Human Memory II

Acquisition and Retrieval Presumably, we put information into LTM with the idea that we might want to access it at a later time. If, however, we are unable to retrieve it, having it in LTM would be of little value. There are, of course, several ways of retrieving that information. Most commonly by “recall” or “recognition.” We might ask, then, how are acquisition and retrieval related?

Context-Dependent Learning There are a variety of such “context- dependent” learning situations: Physical Emotional Mood congruence State-dependent There is a great deal of evidence to support the notion that the presence of connections formed during learning is important for retrieval.

Context-Dependent Learning (con’t) You need not be physically in the same “place” when you are learning and recalling. So long as the connections are reinstated, successful retrieval is likely to occur. The conclusion is clear: recall is best when the external (or internal) contexts of study and recall match.

Encoding Specificity However, the “extra” thoughts and perceptions can also alter the meaning of what is remembered and, therefore, may affect whether you can recall the information at a later time. The to-be-remembered information is not the only thing that is connected or “encoded” during learning. The specific thoughts you have or perspective you take regarding the material during learning are also encoded and, therefore, may serve as retrieval paths. For example, “The man lifted the piano” or “The man tuned the piano” When a hint suggests a different context, recall suffers. This is because we learn the word and context as a whole, not as individual parts.

Different Forms of Memory Testing We have just noted the importance of having study and testing contexts match. Does our initial learning make a difference if the retrieval is one of recall or recognition? “Recall” refers to retrieving the material from memory by searching until you’ve found what you’re looking for on your own (e.g., Who wrote David Copperfield?). “Recognition” refers to identifying “presented” material as the material you are looking for. For example, _____ wrote Little Women. a) Laura Ingalls Wilder b) Louisa May Alcott c) Charlotte Brontë d) Jane Austen

Memory Testing (con’t) In both cases, we may be aware that we “know” the correct response. With “recognition,” however, we sometimes seem to get a feeling that the material is “familiar,” but we don’t quite know why (e.g., that person looks familiar, but I can’t put my finger on where I know her). That is, you lack source memory for the information. Thus, our ability to recognize information sometimes occurs because of “source memory” and sometimes because of “familiarity.”

Implicit Memory While we have conscious access to many of our memories, there are those memories for which we do not, or only with great difficulty (e.g., position of keys on typewriter, how to shift gears in a car, how to tie a shoestring, etc.). Explicit memories are those of which you are aware and can recall or recognize. Implicit memories are those of which you are unaware or cannot recall, but can influence your behavior in some manner (e.g., improved performance on a task) – what some refer to as “memory without awareness.”

Implicit Memory (con’t) There are a variety of ways we can demonstrate the existence of implicit memories: Lexical-decision task Word-stem completion Savings In these instances, subjects were influenced by previous exposure to the material, yet were not able to directly recall the material. That phenomena is not limited to lists of words, but is easily demonstrated in many real-world circumstances: False fame Illusion of Truth

Implicit Memory (con’t) What is different in the False Fame and Illusion of Truth examples is that subjects had a “feeling of familiarity” or “that rings a bell” feeling and were required to interpret their feelings. In these instances, subjects were influenced by previous exposure to the material, but in the absence of being able to identify the “source” of the familiarity, their behavior was determined by how they interpreted their feelings of familiarity. In real terms, seeing, hearing, or reading false information provides familiarity and, at some later time, that familiarity may be misinterpreted as “I’ve heard that before… I guess is must be true.”

What Is Implicit Memory? The idea that we can have “memory without awareness” seems quite clear. It is important, then, to be able to explain “implicit memory.” Consider the following possibility: Implicit memory is the manifestation of increased “processing fluency” resulting from “practice” (i.e., previous exposure or mental effort) Processing fluency may be thought of as an enhanced ability to more quickly or efficiently process a stimulus.

What Is Implicit Memory? (con’t) A few more (reasonable?) assumptions are needed to explain other results (e.g., “familiarity”): 1. People are sensitive to degrees of processing fluency and easily processed material results in a sense of “distinctiveness” or being “special.” 2. An attribution process is triggered when material results in a sense of distinctiveness and people are motivated to interpret the feeling as familiarity and attribute it (correctly or incorrectly) to a source. 3. Decreases in processing fluency can result in material feeling distinctive as well (e.g., when a friend shaves off their beard… you know something is different, but can’t put your finger on it) which will also trigger an attribution process.

The hippocampus is a structure embedded within the temporal lobes and is considered critical for the formation of new memories. As such, amnesia patients offer a unique opportunity for the study of memory. Damage (e.g., head injury, surgery, infection -- encephalitis, Korsakoff’s syndrome resulting from chronic alcoholism) to the hippocampus and surrounding structures can produce retrograde (loss of memories before the damage) or anterograde (inability to form new permanent memories) amnesia. Hippocampal Formation and Amnesia

In cases where the damage is not permanent (e.g., a blow to the head) anterograde and retrograde amnesia show a “contracting” pattern of recovery. Slowly, the patient shows the ability to learn new things and recall of past events returns. Patients are able to remember things for short periods of time (e.g., 10 seconds), but then forget them. Older memories are usually preserved, but memories temporally close to the injury are permanently lost. Amnesia (con’t) “Working memory” seems to function normally, allowing for interactions in the here-and-now.

It has longed be argued that anterograde amnesia was the result of an inability for working memory to transfer information into LTM. However, there are many studies that question that argument: Acquisition of trivia Preference to previously heard songs Improvement in “mirror-drawing” It seems that anterograde amnesic patients are able to acquire new “implicit” memories but not new “explicit” memories, while other cases show just the opposite. Such evidence supports the idea that implicit and explicit memory are independent of each other. What Is The Problem? Similar patterns of memory disruption are also seen in cases where the damage is permanent.

Practical Advice For Optimal Learning Since you will not always know under what conditions you will be asked to recall or in what way you will be asked to recall (i.e., recall or recognition), it is best to learn from as many different perspectives as you can so you can establish numerous connections between memories: Use elaborative rehearsal Paraphrase the information Develop multiple examples Explain it to someone else Get someone to quiz you Etc. What practical lessons can we draw from all of this?