Memory (P1) Flashcards
Jacobs (1887) capacity of STM
- Aim: to investigate the capacity of STM
- Procedure: A laboratory experiment, participants were asked to recall a sequence of either letters or digits, they had to recall them in the order in which the sequence was presented, they repeated this procedure until they could not recall the sequence accurately.
- Findings: Generally, participants could recall a longer string of digits and letters (average 9 digits and 7 letters), capacity of STM increased with age
-Conclusions: STM has a limited capacity of 7 plus or minus 2 (5-9)
Evaluation of Jacobs (1887) study into the capacity of STM
-Limitations: lab experiments are artificial and lack ecological validity, strings of random digits and letters are not meaningful so less likely to be recalled
-Strength: high control of extraneous variables due to laboratory environment
Sperling (1960) study into the capacity of the sensory register (aim and procedure)
Aim: to investigate the capacity of the sensory register
Procedure: participants were shown grids of letters: three rows of four letters, control tests were done to establish baseline of individuals ability to recall letters. The experiment showed the participants a grid of letters (three rows of four letters for 0.05 seconds. There were two conditions (recall the whole grid and recall a single row). The row to be recalled was identified by a high/medium/low tone that was played directly after the grid was flashed. The participants did not know which row was to be selected.
Findings of sperling (1960) study into capacity of STM
-First scenario-recall the whole grid: participants only managed to recall 4-5/12 letters
- Second scenario-recall a single row:
Participants could recall 3/4 letters in a row
-These results were consistent no matter which row was selected
Conclusions of sperlings (1960) study into capacity of the sensory register
-The sensory register is finite, humans can only process and recall a limited amount for sensory information
-Participants did not know which row was to be selected, so they viewed the whole grid, meaning the entire grid was in their sensory register.
-They could not recall all of the letters as the trace faded and the information decayed.
Evaluation of Sperlings (1960) study into the capacity of the sensory register
-Strengths: highly controlled lab experiment so has control over extraneous variables, scientific and easy to replicate, results more reliable
-Limitation: lab experiments do not reflect real life scenarios (you are hardly ever expected to recall a grid of letters) so study has low ecological validity
Visio-spatial sketchpad
-The component of working memory that processes visual information (the visual cache) and spatial information (the inner scribe)
-The visual cache stores visual information in the form of colour
-The inner scribe handles spatial relationships, rehearses and transfers information from the visual cache to the central executive.
-The VSS temporarily stores visual and spatial information, including the relationship between them
What have PET scans shown about locations of the visual cache and inner scribe? (Parts of VSS)
-The left hemisphere of the brain is activated by visual tasks and the right hemisphere by spatial tasks
-As the visual cache stores visual information and the inner scribe spatial relationships, this shows that they are separate distinct stores in different areas of the brain
The episodic buffer
- Added to the working memory model in 2000 as it had been suggested that WMM needed a general store to operate properly
- Explains how information is integrated between sub systems
-Explains how it is possible to temporarily store information combined together from CE, PL and VSS in LTM
-Tries to correct problems caused by the limited capacity of both the PL and VSS and problems with CE storage of visual and acoustic information
What have fMRI scans shown about episodic buffer? (AO3 research support)
-provides research support
-Prabhakaran et al used fMRI scans and found greater right-frontal brain activation for combined verbal and spatial information, but greater posterior activation for non-combined information
-This provides biological support for an EB that allows the temporary storage of integrated information
What is interference? (2 types)
-When some information in our memory is inaccessible because of old or new information blocking retrieval.
- Proactive: when old information hinders recall of newly learned information
-Retroactive: when newly learned information hinders the recall of old information
What type of interference occurs when new information hinders the recall of old information?
Retroactive interference
What type of interference occurs when old information hinders learning of new information?
Proactive interference
AO1- effects of leading questions on EWT- key study loftus and palmer (cars)
-Loftus and Palmer investigated the effects of leading questions on the reliability of eyewitness testimony.
-They examined three groups of students who watched a one minute video of a car accident. One group was asked ‘’how fast were the cars going when they smashed into eachother?”, while the other group was asked the same question with the verb ‘’hit’’.
-One week later they were asked: ‘’did you see any broken glass?’’, despite the fact there was none.
-32% participants in smashed conditions said yes, compared to 14% hit and 12% control, suggesting that misleading questions can significantly affect the reliability of EWT and make people report seeing things they didn’t.
AO1- key study- effect of anxiety on EWT: Johnson and Scott (1976)
-Anxiety is another key factor affecting the reliability of EWT and was investigated by Johnson and Scott (1976)
-Participants were invited to a laboratory where they were exposed to one of two conditions in which a person, known as the target, left the laboratory either holding a pen or bloodied knife.
-The participants were then shown 50 photos and asked to identify the person.
-Those in the pen condition correctly identified the target 49% time, compared to just 33% knife condition.
-Loftus claimed that the participants who were exposed to the knife condition had higher levels of anxiety and were more likely to focus their attention on the weapon, known as the weapon focus effect, suggesting that anxiety can affect the reliability of EWT.
