Chapter 2 Review
Key Terms from Lecture
Short-term memory (STM): the capacity to store small amounts of information over a short
period of time. It is part of the working memory system.
Working memory (WM): a system that allows us to temporarily store and actively manipulate
information for problem solving, reasoning, learning, and comprehension.
Chunking: refers to the process of organizing or grouping individual components into
meaningful larger units. During word list learning, for example, one may automatically group
words according to semantic categories such as animals with fur.
Simple trace decay: thought to explain forgetting in STM when rehearsal is prevented. Simple
trace decay is thought to occur over a very short time interval (15-18 sec).
Proactive interference: occurs when old or previously learned information interferes with
memory for new information. For example, studying for a Spanish language exam before
studying for a German language exam may result in proactive interference of information. The
Spanish words that you just studied interfere with your ability to memorize new words in
German because you mix them up.
Retroactive interference: occurs when newly learned information interferes with memory for
old or previously learned information. For example, once a new telephone number is memorized
it may interfere with memory for the old telephone number.
Verbal short-term memory: refers to STM for verbal or acoustic information.
Phonological loop: the term applied by Baddeley and Hitch (1974) to describe the process of
articulatory or speech-like rehearsal in verbal STM. It is made up of two subcomponents called
the short-term store and articulatory rehearsal process.
Short-term store: a limited capacity store for sounds or phonological code. Items in this store
decay within a few seconds if they are not rehearsed.
Articulatory rehearsal process: involves saying the word or digit to oneself aloud or
subvocally in order to refresh the memory traces in the short-term store.
Visual short-term memory: refers to memory for objects and visual patterns.
Spatial short-term memory: refers to memory for where objects are located in space.
Phonological similarity effect: describes the detrimental effects on memory of having similar
sounding items grouped together. For example, if recognition memory is tested for letters of the
1 alphabet, presenting letters with similar phonological characteristics (e.g., B and V) may
interfere with correct recognition of letters.
Word length effect: describes the detrimental effects on memory of having longer words that
take longer to say grouped together. This is because rehearsal involves articulating longer words
so more trace decay and/or forgetting occurs.
Articulatory suppression: refers to the interference or prevention of articulatory rehearsal by
having participants continuously repeat a language-like sound such as “la-la-la-la-la.”
Double dissociation: is a term that is often used in neuropsychology when two patient groups
show opposite patterns of deficit linked to different areas of brain damage.
Key Concepts from Lecture
Differences between STM and WM:
• More passive rehearsal process for • More active manipulation of
maintaining information. information.
• Temporary “working on” memory • Temporary “working with” memory
• Part of WM. • Works with information from STM and
long-term memory (LTM) for the task
Working memory allows for temporary storage and manipulation of information for problem
solving, reasoning, learning, and comprehension.
Memory span capacity
George Miller worked for Bell Laboratories and found that most individuals can remember
7 +/- 2 items in STM. He also showed that chunking increases the number of items that can be
remembered because the unit then becomes the group of “chunked” items. Thus, most people
can remember 7 +/- 2 chunks. If each chunk includes many items, you can store significantly
more items in STM through this process.
Duration of memory trace in STM
Peterson and Peterson (1959) trace-decay experiment:
1. They presented participants with trigrams (3-letter sequences) for study.
2. Participants were then asked to count backwards by 3 starting from the number 49. In
other words, they were given a distractor task.
3. Participants were asked to recall the trigrams.
1. Introducing an unrelated distractor task lowers participants’ memory for studied trigrams.
2 2. Peterson and Peterson (1959) concluded that STM traces decay quickly as a function of
time, which they called simple trace decay.
Does forgetting occur because of decay or distraction?
Paul Muter (1980) distraction experiment:
1. Participants were presented with tr