Memory Processes PDF

MEMORY Memory is the term given to the structures and processes involved in the storage and subsequent retrieval of information. ◦Memory is essential to all our lives. Without a memory of the past we cannot operate in the present or think about the future. We would not...

MEMORY Memory is the term given to the structures and processes involved in the storage and subsequent retrieval of information. ◦Memory is essential to all our lives. Without a memory of the past we cannot operate in the present or think about the future. We would not be able to remember what we did yesterday, what we have done today or what we plan to do tomorrow. Without memory we could not learn anything. ◦Memory is involved in processing vast amounts of information. This information takes many different forms, e.g. images, sounds or meaning. ◦Memory covers three important aspects of information processing: ◦1. Encoding ◦2. Storage ◦3. Retrieval  Encoding and Recoding ◦The process of initial recording of information: information is recorded in a form that is ready for use by our memory anytime. ◦Encoding is the process of perceiving information and bringing it into the memory system. ◦Encoding is not simply copying information directly from the outside world into the brain. Rather, the process is properly conceived as recoding, or converting information from one form to another. ◦ The human visual system provides an example of how information can change forms. Light from the outside world enters the eye in the form of waves of electromagnetic radiation. The retina of the eye converts this radiation into bioelectrical signals that the brain interprets as visual images. Similarly, when people encode information into memory, they convert it from one form to another to help them remember it later.  Storage ◦In the storage part of the memory processes, information saved in the memory is maintained in an identifiable form. ◦Storage is also the retaining information in memory so that it can be used at a later time  Retrieval The information recorded and stored is approached, located, brought into awareness, and used under the memory retrieval system. Encoding and storage are necessary to acquire and retain information but the crucial process in remembering is retrieval, without which we cannot access our memories. Unless we retrieve an experience, we do not really remember it.  The Memory Storage Systems: Memory Stages Sensory Memory Short - term Memory Long - term Memory  Sensory Memory/Sensory Register ◦Storage of memory lasting for a while; this is the initial momentary stage. ◦Sensory memory refers to the initial, momentary recording of information in our sensory systems. ◦The person's sensory system records information as a raw and non-meaningful stimulus: e.g., a fly that sat on your nose in the park this morning, the sound of the car that passed by you, or the feel of dry leaf that landed on your head when you were waiting for the bus. ◦Sensory memory systems typically function outside of awareness a nd store information for only a very short time Types of Sensory Memories I. Iconic Memory The information gathered by our visual sense is reflected by the iconic memory; memory in the visual domain II. Echoic Memory The information coming from our auditory sense is dealt with by the echoic memory; i.e., memory for sounds III. Memories related to other senses Similar systems are assumed to exist for the sensory systems (taste, touch and smell)  CHARACTERISTICS OF SENSORY MEMORY Sensory memory is short lived. Ranging from just about one second to a few seconds, its duration depends upon the intensity of stimulus too.  Iconic memory may fade in less than a second, whereas the echoic memory may last for 3-4 seconds. The stimuli that have a high intensity may stay for a bit longer Sensory memory is like a temporary image that may vanish forever, and may be replaced by another if it is not shifted to another processing system or memory storehouse  SHORT-TERM MEMORY/ WORKING MEMORY ◦ Psychologists originally used the term short-term memory to refer to the ability to hold information in mind over a brief period of time. As conceptions of short-term memory expanded to include more than just the brief storage of information. ◦ The term working memory is now commonly used to refer to a broader system that both stores information briefly and allows manipulation and use of the stored information.  This system is higher in functioning than sensory memory, as it stores information in terms of meaning and not just simple sensory stimulation.  Sensory information is meaningless and therefore discarded. If it is sent to the short- term memory then a meaning is added to it. Since now it is meaningful it will be retained, though for not very long.  Short-term memory retains information for 15 to 25 seconds, unless it is moved into the long- term memory.  