PSY100H1 Lecture Notes - Short-Term Memory, Implicit Memory, Episodic Memory
Chapter 7: Attention and Memory
Henry Molaison (HM) had uncontrolled seizures, the anticonvulsive drugs at the time couldn’t
Underwent surgery, removed parts of his medial temporal lobes, including hippocampus.
Seizures were quieted, but lost ability to form new long term memory.
Short term memory was intact but it could not be transformed to long term memory. Brenda
Miller studied him for 40 years, Tracing Task: his performance improved gradually, proving he
could retain some information.
Memory: The nervous system’s capacity to acquire and retain usable skills and knowledge.
(incomplete, biased and distorted)
How does attention determine what is remembered?
Look and Listen commands that direct attention. To get info into memory person needs to
attend “Pay attention”
Visual Attention is Selective and Serial (Anna Treisman)
We automatically identify “primitive” features, such as color, shape, orientation, and
movement. Separate systems analyze objects’ different visual features.
Parallel Processing: Allows us to process info from different visual features at the same time by
focusing on targets over distracters.
Treisman’s visual search tasks (feature search tasks) participants search for targets that differ
from the others in only one feature. Other objects on screen are called distracters.
Searching for a single feature, such as a red stimulus, is fast and automatic, searching for two
features is serial -> you need to look at the stimuli one at a time) and effortful ( takes longer and
requires more attention.
Conjunction Task: The stimulus you are looking for is made up of two simple features.
Auditory Attention Allows Selective Listening
Attention is limited; it is hard to perform two tasks at the same time, esp. if you rely on the
1953 psychologist E.C. Cherry Cocktail Party Phenomenon: you can focus on a single convo in
the midst of a party, yet a pertinent stimulus, like hearing your name in another convo, or jucy
gossip can capture your attention.
Cherry developed selective listening studies to examine what people’s minds do with
unattended info when people pay attention to one task.
His developed Shadowing: Participant receives a different auditory messages in each ear, but is
required to repeat (“shadow”) only one.
Some info goes through the filter of attention eg: hearing your name, or the name of someone
Selective Attention Can Operate at Multiple Stage of Processing
1958 Psychologist Donald Broadbent developed filter theory to explain selective nature of
Attention is like a gate that opens for important info and closes for irrelevant info.
Some stimuli demand attention and shut off the ability to attend to anything else.
Faces are good example of stimuli that capture attention provide social info such as potential
mate or potential danger.
Threats are prioritized over less meaningful stimuli by the attention system.
Decisions about what to attend to are made early in the perceptual process, but other studies
reveal unattended info is processed at least to some extent.
Selective-listening studies have found that even when participants cannot repeat an unattended
message, they still have processed its contents.
Change Blindness: The common failure to notice large changes in the environment.
o Shows large discrepancies exist between what people believe they see and what they
actually see. Shows how attention influences memory.
What are the Basic Stages of Memory?
In late 1960s psychologists thought memory processing is analogous to computers info
processing. Memory’s multiple processes operate in 3 phases:
o Encoding Phase: occurs at time of learning, as info is encoded or changed into neural
code that the brain can use.
o Storage Phase: Can last a sec to a lifetime (there are 3 storage systems; they differ in
how long they store information.)
o Retrieval Phase: Act of recalling or remembering stored information to use it.
Atkinson and Shriffin’s Model Memory Model: The three-stage memory system that involves
Memory is a three part system that involves: Sensory Memory, Short-Term (working memory)
The model is somewhat inaccurate and incomplete, vocabulary from it remain widely used
A: Information Processing Model
B: Modal Memory Model
Info is acquired and
processed into neural code
(just as info is entered with
Info is stored in brain (just
as it is stored in a
computer’s hard drive)
Info is retrieved when it is
needed (just as it shows up
on screen to be viewed)
Unattended info is lost
2.Short Term Memory
rehearsed info is lost
3. Long Term Memory
Some info may be lost
Sensory Memory Is Blind
Sensory Memory: Memory for sensory information that is stored briefly close to its original
A sensory memory occurs when a light, a sound, an odor, a taste, or a tactile impression leaves a
vanishing trace on the nervous system for a fraction of a second.
o When someone says, “ You are not paying attention to me,” you can often repeat back
the last few words the person spoke even of you were think of something else. (Dolder)
1960 Cog Psy. George Sperling provided initial empirical support for sensory memory.
o His experiment: 3 rows of letters were flashed on screen 1/20 of second. Most people
believed they had seen all the letters, but could recall 3 or 4. The time it took them to
name the first 3 or 4, they forgot the others.
o Participants very quickly lost their memories of exactly what they had seen. Tested this
hypothesis by showing the same letters, but signaling a H (top row), M (Middle row),
and L (bottom row) pitched sound as soon as the letters disappeared. Now people were
able to tell almost all of the letters. But this correlated with the delay between the
letters’ disappearance and the sound.
o Conclusion: Visual Memory for ~1/3 sec, after which the sensory memory trace faded
progressively until it was no longer accessible.
Our sensory memories allow us to experience the world as a continuous stream rather than in
discrete sensations. (Like a motion picture: movie)
Working Memory is Active
Info attended to is passed from sensory stores to Short-Term Memory (STM): A limited capacity
memory system that holds info in awareness for a brief period, but longer than sensory memory
This short term system also called Working Memory(WM): to indicate it is a memory(storage)
system that combines info from different sources and can work on the info we have in memory.
Also called Immediate Memory: consists of our fleeting thoughts, ever-shifting feelings, and
temporary impressions of things in the world. Analogous to the RAM.
Info remains in the WM for 20 to 30 seconds, then disappears until you actively prevent that
from happening by thinking about or rehearsing the information.
Memory Span and Chunking
WM can hold a limited amount of information.
Cognitive psychologist George Miller said the limit is generally 7±2, a figure referred to as
memory span. Some intelligence tests use memory span as a measure of IQ.
Chunking: Organizing information into meaningful units to make it easier to remember.
o Master chess players can reproduce exact arrangement of pieces moments later.
The greater your expertise with the material, the more efficiently you can chunk information,
and therefore the more you can remember.
Updating of old WM; retrieval, transformation, and substitution -> eg: 20+5=25