SAQs Brain and Behavior Flashcards
Outline/describe/explain
One research method (approach to research) used when investigating the brain and behaviour
Maguire et.al (2000)
Method : Natural experiment; IV is done on the basis of pre-existing differences and DV is measured; cannot have cause-and-effect inference - using MRIs
Aim : To study how brain affected behavior
Experimental group : Taxi Drivers in London ; they had to remember the map of London to gain their license
Control groups : Non-taxi drivers in London
Procedure : Used MRI scans to compare the two groups
Results : Posterior hippocampus had increased grey matter in taxi drivers while non-taxi drivers had larger anterior hippocampus size; the size of posterior hippocampus positively correlated with the number of years driving taxis
Conclusion : Redistribution of grey matter in the hippocampus occurs with experience in a subject
Outline/describe/explain
One ethical consideration when investigating the brain and behaviour
Maguire et al (2000) - Protection of participants
- non-invasive techniques such as MRI scans to correlate the posterior hippocampus volume to spacial memory.
- Participants were not physically harmed
- Allowed the participants to remain anonymous
Outline/describe/explain
One technique (or one study into one technique) used to understand the brain and behaviour
Maguire et al. (2000)
Utilises MRI (Magnetic Resonance Image) scanning to produce 3-D image of brain structure
- For a long time, brain research was limited to post mortem autopsies on target patients
- Non-invasive method that can be used to study living humans/organisms
- MRI is commonly used to study brain in relation to behavior
- Maguire et al. used MRIs to study the brain between london taxi drivers and normal individuals
- MRI image showed larger posterior hippocampus grey matter volume for taxi drivers
- For control group, showed larger anterior hippocampus grey matter volume
- Thus, experience affects grey mater redistribution which in turn affects behavior
Outline/describe/explain
Localization (or one study into localization) of function and behaviour
- Localization of function is a theory that certain areas of the brain are responsible to certain functions
- The theory shifted from strict localization –> weak localization and widely distributed functions
- Strict localization : Brain function can be mapped clearly, clear correspondence between function and brain part
- Weak localization : One area may be responsible for a function but not strictly, other brain parts may take over
- Widely distributed functions : Functions that can’t be localized
Maguire et al. (2000)
- MRI showed correlation between the posterior hippocampus grey matter volume of taxi drivers and the number of years taxi driving
- Thus spacial navigation may be localized in posterior hippocampus
Outline/describe/explain
Neuroplasticity (or one study into neuroplasticity) and behaviour
- Neuroplasticity : The brains ability to change by making/ breaking synaptic connections between neurons
- Occurs due to change in environment
- Significant during child’s early development
Maguire et al.
- Maguire et al. showed redistribution of grey matter in a taxi driver’s brain
- Brain is changing to accomodate the environment of the person
Outline/describe/explain
Neural networks (or one study into neural networks)
- A neural network is a series of connected neurons that allows the processing and interpreting of information
- Specific networks are for specific tasks
Maguire et al. (2000)
- Difference in grey matter volume in taxi and non-taxi drivers
- task specific
Outline/describe/explain
Neural pruning (or one study into neural pruning)
- Neural pruning is a process by the brain to increase efficiency
- Synapses and neurons no longer in use is eliminated by the brain
- Key function in neuroplasticity; synapses in use are increased (increase in grey matter) and synapses not un use is decreased (decrease in grey matter)
Draganski et.al (2004)
- Method : Field experiment
- Sample : Simple random sampling
- Aim : Investigate if after learning a new motor skill, if there would be functional/structural changes in the brain
- Control group : Non-jugglers
- Experiment group : People learning how to juggle
- Technique : MRI scans
- Procedure : Use MRI scanning to see if their brain changed in the span of 3 months learning how to juggle compared to control group. They were scanned :
- Before juggling
- After juggling
- 3 months after they stopped juggling
Result :
- No difference in fist scan
- Second scan : Jugglers had 2 areas significantly different than control group
- Third scan : The difference decreased
Conclusion : Juggling strengthened the neural connection in the area responsible for the activity, but after they stopped juggling, neural pruning took place and the differences became smaller.