Chunking and the capacity of Short-term memory ◦A meaningful grouping of stimuli that can be stored as a unit in short-term memory. ◦A chunk is an understandable or meaningful set or grouping of stimuli e.g., "001023" can be learnt as "0 0 1 0 2 3" OR "00 10 23".· ◦Short-term memory can carry seven chunks at a time on average; the capacity may be two more or two less than seven ◦Chunking is a term referring to the process of taking individual pieces of information (chunks) and grouping them into larger units. By grouping each piece into a large whole, you can improve the amount of information you can remember. ◦Probably the most common example of chunking occurs in phone numbers. For example, a phone number sequence of 4-7-1-1-3-2-4 would be chunked into 471-1324.  Long-Term Memory In Long-term memory, the system stores information on a permanent or relatively permanent basis; the information thus stored may or may not be retrieved easily. The term long-term memory is somewhat broad meaning phrase because it can refer to facts learned a few minutes ago, personal memories many decades old, or skills learned with practice Generally, however, long-term memory describes a system in the brain that can store vast amount of information on a relatively enduring basis ◦ The information that is typically encoded and stored in long-term memory is either important (a parent’s or spouse’s birthday, for example) or is used frequently (your telephone number) ◦ Maintaining information in long-term memory often involves rehearsal or repetition.  Rehearsal ◦ The transfer of material from short- to long-term memory proceeds largely on the basis of rehearsal, the repetition of information that has entered short-term memory. ◦ Rehearsal accomplishes two things. First, as long as the information is repeated, it is maintained in short- term memory. More important, however, rehearsal allows us to transfer the information into long-term memory  REHEARSAL Maintenance Rehearsal It typically involves rote repetition, either out loud or covertly. It is effective for maintaining relatively small amounts in memory for brief periods, but is not likely to affect retention in the long term. It is in the short term memory ◦Whether the transfer is made from short- to long-term memory seems to depend largely on the kind of rehearsal that is carried out. ◦If the information is simply repeated over and over again—as we might do with a telephone number while we rush from the phone book to the phone—it is kept current in short-term memory, but it will not necessarily be placed in long-term memory. ◦Instead, as soon as we stop punching in the phone numbers, the number is likely to be replaced by other information and will be completely forgotten. Elaborative Rehearsal  In order to retain information for longer periods of time, it involves associating new material with information that already exists in long-term memory  For elaborative rehearsal, reciting the information over and over again is not going to help commit it to memory. Such a strategy would be hopelessly inefficient and ineffective.  Instead, elaboration strategies that engage the learner in understanding the material are helpful, both for storing information, and for retrieving it in the future. For example the learner can generate personal examples that help illustrate concepts or principles. Enriching the material by concentrating on its meaning not only makes it more understandable, it also helps establish potential pathways for subsequent retrieval. Study groups provide a context for elaborative rehearsal. Discussions or arguments about various topics will enrich the subject matter and add to its meaningfulness. ◦If the information in short-term memory is rehearsed using elaborative rehearsal, it is much more likely to be transferred into long-term memory ◦ More examples could be: ◦ Imagining a relationship that strengthens the association between material to be learnt e.g., learning a new name by relating it to an emperor with the same name. ◦ The information may be expanded to fit into an already existing logical framework e.g., learning a car's number "2346" by considering the relationship i.e., 23 x 2 = 46 Types of Long-term Memory Declarative memory Procedural memory Semantic memory Episodic memory Declarative Memory The module responsible for factual data, dates, faces, names etc. Procedural Memory The memory center for skills and habits e.g., playing cricket, driving a car etc. It refers to the skills that humans possess. Tying shoe laces, riding a bicycle, swimming, and hitting a football are examples of procedural memory. Semantic Memory  It is a storehouse for facts and general knowledge about the world e.g., historical facts, or scientific formulae. It refers to our general knowledge of the world and all of the facts we know. Semantic memory allows a person to know that the chemical symbol for water is H2O, or that cats have a tail etc. Episodic Memory  In this type of memory the information pertaining to life events, episodes, biographical