Unit 3 - Forgetting and learning (psych)

Forgetting

The inability to retrieve memories

4 types of forgetting

1. Retrieval failure

2. Interference

3. Motivated Forgetting

4. Decay theory

1. Retrieval failure (type of forgetting)

The inability to consciously recall information stored in the LTM due to an absence of retrieval cues

• Retrieval cues: mental reminders/prompts that we create to assist with our recollection later. They come in a range of formats including context-dependent

2. Interference (type of forgetting)

When info in the LTM store cannot be retrieved due to it being disrupted by similar information

2 types of interference

1. Proactive interference: when OLD information moves forward and interferes with our retrieval of NEWER information

   • e.g. remembering a friends new phone number after memorising their old number

2. Retroactive interference: when NEW information interferes with the retrieval of OLDER information stored in the LTM

   • e.g. driving a manual car (your first car) after driving an automatic car for a month

3. Motivated forgetting (type of forgetting)

The intentional or unintentional suppression of memories or thought from conscious awareness to minimise emotional distress

• can occur consciously = suppression

• can occur unconsciously = repression

• RUSC - repression unconscious, suppression conscious

4. Decay theory (type of forgetting)

A theory that suggests that memories fade over time

• According to Atkinson and Shiffrin, information is transferred between memory stores and memory traces (evidence of memory) are left behind

• These traces disappear rapidly unless information is used quickly or actively rehearsed

Remembering

The process of consciously recalling or becoming aware of past experiences, information or events

The role of the recall (3 methods of retrieval)

1. Recall

2. Recognition

3. Relearning

1. Recall (method of retrieval)

Retrieving information from LTM with minimal or no cues

• cues = stimulus that help us retrieve memories

Three subtypes of recall

• Free recall: retrieval of as much info, no cues

• Serial recall: the retrieval of info in an order (series)

• Cued recall: retrieval is assisted via cues (hints)

2. Recognition (method of retrieval)

Identifying wanted/correct information from a list that also includes unwanted/incorrect info

• recognition yields more remembering than recall

• cued recall does not equal recognition

3. Relearning (method of retrieval)

Involves learning something that you have previously already learnt

• quicker the second time → savings score

• most sensitive/successful method of retrieval

Levels of processing

Craik and Lockhart (1972) state that the strength and endurance of long term memories depend on the depth of cognitive processing

*depth = meaning derived from stimuli

• 2 depths of processing: shallow processing and deep processing

1. Shallow processing (levels of processing)

Involves structural and phonemic rehearsal

• Structural: processing using the physical appearance of the word

• Phonemic: processing based on the verbal sounds related to the word

  *maintenance rehearsal is used

2. Deep processing (levels of processing)

Semantically encode/process words by attaching meaning to them

• elaborative rehearsal is used

• more success using deep processing than shallow

• linking info already in the LTM

Table of levels of processing

Study: Depths of Processing

Craik and Tulving (1975) created a study - depths of processing and the retention of words in episodic memory

Aim (study: depths of processing)

To determine the impact the levels of processing have on the recall of memory

Method - participants (study: depths of processing)

60 male and female students were recruited using convenience sampling from University of Toronto

Method - materials (study: depths of processing)

• A list of 60 words

• A set of questions

• A second list of 180 words (incorporating the original 60)

Method - design (study: depths of processing)

• IV: type of encoding (structural, phonemic, semantic)

• DV: the number of words recalled

Procedure (study: depths of processing)

1. Participants choose to take part in a study on perception (deception used). They are randomly allocated into 1 of 3 conditions. All participants are given a list of 60 words that have a corresponding set of questions.

2. The questions are designed to fit either structural, phonemic or semantic encoding e.g. capital or lowercase, rhyming and context in a sequence.

3. Participants are then given a list of 180 words (no questions). They are asked to indicate which words were on the original list.

