Memory Chapter 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