Memory
KEY POINTS
Introduction: What Is Memory?
Memory refers to the mental processes that enable us to acquire, retain, and retrieve information. Key memory processes are encoding, storage, and retrieval.
The Stage Model of Memory
The stage model of memory describes human memory as the process of transferring information from one memory stage to another. The three stages of memory are sensory memory, short-term memory, and long-term memory.
Sensory memory briefly stores information about the environment. Information that we attend to is transferred from sensory memory to short-term memory; other information fades quickly.
George Sperling discovered that visual sensory memory holds information for about half a second before the information fades.
There is a separate sensory memory for each sense. Visual and auditory sensory memory are the most thoroughly studied. Auditory sensory memory lasts up to a few seconds.
Short-term memory provides temporary storage for information transferred from sensory memory and information recalled from long-term memory. Maintenance rehearsal keeps information active in short-term memory. Because of either decay or interference, information that is not rehearsed is lost within about 20 seconds.
The capacity of short-term memory is limited to about seven items, plus or minus two. Chunking can be used to increase the amount of information held in short-term memory.
Alan Baddeley’s model of working memory has three components: the phonological loop, the visuospatial sketchpad, and the central executive. Working memory is the short-term memory system that involves the active, conscious manipulation of verbal or spatial information.
Long-term memory stores a limitless amount of information for extended periods of time.
Encoding transforms information into a form that can be stored and retrieved later. The most effective encoding strategies involve elaborative rehearsal.
Long-term memory includes procedural, episodic, and semantic memory. Explicit memories can be consciously recalled. Implicit memories cannot be consciously recalled, but affect behavior or performance. Information in long-term memory is clustered into related groups during recall. The semantic network model describes the organization of long-term memory.
Retrieval: Getting Information from Long-Term Memory
Retrieval refers to the process of accessing information stored in long-term memory.
Retrieval cues are hints that help us retrieve stored memories. Sometimes stored memories cannot be retrieved because of retrieval cue failure, such as in tip-of-the-tongue (TOT) experiences.
Retrieval can be tested using recall, cued recall, and recognition measures. The serial position effect is our tendency to remember the first and last items in a series best.
According to the encoding specificity principle, recreating aspects of the original learning conditions is one way to increase retrieval effectiveness. Examples of the encoding specificity principle include the context effect and mood congruence.
Memories that are highly unusual tend to be easier to retrieve from long-term memory. Flashbulb memories can be extremely vivid, but, like normal memories, they are not always accurate.
Forgetting: When Retrieval Fails
Forgetting refers to the inability to recall information that was previously available.
The general pattern of forgetting is reflected in the forgetting curve, which is based on the classic research of Hermann Ebbinghaus.
Psychologists have identified several factors that contribute to forgetting. Encoding failure, one cause of forgetting, is especially common when attention is divided. Divided attention may contribute to déjà vu experiences. Retrieval cue failure is implicated in prospective memory failures. Decay theory makes sense intuitively but has little research support.
According to interference theory, forgetting results from retroactive and proactive interference with other information.
Motivated forgetting can result from suppression or repression. Research support for repression is mixed.
Imperfect Memories: Errors, Distortions, and False Memories
Misidentification by eyewitnesses is the leading cause of false conviction in rape and murder cases. Because retrieval involves the reconstruction of memories, memory details can become distorted. The misinformation effect and source confusion are both potential causes of eyewitness error and false memories. Schemas and scripts also contribute to memory errors.
Imagination inflation helps explain how false memories of childhood experiences can be created. Being lost in a shopping mall and putting slime in the teacher’s desk in elementary school are some examples of false memory studies. Imagining vivid sensory details adds greatly to confidence in false memories.
The Search for the Biological Basis of Memory
After extensive research, Karl Lashley concluded that memories are distributed rather than localized as a memory trace. Richard Thompson showed the physical changes that are associated with a simple conditioned reflex in rabbits. Today, it is believed that memories are both localized and distributed. Complex memories involve interrelated changes among many different brain areas.
Eric Kandel showed that functional and structural changes in neurons are associated with acquiring a conditioned reflex in the sea snail Aplysia. Enduring memories are believed to be stored through long-term potentiation, a long-lasting increase in synaptic strength.
Retrograde amnesia results when memory consolidation is disrupted. Anterograde amnesia results when the hippocampus is damaged, as in the case of H.M. Amnesia affects episodic memories rather than procedural memories and explicit memory rather than implicit memory. Brain structures involved in memory include the hippocampus, the amygdala, the cerebellum, the frontal lobes, the medial temporal lobes, and the prefrontal cortex.
Alzheimer’s disease (AD) is the most common cause of dementia, which refers to impairment in memory, reasoning, language, and other cognitive functions.
