Chapter 6

The Atkinson-Shiffrin Model

n Information-Processing theory

• Uses computer science to provide models to help psychologists understand the processes of memory

n Three different memory systems:

• Sensory

n Holds information from the senses for a period of time ranging from only a fraction of a second to about 2 seconds.

TRY IT: Glance at the three rows of letters to be shown below, then close your eyes. How many letters can you recall?

X B D F

M P Z G

L C N H

Process of Remembering

Three Memory System

Sensory memory
holds a visual image, like a lightening bolt, for a fraction of a second – just long enough for you to perceive a flow of movement.

Short Term Memory

• Codes information according to sound

• Holds about seven items for less than 30 seconds without rehearsal

• Also called working memory

• Displacement

n Event that occurs when short-term memory is filled to capacity

n Each new, incoming item pushes out an existing item which is then forgotten

• Chunking

n Grouping or organizing bits of information into larger units

Short-Term Memory

n Rehearsal

• Purposely repeating information to maintain it in short-term memory

• Maintenance rehearsal

n Repeating information over and over again until it is no longer needed

n May lead to storage of information in long term memory

n Saying a phone number over and over until you dial it

• Elaborative rehearsal

n A memory strategy that involves relating new information to something that is already known

n Memorize the French word for stairs e’scaliers by associating it with the English word escalator

Long-Term Memory (LTM)

The memory system with virtually unlimited capacity that contains vast stores of a person’s permanent or relatively permanent memories

n Declarative memory

• Stores facts, information, and personal life events

• Can be brought to mind verbally or as images

• Also called explicit memory

n Episodic memory

• Records events as they have been subjectively experienced

n Semantic memory

• Stores general knowledge or objective facts and information

n Nondeclarative memory

• Stores motor skills, habits, and simple classically conditioned responses

n Priming

• An earlier encounter increases speed or accuracy at a later time

Subsystems of Long-Term Memory

Declarative Memory

Three Kinds of Memory Tasks

n Recall

• Producing required information by searching memory

• Retrieval cue

n Any stimulus or bit of information that aids in retrieval

n Recognition

• Identifying material as familiar or as having been encountered before

• Only requires that you recognize it, not recall all the information

n Relearning

• Retention expressed as the percentage of time saved when material is relearned

Serial Position Effect

For information learned in a sequence, recall is better for the beginning and ending items than for the middle items in the sequence.

n Primacy effect

• Tendency to recall the first items in a sequence more readily than the middle items

n Recency effect

• Tendency to recall the last items in a sequence more readily than those in the middle

n Poorer recall of information in the middle of a series because it is no longer in short-term memory

n Serial position effect supports notion of separate systems for short- and long-term memory

Context Dependent Memory

• Information is easier to recall when a person is in the same environmental context they were in when they learned it.

• Elements of the physical setting where information is learned are encoded along with the memory

The Nature of Remembering

n Reconstruction

• Account of an event pieced together from a few highlights

• May or may not be accurate

n Schemas

• Integrated framework of knowledge and assumptions about people, objects, and events

• Affect how the person encodes and recalls information

• May or may not be accurate

• Memories are usually reconstructed, shorter, and more consistent with an individual’s viewpoint

• Puzzling features are adapted to fit expectations or familiar objects

• Positive bias

n Pleasant events are remembered more than unpleasant events

n Aids with current emotional well-being

Reconstruction

Flashbulb Memories

n An extremely vivid memory of the conditions surrounding one’s first hearing the news of a surprising, shocking, or highly emotional event

• News of the death or injury of a family member or friend

• News of a catastrophe

n Easily recalled due to high:

• Emotionality

• Consequentiality – importance of the consequences of the event

• Rehearsal – how often people think or talk about events afterward

n Appear to be forgotten at about the same rate and ways as other kinds of memories

n Eyewitnesses to the aftermath of the terrorist attacks on the Pentagon almost certainly formed flashbulb memories of the witnessed events.

n Do you remember where you were and what you were doing when you heard the news on September 11, 2001?

Memory and Culture

n The matter and manner of recall are often predominantly determined by social influences.

• Swazi herdsman recall minute individual differences of every cow

• History of a tribe preserved orally by specialists

n Impressive memory feats possible because its an integral and critically important part of the culture in which they live

• Other memory components usually no different

n Stories set in own cultures more easily remembered than those set in other cultures

n Culturally based schemas may also influence memory and recall

Eyewitness Testimony

n Highly subject to error — should be viewed with caution

• U.S. Department of Justice prepared national guidelines for collecting eyewitness evidence in 1999

• Minimize errors in the identification of suspects by asking eyewitness to first describe the perpetrator and then search for photos to match the description

• Lineup errors are minimized through sequential viewing

n Viewing members of lineup one at a time rather than all together

• Mistakes are more likely if person is of another race or if a weapon was used in the crime

