Cognitive Psychology, 2nd Ed.
Chapter 5
Basic Processes of Memory
Encoding concerns perceiving, recognizing,
and further processing an object so that it
can be later remembered.
Storage refers to transferring information
from short-term memory to long-term
memory.
Retrieval concerns searching long-term
memory and finding the event that has been
stored and retrieved.
Sensory Memory
Refers to brief persistence of stimuli following
transduction. Its function is to permit stimuli
to be perceived, recognized, and entered into
short-term memory.
Duration of 250 ms and large capacity.
Iconic vs. echoic sensory memory are similar
but estimates of echoic duration were
distorted by retrieval from short term
memory.
Short- vs. Long-Term Stores:
Behavioral Dissociations
Serial position effect with primacy
caused by retrieval from rehearsed
items stored in long-term memory;
recency benefits from short-term store.
Rapid presentation eliminates primacy
but preserves recency.
Delayed recall eliminates recency but
preserves primacy.
Short- vs. Long-Term Stores:
Neurological Dissociations
Anterograde amnesia refers to difficulty in
remembering events that occur after the
onset of amnesia; disruption in transfer from
short- to long-term store.
Retrograde amnesia refers to the loss of
memory of events that occurred prior to the
onset of the illness; disruption in long-term
storage or retrieval of past events.
Differences Among 3 Memory
Stores
Capacity—only short-term memory is
severely limited in capacity, namely, to
4 chunks.
Duration—differences are an order of
magnitude or more among sensory
(250 ms), short-term (20 s), and longterm (20 years or more).
Similarities Among 3 Memory
Stores
Difficult to distinguish sensory and
short-term memory on the basis of
coding.
Short- as well as long-term stores use
semantic coding, although acousticarticulatory coding dominates shortterm memory as seen in the phonemic
similarity effect.
Similarities among 3 Memory
Stores
Forgetting follows the same power
function regardless of whether the
duration is 20 s or 20 years.
Retrieval may be serial and exhaustive
in short-term memory and parallel in
long-term memory, but the evidence is
mixed.
Working Memory
Refers to the system for temporarily
maintaining mental representations that
are relevant to the performance of a
cognitive task in an activated state.
Reading span measures the capacity of
working memory when attention must
be paid to comprehension of sentences
and to remembering a list of words.
Models of Working Memory
Baddeley proposed a phonological loop and a
visual-spatial sketch pad coordinated by a
central executive.
The loop stores and rehearses verbal
representations whereas the sketch pad does
the same for visual/spatial representations.
Central executive focuses and switches
attention, supervises and coordinates the
storage components, and retrieves
representations from long-term memory.
Neurological Dissociations and
Working Memory
Case studies suggest (1) a semantic
component separate from the
phonological or verbal component, and
(2) a spatial store separate from a
visual store.
Neuroimaging confirms separate spatial,
visual, and verbal stores.