Forgetting: Causes and Effects

Forgetting

• Forgetting is a complex process with various causes.
• Incidental forgetting occurs without intent to forget.
• Motivated forgetting includes intentional forgetting and unconscious forgetting, often triggered by motivations.
• Forgetting is influenced by time, with information becoming less accessible over time.
• Factors affecting forgetting include decay, interference (similar memories competing), and contextual shifts (changes in memory retrieval context).
• The Ebbinghaus forgetting curve illustrates how information is lost over time, typically at a rapid rate initially and then more slowly as time increases. The curve shows higher retention initially and lower retention when longer intervals occur.
• The forgetting curve is applicable to both well-learned and poorly-learned information.
• In recall, forgetting is often more pronounced than in recognition.
• Permastore refers to information that stays accessible for a long period.

Forgetting Curve

• The forgetting curve shows a logarithmic decline in memory over time.
• It's also sometimes called the retention function.
• The curve's application is not limited to a single category of memory, as it applies to both poorly and well-learned information.
• The curve is also relevant to more than just recall, as it has demonstrable implications for recognition.
• A related concept to forgetting is permastore. Permastore is when information stays in memory over a long length of time.

Accessibility vs. Availability

• Forgetting is often measured by a failure to recall, although recognition is generally easier.
• Accessibility is the ease with which a retrieved memory can be retrieved.
• Availability refers to whether a memory exists and is stored.
• Recognition and recall can both be inaccessible but still available. (e.g., multiple choice tests).
• We cannot quantify memory storage; measuring availability is currently impossible.

New Memories Are Vulnerable

• Jost's Law suggests older memories are more durable.
• New memories are vulnerable to forgetting as they are not yet well consolidated.
• Synaptic and System consolidation take time; episodic memories need the hippocampus less.

Reactivated Memories

• Reactivated memories can be disrupted and require restabilization.
• Reactivated memories are vulnerable to forgetting.
• Reconsolidation is the process of memory restabilization after reactivation.

Retesting

• Retesting frequently leads to less forgetting.
• Retesting should focus on recalling the correct information.
• Retrieving a memory about a memory can occur.

Passage of Time

• Passage of time often causes forgetting. While time plays a key role, other variables may also contribute to forgetting.
• Trace decay is the idea that memories weaken over time.
• Memory structures may decay, supported by evidence of memory degradation in animals..
• Neurogenesis, particularly in the hippocampus, might be involved.
• Infantile amnesia is an example of the impact of time on memory.

Trace Decay is Controversial

• For trace decay to be valid, forgetting must increase with time.
• Other variables must be controlled.
• Models usually focus on interference rather than trace decay.
• It's possible time co-occurs with another forgetting factor, like shifts in context or interference.

Contextual Fluctuation

• Contextual fluctuation reflects how incidental contextual changes over time can impact memory retrieval.
• Distant memories often deviate more from the current context than newer memories. Daydreaming is associated with worsened memory recall after a study period.

Interference

• Interference occurs when similar memory traces impair retrieval.
• Many memories are functionally similar to others.
• Competitors refer to memory traces that compete with a target trace. Many cues associated with a target can activate competing memory traces.
• Interference increases with more competing memory traces.

Retroactive Interference

• Retroactive interference involves newer memories impeding retrieval of older information.
• This can be seen when a newly learned language is used to substitute for a formerly known language.
• The more new items learned, the more they interfere with older information.

Proactive Interference

• Proactive interference is when older memories impede the retrieval of newer information.
• This is demonstrated by the increased difficulty of using newer information when the same information in a similar context has been used before.
• Studying multiple lists of memories results in poorer recall of subsequent lists.

Part-Set Cuing Impairment

• Part-set cuing impairment occurs when presenting part of a set impedes recall of the remaining items.
• Cues increase competition for recall.
• Cued items in partial sets are not always stronger.
• Forgetting and associated issues are usually focused on memory retrieval.
• Group recall is often less than when individuals separately attempt to recall the same information

Retrieval-Induced Forgetting

• Retrieval of target items negatively impacts recall of associated information.
• The retrieval process procedure used to study retrieval-induced forgetting is the retrieval practice paradigm.
• Practicing one concept or word can result in forgetting other associated words.
• Studying half of a list of items helps recall those items, but hurts recall of items not studied.
• This primarily impacts recall and not recognition.

RIF Influences on Memories

• Children's memories of unretrieved events are negatively affected during retrieval.
• Physically painful memories can be forgotten while positive aspects of a memory are recalled.
• Socially shared memories are forgotten if parts are not recalled during a reminiscence period.
• Discussions related to memory retrieval can cause mnemonic convergence, which can align memories in a socially constructed way. This sometimes occurs in political arenas.

Causes of Interference

• Associative blocking occurs when a cue fails to retrieve a target due to a strengthened competing memory trace.
• Associative unlearning is the weakening of connections between a stimulus and memory trace over time.
• A two-factor model of retroactive interference is required when both blocking and unlearning are applied.
• Interference from competing memories is also influenced by inhibition of competing memory traces, thereby causing them to be less active.

Inhibition

• Inhibition differs from associative unlearning because the link between elements is not broken, just inhibited.
• The associative link still exists.
• Inhibition is due to preventing interference.

Properties of Inhibition

• Inhibited memories generalize to other cues.
• Retrieval specificity refers to the act of retrieval causing retrieval-induced forgetting.
• Strength independence means the strength of practiced memories does not impact retrieval-induced forgetting.
• Retrieval-induced forgetting is only present when interference is relevant.
• Memory retrieval performance can be affected by attention level. Lower attention leads to lower retrieval-induced forgetting.

Neural Evidence of Inhibition

• Cortical pattern suppression means patterns from forgotten elements are suppressed/inhibited.
• Inhibition involves the ventral/inferior prefrontal cortex and the anterior cingulate cortex (ACC).
• Evidence supports retrieval-induced forgetting in rats; this supports that RIF generalizes across species.
• Memory retrieval also activates the prefrontal cortex (PFC); therefore, RIF also involves the PFC.

Functional Purpose of Forgetting

• Forgetting may be necessary for cognitive flexibility.
• Forgetting allows for effective cognitive control.

Questions

• Are there any remaining questions about the material?

Problem for Next Class

• What are some reasons why we would want to forget things?
• An assignment is due Nov. 19th.
• Read chapter 10.
• Have a good reading week.

Explore the intricate process of forgetting in this quiz, which covers various causes such as incidental and motivated forgetting. Learn about the Ebbinghaus forgetting curve, how time impacts memory retention, and the concept of permastore. Test your understanding of these key principles of memory and information retrieval.