• Misinformation effect — misleading information supplied after the event confounds a witnesses memory

• Stress of the event does not lessen ability to remember critical details while less important details may be lost

• Confidence of eyewitnesses has much to do with ease of recall, not accuracy of information

Repressed Memories

n Controversy initially surrounded sex abuse victims and the idea:

• “If you think you were abused and your life shows the symptoms, then you were” — removed responsibility of establishing proof

n May be false — “recovered” memories influenced by suggestions

n Hypnosis techniques often used to aid in recovery of memories

• Hypnosis does not improve the accuracy of memory, only the confidence in what was remembered

n Persons asked to imagine a fictitious event develop a false memory of the event

n Repeated exposure to suggestions of false memories can create them

n Individual differences in suggestibility may also play a role

n Infantile amnesia – the inability to recall events from the first few years of life likely due to limited language and hippocampus development

n APA & AMA both agree that repressed memories exist and that false memories can be constructed.

Biology and Memory

n Hippocampal region

• Part of the limbic system which includes the hippocampus and underlying cortical areas

• Involved in the formation of semantic memories

n Anterograde amnesia

• Inability to form long-term memories of an event occurring after brain injury or surgery

• Other long- and short-term memories usually are intact

Biology and Memory

n Hippocampus

• Especially important in forming episodic memories

• Memories can be retrieved without hippocampal involvement

• Involved in creating intricate neural spatial maps

n Semantic memories

• Involve the hippocampus and other parts of hippocampal region

• Other long- and short-term memories are usually intact

The posterior (rear) hippocampus of an experienced London taxi driver, shown in red in the MRI scan on the left, is significantly larger than the posterior hippocampus of a research participant who was not a taxi driver, shown in red in the scan on the right.

Biology and Memory

n Neuronal changes and memory

• Aplysia sea snail study mapped neural circuits formed as the animal learned and remembered

• Donald Hebb argued in 1940s that learning and memory must involve the enhancement of transmission at the synapses between neurons

n Long-term Potentiation (LTP)

• An increase in the efficiency of neural transmission at the synapses that lasts for hours or longer

• Does not take place unless sending and receiving are activated at the same time by intense stimulation

• Receiving neuron must be depolarized (ready to fire) when the stimulation occurs

Hormones and Memory

n Strongest and most lasting emotions are usually fueled by emotion

• Cahill and McGaugh two pathways for forming memories

q Ordinary information

q Memories fired by emotion

• Adrenal glands release epinephrine and norepinephrine into bloodstream

• Fight or flight response imprints powerful and enduring memories surrounding threatening situations

• Amygdala activates during emotional episodes and may explain the intensity and durability of flashbulb memories

• High levels of stress hormone cortisol interferes with memory

• Estrogen improves working memory efficiency and the development and maintenance of synapses in the brain

Ebbinghaus’s Curve of Forgetting

Cause of Forgetting

Causes of Forgetting

n Interference

• Information or associations stored hinder the ability to remember it

• Proactive interference

n Information or experiences already stored hinder memory

• Retroactive interference

n New learning interferes with recall of previous learning

Causes of Forgetting

n Consolidation failure

• Any disruption in the consolidation process that prevents a long-term memory from forming

n Retrograde amnesia

• Loss of memory for experiences that occurred shortly before a loss of consciousness

n Motivated forgetting

• Suppression or repression in an effort to protect from material that is painful, frightening, or otherwise unpleasant

n Repression

• Removing unpleasant memories from one’s consciousness, so that one is no longer aware that a painful event occurred

Causes of Forgetting

n Amnesia

• Partial or complete loss of memory due to loss of consciousness, brain damage, or psychological cause

n Prospective forgetting

• Not remembering to carry out some intended action

n Forgetting to do something that is unimportant or unpleasant

n Retrieval failure

• Not remembering something one is certain of knowing

• Tip-of-the-tongue phenomenon

n Trying to recall some bit of information, knowing you knew it, but not able to come up with it

Improving Memory

n Over-learning

• Practicing or studying material beyond the point where it can be repeated once without error

• People remember material better and longer if they over-learn it

Improving Memory

n Massed practice

• Learning in one long practice session with out rest periods

n Spaced practice

• Learning in short practice sessions with rest periods in between

• More effective with learning than massed practice

• Applies to motor skills, learning facts and information

Improving Memory

n Method of Loci

• Begin by thinking of locations that are in sequence

• Visualize one item to be remembered in each location

Improving Memory

The First-Letter Technique

n Take the first letter of each item to be remembered and form a word, a phrase, or a sentence with those letters

n To remember the colors:

• Red, orange, yellow, green, blue, indigo, violet

• Form the name Roy G. Biv

.

Improving Memory

Pegword System

• Connect each item with a “peg”

• Tell a brief story about the item and the peg