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MemoryChapter 6
Memory
Memory is the ability to recall past learning, events, images, and ideas
It is also the storage system that allows a person to retain and retrieve information
Neuroscience and Storage
Hebb suggested that when groups of neurons are stimulated, they form patterns of neural activity
When specific groups of neurons fire frequently, they establish regular neural circuits
Neuroscience and Storage
H. M. was a man whose brain was damaged as a result of a surgery performed to control epilepsy
His short-term storage was intact, but he was unable to form new long-term declarative memories
The process of forming permanent memories is called consolidation
Neuroscience and Storage
If a neuron is stimulated, biochemical processes make it easier for the neuron to respond again
This increased responsiveness is long-term potentiation
It is now accepted that the structure of synapses change after learning
Retrieval
Retrieval is the process by which stored information is recovered from memory
Two measures of retrieval are recall and recognition
Recall
In recall tasks, participants must retrieve previously presented information
The information usually consists of lists of digits or letters
Recall
In free recall, participants can remember items in any order
Serial recall is more difficult because the items must be recalled in the order they were presented
In paired associates tasks, participants are given a cue to help them recall the second of a pair of items
Recognition
In a recognition task, the participant must recognize a previously encountered item
Multiple choice questions are an example of a recognition task
Relearning
Relearning assesses how long it takes to relearn previously learned material
Rapid relearning is assumed to indicate some residual memory
Encoding Specificity
Retrieval is faster and more accurate if given a cue that relates to some aspect of the originally restored item
This supports the encoding specificity principle, that the effectiveness of a retrieval cue depends on how well it matches up with the original encoded memory
State-Dependent Learning
State-dependent learning is that information learned while a person is in a specific state is recalled most accurately if the person is in that state again
State-dependent learning is associated with drug use, time of day, and traumatic experiences
Flashbulb Memory
Vivid memories of dramatic events are referred to as flashbulb memories
Brown and Kulik argued that there is a special type of memory for events that have a critical level of emotionality and what they called consequentiality
Gender and Memory
Research shows very few differences between women’s and men’s memories
Men and women do attend to different types of information
Primacy and Recency Effects
In a serial position study, participants are asked to recall a list of words
Typically, recall is high for words at the beginning of the list, a primacy effect, and for words at the end of the list, a recency effect
Figure 6.8 A Serial Position Curve
Imagery
Imagery is the creation of a mental picture of a sensory or perceptual experience
Paivio suggests that words connected via images become conceptually linked
Forgetting: When Memory Fails
Hermann Ebbinghaus was the first person to study memory scientifically and systematically
His research was performed with three letters strung together to form nonsense syllables
Initially, he found that shorter lists could be learned more rapidly than longer ones
Forgetting
Later, Ebbinghaus used relearning, or what he called the savings method
In this method, he measured how long it took people to relearn a list after varying amounts of time
Ebbinghaus found that forgetting occurs rapidly
Figure 6.12 Ebbinghaus’s Forgetting Curve
Forgetting
Frederick Bartlett found that college students changed stories when they recalled the stories
Students shortened and simplified details (leveling)
Other details were emphasized more (sharpening)
Participants also altered facts to fit their world view (assimilation)
Forgetting
Reconstruction occurs because people develop a schema
A schema is a conceptual framework that organizes information
Key Causes of Forgetting
Decay is the loss of information from memory due to disuse and the passage of time
Interference is the suppression of one bit of information by another
Interference
Proactive interference (inhibition) is a decrease in accurate recall of information as a result of the effects of previous learning
Retroactive interference (inhibition) is a decrease in accurate recall as a result of the subsequent presentation of information
Figure 6.14 Proactive and Retroactive Interference
Interference in Attention
Schacter (2001) says interference causes absentmindedness
When people attend to more than one thing at a time, their attention is divided
Eyewitness Testimony
The legal system has generally accepted eyewitness testimony as some of the best evidence
If memory is a reconstructive process, then it is not a literal reproduction of the past
Neuroscience and Forgetting
Much of the early work on the neuroscience of forgetting began with the study of amnesics
Retrograde amnesia is the inability to remember events and experiences that preceded a damaging event
Anterograde amnesia is the inability to remember events and experiences that occur after an injury or brain damage