details. It refers to memories of specific episodes in one's life and is what most people think of as memory. Episodic memories are connected with a specific time and place. ◦Episodic memories relate to particular contexts. For example, remembering when and how we learned that 2 x 2 = 4 would be an episodic memory; the fact itself (that 2 x 2 = 4) is a semantic memory. ◦Procedural memory is often contrasted with episodic and semantic memory. Episodic and semantic memory are both classified as types of declarative memory because people can consciously recall facts, events, and experiences and then verbally declare or describe their recollections. ◦In contrast, non-declarative, or procedural, memory is expressed through performance and typically does not require a conscious effort to recall.  Explicit and Implicit Memory Explicit Memory Recollection of memory that is intentional and conscious e.g., date of your interview, or the day when your course started. Explicit memory refers to the deliberate, conscious recollection of facts and past experiences. If someone asked you to recall everything you did yesterday, this task would require explicit memory processes. There are two basic types of explicit memory tests: recall tests and recognition tests. ◦A recall test is a measure of explicit memory that involves retrieving information that has been previously learned. For example: We rely on our recall memory when we take an essay test, because the test requires us to generate previously remembered information. Recognition memory test is a measure of memory that involves determining whether information has been seen or learned before. For example: A multiple-choice test is an example of a recognition memory test Recognition refers to our ability to “recognize” an event or piece of information as being familiar, while recall designates the retrieval of related details from memory. Implicit Memory There are many pieces of information or memories that are stored in our system but which we are not aware of at the conscious level. These can and do affect our behavior and performance later e.g., childhood fear of blood hindering the performance of becoming a doctor. Implicit memory refers to using stored information without trying to retrieve it. People often retain and use prior experiences without realizing it. There are three general types of implicit memory: procedural memory, classical conditioning effects, and priming. ◦Procedural memory refers to our often unexplainable knowledge of how to do things. ◦Procedural memory allows us to perform complex tasks, even though we may not be able to explain to others how we do them. It is difficult to tell someone how to ride a bicycle; a person has to learn by doing it. ◦The idea of implicit memory helps explain how infants are able to learn. The ability to crawl, walk, and talk are procedures, and these skills are easily and efficiently developed while we are children despite the fact that as adults we have no conscious memory of having learned them. ◦ A second type of implicit memory is classical conditioning effects, in which we learn, often without effort or awareness, to associate neutral stimuli (such as a sound or a light) with another stimulus (such as food), which creates a naturally occurring response, such as enjoyment or salivation. ◦ The final type of implicit memory is known as priming, or changes in behavior as a result of experiences that have happened frequently or recently. ◦ Priming refers both to the activation of knowledge (e.g., we can prime the concept of “kindness” by presenting people with words related to kindness) and to the influence of that activation on behavior (people who are primed with the concept of kindness may act more kindly). ◦Our everyday behaviors are influenced by priming in a wide variety of situations. Seeing an advertisement for cigarettes may make us start smoking, seeing the flag of our home country may arouse our patriotism, and seeing a student from a rival school may arouse our competitive spirit. And these influences on our behaviors may occur without our being aware of them.  The Serial Position Effect ◦The primacy effect and the recency effect are the two main components of a broader concept known as the serial position effect. ◦The serial position effect says that when given a list of information and later asked to recall that information, the items at the beginning (primacy) and the items at the end (recency) are more likely to be recalled than the items in the middle.  Flashbulb Memories ◦The memories that are as clear and vivid as a snapshot are known as Flashbulb Memories. ◦Such memories are of events that are important for us, are specific, or surprising or astonishing e.g., an interview room, an accident, first day at class. ◦Although flashbulb memories are vivid, clear and detailed, still they may be lacking many important details.  