CHAPTER 9 (SUMMARY): MEMORY
Memory is the persistence of learning over time. One helpful model of human memory is the
Atkinson-Shiffrin three-stage processing model, which describes how information is encoded,
stored, and retrieved.
Although some types of information are encoded automatically, other types, including
information involving meaning, imagery, and organization, require effort. Mnemonic devices that
use imagery and that organize information into chunks aid memory. Organizing into hierarchies
Information first enters the memory through the senses. We register visual images via iconic
memory and sound via echoic memory.
Although our memory for information just presented is limited to about seven items, our
capacity for storing information permanently is essentially unlimited. The search for the physical
basis of memory has focused on the synapses and their neurotransmitters and on brain circuits.
The hippocampus processes explicit (declarative) memories; even more ancient brain regions—
for example, the cerebellum—process implicit (nondeclarative) memories.
To be remembered, information that is “in there” must be retrieved with the aid of
associations that serve as primers. Returning to the original context sometimes aids retrieval.
While in a good or bad mood we often retrieve memories congruent with that mood. Forgetting
sometimes reflects encoding failure. Without effortful processing, much of what we sense we
never notice or process. Memories may also fade after storage—often rapidly at first and then
leveling off. Retrieval failures may be caused by proactive or retroactive interference or even by
Memories are not stored as exact copies. Rather, they are constructed, using both stored
and new information. Thus, when eyewitnesses are subtly exposed to misinformation after an
event, they often believe they saw the misleading details as part of the event. Memory
researchers are especially suspicious of long-repressed memories of sexual abuse, UFO
abduction, or other traumas that are “recovered” with the aid of a therapist or suggestive book.
Among strategies for improving memory are spaced practice; active rehearsal; encoding of
well-organized, vivid, meaningful associations; mnemonic devices; the return to contexts and
moods that are rich with associations; self-testing and rehearsal; and minimizing interference.
The Phenomenon of Memory
mory as information processing; Sensory memory, short-term memory, and long-term memory.
Our capacity for remembering countless faces, sounds, places, and events, including the
formation of flashbulb memories, raises questions about how our memory system works.
One helpful model of human memory is that of a computer-like information-processing system,