brain scans

explain pet scans

-produces a 3D image of how the Brain functions

-Radioactive tracer is injected into the bloodstream with another substance this allows us to see which areas of the Brain are active.

-the radioactive particle emissions fro the tracer given signals to the scanner which records the levels of activity in different parts of the Brain.

-scans produced are colour coded to determine which parts are the most or least active at any one time.

-in psychological research, participants are scanned: when the brain is inactive which creates a baseline to measure and when performing an activity.

advantage of pet scans

-Useful as can be used to compare brain activity between normal and abnormal brains so can identify clear causes of differences in behaviours which could be causing abnormality.

-standardised method of measuring the metabolism of glucose in the brain to measure brain activity so higher reliability as can be replicated to check for consistencies in brain activity.

-produces quantitative data so objective with how PET scans are conducted by injecting glucose to measure brain level activity, which allows us to precisely pinpoint the specific areas of Brian activity without bias so more accurate.

disadvantages of PET scans

-carried out in artificial setting using tasks that are unrealistic so cannot show how the brain responds in real life situations, therefore low in ecological validity as may not reflect brain activity in the real world.

-the colour coded images may be open to interpretation bias from researchers in terms of the level of brain activity so may not be a true accurate measure of the brain activity.

-Ethical issue with an invasive injection as could be distressing or frequent exposure to radiation could make It unethical/ hard to replicate to check consistencies of brain activity.

explain CAT scans

-shows structural changes of different areas of the brain

-produces multiple images of the brain.

-it produces many x-ray images taken from different angles to produce cross-sectional images of specific areas of the brain. allow users to see inside the object, ‘slice by slice’ without actually cutting the Brain.

-converts the 2D images to generate a 3D image.

-can be used to detect tumours and early signs of haemorrhages in the brain.

advantages of CAT scans

-useful as can be used to compare differences between different brain structures to identify causes of differences in behaviour and detect issues such as tumours.

-objective and no interpretation bias as allows us to precisely pinpoint the specific areas of brain structure without bias so more accurate measure of its brain structure and tumours are effective behaviour.

-safer as non-invasive procedure is used as just 2D images to create 3D image of the brain so less distressing for patients when measuring brain structure.

disadvantage of CAT scans

-only produce black and white structural images so can be difficult to spot any subtle changes in affected brain areas so low validity as less accurate conclusions drawn about brain structure.

-X-ray images require interpretation from the researchers as subjective due to subtle interpretations of the structure of the brain so may not be a true valid measure of the brain structure.

explain fMRI

-help measure brain activity by detecting changes associated with blood flow within the brain.

-use a strong magnetic field and radio waves to create detailed images of the brain by looking at blood flow in the brain to detect areas of activity by monitoring its level of oxygen.

-oxygen rich blood differs in texture and colour to oxygen poor blood and monitoring the changes in oxyhemoglobin molecules In the blood enable scientists to determine which parts of the Brian are most active.

-the scans cannot be used by everyone as the magnetic feudal reacts to pacemakers and therefore is not suitable for pacemaker users.

advantages of fMRI

-useful as can be used to compare to other brains to explain functional changes in different areas of the Brian so can show the early onset of malfunction and differences in behaviour.

-produces quantitative data so objective and no interpretation bias in terms of the blood flow in different areas of the brain so allows us to precisely pinpoint the specific areas of brain functioning without bias so more accurate.

-standardised method od nearing brain functioning and monitoring blood flow in the same way so higher reliability as can be replicated to check for consistencies in brain functioning.

disadvantages of fMRI

-carried out In controlled settings so do not showing functioning of the brain in real life situations, therefore low in ecological validity as brain functioning may be different in the real world.

-the brain scan images require interpretation which may differ between specialists so is highly subjective in terms of brain functioning and so may not be a true valid measure of brain functioning of the individual.

-less practical as the scans cannot be used by everyone as the magnetic field reacts to pacemakers, therefore not suitable or practical to measure brain functioning for pacemaker users.