Psychology- Chapter 7: Human Memory
Encoding: involves forming a memory code.
Storage: involves maintaining encoded information in memory
The Role of Attention
Attention involves focusing awareness on a narrowed range of
stimuli or events.
Attention is often linked to a filter that screens out most
potential stimuli while allowing a select few to pass through
into conscious awareness.
Cocktail party phenomenon suggests that attention involves
late selection, based on the meaning of input.
According to Lavie, the location of our attention filter
depends on the cognitive load of our current information
processing. When we are attending to complicated, high-load
tasks that consume much of our attentional capacity, selection
tends to occur early. However, when we are involved in
simpler, low-load tasks, more attentional capacity is left
over to process the meaning of distractions, allowing for
While much of the information we want to remember is encoded
as a result of effortful processing, some types of information
may be acquired more automatically.
Levels of Processing
According to some theorists, differences in how people attend
to information are the main factors influencing how much they
Different rates of forgetting occur because some methods of
encoding create more durable memory codes than others.
People engage in three progressively deeper levels of
encoding: structural, phonemic, and semantic encoding.
Structural encoding is relatively shallow processing that
emphasizes the physical structure of the stimulus. Ex. If
words are flashed on a screen, structural encoding registers
such things as how they were printed (capital letters,
lowercase, etc.) or the length of the words.
Further analysis may result in phonemic encoding, which
emphasizes what a word sounds like. Phonemic encoding involves
naming or saying (perhaps silently) the words.
Finally, semantic encoding emphasizes the meaning of verbal
input; it involves thinking about the objects and actions the
Levels-of-processing theory proposes that deeper levels of
process result in longer-lasting memory codes.
There are other dimensions to encoding, dimensions that enrich
the encoding process and thereby improve memory: elaboration,
visual imagery, and self-referent coding. Elaboration
Semantic encoding can often be enhanced through a process
Elaboration is linking a stimulus to other information at the
time of encoding.
The additional associations created by elaboration usually
help people to remember information. Elaboration often
consists of thinking examples that illustrate and idea.
Imagerythe creation of visual images to represent the words
to be rememberedcan also be used to enrich encoding.
According to Paivio, imagery facilitates memory because it
provides a second kind of memory code, and two codes are
better than one.
His dual-coding theory holds that memory is enhanced by
forming semantic and visual codes, since either can lead to
Self-referent encoding involves deciding how or whether
information is personally relevant.
Self-referent encoding appears to enhance recall by promoting
additional elaboration and better organization of information.
Storage: Maintaining Information in Memory
Richard Atkinson and Richard Shiffrin proved to be the most
influential of the information-processing theories. According
to their model, incoming information passes through two
temporary storage buffersthe sensory store and short-term
before it is transferred into a long-term store.
The sensory memory preserves information in its original
sensory form for a brief time, usually only a fraction of a
Sensory memory allows the sensation of visual pattern, sound,
or touch to linger for a brief moment after the sensory
stimulation is over.
The brief preservation of sensations in sensory memory gives
you additional time to try to recognize stimuli.
Short-term memory (STM) is a limited-capacity store that can
maintain unrehearsed information for up to about 20 seconds.
There is a way to maintain information in your short-term
store indefinitely by engaging in rehearsalthe process of
repetitively verbalizing or thinking about the information.
Cognitive psychologists often distinguish between maintenance
rehearsal and more elaborative rehearsal or processing.
In using maintenance rehearsal you are simply maintaining the
information in consciousness, while in more elaborative
processing, you are increasing the probability that you will retain the information in the future by, for example, focusing
on the meaning of the words in the list you are trying to
Durability of Storage
Without rehearsal, information in STM is lost in less than 20
Theorists originally believed that the loss of information
from STM 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
The small capacity of STM was pointed out by George Miller in
a famous paper called The Magical Number Seven, Plus or Minus
Two: Some Limits on Our Capacity for Processing Information.
Miller noticed that people could recall only about seven items
in tasks that required them to remember unfamiliar material.
You can increase the capacity of your STM by combining stimuli
into larger, possibly higher-order units, called chunks.
A chunk is a group of familiar stimuli stored as a single
Short-Term Memory as Working Memory
Studies showed that STM is not limited to phonemic encoding as
originally though and that decay is not the only process
responsible for the loss of information from STM.
These and other findings suggested that STM involves more than
a simple rehearsal buffer, as originally envisioned.
Alan Baddeley proposed a more complex, modularized model of
STM that characterizes it as working memory.
Baddeleys model of working memory consists of four
The first component is the phonological loop that represented
all of STM in earlier models. The component is at work when
you use recitation to temporarily remember a phone number.
Baddeley believes that the phonological loop evolved to
facilitate the acquisition of language.
The second component in working memory is a visuospatial
sketchpad that permits people to temporarily hold and
manipulate visual images. This element is at work when you try
to mentally rearrange the furniture in your bedroom or map out
a complicated route that you need to follow to travel
somewhere. Researchers investigate this module of working
memory by showing subjects visual sequences and spatial
arrays, which they are asked to re-create.
The third component is a central executive system. It controls
deployment of attention, switching the focus of attention and
dividing attention as needed (diving attention between a
conversation with your mother and a TV show you are