心理学概论第六章记忆

Chapter 6 Memory

第6章记忆

This chapter includes three modules: first, module 18 tells us how the memory works; second, module 19 introduces recalling in long-term memories; last, we will learn why we forgetting when our memory fails.

MODULE 18 ENCODING, STORAGE AND RETRIEV AL OF MEMORY

Memory is any system—human, animal, or machine—that encodes, stores, and retrieves information. The process of memory is encoding, storage and retrieval. Encoding is involving the modification of information to fit the preferred format for the memory system. Storage is involving the retention of encoded material over time. Retrieval is involving the location and recovery of information from memory.

THE SENSORY REGISTERS

Scientific research on memory began with Ebbinghaus's experiments in the nineteenth century. Today the information-processing model of memory describes how information is encoded, organized, and stored in memory, and how it is retrieved from memory.

THE SENSORY REGISTERS

Sensory registers are the entry points for raw information from all the senses. If we do not process this information further, it disappears.

Visual and Auditory Registers

As new visual information enters the registers, old information (the icon, or visual image) is "masked" almost immediately and disappears. Otherwise, the registers would overload as visual information piled up and became scrambled. Auditory information fades more slowly; the echo may last for several seconds.

Initial Processing

From the mass of incoming information, we select elements and hold them for further processing. In this process, called attention, we also give meaning to the information.

SHORT-TERM MEMORY

Information that we attend to enters short-term memory (STM), also called primary memory and working memory. STM contains everything that we are consciously aware of at any instant. STM not only briefly stores information but also processes that information further.

Capacity of STM

STM has its limits. Researches have found that STM can hold only as much information as can be repeated or rehearsed in 1.5 to 2 seconds, which is usually 5 to 10 separate bits of information. We can process more information by grouping it into larger meaningful units, a process called chunking.

Encoding in STM

Information can be encoded for temporary storage in STM phonologically (according to the way it sounds), in visual form, or in terms of its meaning. Researchers conclude that STM has a greater capacity for material encoded visually than for information encoded phonologically.

Retention and Retrieval in STM

Material in STM disappears in 15 to 20 seconds unless it is rehearsed or practiced. According to decay theory, material is lost from STM simply because of the passage of time. Interference theory contends that interference from other information leads to forgetting from STM. Memory loss from STM is permanent. This prevents us from becoming overwhelmed with a mass of irrelevant, trivial, or unrelated data.

Rote Rehearsal

Through rote rehearsal, or maintenance rehearsal, we retain information in STM for a minute or two by repeating it over and over again. However, rote memorization does not promote long-term memory.

Elaborative Rehearsal

Elaborative rehearsal, or "the linking of new information in STM to familiar material stored in long-term memory," enables us to retain information for a longer time in STM. Through elaborative rehearsal, we process new data in a deeper and more meaningful way than through simple rote repetition.

An accident or severe interference can make unrehearsed information disappear. Retrograde amnesia (the inability to recall events immediately preceding an accident or injury) is caused by an interruption in elaborative rehearsal.

LONG-TERM MEMORY

Long-term memory (LTM)is more or less permanent and stores everything we "know." Semantic memory is the portion of LTM that stores general facts and information in dictionary or encyclopedia form. Another facet of LTM, episodic memory, stores information rich with personal meaning.

Encoding in LTM

Most of the information in LTM seems to be encoded in terms of meaning. Through rehearsal, we extract the meaning of information and link it to as much

material that is already in LTM as possible. The way in which we encode material for storage in LTM affects the ease with which we can retrieve it later on.

Implicit Memory

Implicit memory refers to memories for information that either was not intentionally committed to LTM or is retrieved unintentionally from LTM. By contrast, explicit memory allows us to recall information that is intentionally committed to LTM and retrieved from LTM.

Storage and Retrieval in LTM

Most, if not all, of the information in LTM remains there more or less permanently, but we can''t always retrieve it when we need to, as the tip-of-the-tongue phenomenon shows.

Especially disturbing events may cause us to repress memories or even to forget personal memories altogether (hysterical amnesia). Sometimes we "reconstruct" our memories for social or personal self-defense.

Recognizing that past reactions and experiences affect our present memory, researchers developed the schema theory. A schema(plural: schemata) is a set of beliefs or expectations about something based on past experience, and it serves as a basis or standard for comparison with a new experience. Using schemata, we not only comprehend and interpret present circumstances but also streamline our retrieval processes. Retrieval is also aided by extensive cues and links with other material in LTM.

BIOLOGICAL BASES OF MEMORY

Research has shown that some memories may be localized in certain portions of the brain; however, most memories are stored in various parts of the brain. One reason may be that several senses can contribute to one memory and might be stored in the brain''s centers for vision, speech, smell, and touch. Also, a recent finding shows that the basal forebrain may be involved in binding together information stored separately throughout the brain. The hippocampus is involved in transferring information from short-term to long-term memory.

MODULE 19 RECALL LONG-TERM MEMORIES

Retrieval cues are the “search terms” used to active a memory. It maybe a word, an emotion, or a sound.

Flashbulb memories

Flashbulb memories are a clear and vivid long-term memory of an especially meaningful and emotional event.Years after a dramatic or significant event occurs, people often have vivid memories of that event as well as the incidents surrounding it.

These memories are known as flashbulb memories. According to the "now print" theory, the event triggers a mechanism in the brain that captures the memory, prints it, and stores it for a long time essentially unchanged. Recent research has challenged the assumptions that flashbulb memories are accurate and stable.

Autobiographical Memory

Autobiographical memory refers to your recollection of events that happened in your life and when those events took place. People generally cannot remember events that occurred prior to age 2, and our earliest memories frequently concern events that significantly changed our lives or were particularly frightening.

MODULE 20 FORGETTING: WHEN MEMORY FAILS

Several reasons for Forgetting

Information in sensory and short-term memory appears to decay if it does not receive further processing. New information may "erase" old information in long-term memory. Proactive and retroactive interference may take place. Cue-dependent forgetting may occur when retrieval cues are inadequate. Some lapses in memory may be due to psychogenic amnesia, which is the forgetting of disturbing or shocking events and psychologists are divided about why this occurs.

To the extent that information is apparently lost from LTM, researchers attribute the cause to interference from competing information. Interference may come from two directions: in retroactive interference, new information interferes with old information already in LTM; proactive interference refers to the process by which old information already in LTM interferes with new information. Interference affects both storage and retrieval of information.