Human Memory Early Memory Studies Ebbinghaus Hermann Ebbinghaus

Human Memory

Early Memory Studies Ebbinghaus Hermann Ebbinghaus began his work in 1885 using himself as his only subject. He used CVC nonsense trigrams (e. g. , DAX, BIV) for memory materials and identified several basic memory principles which have stood the test of time: Forgetting function -- material is forgotten rapidly, then decreases more slowly over time (i. e. , a negatively accelerated curve): 100 Percent Savings 20 minutes 1 hour 9 hours 50 0 1 2 6 31 Delay (days)

Early Memory Studies (con’t) Savings -- given material which has been forgotten to some degree after a delay, it takes less time to relearn the material a second time. Overlearning -- additional rehearsal after reaching criterion increases savings after a delay compared with the savings without the additional rehearsal.

Stage Model of Memory The 1960’s and 70’s saw the development of a “Stage” model of memory. Separate stores, or stages, were proposed which handled different stages in the processing of memory from input into permanent storage. Rehearsal Input Sensory Memory Decay Attention Short-term Memory Displaced Transfer Retrieval Long-term Memory Forgotten?

Serial Position Effect This model suggests there are two different main memory systems: the STM and LTM. The “serial position effect” provides considerable evidence to support that idea. The enhanced recall of early items is called the “primacy effect” and the enhanced recall of later items is called the “recency effect. ”

Serial Position Effect (con’t) Additional support is provided when variables are manipulated to affect the STM and LTM independently. When subjects are asked to count backward before recall, the recency effect disappears. When the word list is presented slower, pre-recency recall is improved, but not recent terms.

Capacity of Working Memory Just how big is working memory? A common test for measuring the capacity of working memory is “digit span. ” The recall 7± 2 items. Thistypical model person impliescan there are static “slots” into which the information is placed. The STM is, however, a dynamic environment. More dynamic Individuals withmethods larger working-memory of measuring capacity capacities have tend beento be better at verbal developed to measure tasks, reasoning the STM’stasks, capacity and to lessdolikely things to when be working, not distracted andpassively more able holding to “keep items on task. ” for immediate recall.

The Central Executive Today, psychologists do not believe there is a single STM structure as suggested in the stage model, but actually working memory consists of several components: l l l Visuospatial buffer - temporary storage of spatial information that will be needed in the near future. Articulatory rehearsal loop - temporary storage for verbal material. Most importantly, the “central executive” - a collection of cognitive resources needed to organize and control our thoughts and actions.

The Central Executive (cont’) One area believed to be crucial for the functioning of the central executive is the prefrontal cortex (PFC). Damage to this area may result in difficulties with inhibiting habitual responses. For example: • goal neglect – relying on habitual responses even though they do not move one toward their goal • perseveration – produce same response over and over even though the task changes and requires a different response Damage to the PFC also reduces one’s ability to organize or plan. Additional evidence comes from studies involving chimps. In a typical delayed match-to-sample task, the monkey’s area 46 (a prefrontal area) is active only during the delay, perhaps “holding” the information until the curtain is removed.

From STM Into LTM How does working memory get information into the LTM? “Rehearsal” is the means by which information is transferred into LTM. There are, however, two types of rehearsal: maintenance rehearsal and elaborative rehearsal. “Maintenance rehearsal” is simply thinking about items over and over in a mechanical way with little attention to or concern for meaning. “Elaborative rehearsal” involves thinking about the meaning of the to-be-remembered material and relating it to things you already know.

Depth-of-Processing If repetition does not result in transfer to LTM, what does? Clearly, seeing something over and over is insufficient for getting something into LTM. Unless some “effort” is given to the material, it is unlikely the information will make it into LTM. The idea of “depth-of-processing” suggests that the manner in which material is rehearsed (i. e. , deeply and meaningfully) is most critical, not the amount of rehearsal.

Isn’t “Desire” More Important? It seems reasonable to believe that if one truly wants to remember something, just repeating it over and over could work. What role, then, does one’s intentions to learn affect getting information into LTM? Whether one “intends” to learn or not, it is what happens at the time of learning that makes the difference. So long as effective rehearsal strategies are used, it doesn’t matter whethere is an intention to learn or not.

Memory Connections While our intentions are of little importance, it is clear that how we first interact with the material at the time of learning is crucial for subsequent recall. How does deep processing at time of learning lead to improved recall? Simply, it provides better or more connections to the tobe-remembered material. Connections provide numerous retrieval paths by which you can access or retrieve the to-be-remembered information. Elaborative rehearsal – embellishing with additional, relevant information – is an effective rehearsal strategy for increasing connections.

Elaborative Rehearsal For example. . . Suppose you were trying to learn how an action potential occurs. You might imagine a department store (the axon) about to open for a big sale. Inside are a number of employees with somewhat “negative” attitudes (negatively charged ions) regarding the madness that is about to occur. Outside the store are many people with “positive” attitudes regarding the good deals they may find inside (positively charged ions), so they are anxious to get in. The excitement builds (excitatory stimulation) until the crowd can’t stand it any longer (threshold is reached), when suddenly the doors open and the customers come rushing in (depolarization) and then the action is non-stop (the action potential). The extra thought and additional embellishments provide a greater number of potential connections to the material.

Elaborative Rehearsal (con’t) Additionally, you process material more deeply when: • you come up with your own examples • explain the material to another person • just talk and think about the material. All of those activities can establish new connections.

Organization And Memory There standard Identifying Some is, however, the organization mnemonics a downside include: or to order using of mnemonics… to-be-remembered they tend material to limit • First-letter the is an number excellent association of connections way to establish to theconnections. material you want to remember • Visual andimagery what you know (e. g. , the “peg” word). If no • organization is present, you can impose your own Method of Loci organization on material. That is the basis of “mnemonics. ” • Peg Word

Multiple Connections “Understanding, ” By focusing the link, then, you is may the best be missing means by thewhich opportunity we canto form understand the material and establish many more useful connections that might lead to better retrieval. Multiple connections serve two purposes: • facilitates understanding of the to-be-remembered material, providing better learning • multiple connections provide more retrieval paths during recall.

What You Know Matters In short, Where An individual dothe you more with make you a all wealth already theseofconnections? know, relevant theknowledge easier Simply it isput. . . will, to when to other (relevant) with presented remember memories more. new material, or knowledge. have a ready structure or framework onto which connections can be made. In short, the more you already know, the easier it is to remember more.

A Technique To Help PQ 4 R Method - useful technique for reading textbooks: • • Preview - read each subheading in the chapter Questions - develop questions based on each subheading Read - try to answer questions for each section while you read Reflect - think about the text as you read it and try to understand it, come up with your own examples, and try to related the material to your prior knowledge and personal experience • Recite - try to recall the material and the answers to your questions when you finish reading a section. If you cannot, reread the portions with which you had trouble. • Review - once you have finished reading the entire chapter, try to recall the main points and the answers to your questions.