Key findings (study: depths of processing)

• Participants in the semantic encoding condition recalled a higher percentage of words than the participants in the structural and phonemic conditions

• This is because the semantic condition required deep processing whereas the structural/phonemic condition required shallow processing

• Percentage of recall:

  • semantic (deep): 80%

  • phonemic (shallow): 50%

  • structural (shallow): 20%

Contributions to psychology (study: depths of processing)

• The study provided empirical evidence which inspired further studies of a similar nature

• The results were similar each time the study was repeated, therefore, high in reliability

Criticisms/limitations (study: depths of processing)

• Ethical guideline of debriefing was violated

• It was unclear whether it was depth of processing or time/effort that produced the results

  • Time/effort could be either an extraneous or confounding variable

2 types of rehearsal strategies

1. Maintenance rehearsal

2. Elaborative rehearsal

1. Maintenance rehearsal (type of rehearsal strategy)

Strategy that keeps the information in our STM for longer than its 15-30 second duration

• This occurs through repeating the information over and over *no meaning added

2. Elaborative rehearsal (type of rehearsal strategy)

Strategy that involves attaching meaning to information that I want to encode in LTM

• Successful encoding involves linking the new information with information already being stored in the LTM

Ebbinghaus (1885) and the forgetting curve

• Ebbinghaus (1885) results show that after learning, forgetting occurs rapidly for 20 minutes after, moderately for the remaining hour (40 minutes) and then gradually for 31 days

• If the material is repeated/over-learnt, it will be retained for longer

• Supports the decay theory

Traumatic memory loss

Chronic traumatic encephalopathy (CTE) is a progressive brain disease associated with repeated traumatic brain injuries that causes problems with cognition and memory.

• This disease is not well understood, it is somewhat agreed that it is caused by multiple traumatic brain injuries commonly associated with:

  • Military combat due to exposure to explosive blasts

  • Sports such as boxing, ice hockey, soccer, rugby and football

• The degeneration of brain cells caused by CTE is thought to be to related to the development of memory problems

How CTE impacts behaviour

• impulsive behaviour

• aggressive behaviour

How CTE impacts emotion

• Emotional instability in the form of intense mood swings

• depression

Degenerative Memory Loss - Alzheimer’s disease (AD)

Alzheimer’s disease (AD) is a brain disease that involves the degeneration of neurons in regions of the brain that are involved in cognitive skills and memory formation and retrieval

Two causes of AD

IF Q IS 1-2 MARKS: neuron degeneration

IF MORE THAN 2:

Neurofibrillary tangles, amyloid plaques and neuron loss are the causes of AD

Neurofibrillary tangles

• Neurofibrillary tangles involve a protein called tau, mainly found in the axon and dendrites of neurons.

• It clumps together, breaking down the microtubule structure that supports the axon

• This prevents normal transmission

*within neurons

Amyloid plaques

• Beta amyloid is found in abnormally high levels of people with AD

• They clump together to form amyloid plaques

• The plaques clump together between neurons and interrupt functioning

*between neurons

Brain areas associated with degenerative memory loss

The degeneration is more prevalent in the hippocampus, amygdala and cerebral cortex - all areas that are associated with memory, reasoning and language processing

Impact of Alzheimer’s disease on behaviour

• Lost/disoriented

• Habit change

Impact of Alzheimer’s disease on emotion

• Fearful/suspicious

• Anxious

Drug induced memory loss

Wernicke Korssakof syndrome (WKS) is a neurological disorder caused by a thiamine deficiency (vitamin B)

Effects of Wernicke Korsakoff Syndrome (WKS)

• Leads to the degeneration of brain cells and is characterised by difficulties forming new memories and retrieving stored memories

• The degeneration of brain cells occurs in the thalamus, hypothalamus and mamilliary bodies

• Chronic alcohol abuse leads to a thiamine deficiency which then develops into WKS

2 stages of WKS

1. Wernicke encephalopathy

   • this is severe yet reversible

2. Korsakoff amnesic syndrome

   • chronic and irreversible

Impact of WKS on behaviour

• Confabulation (making up stories to fill in gaps in memory)

• Slurred speech, poor coordination and balance (Ataxia)

Impact of WKS on emotion

• Frustration

• Apathy