Memory

Atkinson and Shiffrin as a cognitive explanation of memory.

• Stimuli reach the sensory register (info lost immidiately if not significant)
• Attention pass to STM 
• Rehersal loop maintains information to retain it for LTM
• All info in LTM
• information retrived to STM for use or forgotten 

- modern scanning techniques show just 3 sections too simple (reductionsist) i.e 3 types of LTM

- retaining m=information in the LTM is not done just by rehersing

+Case studies of stroke patients support MSM as different types of memory loss to different locatin of brain damage

+ HM lost hippocampus in surgery, lost all ability to make long term memories but his STM duration was 25x bigger than average human

Capacity

• very large
• Sperling (ding): 3x4 grid with 3 tones for 1/20 second. Recall correct 70% of the time 

- Hard to investigate capacity without highly controlled setting, low ecological validity

Coding 

• echoic, haptic, ol factory, gustatory, iconic ]
• Crowder: only in iconic for milleseconds but seconds for echoic (suggets different stores)

Duration:

• milleseconds- several seconds 
• Walsh and Thomposon: 1/4 - 2 seconds

- probably an evolutionary explanation why duration is short, keeping all information for long times would be overwhelming.

Capacity:

• 7+- 2 with chunking 
• Miller: magic number
• Jacobs: serial digit span for 7 for letter and 9 for numbers 

Coding 

• Visually, acoustically, semantically
• Baddeley: STM is mainly acoustic. Acoustically similar (10% correct) and acoustically disimilar (60% correct) shows accoustic coding as confusion when trying to process

Duration

• maximum 30 seconds (extended by repetition or rehersal)
• Petersona and Peterson: nonsense trigrams , then count down from 100 in 3s amd timed at 3 second intervals for correctness

Capacity:

• unlimited (depending on age etc)
• Anokhin: millions of millions of millions of neurons etc

Coding 

• Acoustic, semantic and visual
• Baddeley found mainly semantic: semantically similar and semantically disimilar

Duration

• lifetime 
• Bahrick: names to faces in year book from 48 years ago (70% correct).

- research from labs, low ecological validity

LTM is split into two sections, implicity memory (unconsious recall) and explicit memory (consious recall). This is then further split into 3 sections: episodic, sematic and procedural memory.

Episodic:

• Explicit, memories of life events. Usually moved to LTM for their meaning and emotional value 
• Clive Wearing: viral infection to brain, can play piano but doesnt remember wife after a minut

Semantic:

• Explicit, memories that make up our knowlege (facts, events etc)
• Tulving: left prefrontal cortex = semantic memories, right = episodic

Procedural:

• Implicit, how to do things i.e. how to ride a bike, requires little effort to recall

Baddely and Hitch- STM more complicated than what the MSM suggests. 

1. Central Executive: coordinator of slave systems, flters stimuli, limited capacity

2. Phonological loop: temporary acoustic store for verbal info or words before we speak

• Primary acoustic store- inner ear
• Articulatory process - inner voice

3. Visuo-spatial Sketchpad: inner eye, reherses viusal information

• visual cache- stores visual information
• inner scribe - stores information about spacial relationships 

4. Episodic Buffer: temporary store for information between all other stores 

CE: Baddeley and Hitch 

Ptps complete a list of numbers and answer true or false questions. Found as more numbers in digit span, ptps took longer answer T or F. Suggests questions used the CE and digit span used PL

PL: Baddeley

Ptps remembered either short or long words. Harder to rember long words as they took up information space. However, if they had to speak while learnign short words, tehy also struggled to remeber them; PL was busy with speech.

VSSP: Gathercole and Baddeley

Ptps track a moving light while describing the angles on the letter F. As both tasks involved VSSP, performance dropped but when two systems in use, was easier.

- dual tasks lack mundane reaslism and ecological validity.

Retroactive interferance: when new information interferes with retrival of old information. E.g. new phone number messes up remembering your old one 

Proactive interferance: when old information interferes with retreval of new information. E.g. you cant rember your new postcode because you are thinking about your old one. 

Serial position curve: primacy and regency effect.

• Primacy: remembering the first few items as they were said first
• Regency:  remebering the last few items as they were said more recently 

+ lots of highly controlled lab experimants with standardised procedures back it up

+ easily applied to real life settings - mundane realism 

- not very useful as instnaces of interferance are rare 

Context-Dependant Forgetting:

Retreval failure due to being in a different context to when the information was coded

• Abernethy (nessie): ptps who leaned with a teacher and had that same teacher when they took tests performed better than those who took tests with different teachers

State-Dependant Forgetting:

Retreval failure due to a different state to when infirmation was coded.

• Overton: ptps learnt information when drunk and tried to recall when sobre. Worked best if learned and recalled in the same state.

- lab research so lacks mundane realism 

- unethical: ptps drunk even with consent, could long term damage liver 

+ Good explanation for LTM forgetting 

Leading questions: questions that will sway the whitness ( e.g. did you see the broken glass?)

• Response-bias explanation: leading questions alters their bias, not memory
• Memeory substitution explanation: leading questiosn actually alter memories

Loftus and Palmer (car crash): students watched videos of a car crash. Asked how fast the cars were going when it: contacted, bumped, collided, hit and smashed. Significant diference between basic and stimulating words, contacted= 31.8 mph smashed = 40.8mph

Post-event discussion: a discussion after the event can contaminate memories from factors others say or misleading information

Loftus and Pickrell (bugs bunny): ptps given an advert for disney land with bugs bunny on or woth a cutout of bugs bunny in the room. Asked to detail their trip. 30% stated they remeber meeting bugs bunny, which is impossibel as he is not a disney character.

- early resreach was very artificial and used psychology students as sample, so not very generalisable

Weapon Focus: Loftus suggested that as weapons are alien objects to most people that carry many fears, when in a situation, many will focus on weapons due to their anxiety surrounding them

Yerks-Dodson inverted U hypothesis:

Emotional arousal is beneficial upto a threshold where it becomes detrimental and performance dramatically declines.

- difficult to investugate anxiety while remaining ethical 

- findings vary alot and are sometimes contradictory and vary if crime was violent or not

+ added to understanding of real life what happens to whitnesses

1. Report everything 

2. Reinstate the context (imagine back at the scene)

3. Reverse narritive order (can help fill in gaps)

4. Change perpective (change side, i.e. as a random person on the street)

Enhanced CI: not be interupted, no leading information

- only works for some whitnesses and crime 

+ Fisher found CI achieved more accuarte detailed memories than standard police interviews 

+ all police forces trained for cognitive interviews