G textbook IB psych review

localization of function

the idea that various brain regions have particular functions

strict localization

the idea that very particular parts of the brain perform particular functions

weak localization

the idea that one brain area may be responsible for a function, but not exclusively, and other areas may also take over the function

hippocampus

a neural center located in the limbic system; helps process explicit memories for storage (long-term memory)

neuroplasticity

the ability of the brain to change itself in response to environmental demands

draganski et al (2004) - structural changes in the brain in response to juggling

Essential understanding
- Neuroplasticity occurs in response to regular learning practices, which suggests that neuroplasticity is the neural basis of learning

Aim
- To investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine.

Participants
- A self-selected sample of volunteers with no prior experience of juggling

Method
- Experiment; mixed design

Procedure
- The sample was randomly divided into two groups: jugglers and non-jugglers. Jugglers spent three months learning a classic juggling routine with three balls followed by three months in which they were instructed to stop practicing. Participants in the control group never practiced juggling. Three brain scans (MRI) were performed in both groups: one before the start of the experiment, one after three months, and one after six months.

Results
- There were no differences in brain structure between jugglers and non-jugglers before the experiment. After three months of practice, the jugglers had significantly more grey matter in both hemispheres' mid-temporal area of the cortex. These areas are known to be responsible for the coordination of movement. After six months (that is three months of non-practice the differences decreased. However, the jugglers still had more grey matter in these areas than at the first brain scan.

Conclusion
- Grey matter grows in the brain in response to environmental demands (learning) and shrinks in the absence of stimulation (lack of practice). This shows that there is a cause-and-effect relationship between learning and brain structure.

maguire et al (200) - neuroplasticity in London taxi drivers

Essential understanding
- Neuroplasticity occurs in natural settings, Redistribution of grey matter in the hippocampus is observed in taxi drivers as a function of their driving experience

Aim
- To investigate how the brain structure of London taxi drivers is different from the average brain.

Participants
-16 right-handed male taxi drivers. The average experience as a taxi driver was 14.3 years. A control group: 50 healthy right-handed male subjects who did not drive a taxi

Method
- Quasi-experiment (comparison of two pre-existing groups); correlational study in the part where driving experience was correlated with grey matter volume. MRI was used to measure the variables.

Procedure
- MRI scans were compared between drivers and non-drivers. Researchers also correlated the number of years of taxi driving experience with results of the MRI scans.

Results
- Taxi drivers had increased grey matter volume in the posterior hippocampus, compared to the control subjects had increased grey matter in the anterior hippocampus. A correlation was observed between the number of years of taxi driving experience and grey matter volume in the hippocampus: the longer they drove a taxi, the larger the volume of their posterior hippocampus. The opposite was true for anterior hippocampus. This means that redistribution of grey matter occurred in the hippocampus of taxi drivers, from anterior to posterior.

Conclusion
- Redistribution of grey matter in the hippocampus occurs in taxi drivers in response to gaining navigational experience. The posterior hippocampus is known to be involved in using previously learned spatial information, while the anterior hippocampus is known to be responsible for learning new spatial information.

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

fisher et al (2005) - dopamine and romantic love

Essential understanding
- Dopamine activity may be the biological basis of romantic love.

Aim
- To investigate neural mechanism of romantic love.

Participants
- 17 participants who were "intensely in love" with someone, mean age 21 and mean duration of being in love 7 months.

Method
- Experiment; repeated measures design. Variables were measured in fMRI scans

Procedure
- Participants were placed in a fMRI scanner and went through the following four steps, which were repeated six times:
- viewing a photograph of the person they love-30 seconds
- filler activity- 40 seconds
- viewing a photograph of an emotionally neutral acquaintance-30seconds
- filler activity-20 seconds
Brain responses to the picture of a loved one and the picture of a neutral acquaintance were compared.

Results
- There was a specific pattern of activation in the brain in response to the photographs of the loved ones. Activation was especially prominent in dopamine-rich brain areas.

Conclusion
Dopaminergic activity plays a role in feelings of romantic love

CAT Scans

generate cross-sectional images of the brain using a series of X-ray pictures taken from different angles

MRI

a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

fMRI

a form of magnetic resonance imaging of the brain that registers blood flow to functioning areas of the brain

PET

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

EEG

an amplified recording of the waves of electrical activity that sweeps across the brain’s surface. these waves are measured by electrodes placed on the scalp

endocrine