Ib Psychology Studies - Biological
ROLE OF NEUROTRANSMITTERS IN LEARNING AND MEMORY – Martinez and Kesner (1991)
Aim: determining the role of the neurotransmitter acetylcholine on memory
Method:
* Rats were trained to go through a maze and get to the end, where they received food * Researcher injected one group of rats with scopolamine (blocks acetylcholine receptor sites thus decreasing available acetylcholine) * Injected second group of rats with physostigmine (blocks the production of cholinesterase – cholinesterase does the ‘clean-up’ of acetylcholine from the synapse and returns the neuron to its ‘resting state’. * Third group (control group) were not given any injections
Results:
* Scopolamine group – slower at finding their way round the maze and made more errors than both the control group and physostigmine group. * Physostigmine group – ran through the maze and found the food even more quickly than the control group, and took fewer wrong turns
Conclusion: Acetylcholine plays an important role in creating a memory of the maze. * Strengths - research lie in its design and its application; use of an experimental method with a control group made it possible to establish a cause-and-effect relationship between levels of acetylcholine and memory * Limitations – questionable to what extent these findings can be generalised to humans; assumed that memory processes are the same for all animals.
Case study: PHINEAS GAGE
Aim: the most famous study of how brain damage can affect behaviour * Phineas Gage, 25 years old railroad worker, got in a serious accident. While trying to blast through a rocky cliff, an explosion sent a metal pole through his skull. Iron entered Gage’s left cheek, pierced the base of the skull, went through the front of his brain, and exited at high speed through the top of his head.
Method/ Results: Balance between his intellectual abilities and his emotional control had been destroyed. * He became highly agitated and
Aim: determining the role of the neurotransmitter acetylcholine on memory
Method:
* Rats were trained to go through a maze and get to the end, where they received food * Researcher injected one group of rats with scopolamine (blocks acetylcholine receptor sites thus decreasing available acetylcholine) * Injected second group of rats with physostigmine (blocks the production of cholinesterase – cholinesterase does the ‘clean-up’ of acetylcholine from the synapse and returns the neuron to its ‘resting state’. * Third group (control group) were not given any injections
Results:
* Scopolamine group – slower at finding their way round the maze and made more errors than both the control group and physostigmine group. * Physostigmine group – ran through the maze and found the food even more quickly than the control group, and took fewer wrong turns
Conclusion: Acetylcholine plays an important role in creating a memory of the maze. * Strengths - research lie in its design and its application; use of an experimental method with a control group made it possible to establish a cause-and-effect relationship between levels of acetylcholine and memory * Limitations – questionable to what extent these findings can be generalised to humans; assumed that memory processes are the same for all animals.
Case study: PHINEAS GAGE
Aim: the most famous study of how brain damage can affect behaviour * Phineas Gage, 25 years old railroad worker, got in a serious accident. While trying to blast through a rocky cliff, an explosion sent a metal pole through his skull. Iron entered Gage’s left cheek, pierced the base of the skull, went through the front of his brain, and exited at high speed through the top of his head.
Method/ Results: Balance between his intellectual abilities and his emotional control had been destroyed. * He became highly agitated and