Why do we forget things?

Why do we forget? As you may know, memory has three interrelated components, i.e., encoding, storage, and retrieval. Forgetting may occur because of problems experienced at any one these stages. If the material is not properly encoded, the relevant aspects of what is to be remembered would not be stored.

Even after efficient encoding, if the materials are not properly stored in the LTM, they cannot be retrieved at the time of need. Even if the storage is proper, the learnt material may not be retrieved because of some interference.

Besides all these, some painful experiences may be repressed in the unconscious and not available to our consciousness. In other words, we forget some painful experiences, because we want to forget those. All these causes of forgetting are discussed below.

Encoding Failure

The process through which information is converted into a form that can be entered into memory is known as encoding. You know that the informational impact at the sensory register should be properly processed to be passed on to the STM, and then to LTM. Massive forgetting occurs at the level of encoding. Without deep level processing, materials may be lost at the level of encoding itself.

Sometimes, we think that we have forgotten because what we remember does not match with what actually occurred. Constructive processes distort what is stored in memory and we remember the distortions. For instance, we remember the gist or meaning of what we have read or heard in a conversation but not the time the information was encoded for storage or we encode only selected portions of the to-be-remembered information. Strictly speaking, such faulty remembering is not forgetting, in fact, we remember what was encoded, and stored.

Much of what we think we have forgotten does not really qualify as being forgotten, because it was never encoded and stored in the first place.

According to the information theory, some information might not have reached STM because of lack of attention. Due to inadequate encoding, the information may not have been transformed from STM to LTM. If the encoding is not proper, the information reaching STM might have been knocked out, because the STM has a limited storage capacity.

Thus, a person may forget because of encoding failure. What are the different factors that influence the encoding of the materials?

The factors operating at the time of encoding are (i) strength of original learning, (ii) nature of material, (iii) method of learning, and (iv) speed of learning. Although amount of retention cannot increase indefinitely as a function of the degree of over learning, over learning is preferable than under-learning.

Forgetting involves both verbal and nonverbal learning. Meaningful and rhythmic materials decrease the rate of forgetting because of their associative value. Motor learning is retained for a long period in comparison to verbal learning. Speed of learning is conversely related to the degree of forgetting.

According to Underwood, "when learning is rapid, forgetting will be slow and when learning is slow forgetting will be rapid. Attitude towards learning material, motivation and interest to learn are also important determinants influencing the nature of encoding. Emotional shock such as failure in examination, suspension from job etc. seriously interferes with encoding and leads to forgetting.

The rate of forgetting varies from individual to individual. It is found that some forget sooner than others. Some people easily learn and retain certain materials in comparison to others. So, whether forgetting will be slow or fast depends upon the individuals, the situation, and the nature of the information to be remembered.

Storage Failure

Even if the encoding is proper, materials may be forgotten because of improper storage. As you know, materials have to be finally stored in the LTM to be retrieved at the time of need. Forgetting takes place because either the material is not properly stored in the LTM, or the storage is affected by interference or disuse. The LTM storage may face problems because of several factors.

The oldest and simplest view of forgetting is that information entered into memory fades or decays with passage of time during which it is not used.

Thus, forgetting is a function of the passage of time. This explanation assumes that learning leaves a trace in the brain, which is known as memory trace or engram. The memory trace involves some sort of physical changes not processes prior to learning. With the passage of time, the normal metabolic process of the brain cause a fading or decay of the memory traces so that traces material once learned gradually disintegrate and eventually disappear.

As a result, the memory storage is greatly disturbed. This theory fits our commonsense understanding of forgetting and is consistent with our informal day - day experience.

Often information we acquired quite sometime ago is more difficult remember than information learned only recently. Does it mean that the memory traces of earlier learning are completely wiped out? Considerable evidence suggests that decay is probably not the key mechanism in forgetting if the material is re-learnt, it could be done quickly. The process is known saving.

Furthermore, in many instances, learning (e.g., motor skills like cycling driving etc.) is retained for a long period of time with no intervening practice (Even in some cases, verbal materials may be retained over long periods time. For example, we may recall a poem learned in the XI standard and yet be unable to remember a part of a play we learned in XII standard. Why should the decay process affect the second material and not the first?

Evidence, which goes against the trace-decay theory, rests on the recovery of memory supposedly lost. People approaching senility, who can barely remember the events of the day, often vividly recall events of their you Findings of the study by Jenkins and Dallenbach (1924) and Minami a Dallenbach (1964) argue against the suggestion that forgetting is primal the result of gradual decay of information over time. It appears that simple passage of time is a cause of forgetting both in the sensory register and short-term memory, but not in long-term memory.

Memory traces seem too permanent once they make it into long-term memory. Forgetting does not seem to happen in long-term memory because of disuse overtime. Forgetting m simply is a matter of retrieval failure in that some other additional experience may interfere with the systems at the time of retrieval.

Retrieval Failure

The failure of retrieval provides the most important explanation forgetting. Even when the material is properly coded, and stored in the LTM for some reason, the material cannot be retrieved when needed, it is deemed to be forgotten.

There are several factors influencing retrieval from the LTM them is the context of memorization. If our memory for persons and events has taken place in one context, and we are asked to recall it another ext some amount of retrieval failure may take place.

Many of us fail to the names of our high school classmates, when we meet them later in the out of-school settings. This means that we have lost social-context- retrieval cues that we used while forming the initial memories of those classmates. Hence, the change of the memorization context leads to retrieval failure, and consequently, poor memory. It seems that many memory failures are to poor encoding and inadequate retrieval cues rather than loss of memories. Failure to call up memories cannot be taken as a positive proof that memory was not there.

Another important source of influence for memory failure comes from interference. The theory of interference suggests that forgotten memory is either lost or damaged, but is only misplaced. The memories for other Materials interfere with the retrieval of the one that is sought.

Our inability to remember the names of our high school friends is similar to what happens a clerk fails to locate a letter that he received a year ago. The letter is still somewhere in his file but it has been buried among a host of other letters buried the clerk filed before and after this letter. The modern theorists accept interference a major cause of forgetting.

The interference takes place in two different forms such as proactive interference, and retroactive interference. Proactive interference refers to a phenomenon, when old memories displace or block out new memories. On the other hand, when new memories knock out the old memories, the phenomenon is known as retroactive interference.

A vast amount of experimental evidence as well as everyday experiences indicate the occurrence of both proactive and retroactive interferences. When you fail to recall the names of your high school classmates, because you had so many friends in colleges, you are experiencing the phenomenon of retroactive interference.

On the other hand, if you had difficulty recalling the names of your college friends because of your memories for close friends in your high school, you are experiencing what is called proactive interference. Memory references are easily demonstrated in the experimental laboratory.

Suppose you want to demonstrate experimentally the retroactive interference that affects retrieval memory. The prefix 'retro' means 'backward acting'. Retroactive interference occurs when a new learning works backward and interferes with the previously learnt material.

In a typical experiment, there are two groups known as the control group and the experimental group. The control group learns some materials such as a list of nonsense syllables (List A), and is tested after a specified rest interval. The experimental group learn the same list (List A), and then learns a second list (List B) during the period when the control group takes rest. The learning of List B by the experiment; group is an interpolated activity. Then both the groups are asked to recall List A), which was previously learned.