Biological Factors in Cognitive Processes
- Neurotransmitters may play a role in memory, such as acetylcholine (ACh) and spatial memory.
- ACh mainly operates in the hippocampus.
Case study
Martinez & Kesner (1991)
Aim
to see what role ACh played in spatial memory
Method
Injected rats with 3 types of injections:
- Scopolamine, to stop ACh (antagonist)
- Physostigmine, which increases ACh because it blocks production of cholinesterase which cleans up ACh from synapses (agonist)
- Third group was a placebo.
All rats underwent a maze.
Results
- Rats injected with scopolamine made more mistakes, whereas rats with physostigmine made fewer mistakes
- Therefore, ACh is a neurotransmitter that boosts spatial memory.
Note
Critical Thinking
- True experiment increases internal validity.
- ACh has been linked to Alzheimer's disease, indicating a possible role in memory.
- It is an animal study. Can it be generalized to humans?
Cognitive Models
Multi-Store Model of Memory
- Proposed by Atkinson & Shriffin (1968)
- It posits that information flows through 3 stores, with each store having a different capacity and duration.
- The first one is sensory memory, which holds one piece of information for a fraction of a second.
- Short term memory has a limit of 7±2 items, and information is stored for around 30 seconds. then, we go to
- Long term memory, which may have unlimited storage, but its information is subject to decay over time.
Case study
Glanzer & Cunitz (1966)
Aim
To test their hypothesis that there are 2 distinct storage mechanisms, LTM and STM
Method
- 2 repeated measures experiments
- Participants presented with lists of 20 1 syllable nouns, but the time in between saying each word varied from 3 to 6 to 9.
- Experiment 2 asked participants to recall 15 1 syllable nouns, and asked to recall them immediately or after 10 or 30 seconds.
Results
- Middle words were often forgotten.
- This may be due to it being stored in the STM but getting lost due to interference.
- The ability to recall first few words is called the primary effect, and the ability to recall the last few words is called the recency effect.
Note
Critical Thinking
- How do we pick which information to store?
- May oversimplify memory storage.
- Still incredibly influential for future theories.
Working Model of Memory
- A model of short term memory with the following parts:
- Central executive decides which information to attend to and where to send it, and it acts as a control center rather than a memory store.
- The phonological loop deals with spoken and written material and it contains 2 parts: the phonological store, which acts as an inner ear, and the articulatory control process which converts written words into spoken code
- The visuospatial sketchpad deals with what things look like.
Case study
Robbins et al. (1996)
Aim
To demonstrate the working memory model
Method
- Asked participants to play chess (visuospatial sketchpad)
- Also asked to either repeat words (phonological loop) or type on a keyboard (visuospatial sketchpad)
Results
- Playing chess involves visuospatial sketchpad, so repeating words, which uses the phonological loop, did not affect the playing.
- Typing on a keyboard also uses visuospatial sketchpad so it hindered the performance
- Overall, this demonstrates WMM.
Note
Critical Thinking
- The central executive is criticized to be a very vague concept.
- It is considered more comprehensive than MSM.
Cultural Factors in Cognitive Processes
- Researchers initially assumed that cognitive processes were universal.
- We know now that this is not true.
Case study
Cole & Scribner (1974)
Aim
To see what strategies children from the USA and Kpelle children use to remember things.
Method
- Worked with local researchers to create a list of words children would encounter in daily life.
- They asked participants to try and remember the list of words.
Results
- Formally schooled Kpelle children performed as well as children in the USA and used similar strategies.
- Children who were not formally schooled underperformed but when encouraged to use storytelling as a strategy to remember, their performance drastically increased.
- Memory capacity may be similar, but strategies may vary across culture.
Note
Critical Thinking
- Has been empirically supported by others (e.g. Rogoff and Wadell, 1982)
- Some studies, however, do not demonstrate cultural differences (e.g. Conway et al., 2005)
Environmental Influences on Cognitive Processes
- Stereotyping may affect memory.
Case study
Cohen (1985)
Aim
To determine whether stereotypes affect memory.
Method
- Participants watched a video, were told the woman was either a waitress or a librarian.
- Then they were asked questions about the video.
Results
- Answers were more consistent with stereotypes surrounding the jobs, eg the librarian wore glasses or the waitress drank alcohol.
- Therefore, stereotypes can affect information we focus on and remember.
Note
Crticial Thinking
- Take into account the temporal validity of the study.
- This study also does not take into account memory capacity of the participants.
- However, it is not a coincidence that answers were consistent with stereotypes.
Potential for Improving a Cognitive Process
- Video games may enhance working memory.
Case study
Blacker et al. (2014)
Aim
To see if video games could expand capacity of visual working memory (VWM)
Method
- Action game group played things like call of duty.
- Control group played sims
- Both played their games for 1 hour every day for 30 days. A
- Before and after training, VWM was tested.
Results
- People who played action games (rich visual environment) had better measures of VWM capacity than control group
- Therefore, engaging with rich visual environments may increase VWM capacity.
Note
Critical Thinking
- How can video games also affect behaviour and cognition adversely?
- Pretest Posttest design shows that improvement was not due to individual differences in VWM.
Self review
- Contrast the working memory model and the multi-store memory model.
- How can scopolamine affect spatial memory?
- To what extent does culture affect cognition?
