Psychology Chapter 7 Human Memory

Encoding: Encoding is registering the incoming information in a way that it becomes compatible to the memory system. It is the first stage of memory.

Storage: It is the second stage of memory. It refers to the process through which information is retained and held over a period of time.

Retrieval: This is the third stage of memory. It refers to bringing the stored information to her/his awareness so that it can be used for performing various cognitive tasks such as problem solving or decision-making.

According to the stage-model, there are three memory systems through which information is processed. These are – sensory memory, the short-term memory and the long term memory.

(i) Sensory memory: The incoming information first enters the sensory memory. Sensory memory has a large capacity. However, it is of very short duration i.e., less than a second. It is a memory system that registers information from each of the senses with reasonable accuracy. Often this system is referred to as sensory memories or sensory registers because informations from all the senses are registered here as exact replica of the stimulus.

(ii) Short-Term Memory: Information that is attended to enters the second memory store called the short-term memory (STM), which holds small amount of information for a brief period of time (usually for 30 seconds or less). As Kinson and Shiffrin propose that information in STM is primarily encoded acoustically i.e., in terms of sound and unless rehearsed continuously, it may get lost from the STM in less than 30 seconds. The STM is fragile but not as fragile as sensory registers where information decays automatically in less than a second.

(iii) Long term Memory: Materials that survive the capacity and duration limitations of the STM finally enter the long-term memory (LTM) which has a vast capacity. It is a permanent storehouse of all informations. It has been shown that once any information enters the long-term memory store it is never forgotten because it gets encoded semantically, i.e., in terms of the meaning that any information carries.

Maintenance rehearsals: These kinds of rehearsals simply maintain information through repetition and when such repetitions discontinue the information is lost. They are carried through silent or vocal repetition.

Elaborative rehearsals: These rehearsals attempt to connect the ‘to be retained information’ to the already existing information in long-term memory. In elaborative rehearsals one attempts to analyse the information in terms of various associations it arouses. It involves organisation of the incoming information in as many ways as possible.

Declarative memories: All information pertaining to facts, names, dates, etc. are port of declarative memory. Example: A rickshaw has three wheels, or India became independent on August 15, 1947, a frog is an amphibian, etc. are parts of declarative memory. Facts retained in declarative memory are amenable to verbal descriptions.

Procedural memory: It refers to memories relating to procedures for accomplishing various tasks and skills. Example: How to ride a bicycle, how to make tea, how to play basketball, etc. The contents of procedural memory cannot be described easily.

Depending upon how much time people take in responding to questions, the nature of organisation in long-term memory, has been inferred.

The most important unit of representation of knowledge in long-term memory is a concept. Concepts are mental categories for objects and events, which are similar to each other in one or in more than one way. Concepts may also get organised in schemas which are mental frameworks which represent our knowledge and assumptions about the world.

In the year 1969, Allann Collins and Ross Quillian suggested that knowledge in long-term memory is organised hierarchically and assumes a network structure. Elements of this structure are called nodes. Nodes are concepts while connections between nodes are labelled relationships, which indicate category membership or concept attributes.

Fig: The Hierarchical Network Model

Forgetting refers to loss of stored information over a period of time. After a material is learnt, there is a sharp drop in its memory and then the decline is very gradual. Forgetting may take place due to trace decay and interference. It may also caused due to absence of appropriate cues of the time of retrieval.

Forgetting due to retrieval failure:

Forgetting can occur because at the time of recall, either the retrieval cues are absent or they are inappropriate. Retrieval cues are aids which help us in recovering information stored in the memory. This view was advanced by Tulving and his associates who carried out several experiments to show that contents of memory may become inaccessible either due to absence or inappropriateness of retrieval cues that are available/employed at the time of recall.

Forgetting due to interference: It suggests that forgetting is due to interference between various informations the memory store contains. According to this theory learning and memorising involve forming of associations between items and once acquired, these associations remain in fact in the memory. People keep acquiring numerous such associations and each of these rests independently without any mutual conflict. However, interference comes about at a time of retrieval when these various sets of associations compete with each other for retrieval.

According to Bartlett memory is a constructive process using meaningful materials such as texts, folk tales, fables, etc. Bartlett showed the manner in which content of any specific memory gets affected by a person’s knowledge, goals, motivation, preferences and various other psychological processes. He conducted experiments in which reading of such stimulus materials was followed by fifteen minutes break and then the participants of his experiment recalled what they had read.

Bartlett used the method of serial reproduction in which the participants of his experiments recalled the memory materials repeatedly at varying time intervals. While engaging in serial reproduction of learned material his participants committed a wide variety of ‘errors’ which Bartlett considered useful in understanding the process of memory construction. His participants altered the texts to make them more consistent with their knowledge, glossed over the unnecessary details, elaborate the main theme and transformed the material to look more coherent and rational.