Tip-of-the-tongue Phenomenon ◦Inability to recall events, details, or information that we thought we knew very well. ◦The inability to recall information that one realizes one knows—a result of the difficulty of retrieving information from long-term memory. FORGETTING  Forgetting is the inability to retrieve or recall information from the long- term memory Forgetting may occur due to a number of factors such as:  Information discarded / decayed due to the non- use of the learned material.  At times we know something, but are unable to access and retrieve it properly. Several processes account for memory failures, including decay, interference, and cue-dependent forgetting.  Theories of Forgetting Decay theory of forgetting Interference theory of forgetting Cue Dependent Forgetting Repression  Interference Theory of Forgetting Interference results when the recall of the learned phenomena is blocked/ displaced by other information. There 2 types of interference: i. Proactive interference ii. Retroactive interference Proactive interference Proactive interference occurs when the already stored memories come in between or interfere with the recall of the newly learned material For e.g., you learned psychology this semester and sociology in the last semester. When exam was taken in psychology, material from sociology, rather than that of psychology, kept coming into mind. Retroactive interference ◦Retroactive interference occurs when the newly learned material interferes with or blocks our ability to recall the previously learned material in the psychology-sociology example, when examinations were taken, the memories of newly learned material (psychology) may interfere with recall of the formerly learned material (sociology)  Cue Dependent Theory of Forgetting ◦This is a theory of why forgetting occurs in LTM. According to this theory proposed by Tulving, forgetting occurs when the right cue is not available for retrieving the memory. ◦When a memory is encoded it leaves a memory trace which also stores information about the way we felt or the place we were in at the time of encoding. In order for this memory to be accessed again a retrieval cue (prompt) is required. The encoding specificity principle states ‘the greater the similarity between the encoding event and the retrieval event, the greater the likelihood of recalling the original memory’.  Repression Repression is putting the undesirable thoughts, events and fears into the unconsciousness and trying not to remember it again. Repression is a Freudian concept. In spite of being sent into the unconscious, unpleasant feelings continuously influence person's attitudes and behaviors.  State Dependent Memory Learning is better when the recall context matches the learning context – state dependent memory.  Strategies for Better Memory ◦Keeping distractions away ◦Chunking ◦Rhyming ◦Reading aloud ◦Sleep intervals  MEMORY DISORDERS/DYSFUNCTIONS  Alzheimer's disease ◦Alzheimer's disease is a progressive disease that destroys memory and other important mental functions. At first, someone with Alzheimer's disease may notice mild confusion and difficulty remembering. ◦Eventually, people with the disease may even forget important people in their lives and undergo dramatic personality changes. ◦In Alzheimer's disease, the brain cells degenerate and die, causing a steady decline in memory and mental function.  Amnesia ◦Greek word which means “forgetfulness”. ◦ Amnesia refers to the loss of memories, such as facts, information and experiences. ◦ Amnesia can be caused by damage to areas of the brain that are vital for memory processing. ◦Includes two types of amnesia. Retrograde amnesia Anterograde amnesia Anterograde amnesia where the ability to memorize new things is impaired or lost because data does not transfer successfully from the conscious short- term memory into permanent long-term memory. You cannot form new memory Retrograde amnesia where a person's pre-existing memories are lost to conscious recollection, beyond an ordinary degree of forgetfulness, even though they may be able to memorize new things that occur after the onset of amnesia. Unable to access memory  THE NEUROSCIENCE OF MEMORY ◦The search for the engram , the term for the physical memory trace that corresponds to a memory, has proved to be a major puzzle to psychologists and other neuroscientists interested in memory. ◦The hippocampus, a part of the brain’s limbic system plays a central role in the consolidation of memories. The amygdala , another part of the limbic system, also plays an important role in memory. The amygdala is especially involved with memories involving emotion For example, if you are frightened by a lizard, you’re likely to remember the event vividly—an outcome related to the functioning of the amygdala. Encountering the lizard or any creature you are in in the future is likely to reactivate the amygdala and bring back the unpleasant memory The physical stuff of memory—the engram—is produced by a complex of biochemical and neural processes