Learning refers to the processes of acquiring information for mental storage and later use. Forgetting refers to processes leading to a loss of ability to retrieve previously learned information. The first step in learning new information is to encode that information in an internal representation in working memory. This representation needs to be processed further in order to develop a mental trace, a mental representation of stored information.

Craik’s theory of levels of processing states that the strength of the memory traces depends on the levels of processing. Deep processing (e.g: adding meaning to a word) leads to stronger memory traces than superficial processing (e.g: just reading a word). According to this theory, learning does not have to be intentional, as incidental learning can take place. Positive trial encodings strengthen pre-existing links between stimuli. A pitfall of this theory that it could be using circular reasoning.

Mnemonics are strategies to enhance memory performance. There are several mnemonics:

1. Categorization
   This is a mnemonic strategy involving grouping of items into familiar categories. The number of categories and a potential hierarchy in the categorization influences recall.
2. Method of loci
   This is a mnemonic strategy in which a familiar route is imagined and images of the items to be recalled are linked to landmarks on the route.
3. Method of interacting images
   This is a mnemonic strategy in which vivid and bizarre images are formed of the items to be recalled, interacting in some way (e.g: the words ‘dog’ and ‘car’ are imagined together and thus interacting).
4. Pegword method
   This is a mnemonic strategy in which to be recalled items are linked by imagery to an already learned sequence list of imageable words (e.g: linking the number one to a specific word).

The dual-coding hypothesis states that concrete words can be encoded both verbally and visually and thus it is easier to recall them, as there are two possible ways of recalling the words. Abstract words can only be encoded verbally.

The encoding specificity principle is that if the context at recall is similar to the context at encoding then memory will be enhanced. If the cues at the time of learning are the same as the cues at the time of recall, then the memory will be enhanced. Context effects occur if memory is better when the external environment at testing is the same as at learning (e.g: learning while in a quiet room and recalling information in a quiet room). State-dependent memory effects occur if memory is better when internal physiological conditions at learning are reinstated at testing (e.g: when learning drunk, recall is better while drunk than when sober). Mood dependent memory means that memory is better when mood at learning is reinstated at testing.

The spacing effect occurs when material studied on many separate occasions is better learned than material studied in one continuous session, even if the total study times are equal. There are several explanations for the spacing effect:

1. Deficient processing
   Massed repetition leads to deficient processing of the second presentation. We do not pay as much attention to the thing that is presented later than at the thing that is presented first and thus we remember less because we do not process it fully.
2. Encoding variability
   Spaced repetition is likely to cause some variability in representation. There are more cues for the learned material and this wide range of cues associated with items at study are more likely to recur at a test with spaced as against massed learning conditions.

Forgetting occurs when someone cannot retrieve information that had been previously available from memory. Savings is a way of assessing forgetting by comparing trials needed for relearning as against trials required for original learning. If fewer trials are needed for relearning, then savings have been demonstrated. Forgetting occurs because of decay due to the passing of time, but the principal explanation of forgetting is interference. Interference occurs when remembering is disrupted by related memories. There are two types of interference:

1. Proactive interference
   This occurs when previous learning impairs later learning (e.g: learning Spanish while speaking fluent French can be difficult).
2. Retroactive interference
   This occurs when later learning impairs memory for earlier memory (e.g: learning Spanish while speaking fluent French can interfere with the fluency of speaking French).

The paired associates learning paradigm is a memory task in which participants are presented with pairs of items at study and on a test are given the first word and asked to recall the second word in each pair. People forget fewer things while they are sleeping because there is reduced conscious activity compared to when they are awake. Sleep or inactivity allows consolidation of new memories takes place without a lot of interference. The beneficial effect of a period of sleep or inactivity is called retrograde facilitation.

Long-term potentiation is the long-lasting improvement in signal transmission between two neurons that result from stimulation them at the same time (neurons that fire together wire together). REM sleep does not facilitate memory, mostly because it induces long-term potentiation.

Anterograde amnesia is the inability to lay down new memory records is also associated with temporally graded retrograde amnesia, in which memories formed prior to brain damage are impaired, but the effect depends on the age of the memory trace at the time the damage occurs, with more recent memories suffering the most. The medial temporal lobes, which includes the hippocampus, play a critical role in the formation of new memories. Temporary anterograde amnesia can be induced by certain drugs which can also produce retrograde facilitation. Newly formed memories can be retained more easily, but new memories cannot be formed in the drugged state. Black-outs because of alcohol are the result of a failure to encode or consolidate new memories. An important factor in retrograde amnesia is a heightened susceptibility to retroactive interference preventing consolidation.

Forgetting helps us forget the things we don’t need to know anymore and not remember intrusive memories, persistent, unwanted memories for example of traumatic experiences. There are several functional approaches to forgetting:

1. Retrieval-induced forgetting (RIF)
   This is an impaired ability to recall some items caused by earlier retrieval of related items (e.g: thinking about what went well on a holiday improves the likelihood of forgetting what went wrong).
2. Directed forgetting (DF)
   This is memory impairment brought about by instructions to forget some items. There are two variants of directed forgetting. The item-based form of DF and the list-based form of DF. In the item based form of DF, people are shown items of which some are then to be forgotten. In the list based form of DF, people are shown two lists of items of which one of the lists is instructed to be forgotten.
3. Think/no-think (TNT)
   This is a memory manipulation in which participants are instructed not to retrieve a memory even when a strong cue is present.

Ecological validity is the degree to which the results of a laboratory study can be applied to a real-life situation. Ecological validity consists of two aspects:

1. Representativeness
   This increases with the realism and the naturalness of the study’s materials and tasks.
2. Generalizability
   This is the degree to which results are broadly applicable to a wide range of situations.

A flashbulb memory is a vivid memory of a dramatic event and of the circumstances in which the event was experienced or heard about. Flashbulb memories are open to the effects of leading questions and can show inaccuracies. Accuracy of the recalling of the events change quite drastically over the three months but remain relatively stable after that. There are several factors that influence eyewitness testimonies, such as stress, not recalling something accurately because we deem it not important enough at the moment of the event, leading questions and gestures.

There are three main types of studying:

1. Surface learning
   Here students try to learn texts by heart without seeking understanding
2. Deep learning
   Here students make a determined effort to understand the material and make it meaningful to them
3. Strategic learning
   Here students put effort into finding out what topics and types of questions are likely in their examinations and devise strategies to cover the minimum number of topics required.