Match each of the terms on the left with its definition on the right. Click on the term first and then click on the matching definition. As you match them correctly they will move to the bottom of the activity.
misinformation effect mood congruence proactive interference procedural memory prospective memory recall recognition repression retrieval retrieval cue retrieval cue failure retroactive interference retrograde amnesia schema script semantic memory semantic network model sensory memory serial position effect short-term memory source confusion source memory or source monitoring stage model of memory storage suppression tip-of-the-tongue (TOT) experience working memory Alzheimer's disease (AD) amnesia anterograde amnesia chunking clustering context effect cued recall déjà vu experience decay theory dementia elaborative rehearsal encoding encoding failure encoding specificity principle episodic memory explicit memory false memory flashbulb memory forgetting imagination inflation implicit memory interference theory long-term memory long-term potentiation maintenance rehearsal memory memory consolidation memory trace or engram | The mental processes that enable you to retain and retrieve information over time. A test of long-term memory that involves retrieving information without the aid of retrieval cues; also called free recall. A test of long-term memory that involves identifying correct information out of several possible choices. A memory phenomenon in which vividly imagining an event markedly increases confidence that the event actually occurred. A memory phenomenon that involves the sensation of knowing that specific information is stored in long-term memory, but being temporarily unable to retrieve it. Information or knowledge that affects behavior or task performance but cannot be consciously recollected; also called non-declarative memory. A model that describes units of information in long-term memory as being organized in a complex network of associations. Severe memory loss. A progressive disease that destroys the brain's neurons, gradually impairing memory, thinking, language, and other cognitive functions, resulting in the complete inability to care for oneself; the most common cause of dementia. The mental or verbal repetition of information in order to maintain it beyond the usual 20-second duration of short-term memory. An organized cluster of information about a particular topic. Motivated forgetting that occurs consciously; a deliberate attempt to not think about and remember specific information. An encoding specificity phenomenon in which a given mood tends to evoke memories that are consistent with that mood. The inability to recall long-term memories because of inadequate or missing retrieval cues. Rehearsal that involves focusing on the meaning of information to help encode and transfer it to long-term memory. The tendency to recover information more easily when the retrieval occurs in the same setting as the original learning of the information. Forgetting in which a new memory interferes with remembering an old memory; backward-acting memory interference. The principle that when the conditions of information retrieval are similar to the conditions of information encoding, retrieval is more likely to be successful. A schema for the typical sequence of an everyday event. The hypothetical brain changes associated with a particular stored memory. Loss of memory, especially for episodic information; backward-acting amnesia. Motivated forgetting that occurs unconsciously; a memory that is blocked and unavailable to consciousness. The tendency to remember items at the beginning and end of a list better than items in the middle. Category of long-term memory that includes memories of different skills, operations, and actions. Organizing items into related groups during recall from long-term memory. The temporary storage and active, conscious manipulation of information needed for complex cognitive tasks, such as reasoning, learning, and problem solving. Information or knowledge that can be consciously recollected; also called declarative memory. The active stage of memory in which information is stored for up to about 20 seconds. The theory that forgetting is caused by one memory competing with or replacing another. Forgetting in which an old memory interferes with remembering a new memory; forward-acting memory interference. The process of transforming information into a form that can be entered into and retained by the memory system. The process of recovering information stored in memory so that we are consciously aware of it. The process of retaining information in memory so that it can be used at a later time. The stage of memory that registers information from the environment and holds it for a very brief period of time. Category of long-term memory that includes memories of general knowledge, concepts, facts, and names. A memory illusion characterized by brief but intense feelings of familiarity in a situation that has never been experienced before. A clue, prompt, or hint that helps trigger recall of a given piece of information stored in long-term memory. A long-lasting increase in synaptic strength between two neurons. A memory-distortion phenomenon in which your existing memories can be altered if you are exposed to misleading information. Category of long-term memory that includes memories of particular events. The gradual, physical process of converting new long-term memories to stable, enduring memory codes. Memory for when, where, and how a particular experience or piece of information was acquired. The recall of very specific images or details surrounding a vivid, rare, or significant personal event; details may or may not be accurate. Progressive deterioration and impairment of memory, reasoning, and other cognitive functions as the result of disease, injury, or substance abuse. The inability to recall specific information because of insufficient encoding of the information for storage in long-term memory. A test of long-term memory that involves remembering an item of information in response to a retrieval cue. A memory distortion that occurs when the true source of the memory is forgotten. The stage of memory that represents the long-term storage of information. Loss of memory caused by the inability to store new memories; forward-acting amnesia. The inability to recall information that was previously available. Remembering to do something in the future. The view that forgetting is due to normal metabolic processes that occur in the brain over time. A model describing memory as consisting of three distinct stages: sensory memory, short-term memory, and long-term memory. A distorted or fabricated recollection of something that did not actually occur. Increasing the amount of information that can be held in short-term memory by grouping related items together into a single unit, or chunk. |
Suzanne Corkin (b. 1937) American neuropsychologist who has extensively investigated the neural basis of memory, including several investigations of the famous amnesia patient H.M. (p. 261)
Hermann Ebbinghaus (1850–
Eric Kandel (b. 1929) American neurobiologist, born in Austria, who won a Nobel Prize in 2000 for his work on the neural basis of learning and memory in the sea snail Aplysia. (p. 257)
Karl Lashley (1890–
Elizabeth F. Loftus (b. 1944) American psychologist who has conducted extensive research on the memory distortions that can occur in eyewitness testimony. (p. 248)
Brenda Milner (b. 1918) Canadian neuropsychologist whose groundbreaking research on the role of brain structures and functions in cognitive processes helped establish neuropsychology as a field; extensively studied the famous amnesia patient H.M. (p. 261)
George Sperling (b. 1934) American psychologist who identified the duration of visual sensory memory in a series of classic experiments in 1960. (p. 229)
Richard F. Thompson (b. 1930) American psychologist and neuroscientist who has conducted extensive research on the neurobiological foundations of learning and memory. (p. 256)