In order to explain such findings, Bartlett invoked the term schema, which according to him was an active organisation of past reactions and past experiences. Memory, therefore, becomes an active process of construction where information is encoded and stored in terms of a person’s understanding and within her/his previous knowledge and expectations.

Mnemonics are strategies for improving memory. There are different plans to improve memory. One of such plans is as follows:

Engaging in deep level processing: If one wants to memorise any information well, he should engage himself in deep level processing. Craik and Lockhart have demonstrated that processing information in terms of meaning that they convey leads to better memory as compared to attending to their surface features. Deep processing would involve asking as many questions related to the information as possible, considering its meaning and examining its relationships to the facts one already knows. In this way, the new information will become a part of his existing knowledge framework and the chances that it will be remembered are increased.

Encoding, retrieval and storage are the three stages of memory.

Atkinson and shiffrin proposed stage model.

Random access memory and Read only memory.

Memory refers to retaining and recalling information over a period of time, depending upon the nature of cognitive task one is required to perform.

Three interrelated stages of memory are encoding, storage, and retrieval.

Encoding is the first stage which refers to a process by which information is recorded and registered for the first time so that it becomes usable by our memory system.

The two memory systems of a computer are:

(i) Temporary memory (Random Access Memory or RAM)

(ii) A permanent memory-a hard disk.

Atkinson and Shiffrin (1968).

In sensory memory.

The second memory holds small amount of information for a brief period of time (usually for 30 seconds or less).

Selective attention.

Chunking is a process through which it is possible to expand the capacity of STM.

7 + 2.

Elaborative rehearsal attempts to connect the ‘to be retained information’ to the already existing information in long-term memory.

The levels of processing view was proposed by Craik and Lockhart in 1972.

According to this view the processing of any new information relates to the manner in which it is perceived, analysed and understood which in turn determines the extent to which it will eventually be retained.

No memories are reported pertaining to early childhood particularly during the first 4 to 5 years. This is called childhood amnesia.

Implicit memory is a kind of memory that a person is not aware of it. It is a memory that is retrieved automatically.

All information pertaining to facts, names, dates, etc. are part of declarative memory.

Procedural memory refers to memories relating to procedures for accomplishing various tasks and skills.

Episodic memory contains biographical details of our lives.

Memories relating to our personal life experiences constitute the episodic memory and it is for this reason that the contents are generally emotional in nature.

Semantic memory is the memory of general awareness and knowledge. All concepts, ideas and rules of logic are stored in semantic memory.

Concept.

Concepts are mental categories for objects and events, which are similar to each other in one or in more than one way.

Schema is a mental framework which represents our knowledge and assumption about the world.

‘Cognitive economy’ means maximum and efficient use of the capacity of long-term memory with minimum redundancy.

An image is a concrete form of representation which directly conveys the perceptual attributes of an object.

Tulving classified as episodic or semantic memory.

Episodic memory contains biographical details of our lives.

Retrieval cues are the aids which help us in recovering information stored in the memory.

Mnemonics are the strategies for improving memory.

Forgetting refers to loss of stored information over a period of time.

Storage refers to process to retain information.

Random access memory (RAM).

It is a permanent memory system of a computer.

Iconic (Sight), Echoic (Sound) and other senses, large storage capacity are the features of sensory memory.

Feature of STM is stores smalll, capacity less than 30 seconds.

Trace decay is the earliest theory of forgetting.

Interference theory of forgetting is due to interference between various information that memory store contains.

All information pertaining to facts names, dates etc. are the part of declarative memory.

Whenever an external stimulus impinges on our sensory organs, it generates impulses. These are received in different areas of our brain for further processing. In encoding, incoming information is received and some meanings is derived. It is then represented in a way so that it can be processed further.

According to dual coding hypothesis, concrete nouns and information related to concrete objects are encoded and stored in the form of images while information related to abstract concepts assume a verbal and a descriptive code.

Mental model refer to our belief about the manner in which our environment is structured and such beliefs are formed with the help of concrete images as well as verbal descriptions.

In proactive interference, past learning interferes with the recall of later learning while in retroactive interference the later learning interferes with the recall of past learning.

Episodic memory: It contains biographical details of our lives. Memories relating to our personal life experiences constitute the episodic memory. It is for this reasons that its contents are generally emotional in nature. Thus, this kind of memory is dated. It is susceptible to forgetting.

