Memory retrieval is the process of remembering information stored in long-term memory. Some theorists suggests that there are three stores of memory: sensory memory, long-term memory (LTM), and short-term memory (STM). Only data that is processed through STM and encoded into LTM can later be retrieved. Overall, the mechanisms of memory are not completely understood. However, there are many theories concerning memory retrieval.
There are two main types of memory retrieval: recall and recognition. In recall, the information must be retrieved from memories. In recognition, the presentation of a familiar outside stimulus provides a cue that the information has been seen before. A cue might be an object or a scene—any stimulus that reminds a person of something related. Recall may be assisted when retrieval cues are presented that enable the subject to quickly access the information in memory.
Memory retrieval can occur in several different ways, and there are many things that can affect it, such as how long it has been since the last time you retrieved the memory, what other information you have learned in the meantime, and many other variables. For example, the spacing effect allows a person to remember something they have studied many times spaced over a longer period of time rather than all at once. The testing effect shows that practicing retrieval of a concept can increase the chance of remembering it.
Memory retrieval, including recall and recognition, is the process of remembering information stored in long-term memory.
Some effects relate specifically to certain types of recall. There are three main types of recall studied in psychology: serial recall, free recall, and cued recall.
People tend to recall items or events in the order in which they occurred. This is called serial recall and can be used to help cue memories. By thinking about a string of events or even words, it is possible to use a previous memory to cue the next item in the series. Serial recall helps a person to remember the order of events in his or her life. These memories appear to exist on a continuum on which more recent events are more easily recalled.
When recalling serial items presented as a list (a common occurrence in memory studies), two effects tend to surface: the primacy effect and the recency effect . The primacy effect occurs when a participant remembers words from the beginning of a list better than the words from the middle or end. The theory behind this is that the participant has had more time to rehearse these words in working memory. The recency effect occurs when a participant remembers words from the end of a list more easily, possibly since they are still available in short-term memory.
Free recall occurs when a person must recall many items but can recall them in any order. It is another commonly studied paradigm in memory research. Like serial recall, free recall is subject to the primacy and recency effects.
Cues can facilitate recovery of memories that have been “lost.” In research, a process called cued recall is used to study these effects. Cued recall occurs when a person is given a list to remember and is then given cues during the testing phase to aid in the retrieval of memories. The stronger the link between the cue and the testing word, the better the participant will recall the words.
Interference occurs in memory when there is an interaction between the new material being learned and previously learned material. There are two main kinds of interference: proactive and retroactive.
Proactive interference is the forgetting of information due to interference from previous knowledge in LTM. Past memories can inhibit the encoding of new memories. This is particularly true if they are learned in similar contexts and the new information is similar to previous information. This is what is happening when you have trouble remembering your new phone number because your old one is stuck in your head.
Retroactive interference occurs when newly learned information interferes with the encoding or recall of previously learned information. If a participant was asked to recall a list of words, and was then immediately presented with new information, it could interfere with remembering the initial list. If you learn to use a new kind of computer and then later have to use the old model again, you might find you have forgotten how to use it. This is due to retroactive interference.
Sometimes a person is not able to retrieve a memory that they have previously encoded. This can be due to decay, a natural process that occurs when neural connections decline, like an unused muscle.
Occasionally, a person will experience a specific type of retrieval failure called tip-of-the-tongue phenomenon. This is the failure to retrieve a word from memory, combined with partial recall and the feeling that retrieval is imminent. People who experience this can often recall one or more features of the target word such as the first letter, words that sound similar, or words that have a similar meaning. While this process is not completely understood, there are two theories as to why it occurs. The first is the direct-access perspective , which states that the memory is not strong enough to retrieve but strong enough to trigger the state. The inferential perspective posits that the state occurs when the subject infers knowledge of the target word, but tries to piece together different clues about the word that are not accessible in memory.