowly. It first involves the parts of the brain that control
thought, memory and language. People with AD may have trouble
remembering things that happened recently or names of people they
know.
• In AD, over time, symptoms get worse. People may not recognize family
members. They may have trouble speaking, reading or writing. They may
forget how to brush their teeth or comb their hair. Later on, they may
become anxious or aggressive, or wander away from home. Eventually,
they need total care. This can cause great stress for family members who
must care for them.
• AD usually begins after age 60. The risk goes up as you get older. Your
risk is also higher if a family member has had the disease.

49. Alzheimer’s Disease
• 5.3 million cases in U.S.
• Primary memory difficulty in Alzheimer’s
is anterograde amnesia
– retrograde amnesia can also occur as the
disease progresses
• There are various drugs in use or in
development for use in slowing or stopping
the progression of Alzheimer’s disease,
but no cure.

50. Alzheimer’s Disease
• Risk factors include
– high cholesterol
– high blood pressure
– smoking
– obesity
– Type II diabetes
– lack of exercise

51. Amnesia
Infantile amnesia: the inability to retrieve
memories from much before age three

52. Amnesia
Autobiographical memory: the memory for
events and facts related to one’s personal
life story (usually after age three)

53. Health and Memory
• Sleep is important in forming memories
– memories rehearsed during sleep as well as during
waking are more likely to be consolidated
– one can’t learn something new while sleeping, but new
information can be better consolidated while sleeping
– sleep deprivation severely interferes with hippocampal
function and memory
• Even brief exercise can be good for your memory
• Fish is brain food?
– omega-3 fatty acid called DHA (docosahexaenoic acid)
appears to help memory cells communicate

54. psychology
fourth edition
Chapter 6
Memory
The End