Semantic memory: It is the memory of general awareness and knowledge. All concepts, ideas, and rules of logic are stored in semantic memory. Example: It is because of semantic memory that we remember the meaning of say ‘non-violence’ or remember that 4 + 6 = 10 or the STD code of New Delhi is 011 or that the word ‘lion’ is misspelt. This kind of memory is not dated. It is not susceptible to-forgetting.

Flashbulb Memories: These are memories of events that are very arousing or surprising. Such memories are very detailed. They are like a photo taken with an advanced model camera. One can push the button, and after one minute he has a recreation of the scene. One can look at the photograph whenever he want. Flashbulb memories are like images frozen in memory and tied to particular places, dates, and times.

Hermann Ebbinghaus was the first who made the first attempt to understand the nature of forgetting. He memorised lists of nonsense syllables and then numbered the number of trials he took to relearn the same list at varying time intervals. He observed that the course of forgetting follows a certain pattern.

The rate of forgetting is maximum in the first nine hours, particularly during the first hour. After that the rate slows down and not much is forgotten even after many days. It is now upheld, almost unanimously, that there is always a sharp drop in memory and thereafter the decline is very gradual.

Diagrammatic representation of the stage model of memory:

The major methods which are used for memory measurement are as follows:

(i) Free Recall and Recognition (for measuring facts/episodes related memory): In free recall method, participants are presented with some words which they are asked to memorise and after some time they are asked to recall them in any order. The more they are able to recall, the better their memory is. In recognition, instead of being asked to generate items, participants see the items that they had memorised along with distracter items (those that they had not seen) and their task is to recognise which one of those they had learnt. The greater the number of recognition of ‘old terms’, better is the memory.

(ii) Sentence Verification Task (for measuring semantic memory): In sentence verification task, the participants are asked to indicate whether the given sentences are true or false. Faster the participant’s respond, better retained is the information needed to verify those sentence.

(iii) Priming (for measuring information we cannot report verbally): In priming method, participants are shown a list of words, such as garden, playground, house, etc. and then they are shown parts of these words like gar, pla, ho, along with parts of other words they had not seen. Participants complete parts of seen words more quickly than parts of words they had not seen. When asked, they are often unaware of this and report that they have only guessed.

Some approaches to improve memory are as follows :

(i) Engage in Deep Level Processing: If one wants to memorise any information well, s/he should engage her/himself in deep level processing. Craik and Lockhart have demonstrated that processing information in terms of meaning that they convey leads to better memory as compared to attending to their surface features. Deep processing would involve asking as many questions related to the information as possible, considering its meaning and examining its relationships to the facts one already knows. In this way, the new information will become a part of her/his existing knowledge framework and the chances that it will be remembered are increased.

(ii) Minimise Interference: Interference, is a major cause of forgetting and therefore one should try to avoid it as much as possible. Maximum interference is caused when very similar materials are learned in a sequence. So, one should avoid this. One should arrange her/his study in such a way that s/he does not learn similar subjects one after the other. Instead s/he should pick up some other subject unrelated to the previous one. If that is not possible, s/he should distribute her/his learning/practice. This means giving herself/himself intermittent rest periods while studying to minimise interference. (iii) Give Yourself enough Retrieval Cues: While learning something, one should think of retrieval cues inherent in her/ his study material. They should be identified and should be linked to parts of the study materials to these cues. Cues will be easier to remember compared to the entire content and the links one has created between cues and the content will facilitate the retrieval process.

Implicit memory: Recent studies have indicated that many of the memories remain outside the conscious awareness of a person. Implicit memory is a kind of memory that a person is not aware of. It is a memory that is retrieved automatically. One interesting example of implicit memory comes from the experience of typing. If someone knows typing that means s/he also knows the particular letters on the keyboard. But many typists cannot correctly label blank keys in a drawing of a keyboard.

Implicit memories lie outside the boundaries of awareness. In other words we are not conscious of the fact that a memory or record of a given experience exists. Nevertheless, implicit memories do influence our behaviour, This kind of memory was found in patients suffering from brain injuries. They were presented a list of common words. A few minutes later the patient was asked to recall words from the list. No memory was shown for the words, However, if s/he was prompted to say a word that begins with these letters and two letters are given the patient was able to recall words. Implicit memories are also observed in people with normal memories.

D.

All of the above

B.

encoding

A.

sensory memory

C.

large capacity

B.

less than one second

C.

for 30 seconds or less

A.

less than a second

C.

LTM

A.

repetition

C.

chunking

A.

7 + 2

C.

elaborative rehearsals

A.

Craik and Lockhart

B.

two seconds

B.

declarative memory

D.

procedural memory

C.

Episodic memory

C.

Implicit memory

A.

Semantic memory

C.

Concept

A.

Schema

D.

all of the above

C.

later learning interferes with the recall of past learning

B.

proactive interference

D.

all of the above