Outline/describe/explain
One neurotransmitter and its effect on behaviour
- Neurotransmitters are chemical messenger used to transmit signals
- They are fast acting
- Ach is a neurotransmitter
Antonova et al. (2001)
Aim : How blocking Ach with scopolamine affect spacial memory
Method : Laboratory experiment; double blind
Participants : 20M
Procedure :
- Participants were injected with scopolamine or placebo 70-90 minutes before set task
- Then put into fMRI scans while playing a navigation game : Navigating around an area to find the goal, after 30 seconds of black screen, starting from a different starting point
- Repeat 3-4 weeks later with opposite treatment
Result : When under scopolamine, participants made more mistakes and had significantly less use of the hippocampus area
Conclusion : Ach plays a key role in spacial memory formation
Outline/describe/explain
How one excitatory or inhibitory neurotransmitter (synapse) affects behaviour
- Neurotransmitter : Chemical messengers used to
transmit signals - Fast acting
- e.g Ach, dopamine
- For a signal to be transmitted, the neurotransmitter must bind to a specific receptor.
- When a neurotransmitter combines with a molecule at the receptor, it causes a voltage change called post synaptic potential (PSP) whith transmits the signal
- Inhibitory neurotransmitter : Type of PSP which decreases the probability of action potential firing
- Excitatory neurotransmitter : Type of PSP which increases the probability of action potential firing
Whether the neuron fires depends on the number of Inhibitory/Excitatory synapses
Streeter et al. (2010)
Aim : If Yoga is related to increase in GABA levels : decreased anxiety
GABA is inhibitory neurotransmitter
Participants : Simple sampling of 34 healthy adults
Participants: 34 healthy adults, 19 of whom were randomly allocated to the yoga group and 15 to the walking group.
Procedure:
- The participants were instructed to either practice yoga or take walking exercise for 60 minutes at a time, three times a week across the course of 12 weeks.
- Mood and anxiety scales were taken at weeks 0, 4, 8, 12.
- The participants also underwent magnetic resonance spectroscopy (MRS) scans at each of these time intervals as well
Results:
- The participants who had engaged in yoga practice reported increased mood and a decrease in anxiety than the walking exercise group.
- There were positive correlations between improved mood and decreased anxiety and GABA levels in the thalamus
The yoga group had positive correlations between changes in mood and changes in GABA level
Conclusion: Yoga may be linked to an increase in GABA which in turn may be linked to increased mood and decreased anxiety.
Outline/describe/explain
One agonist and its effect on one behaviour
- Agonist is a molecule that binds to a synaptic receptor and promote a reaction
Crokett et al. (2010)
Aim : Role of serotonin agonist in prosocial behavior
Participants : 24 males from Cambridge tested for neurological disorders beforehand
Experiment group : SSRI
Control group : Placebo
Procedures:
Participants were asked hypothetical questions like
- Would you push someone in front of a train if it meant saving five other people? This was the emotionally salient ‘personal harm’ condition i.e. the idea involves actually physically pushing someone in front of a train
- Would you flick a switch so that a train hits one person instead of five? This was the less emotionally salient ‘impersonal harms’ condition i.e. the idea involves harming someone at a distance and is thus less personal
Result : Option one had least amount of “acceptable” as an answer for both groups. Participants with SSRIs made more prosocial behaviors such as condemning harmful actions.
Conclusion : Agonists may enhance the effect of some neurotransmitters which in turn changes behavior
Outline/describe/explain
One antagonist and its effect on behaviour
- Neurotransmitters are chemical messenger used to transmit signals
- They are fast acting
- Ach is a neurotransmitter
- Scopolamine is an antagonist to Ach
Antonova et al. (2001)
Aim : How blocking Ach with scopolamine affect spacial memory
Method : Laboratory experiment; double blind
Participants : 20M
Procedure :
- Participants were injected with scopolamine or placebo 70-90 minutes before set task
- Then put into fMRI scans while playing a navigation game : Navigating around an area to find the goal, after 30 seconds of black screen, starting from a different starting point
- Repeat 3-4 weeks later with opposite treatment
Result : When under scopolamine, participants made more mistakes and had significantly less use of the hippocampus area
Conclusion : Ach plays a key role in spacial memory formation
