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.
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.
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.
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.
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
