Sensory memory:
- Enters via sensory input
- Brief and only lasts 1-2 seconds.
- Paying attention to the info passes it to STM
- Forgotten through decay/ lack of attention to info
Short Term Memory (STM):
- Lasts 15-30 seconds, stores 5-9 items.
- Has subvocal rehearsal loop
- Not paying attention/ rehearsing info leads to displacement
- Passed to LTM via encoding & rehearsal
Long Term Memory (LTM):
- Appears to be infinite
- We are not sure how long information in LTM lasts
- Information lost via trace decay or inference
| Strengths | Weaknesses |
| Murdock – serial position curve shows information is rehearsed because greater number of words recalled at the start & end shown in recency curve.
Glanzer and cunits- shows that by destroyed the recency curve by delaying recall by 30 seconds destroys STM info. – selective damage of recall shows there is STM. Peterson & Peterson – investigate duration of STM rehearsals by asking ppts to recall trigrams after 3-18 seconds delays. After 18 seconds fewer than 10% recall – supports idea that STM lasts between 15-30 seconds. Application – theory states that we need to repeat information in the stm for it to pass onto the ltm – help develop recall techniques to help revision. |
Clive wearing – because amnesia stripped him of his episodic memory but he still knows procedural skills e.g playing piano – showing more section of LTM. MSM too simplistic.
Other theory – level of processing because the theory states info is retained by the depth it is processed on memory traces. – MSM is too simplistic & ignores processing effort. Working memory model – believe that STM and LTM have several separate store systems; central executive, phonological loop, visueo-spacial sketchpad, episodic buffer – shows it’s not just one separate system & not passive. Procedural & declarative – shows LTM store info in different stores. Procedural for skills, episodic for events, and semantic for meaning – shows LTM is not just one passive store. |
Cognitive Practical: To investigate the duration of STM as proposed by Atkinson & Shiffrin. To investigate the effect of a 30 second delay to recall from STM.
Hypothesis: Predicted that significantly more words out of 15 will be correctly recalled from condition A (immediate recall) than condition B (30 sec delay).
Variables: Iv- manipulating the 30 second delay. Dv – correct number of words recalled out of 15. Controls – background noise, same delay timing, same word list tested, ppt variables & environment.
PPTS: 18 king ed. Students 1 male & 17 females.
Methods: opportunity sample. Lab
Procedure:
- Ppts were asked to recall a series of 15 words from a PowerPoint. Each words shown for 2 seconds.
- They were then asked to write down the words they could recall.
- In condition B, after ppts were shown a slideshow of 15 new word. A distractor task was give, to count down in 3’s from 99. This task lasted 30 seconds and was used to delay recall.
Results: immediate 8.8 – 30 second delay 6.7
Conclusion: That a 30 second delay effects recall by destroying the recency affect in the STM. Proven that there is a small duration in the STM
Improvements: used a better task, or use more words to recall (more than 15).
| Strength | Weakness |
| High R – used a standardized procedure by everyone having the same instructions, recalling the same 15 words & same 30 second delay – easier to replicate to test for consistencies.
High R – based off previous research from Glanzer & cunits who destroyed recency effect with a 30 second delay – making our results more reliable. Application – results show 8.8 had better recall from immediate than 6.6 from after 30 seconds finding STM can be disrupted by a delay – devise better revision techniques to help retain information. High objectivity – uses quantitative data on results by using means so it is narrow & easily interpreted – reduces researcher bias as interpreted one way. |
Low G- uses an opportunity sample consisting of 18 ppl – 17 female, 1 male – cannot generalise to all males or whole pop.
Low eco V – was done in an artificial experiment which could lead to ppts guessing the aim due to not concealing it well – demand characteristics could arise & behaviour not natural. Low task V – not a normal activity on being asked to remember 15 words, and experience and artificial 30 second delay – therefore task has lower mundane realism not reflecting normal memory.
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