I.
The Nature of Memory – Four common memory models are presented. Table 7.1
provides an overview comparing each of these models.
Four Models of Memory
1.
Information Processing Model – The information processing model of
memory proposes a computer model to explain how information in
memory is processed using the operations of encoding, storage, and
retrieval. Encoding gets information into the brain and is similar to a
keyboard. Storage retains information like the computer’s hard drive or
disk. And, retrieval is the process of getting the information out of memory
storage.
B.
2.
Parallel Distributed Processing Model – The PDP or connectionist
model of memory views memory as more distributed rather than a
sequential operation.
3
Levels of Processing Model – Craik and Lockhart’s levels of processing
model suggest that memory relies on the degree or depth of mental
processing from shallow to deeper processing.
4.
Three-Stage Memory Model: Sensory Memory, Short-term Memory
(STM), and Long-term Memory (LTM) - This model proposes that
memory needs different storage stages to house information for various
lengths of time. A flowchart for memory processes (Figure 7.2) includes
the three stages: sensory memory, short-term memory (STM), and longterm memory (LTM).
Sensory Memory - Sensory memory occurs within the senses and very briefly
preserves a replica of an image. Visual images (iconic memory) last about 1/4
to 1/2 second and auditory images (echoic memory) up to four seconds.
Sensory memory’s capacity is unclear.
C.
Short-Term Memory - STM is our conscious thoughts or working memory. It
can hold about seven (7 + or – 2) items and can store them for about thirty
seconds; however, its capacity can be increased by chunking and its duration
can be increased by maintenance rehearsal. STM may be viewed as a threepart working memory: Visuospatial Sketchpad, Central Executive, and the
Phonological Rehearsal Loop.
D.
Long-Term Memory - LTM is more permanent and has unlimited capacity.
Organization of information improves transfer and retrieval of information, as
well as, sleep. LTM is divided into two major systems – explicit/declarative and
implicit/nondeclarative procedural memory. Two types of explicit/declarative
memory include semantic and episodic memory. Implicit/nondeclarative
memory includes procedural, classical conditioning, and priming. Like priming,
retrieval involves retrieval cues (recognition and recall) and the encoding
specificity principle.
Applying Psychology to Student Life: Improving Long-Term
Memory (LTM) - To successfully encode information for LTM, it is
important both organize information into chunks and into hierarchies.
Rehearsal also improves encoding for both STM and LTM and
includes both maintenance rehearsal and elaborative rehearsal.
Attempting to recreate the original learning conditions by paying
attention to the retrieval cues of context, mood, and state can also
improve memory.
I.Forgetting
A.
How Quickly Do We Forget? – Hermann Ebbinghaus’ now famous “curve of
forgetting” research demonstrated the rapidness at which information is
forgotten immediately after learning. However, he also found that relearning
can occur more quickly the second time.
B.
Why Do We Forget? Five Key Theories – Five major theories have been
offered to explain why forgetting occurs: decay theory, interference theory,
motivated forgetting, encoding failure, and retrieval failure. The decay theory
proposes that memory deteriorates over time while interference theory
suggests forgetting occurs when there is competing information. Retroactive
interference occurs when new information interferes with the learning of old
information and proactive interference occurs when old learning interferes with
the learning of new information. The motivated forgetting theory proposes that
we may forget or inhibit the retrieval of information that may be unpleasant,
painful, or embarrassing. Encoding failure theory may contribute to information
never being encoded from STM to LTM and thus forgotten. Retrieval failures
may also contribute to the inability to recall information that is stored in LTM.
Applying Psychology to Student Life: Recognizing Problems
with Forgetting – Four important factors that help prevent forgetting
include: (1) the serial position effect in which more forgetting occurs
for material in the middle of a list than at the beginning or end, (2)
source amnesia is a result of confusion or misattribution regarding
the actual occurrence of an event, (3) the sleeper effect is a
tendency to initially discount unreliable sources and later consider it
trustworthy because the source was forgotten, and (4) the spacing of
practice. Forgetting is greatest when students use massed practice
or “cramming” rather than distributed practice with breaks in between
learning.
Gender and Cultural Diversity: Cultural Differences in Memory and Forgetting –
The work of Ross and Millson (1970) used college students from the United States and
Ghana and discovered that the Ghana students were better at memory testing for
themes in stories presented aloud. Wagner (1982) found that previous experience
plays a part in facilitating memory recognition. It appears that STM is not affected by
cultural factors but that a person’s culture provides background of experience and
strategies for remembering factors specific to that culture.Biological Bases of
Memory
A.
How Are Memories Formed? -The biological aspects of memory include
neuronal and synaptic changes, hormonal influences, and structures in the
brain. Changes in the dendrites occur from repeated reverberating circuits.
Hormones produced during stress or excitement, such as epinephrine and
cortical play a significant role in memory. These hormones affect areas of the
brain structures in the limbic system including the amygdala, hippocampus,
cerebral cortex, and other parts of the brain. Hormonal changes during a
heightened state of emotions may produce a vivid image surrounding the
event as in the phenomenon known as flashbulb memories.
B.
Where Are Memories Located? – Lashley concluded after three decades of
research in memory that memories are distributed throughout the cortex.
Current research suggests that memory tends to be both localized and
distributed throughout the brain.
C.
Biological Causes of Memory Loss – Organic causes including traumatic
brain injury, amnesia, and Alzheimer’s disease are presented. Memory loss for
events that occurred before the injury is called retrograde amnesia and
memory loss for events that occur after an injury are called anterograde
amnesia. Alzheimer’s disease is a progressive mental deterioration in memory
which generally begins between the ages of 45 and 55 and may be primarily
genetic.
Research Highlight: Memory and the Criminal Justice –
Research studies are presented which address two areas of memory
problems including the difficulties with eyewitness testimonies and
repressed memories. Primarily because of the constructive nature of
memory the reliability of eyewitness testimonies are questioned. The
area of false versus repressed memories is a hotly contested debate.
Because of the constructive element of memory as well as source
amnesia, the misinformation effect, and the sleeper effect it is difficult
to discern their reliability.
II.
Using Psychology to Improve Our Memory
A.
Understanding Memory Distortions - The explanation for why memories are
often rearranged and distorted can be found in our need for logic, consistency
as well as the need for efficiency.
B.
Tips for Memory Improvement - Eight tips for memory improvement are
highlighted: (1) pay attention and reduce interference, (2) use rehearsal
techniques – maintenance and elaborative, (3) improve your organization, (4)
counteract the serial position effect, (5) manage your time – avoid massed
practice, (6) use the encoding specificity principle-context and state, (7)
employ self-monitoring and over learning, (8) use mnemonics – the method of
loci, peg-word, substitute word, and word association, and (9) avoid the seven
sins of memory – transience, absentmindedness, blocking, misattribution,
suggestibility, bias, and persistence.
Critical Thinking/Active Learning: Using Metacognition to
Improve Your Memory - The active learning exercise for this
chapter allows students to practice reflective thinking—to "think
about thinking"—and to use it to evaluate processes involved in
recalling and storing memories. Students are asked to engage in a
reflective thinking activity by reflecting on their memories of the first
day of their General Psychology course.