Transcript Lecture 16
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 longterm 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